Neurology Flashcards
1
Q
what do oligodendrocytes do?
A
myelinate axons in the brain (CNS)
2
Q
what do Schwann cells do?
A
myelinate axons in the rest of the body (PNS)
3
Q
what are afferents?
A
axons taking information towards the CNS e.g. sensory fibres
4
Q
what are efferents?
A
axons taking information to another site from the CNS e.g. motor fibres
5
Q
what are the functions of the frontal lobe?
A
- voluntary movement on opposite side of body
- frontal lobe of dominant hemisphere controls speech (Broca’s area) and writing
- intellectual functioning, thought processes, reasoning and memory
6
Q
what are the functions of the parietal lobe?
A
receives and interprets sensations, including pain, touch, pressure, size and shape and proprioception
7
Q
what are the functions of the temporal lobe?
A
understanding the spoken word (Wernicke’s area), sounds, memory and emotion
8
Q
what are the functions of the occipital lobe?
A
understanding visual images and meaning of written words
9
Q
what is the CSF produced by?
A
CSF is produced by ependymal cells in the choroid plexuses of the lateral ventricles (mainly)
10
Q
what is the passage of CSF?
A
- from the lateral ventricles it travels to the 3rd ventricle via the interventricular foramen and then from the 3rd ventricle it travels to the 4th ventricle via the cerebral aqueduct (Aqueduct of Sylvius)
- from the 4th ventricle it communicates with the subarachnoid space via the median foramen of Magendie and the two lateral foramens of Luschka
11
Q
what is the Aqueduct of Sylvius?
A
cerebral aqueduct connecting the 3rd and 4th ventricles
- located dorsal to the pons and ventral to the cerebellum
- the cerebral aqueduct is surrounded by the periaqueductal grey
12
Q
what is the interventricular foramen?
A
channels that connect the paired lateral ventricles with the 3rd ventricle at the midline of the brain
13
Q
what is the foramen of Monro?
A
channels that connect the paired lateral ventricles with the 3rd ventricle at the midline of the brain
14
Q
what is the foramen of Magendie?
A
drains CSF from the fourth ventricle into the cisterna magna
15
Q
what is the foramen of Luschka?
A
- opening in each lateral extremity of the lateral recess of the 4th ventricle of the human brain, which also has a single median aperture
- allows CSF to flow from the ventricles into the subarachnoid space
16
Q
how is CSF absorbed?
A
CSF is then absorbed via arachnoid granulations
17
Q
what is hydrocephalus?
A
- abnormal accumulation of CSF in ventricular system
* often due to a blocked cerebral aqueduct
18
Q
what does the sympathetic system supply?
A
- supplies visceral organs and structures of superficial body regions
- contains more ganglia than the the parasympathetic division
19
Q
what are the effects of the sympathetic system?
A
- increases heart rate
- increases force of contractions in the heart
- vasoconstriction
- bronchodilaton
- reduces gastric motility
- sphincter contraction
- decreased gastric secretions
- male ejaculation
20
Q
what are the parasympathetic cranial nerves? what do they supply?
A
- oculomotor nerve CN3 to pupil
- facial nerve CN7 to salivary glands
- glossopharyngeal nerve CN9 for swallowing reflex
- vagus nerve CN10 to thorax and abdomen
21
Q
what does the parasympathetic system innervate?
A
organs of the head, neck, thorax and abdomen
22
Q
what are the effects of the parasympathetic system?
A
- decreases heart rate
- decrease force of contraction
- vasodilation
- bronchoconstriction
- increases gastric motility
- sphincter relaxation
- increased gastric secretions
- male erection
23
Q
what are upper motor neurons?
A
- the descending pathways and neurones that originate in the motor cortex
- control the activity of the lower motor neurones
24
Q
what are lower motor neurons? what are they also known as?
A
alpha motor neurones that directly innervate skeletal muscle that have cell bodies lying in the grey matter of the spinal cord and brainstem
25
what is spasticity? when is it seen?
- increased muscle tone
- muscles do not develop increased tone until they are stretched a bit, and after a brief increase in tone, the contraction subsides for a short time
- the period of ‘give’ occurring after resistance is called the clasp-knife phenomenon, where someone bends the limb of a patient, initially there is some resistance but after a certain point resistance falls dramatically
- seen in Parkinson's
26
what is rigidity?
increased muscle contraction is continuous and the resistance to passive stretch is constant
27
what does the vertebral column consist of? how many cervical, thoracic, lumbar and sacral vertebra are there?
- 7 Cervical vertebra
- 12 Thoracic vertebra
- 5 Lumbar vertebra (fused)
- 4 Coccyx vertebra (fused)
28
what do the spinal nerves consist of? how many cervical, thoracic, lumbar and sacral nerves are there?
- 8 cervical nerves
- 12 thoracic nerves
- 5 lumbar nerves
- 5 sacral nerves
- 1 coccyx nerve
29
where do spinal nerves exit from the cord?
- cervical segments: around 1 vertebra higher than their corresponding vertebra (except C8 which exits below a vertebra)
- thoracic segments: around 1-2 vertebra below their corresponding vertebra
- lumbar segments: 3-4 vertebra below their corresponding vertebra
- sacral segments: around 5 vertebra below
30
what is a dermatome?
area of skin supplied by a single spinal nerve
31
what is the sensory innervation of the hand?
palmar:
- little finger and medial half of ring finger (ulnar nerve, C8)
- lateral half of ring finger, middle finger, index finger and medial half of thumb (median nerve, C7)
- lateral half of thumb (radial nerve, C6)
dorsal:
- thumb, proximal half of index, middle finger and lower 1/4 of the ring finger (radial nerve, C6)
- distal half of index, middle finger and upper 1/4 of ring finger (median nerve, C7)
- half of ring finger and all of little finger (ulnar nerve, C8)
32
what are the different dermatomes and what do they supply?
```
C4: clavicle
T4: nipples
T1: medial arm
T10: umbilicus
L4: knee
S4: perianal area
S5: anus
```
33
what is a myotome?
a volume of muscle supplied by a single spinal nerve
34
what are the motor tracts?
- lateral corticospinal tract
- rubrospinal tract
- olivospinal tract
- vestibulospinal tract
- tactospinal tract
- anterior corticospinal tract
35
what are the sensory tracts?
- fasiculus gracilis
- fasiculus cuneatus
- posterolateral tract
- intersegmental tract
- posterior spinocerebellar tract
- lateral spinothalamic tract
- anterior spinocerebellar tract
- spino-olivary tract
- spinorectal tract
- anterior spinothalamic tract
36
what are the ascending tracts?
- sensory
- dorsal/medial lemniscal columns
- spinothalamic tract
- spinocerebellar tract
37
what are features of the DCML tract?
- dorsal root ganglion is 1st order neuron
- fasiculus cuneatus and fasiculus gracilis
- carries proprioception, vibration and fine touch (via Ruffini endings, Merkel discs, Pacinian corpuscles)
- fasiculus cuneatus is lateral and carries information from the upper body to the cuneate tubercle in the medulla
- fasiculus gracilis is medial and carries information from the lower body to the gracile tubercle in the medulla
- decussation of internal arcuate fibres in the medulla to become the medial lemniscus
- 2nd order neuron is from the midbrain to thalamus (VPLN)
- 3rd order neuron is from the thalamus (VPLN) to the somatosensory cortex (through internal capsule and corona radiata)
38
what is the function of the spinothalamic tract?
- carries pain, temperature (lateral) and crude touch (anterior) information
- 1st order neurones arise from sensory receptors in the periphery and enter spinal cord and ascend 1-2 vertebral levels then synapse at the substantia gelatinosa
- 2nd order neurones synapse with 1st order neurones and then decussate within the spinal cord, then form anterior/lateral tracts, and synapse in the thalamus (VPL)
- 3rd order neurones ascend from the VPL, travel through the internal capsule and terminate at the sensory cortex
39
what are the pathways in the spinocerebellar tracts? what are their functions?
- posterior spinocerebellar tract: carries proprioceptive information from the lower limbs to the ipsilateral cerebellum (from muscle spindle and golgi tendon organs)
- cuneocerebellar tract: carries proprioceptive information from the upper limbs to the ipsilateral cerebellum (from muscle spindle and golgi tendon organs)
- anterior spinocerebellar tract: carries proprioceptive information from the lower limbs, decussates twice and terminates in ipsilateral cerebellum (from golgi tendon organs)
- rostral spinocerebellar tract: carries proprioceptive information from the upper limbs to the ipsilateral cerebellum (from golgi tendon organs)
40
what is the pyramidal pathway?
- include the corticobulbar tract and the corticospinal tract
- aggregations of efferent nerve fibres from the UMNs that travel from the cerebral cortex and terminate in the brainstem (corticobulbar) or spinal cord (corticospinal)
- involved in the control of motor functions of the body and face
41
what is the pathway of the corticobulbar tract?
- originates in the primary motor cortex of the frontal lobe, superior to the lateral fissure and rostral to the central sulcus in the precentral gyrus (Brodmann area 4)
- descends through the corona radiata and genu of the internal capsule
- in the midbrain, the internal capsule becomes the cerebral peduncles
- the white matter is located in the ventral portion of the cerebral peduncles, called the crus cerebri
- corticobulbar fibres exit at the appropriate level of the brainstem to synapse on the LMNs of the cranial nerves
- fibres also end in the sensory nuclei of the brainstem including gracile nucleus, cuneate nucleus, solitary nucleus and all trigemnial nuclei
42
what does the corticobulbar tract innervate?
- directly innervates nuclei for cranial nerves V, VII, IX and XII
- contributes to motor regions of cranial nerve X in the nucleus ambiguus
- most innervate motor neurones bilaterally, except for the UMNs for the facial nerve and hypoglossal nerve (receive contralateral innervation)
43
what is the pathway of the corticospinal tract?
- receive input from the primary motor cortex, premotor cortex, supplementary motor area and the somatosensory area
- converge and descend through the internal capsule, through the crus cerebri of midbrain, the pons and into the medulla
- then the tract divides into the lateral CST (decussates and becomes contralateral) and the anterior CST (remains ipsilateral, then decussates in spinal cord)
- neurones then terminate on the ventral horn (anterior CST only supplies cervical and upper thoracic levels)
44
what is the vestibulospinal tract?
- medial and lateral pathways
- arise from vestibular nuclei (receive input from organs of balance; CN8)
- send information to spinal cord and control balance and posture by innervating anti-gravity muscles (flexors of arm and extensors of leg) via LMNs
- ipsilateral
45
what is the tectospinal tract?
- begins in the superior (visual) colliculus and receives information from the optic nerves
- terminate at the cervical levels of spinal cord
- coordinates movements of head in relation to visual stimuli
- contralateral
46
what is the rubrospinal tract?
- originates from the red nucleus (midbrain)
- facilitates flexors and inhibits extensors; controls fine hand movements
- decussates at the midbrain thus is contralateral
47
what is the pathophysiology of Brown-Sequard syndrome?
* ipsilateral weakness/UMN signs below the lesion due to lateral CST lesion
* ipsilateral loss of proprioception, light touch and vibration sense below the lesion due to DCML lesion
* contralateral loss of pain and temperature sensation below the lesion due to lesions to lateral spinothalamic tract
48
what are the component fibres, structures innervated, function and skull exit point of the olfactory CN?
- component fibres: sensory/special
- structures innervated: olfactory epithelium
- function: olfaction
- skull exit point: cribriform plate
49
what are the component fibres, structures innervated, function and skull exit point of the optic CN?
- component fibres: sensory/special
- structures innervated: retina
- function: vision; pupillary light reflex
- skull exit point: optic canal
50
what are the component fibres, structures innervated, function and skull exit point of the oculomotor CN?
- component fibres: motor-somatic and parasympathetic
- structures innervated:
superior, inferior and medial rectus muscle, inferior oblique muscle, levator palpabrae superioris, sphincter pupillae and ciliary muscle of eyeball
- function: movement of eyeball, elevation of upper eyelid, pupillary constriction and accomodation
- skull exit point: superior orbital fissure
51
what are the component fibres, structures innervated, function and skull exit point of the trochlear CN?
- component fibres: motor/somatic
- structures innervated: superior oblique muscle
- function: movement of eyeball
- skull exit point: superior orbital fissure
52
what are the component fibres, structures innervated, function and skull exit point of the opthalamic CN?
- component fibres: sensory/somatic
- structures innervated: face, scalp, cornea, nasal and oral cavities
- function: general sensation
- skull exit point: superior orbital fissure
53
what are the component fibres, structures innervated, function and skull exit point of the maxillary CN?
- component fibres: sensory/somatic
- structures innervated: muscles of mastication, sub-mandibular, sublingual and parotid glands
- function: opening and closing of mouth
- skull exit point: foramen rotundum
54
what are the component fibres, structures innervated, function and skull exit point of the mandibular CN?
- component fibres: motor/branchial
- structures innervated: tensor tympani
- function: tension on tympanic membrane
- skull exit point: foramen ovale
55
what are the component fibres, structures innervated, function and skull exit point of the abducens CN?
- component fibres: motor/somatic
- structures innervated: lateral rectus muscle
- function: movement of eyeball
- skull exit point: superior orbital fissure
56
what is the function, structures innervated and skull exit point of the sensory facial nerve?
- structures innervated: anterior 2/3 of tongue
- function: taste
- skull exit point: internal acoustic meatus
57
what is the structures innervated, function and skull exit point of the motor facial nerve?
- structures innervated: muscles of facial expression
- function: facial movement
- skull exit point: internal acoustic meatus
58
what is the structures innervated, function and skull exit point of the parasympathetic facial nerve?
- structures innervated: salivary and lacrimary glands
- function: salivation and lacrimation
- skull exit point: internal acoustic meatus
59
what are the component fibres, structures innervated, function and skull exit point of the vestibulocochlear CN?
- component fibres: sensory; special
- structures innervated: vestibular apparatus and cochlea
- function: position and movement of head and hearing
- skull exit point: internal acoustic meatus
60
what are the structures innervated, function and skull exit point of the sensory glossopharyngeal CN?
- structures innervated: pharynx, posterior 1/3 of the tongue, eustachian tube, middle ear, carotid body, carotid sinus
- function: general sensation, taste, chemoreception, baroreception
- skull exit point: jugular foramina
61
what are the structures innervated, function and skull exit point of the motor glossopharyngeal CN?
- structures innervated: stylopharyngeus muscle
- function: swallowing
- skull exit point: jugular foramina
62
what are the structures innervated, function and skull exit point of the parasympathetic glossopharyngeal CN?
- structures innervated: parotid salivary gland
- function: salivation
- skull exit point: jugular foramina
63
what are the structures innervated, function and skull exit point of the sensory vagus CN?
- structures innervated: pharynx, larynx, trachea, oesophagus, thoracic and abdominal viscera, aortic bodies, aortic arch
- function: general sensation, visceral sensation, chemoreception, baroreception
- skull exit point: jugular foramina
64
what are the structures innervated, function and skull exit point of the motor vagus CN?
- structures innervated: soft palate, pharynx, larynx, oesophagus
- function: speech, swallowing
- skull exit point: jugular foramina
65
what are the structures innervated, function and skull exit point of the parasympathetic vagus CN?
- structure innervated: thoracic and abdominal viscera
- function: innervation of cardiac muscle, innervation of smooth muscle, respiratory and GI tracts
- skull exit point: jugular foramina
66
what are the component fibres, structures innervated, function and skull exit point of the accessory CN?
- component fibres: motor/somatic
- structures innervated: sternocleidomastoid and trapezius muscles
- function: movement of head and shoulders
- skull exit point: jugular foramina
67
what are the component fibres, structures innervated, function and exit point of the hypoglossal CN?
- component fibres: motor/somatic
- structures innervated: intrinsic and extrinsic muscles of the tongue
- function: movement of tongue
- skull exit point: hypoglossal canal
68
what are the cranial nerve brainstem nuclei locations?
midbrain: 3,4
pons: 5,6,7,8
medulla: 9,10,11,12
69
what are features of Broca's aphasia?
- damage to this area can result in expressive aphasias (difficulty forming words or sentences)
- they will understand what you are saying and know what they want to say but cannot express the words into meaningful language
70
what are features of Wernicke's aphasia?
- damage to this area results in comprehension/receptive aphasias (difficulty understanding spoken or written language, even though their hearing and vision are not impaired)
- they tend to have fluent speech but they may scramble words so that their sentences make no sense, often adding unnecessary words or made-up words
71
what are features of Berry aneurysms? where do they commonly occur?
- the most common type of intercranial aneurysm
- most common at the anterior cerebellar artery and anterior communicating artery junction
- produces a subarachnoid haemorrhage, resulting in a thunderclap headache
72
what is the cavernous sinus?
- one of the dural venous sinuses
- creates a cavity called the lateral sellar compartment
- chamber of venous blood
- contains CN3, 4, 5.1, 5.2, 6
73
what is the visual pathway?
- fibres from the nasal portion of the retina (carrying the temporal fibres) cross at the optic chiasm located anterior to the pituitary infundibulum
- optic tracts carry the fibres posterolaterally around the cerebral peduncles to terminate at the lateral geniculate bodies of the thalamus
- fibres from the temporal portion of the retina (carrying the nasal fibres) do the same as above
- after the lateral geniculate body, the optic radiations split into two; the fibres carrying information from the inferior portions of the retina (superior visual fields) travel by looping laterally through the temporal lobe to the visual cortex (Meyer's loop)
- the fibres carrying information from the superior portions of the retina (inferior visual fields) travel by looping superiorly through the parietal lobe to the visual cortex (Baum's loop)
74
what is the function of the inferior colliculus and the medial geniculate body?
auditory
75
what is the function of the superior colliculus and the lateral geniculate body?
visual
76
what are the 6 extraocular eye muscles?
- medial rectus
- lateral rectus
- superior oblique
- inferior oblique
- superior rectus
- inferior rectus
- levator palpebrae supeioris
77
what is the function of the medial rectus?
pulls the eye medially (adduction)
78
what is the function of the lateral rectus?
pulls the eye laterally (abduction)
79
what is the function of the superior oblique?
- intorsion (top of eye rotating towards the midline)
| - depresses the eye medially
80
what is the function of the inferior oblique?
- extorsion (top of eye rotating away from the midline)
| - elevates the eye medially
81
what is the function of the inferior rectus?
- pulls the eye down and medially
| - also rotates it
82
what is the function of the levator palpebrae superioris?
lifts upper eyelid
83
what eye muscles does the oculomotor CN innervate?
medial rectus, inferior oblique, superior rectus, inferior rectus
84
what eye muscles does the abducens CN innervate?
lateral rectus
85
what eye muscles does the trochlear CN innervate?
superior oblique
86
what eye muscles does the facial CN innervate?
- levator palpebrae supeioris (also have sympathetic nerve supply - open eyelid in fear)
- loss of function = ptosis
87
what is used to remember direct eye muscle innervations?
LR6SO4
- lateral rectus = CN6
- superior oblique = CN4
- all the rest = CN3
88
what is the function of the superior rectus?
- pulls the eye up and medially
| - also rotates it
89
why is epidural always given below L1?
- allows us to anaesthetise the lower part of body so brain will still control breathing
- tube inserted below L1, outside the dura mater and local anaesthetic administered into the epidural space; it will diffuse into the dorsal root ganglia on sensory nerves
- will stop the cell bodies of the sensory neurones from working and thus no pain is transmitted
- purposely use a blunt needle since don’t want to go into the CSF - if it does then anaesthetic will travel up to the brain and cause respiratory distress
- if dose is just right then since the cell bodies of motor neurones will not be affected; ideal for pregnancy since muscles are required but do not want sensation and proprioception
90
how is lumbar puncture done? at what level is it done?
* best way to sample CSF
* done at L3/4 or L4/L5
* use very sharp needle since want to penetrate dura and extract CSF, then use plunger to aspirate
91
what are the general rules of a nerve conduction study? what do different responses mean?
* small response = axon loss
| * slow response = myelin loss (demyelination)
92
how is electromyography done? what does it look at?
- use a needle to detect the electrical activity from muscle
- records the activity of individual motor units
- can look at big motor units for signs of nerve/motor neurone pathology
- can look at small motor units for signs of myopathy
- EMG can detect myopathies, nerve conduction studies will be normal even in myopathy but EMG will not
- EMG will detect myaesthenia gravis
93
what are the general rules of an electromyography? what do the different responses mean?
* small response = axonal neuropathy; not treatable
| * slow response = demyelinating neuropathy; treatable
94
what can nerve conduction studies and electromyographies be used to investigate?
focal nerve entrapment, generalised peripheral neuropathy, myopathy and motor neurone disease
95
where does CN3 run over? what happens if there is a fracture of this?
- runs over the petrous apex of the temporal bone
- if there is fracture or inflammation then CN3 can get pushed against the bone resulting in a fixed dilated pupil (telltale sign of CN3 under pressure)
96
what does a fixed dilated pupil indicate?
CN3 under pressure; fracture or inflammation of the petrous apex of the temporal bone
97
what are features of cerebellar syndrome?
- ataxia - loss of full control of body movements - limb unsteadiness
- nystagmus - rapid eye movements
- deficit is on same side as cerebellar lesion (ipsilateral)
98
what is the reticular activation system? what is it responsible for?
```
• periaqueductal grey matter on the floor of the 4th ventricle
• responsible for:
- alertness
- sleep/wake
- REM and non REM sleep
- respiratory centre
- cardiovascular centre
```
99
what does the cavernous sinus receive blood from?
superior and inferior opthalamic veins, the middle superficial cerebral veins and a dural venous sinus
100
what structures pass through the cavernous sinus? what mneumonic can help you remember this?
```
O TOM CAT - say trochlear twice
• Oculomotor nerve (3)
• Trochlear nerve (4)
• Opthalmic trigeminal (5.1)
• Maxillary trigeminal (5.2)
• Carotid (internal)
• Abducens (6) - only one going medially
• Trochlear nerve (4)
```
101
what are the criteria for brainstem death?
- pupils
- corneal reflex
- caloric vestibular reflex
- cough reflex
- gag reflex
- respirations
- response to pain
102
what are the main components of head injury examination?
- GCS; glasgow coma scale, measure of level of consciousness
- look at lateralising signs (to check what hemisphere is damaged)
- look at pupils for signs of raised ICP
- monitor vital signs
103
what is the Glasgow Coma Scale? what are its categories?
```
• score adds to 14 and consists of 3 categories:
- motor response (most important)
- verbal response
- eye opening response
• inaccurate within one hour of event
```
104
what is the clinical management of a head injury?
- IV mannitol (diuretic) to reduce oedema and ICP
- management of seizures e.g diazepam for status epilepticus
- intubation usually done if GCS is less than 8
- neurosurgery (ICP monitor insertion or burrholes/craniectomy)
- suture scalp lacerations before moving to CT
105
what is the definition of a transient ischaemic attack?
a brief episode of neurological dysfunction due to temporary focal cerebral ischaemia without infarction
- symptoms generally resolve within 24 hours
106
what is the epidemiology of TIAs?
- 15% of first strokes are preceded by TIA, they are also a foreshadowing of an MI
- more common in males than females
- black ethnicity people are at greater risk due to their hypertension and atherosclerosis predisposition
107
what are causes of TIAs?
- small vessel occlusion
- atherothromboembolism from the carotid artery is the main cause
- cardioembolism resulting in microembolism (mural thrombus post-MI or AF, valve disease, prosthetic valve)
- hyperviscosity (polycythaemia, sickle cell anaemia, raised WCC, myeloma)
- can result from hypoperfusion; most important to consider in younger people (cardiac dysrhythmia, postural hypotension, atherosclerosis)
108
what are risk factors for TIAs?
- risk increases with age
- hypertension
- smoking
- diabetes
- heart disease - valvular, ischaemic or atrial fibrillation
- past TIA
- raised packed cell volume (PCV)
- peripheral arterial disease
- polycythaemia vera
- combined oral contraceptive pill (since increase risk of clots)
- hyperlipidaemia
- excess alcohol
- clotting disorder
- vasculitis e.g. SLE, giant cell arteritis is rare risk factor
109
what is the pathophysiology of TIA?
- the commonest cause of a TIA is cerebral ischaemia resulting in a lack of O2 and nutrients to the brain resulting in cerebral dysfunction, however in a TIA this period of ischaemia is short-lived, with symptoms usually only lasting a maximum of 5-15 minutes after onset, and then resolves with before irreversible cell death occurs
- symptoms that gradually progress suggest a different pathology such as demyelination, tumour or migraine
110
what is the clinical presentation of TIAs?
- sudden loss of function, usually lasting for minutes only, with complete recovery and no evidence of infarction on imaging
- site of TIA is often suggested by symptoms
- 90% of TIA’s affect the anterior circulation (carotid artery)
- 10% affect the posterior circulation (vertebrobasilar artery)
111
what are symptoms of TIAs affecting the anterior circulation (carotid artery)?
* supplies the frontal and medial part of the cerebrum
* occlusion may cause a weak, numb contralateral leg +/- similar, if milder, arm symptoms
* hemiparesis
* hemisensory disturbance
* dysphasia (language impairment)
* amaurosis fugax
112
what is amaurosis fugax? how can it be caused?
- sudden transient loss of vision in one eye
- described as a; “curtain coming down vertically into field of vision”
- occurs due to the temporary reduction in the retinal, opthalmic or ciliary blood flow leading to temporary retinal hypoxia
- TIA causing this is often the first clinical evidence of an ICA stenosis; warning sign of an imminent ICA territory stroke
113
what are symptoms of TIAs affecting the posterior circulation (vertebrobasilar artery)?
* diplopia
* vertigo
* vomiting
* choking and dysarthria (unclear articulation of speech but understandable)
* ataxia - no control of body movement
* hemisensory loss
* hemianopia vision loss
* loss of consciousness (rare)
* transient global amnesia - episode of confusion/amnesia lasting several hours, followed by complete recovery
* tetraparesis
114
what are differential diagnoses of TIAs?
- until there is a full recovery it is impossible to differentiate from a stroke
- hypoglycaemia, migraine aura (symptoms spread and intensify over minutes, often with visual scintillations), focal epilepsy (since limb shaking can occur in a TIA)
- intracranial lesion - tumour or subdural haemotoma
- syncope due to arrhythmia
- Todd’s paralysis (transient weakness of arm, hand or leg after a seizure)
- retinal or vitreous haemorrhage
- giant cell arteritis
115
what is Todd's paralysis?
transient weakness of arm, hand or leg after a seizure, can last up to 48 hours
116
what are features of giant cell arteritis as a differential diagnosis of TIA?
* raised ESR, thickening and tenderness of temporal artery
| * monocular, temporary visual impairment normally presents
117
what is used to diagnose TIA?
- often based solely on its description
- bloods
- carotid artery doppler ultrasound to look for stenosis/atheroma
- MRI/CT angiography if stenosis to determine extent
- ECG (look for AF or evidence of MI/ischaemia)
- CT or diffusion weighted MRI
- echocardiogram/cardiac monitoring to assess for a cardiac cause
118
what is seen on bloods in TIAs?
* FBC - look for polycythaemia
* ESR - will be raised in vasculitis
* glucose - to see if hypoglycaemic
* creatinine, electrolytes
* cholesterol
119
what is the ABCD2 score risk of stroke after TIA? how is it used?
```
• age > 60yrs = 1
• blood pressure > 140/90mmHg = 1
• clinical features:
- unilateral weakness = 2
- speech disturbance without weakness = 1
• duration of symptoms:
- symptoms lasting more than 1hr = 2
- symptoms lasting 10-59mins = 1
• diabetes = 1
```
120
what do the scores for the ABCD2 risk for stroke after TIA indicate?
* score greater than 6 strongly predicts a stroke and should be referred to a specialist immediately
* score greater than 4 should be assessed by a specialist within 24hours
* all patients with a suspected TIA should be seen within 7 days
121
when are people at high risk of an early stroke?
people are also at high risk of an early stroke if they have:
• atrial fibrillation
• more than 1 TIA in one week
• TIA whilst on an anticoagulant
122
what is the treatment of a TIA?
- assess risk factor for a stroke using the ABCD2 score
- antiplatelet drugs
- anticoagulant if they have AF, mitral stenosis or recent big septal MI e.g. warfarin
- statin long term
- control cardiovascular risk factors
- do not drive for at least 4 weeks following a TIA
123
what antiplatelet drugs are given to those with a TIA?
* aspirin immediately and dipyridamole (to increase cAMP and decrease thromboxane A2) for two weeks then lower dose
* P2Y12 inhibitor longterm e.g. clopidogrel
124
what can be given to TIA patients to control cardiovascular risk factors?
* antihypertensives such as ACE-inhibitor e.g. ramipril or angiotensin receptor blocker e.g. candesartan
* improve diet, stop smoking
125
what is the definition of a stroke (ischaemic and haemorrhagic) and what is it characterised by?
- syndrome of rapid onset of neurological deficit caused by focal, cerebral, spinal or retinal infarction
- characterised by rapidly developing signs of focal or global disturbance of cerebral functions, lasting for more than 24hrs or leading to death
126
what is the epidemiology of stroke?
- stroke, whether ischaemic or haemorrhagic, is the major neurological disease of our time
- 3rd most common cause of death in high-income countries; 11% of all deaths in UK
- leading cause of adult disability worldwide
- stroke rates are higher in Asian and black African populations than in Caucasians
- uncommon in those under 40
- incidence increases with age
- more common in males than females
- incidence is falling due to more vigorous approach to risk factors in primary care i.e. statin use and control of BP
127
what are the causes of stroke?
- ischaemic/infarction accounts for 80% of strokes
- haemorrhagic accounts for 17% of strokes
- other causes account for about 3%
- young people
- elderly
128
what are causes of ischaemic strokes?
* small vessel occlusion/thrombosis in situ
* cardiac emboli from AF, MI or infective endocarditis
* large artery stenosis
* atherothromboembolism
* hypoperfusion, vasculitis, hyperviscosity (polycythaemia and sickle cell)
* hypoperfusion/watershed stroke
129
what are features of ischaemic stroke caused by hypoperfusion? what type of stroke does it cause?
hypoperfusion/watershed stroke: where there is a sudden BP drop by more than 40mmHg, then there is low cerebral blood flow, leading to global ischaemia and ‘watershed infarcts’ in vulnerable areas of cortex between boundaries of different arterial territories; seen in sepsis
130
what can cause CNS bleeds that cause haemorrhagic strokes?
- trauma
- aneurysm rupture
- anticoagulation
- thrombolysis
- carotid artery dissection
- subarachnoid haemorrhage
131
what are causes of stroke in young people?
* vasculitis
* thrombophilia
* subarachnoid haemorrhage
* carotid artery dissection - spontaneous, or from neck trauma
* venous sinus thrombosis
132
what are causes of venous sinus thrombosis which causes stroke in young people?
- very rare (only 1%)
- thrombosis within intracranial venous sinuses, such as the superior sagittal sinus, or in cortical veins, may occur in pregnancy, hypercoaguable states and thrombotic disorders or with dehydration or malignancy
- cortical infarction, seizures and raised intracranial pressure result
133
what are causes of stroke in the elderly?
* thrombosis in situ
* athero-thromboembolism
* heart emboli e.g. AF, infective endocarditis or MI
* CNS bleed
* sudden BP drop by more than 40mmHg
* vasculitis
* venous sinus thrombosis
134
what are risk factors for stroke?
- male
- black or asian
- hypertension
- past TIA
- smoking
- diabetes mellitus
- increasing age
- heart disease (valvular, ischaemic)
- alcohol
- polycythaemia, thrombophilia
- AF/stasis of blood in poorly contracting atria leads to thrombus formation
- hypercholesterolaemia
- combine oral contraceptive pill
- vasculitis
- infective endocarditis
135
what is the pathophysiology of ischaemic stroke?
* arterial disease and atherosclerosis is the main pathological process
* thrombosis occurs at site of atheromatous plaque in carotid/vertebral/cerebral arteries
* large artery stenosis acts as an embolism source rather than occluding the vessel
* lipohyalinosis
* cardioembolism
* venous sinus thrombosis
136
how can lipohyalinosis cause ischaemic stroke?
an occlusive vasculopathy known as lipohyalinosis that is a consequence of hypertension results in small infarcts known as ‘lacunes’ and/or the gradual accumulation of diffuse ischaemic change in deep
white matter
137
what can cause cardioembolism which can cause ischaemic stroke?
- AF
- cardiac valve disease
- infective vegetations due to endocarditis
- mural thrombosis from damaged ventricle
- fat emboli after long bone fracture
- hypoperfusion
138
what are causes of haemorrhagic stroke?
* hypertension resulting in micro aneurysm rupture (Charcot-Bouchard aneurysms)
* cerebral amyloid angiopathy (deposition of beta amyloid leading to lobar intercerebral haemorrhage)
* space occupying lesion e.g. tumour - rare
* carotid/vertebral artery dissection in young adults due to neck pain, trauma or neck manipulation
139
what is the clinical presentation of stroke in the anterior cerebral artery territory?
* leg weakness (more likely than arm weakness since more of leg in ACA)
* sensory disturbances in the legs
* gait apraxia
* truncal ataxia; patients can’t sit or stand unsupported and tend to fall backwards
* incontinence
* drowsiness, since part of consciousness is in the frontal lobe
* akinetic mutism (decrease in spontaneous speech, stuporous state)
140
what is the clinical presentation of a stroke in the middle cerebral artery territory?
* contralateral arm and leg weakness
* contralateral sensory loss
* hemianopia
* aphasia (inability to understand or produce speech)
* dysphasia (deficiency in speech generation)
* facial droop
141
what is the clinical presentation of a stroke in the posterior cerebral artery territory?
• contralateral homonymous hemianopia
• cortical blindness (eye healthy, but brain issue
causing blindness)
• visual agnosia (cannot interpret visual information, but can see)
• prosopagnosia (cannot see faces)
• colour naming and discriminate problems
• unilateral headache - rare in ischaemic stroke, so if you see headache then think PCA
142
what is the clinical presentation of stroke in the vertebrobasilar artery (PCA)?
* more catastrophic due to wide region supplied
* likely to get ‘locked in’ in these strokes
* motor deficits such as hemiparesis or tetraparesis and facial paralysis
* dysarthria (unclear speech articulation) and speech impairment
* vertigo, nausea and vomiting
* visual disturbance
* altered consciousness
143
what is the clinical presentation of lacunar strokes?
small subcortical strokes e.g. midbrain, internal capsule, one of:
- unilateral weakness (and/or sensory deficit) of face and arm, arm and leg or all three
- pure sensory loss
- ataxic hemiparesis (cerebellar and motor symptoms)
- in general only 1 modality tends to be affected
144
how can you distinguish between haemorrhagic and ischaemic strokes?
* intracerebral haemorrhage is more often associated with severe headache or coma (signs of raised ICP due to blood forming a space-occupying lesion)
* patients on oral anticoagulants should be assumed to have had a haemorrhage unless it is proved otherwise
145
what are differential diagnoses of stroke?
- always exclude hypoglycaemia as a cause of sudden onset neurological syndrome
- hypoglycaemia, migraine aura (symptoms spread and intensify over minutes, often with visual scintillations), focal epilepsy (since limb shaking can occur in a TIA)
- intracranial lesion; tumour or subdural haemotoma
- syncope due to arrhythmia
146
what is used to diagnose stroke?
- urgent CT head/MRI head before treatment
- pulse, BP and ECG (look for AF)
- bloods (look for thrombocytopenia, polycythaemia and hypoglycaemia)
147
what is seen in an urgent CT head/MRI head in stroke?
• urgent if suspected cerebellar stroke, unusual presentation, high risk of haemorrhage (low GCS and
signs of raised ICP)
• used to rule out haemorrhagic stroke before starting thrombolysis
• infarction is seen as a low density lesion, subtle changes evident within 3 hrs
• in MRI (not done often) appears hyper-intense within hours of onset
148
what is the treatment of stroke?
```
- maximise reversible ischaemic tissue
• ensure hydration
• keep O2 sats > 95%
- thrombolysis
- if time of onset is unknown and thus thrombolysis is unsuitable then give aspirin daily for 2 weeks then lifelong clopidogrel
```
149
how is thrombolysis used to treat stroke?
* can be given up to 4.5 hrs post-onset of symptoms
* must CT head/MRI first to rule out haemorrhage, otherwise will make it worse and cause death
* give tissue plasminogen activator e.g. IV alteplase
* then start antiplatelet therapy 24hrs after thrombolysis
150
what are contraindications of thrombolysis for stroke?
- recent surgery in last 3 months
- recent arterial puncture
- history of active malignancy
- evidence of brain aneurysm
- patient on anticoagulation
- severe liver disease (abnormal clotting)
- acute pancreatitis
- clotting disorder
151
what is the treatment of haemorrhagic stroke?
* frequent GCS monitoring
* antiplatelets contraindicated
* any anticoagulants should be reversed and for warfarin reversal use beriplex and vitamin K
* control hypertension
* manual decompression of raised ICP, can also reduce ICP by giving diuretic e.g. mannitol
* surgery may be required
152
what is risk management for stroke prevention?
* platelet treatment (lifelong if already had stroke)
* cholesterol-lowering treatment
* atrial fibrillation treatment e.g. warfarin or new oral anticoagulants e.g. apixaban
* blood pressure treatment
153
what is the timeframe for giving thombolysis in stroke?
4.5 hour time frame for thrombolysis (alteplase) as long as CT head confirms it's ischaemic and that there are no contraindications
154
what is the epidemiology of subarachnoid haemorrhages?
- spontaneous bleeding into the subarachnoid space between the arachnoid and the pia mater
- can often be catastrophic
- typical age 35-65
- account for 5% of strokes
- most common cause is rupture of Berry aneurysm
155
what are causes of subarachnoid haemorrhages?
- rupture of saccular aneurysms (80%) e.g. Berry aneurysms; associated with PCKD and coarctation of aorta
- atriovenous malformation (10%)
- no cause found (15%)
- rare (bleeding disorders, mycotic aneurysms, acute bacterial meningitis, tumours)
156
what are Berry aneurysms? how can they cause subarachnoid haemorrhages?
appear as a round outpouching; most common form of cerebral aneurysm
• rupture of the junction of the posterior communicating artery with the internal carotid or of the anterior communicating artery with the anterior cerebral artery in the circle of Willis
• 15% are multiple i.e. multiple aneurysms
157
what is an atriovenous malformation? how can it cause a subarachnoid haemorrhage?
vascular developmental malformation often with a fistula between arterial and venous systems causing high flow through the AVM and high-pressure arterialisation of draining veins
158
what are risk factors for subarachnoid haemorrhages?
- hypertension
- known aneurysm
- family history
- disease that predispose to aneurysm
- smoking
- bleeding disorders
- post-menopausal decreased oestrogen
159
what are diseases that predispose to aneurysms?
* polycystic kidney disease
* Ehlers-Danlos syndrome
* coarctation of aorta
160
what is the pathophysiology of subarachnoid haemorrhages?
most common cause is ruptured aneurysm which leads to tissue ischaemia (since less blood can reach tissue) and rapid raised ICP as the fast flowing arterial blood acts like a space-occupying lesion, puts pressure on the brain and results in deficits if not resolved quickly
161
what is the clinical presentation of a subarachnoid haemorrhage?
- sudden onset severe occipital thunder clap headache, like being kicked in the head, severe pain
- vomiting, collapse, seizures and coma often follow
- depressed level of consciousness
- coma/drowsiness may last for days
- neck stiffness
- Kernig’s sign (unable to extend patients leg at the knee when the thigh is flexed)
- Brudzinski’s sign (when patients neck is flexed by doctor, patient will flex their hips and knees)
- retinal and vitreous bleeds
- papilloedema - dilated optic disc
- vision loss or diplopia (double vision)
- marked increase in BP as a reflex to following haemorrhage
- focal neurology at presentation may suggest site of aneurysm
- sentinel headache
162
what is Kernig's sign?
- unable to extend patients leg at the knee when the thigh is flexed
- seen in subarachnoid haemorrhage
163
what is Brudzinski's sign?
- when patients neck is flexed by doctor, patient will flex their hips and knees
- seen in subarachnoid haemorrhage
164
what is a sentinel headache?
- a headache that resolves by itself and no other symptoms are present
- presumed to result from a small leak from an aneurysm
165
what are differential diagnoses of subarachnoid haemorrhage?
- must be differentiated from migraine (short time taken to reach maximal intensity and neck stiffness indicates SAH)
- in primary care only 25% of those with severe, sudden ‘thunderclap’ headache actually have a SAH
- in 50-60%, no cause is found for headache
- meningitis
- intracerebral bleeds
- cortical vein thrombosis
166
what is used to diagnose subarachnoid haemorrhage?
- ABG (to exclude hypoxia)
- head CT
- CT angiography
- lumbar puncture
167
how is head CT used to diagnose subarachnoid haemorrhage?
* detects >90% of SAH within 1st 48hrs
| * seen as a ‘star shaped lesion’ due to blood filling in gyro patterns around the brain and ventricles
168
how is a lumbar puncture used to diagnose subarachnoid haemorrhage?
* done if CT normal but SAH still suspected
* CSF in SAH is uniformly bloody early on and becomes xanthochromic after several hours due to breakdown products of Hb (bilirubin)
* xanthochromia presence confirms SAH
169
what is the treatment of subarachnoid haemorrhage?
- refer all proved SAH to neurosurgeons immediately
- maintain cerebral perfusion by keeping well hydrated (IV fluids) and aim for BP <160mmHg
- administer Ca2+ blocker to reduce vasospasm and consequent morbidity from cerebral ischaemia e.g. IV/oral nimodipine
- endovascular coiling
- surgery; intracranial stents and balloon remodelling for wide-necked aneurysms
170
how is endovascular coiling used to treat subarachnoid haemorrhage?
* preferred to surgical clipping since has lower complication rate where possible
* promotes thrombosis and ablation of aneurysm
* first line treatment where angiography shows aneurysm
171
what are complications of subarachnoid haemorrhage?
- rebleeding
- cerebral ischaemia due to vasospasm can result in permanent deficit
- hydrocephalus due to blockage of arachnoid granulations requires ventricular or lumbar drain
- hyponatraemia
172
what causes subdural haemorrhage?
* caused by the accumulation of blood in the subdural space between the arachnoid and dura mater following rupture of a bridging vein between cortex and venous sinus (vulnerable to deceleration injury)
* considered very treatable in all those whose conscious level fluctuates and also in those having an ‘evolving stroke’, especially if on anticoagulants
173
what is the epidemiology of sub-dural haemorrhage?
- most common where patient has a small brain e.g. alcoholics or dementia, babies that have suffered trauma or elderly that have brain atrophy (makes the bridging veins more vulnerable)
- majority of SDH’s are from trauma but the trauma is often forgotten as it was minor or long ago (up to 9 months)
- chronic, apparently spontaneous SDH is common in elderly and also occurs with anticoagulants
174
what are causes of subdural haemorrhage?
- trauma either due to deceleration due to violent injury or due to dural metastases results in bleeding from bridging veins between the cortex and
venous sinuses
- bridging veins bleed and form a haematoma between the dura and arachnoid which reduces pressure and stops bleeding
- days/weeks later, the haematoma autolyses due to the massive increase in oncotic and osmotic pressure, thus water is sucked into the haematoma resulting in the haematoma enlarging
- this results in a gradual rise in intra-cranial pressure (ICP) over many weeks
- shifting midline structures away from the side of the clot and if untreated leads to eventual tectorial herniation and coning (brain herniates through foramen magnum - causes significant damage)
175
what are risk factors for subdural haemorrhage?
- traumatic head injury, cerebral atrophy/increasing age - makes bridging veins more vulnerable
- alcoholism (caused cerebral atrophy), anticoagulation and physical abuse of infant
176
what is the clinical presentation of subdural haemorrhage?
- interval between injury and symptoms can be days to weeks or months
- fluctuating level of consciousness (35%) and/or insidious physical or intellectual slowing
- sleepiness
- headache
- personality change
- unsteadiness
- signs of raised ICP e.g. headache, vomiting, nausea, seizure and raised BP
- focal neurology e.g. hemiparesis or sensory loss: occurs late and often long after injury, mean time is 63 days
- seizures occasionally
- stupor, coma and coning may follow
177
what are features of subdural haemorrhage in the elderly?
due to decrease in brain weight and increase in subdural space with increasing age, a haematoma and its symptoms develop much slower as brain has more compliance to raised ICP
178
what are differential diagnoses of subdural haemorrhage?
- stroke
- dementia
- CNS masses e.g. tumours or abscess
- SAH
- extradural haemorrhage
179
what is used to diagnose subdural haemorrhage?
- CT head
| - MRI head for subacute haematomas and smaller haematomas
180
what is seen on a CT head in subdural haemorrhage?
• diffuse spreading, hyperdense crescent shaped
collection of blood over 1 hemisphere
• as the clot ages and protein degradation occurs it becomes isodense (same colour as brain tissue) and eventually becomes hypodense
• shifting of midline structures seen
181
what differentiates subdural haemorrhage from extradural haemorrhage?
sickle/crescent shape differentiates subdural haemorrhage from extradural haemorrhage
182
what is the treatment of subdural haemorrhage?
- assess and manage ABCs, prioritise head CT
- stabilise patient
- refer to neurosurgeons: irrigation/evacuation via burr twist drill and burr hole craniotomy
- address cause of trauma
- IV mannitol to reduce ICP
183
what is an extradural haemorrhage? when should this be suspected?
* suspect this if after head injury, conscious level falls or is slow to improve or there is a lucid interval
* collection of blood between the dura mater and the bone usually caused by head injury
* most commonly due to a traumatic head injury to the temple resulting in fracture of the temporal or parietal bone causing laceration of the middle meningeal artery
184
what are risk factors for extradural haemorrhage?
usually occurs in young adults (rare <2 and >60)
185
what are features of the lucid interval in extradural haemorrhage?
- whilst haematoma is still small and there is still some bleeding
- doesn't really bother you physically
- can last several hours or even days
- followed by altered consciousness
186
what is the clinical presentation of an extradural haemorrhage?
- severe headache, nausea and vomiting, confusion and seizures due to rising ICP and/or hemiparesis with brisk reflexes
- rapid rise in ICP as the epidural space is full of blood resulting in brain compression
- ipsilateral pupil dilates, coma deepens, bilateral limb weakness develops and breathing becomes deep and irregular (signs of brainstem compression)
- decreased GCS
- coning: brain herniates through the foramen magnum
- death due to respiratory arrest if surgical intervention not done fast enough
- bradycardia and raised BP are late signs
187
what are differential diagnoses of extradural haemorrhage?
- epilepsy, carotid dissection and carbon monoxide poisoning (fit with lucid period)
- subdural haematoma, subarachnoid haemorrhage, meningitis
188
what is used to diagnose extradural haemorrhage?
- CT head
| - skull X-ray
189
what is seen on a CT head in an extradural haemorrhage?
* gold standard
| * shows hyperdense haematoma that is biconvex/lenseshaped/lemon shaped and adjacent to the skull
190
what is seen on a skull X-ray in an extradural haemorrhage?
- may be normal or show fracture lines crossing the course of the middle meningeal artery
- skull fracture increases extradural haemorrhage risk, so do urgent CT for anyone with suspected fracture
191
what is the treatment of an extradural haemorrhage?
- ABCDE emergency management; assess and stabilise patient
- give IV mannitol if increased ICP
- refer to neurosurgery for clot evacuation and/or ligation of bleeding vessel
- maintain airway via intubation and ventilation in unconscious patient
192
what is the definition of epilepsy?
- the recurrent tendency to spontaneous, intermittent, abnormal electrical activity in part of the brain, manifesting in seizures
- epilepsy is an ongoing liability to recurrent epileptic seizures
- chronic disorder; need at least 2 seizures to be defined as epileptic
193
what is an epileptic seizure?
paroxysmal/unprovoked event in which changes of behaviour, sensation or cognitive processes are caused by excessive, hypersynchronous neuronal discharges in the brain
194
what are convulsions?
- motor signs of electrical discharges
- many of us would have seizures in abnormal metabolic circumstances e.g. low Na+ or hypoxia (reflex anoxic seizures in faints)
- we would not normally be said to have epilepsy
195
what is the epidemiology of epilepsy?
- common
- incidence is age-dependent, it is highest at the extremes of life with most cases starting before 20 or after 60
- can often go into remission
- seizures usually last 30-120 seconds
196
what are causes of epilepsy?
- 2/3rds are idiopathic often familial
- cortical scarring (head injury, cerebrovascular disease, CNS infection)
- space-occupying lesion
- stroke
- tuberous sclerosis
- Alzheimer’s or dementia
- alcohol withdrawal
197
what are risk factors for epilepsy?
- family history
- premature born babies who are small for their age
- abnormal blood vessels in brain
- Alzheimer’s or dementia
- use of drugs
- stroke/brain tumour/infection
198
what are features of prodrome in a seizure?
- lasting hours or days may rarely precede the seizure
| - not part of the seizure, results in change of mood or behaviour
199
what are features of aura in a seizure?
- part of seizure where the patient is aware
- strange feeling in the gut, deja-vu or strange smells or flashing lights
- implies a partial (focal) seizure often but not necessarily from the temporal lobe
200
what are features of the post-ictal period in a seizure?
- headache, confusion, myalgia and a sore tongue
- temporary weakness after a focal seizure in motor cortex (Todd’s palsy)
- dysphasia following a focal seizure in the temporal lobe
201
what are types of seizure?
primary generalised (40%) and partial/focal (57%) seizures
202
what are features of primary generalised seizures? what are the manifestations?
- simultaneous onset of electrical discharge throughout whole cortex (involving both hemispheres), with no localising features referable to only one hemisphere
- bilateral symmetrical and synchronous motor manifestations
- always associated with loss of consciousness or awareness
203
what are features of partial/focal seizures? what are the manifestations?
- focal onset, with features referable to a part of one hemisphere
- often seen with underlying structural disease
- electrical discharge is restricted to a limited part
of the cortex of one cerebral hemisphere
- these may later become generalised (e.g. secondarily generalised tonic-clonic seizures)
204
what are types of primary generalised seizures?
- generalised tonic-clonic seizure (grand-mal)
- typical absence seizure (petit mal)
- myoclonic seizure
- atonic (akinetic seizure)
205
what are the clinical presentations of generalised tonic-clonic seizure?
- often no aura
- tonic phase: rigid, stiff limbs; person will fall if standing
- clonic phase: generalised, bilateral, rhythmic muscles jerking, lasting for seconds to minutes
- loss of consciousness
- eyes remain open and tongue often bitten
- there may be incontinence of urine/faeces
- followed by a period of drowsiness, confusion or coma for several hours post-ictally
206
what are the clinical presentations of a typical absence seizure?
- usually a disorder of childhood
- child ceases activity, stares and pales for a few seconds only
- often do not realise that they've had an attack
- on EEG characterised by a 3-Hz spike and wave activity
- children with petit-mal tend to develop generalised tonic-clonic seizures in adult life
207
what is the clinical presentation of a myoclonic seizure?
- sudden isolated jerk of a limb, face or trunk
| - patient may be thrown suddenly to the ground, or have a violently disobedient limb
208
what is the clinical presentation of a tonic seizure?
- sudden sustained increased tone with a characteristic cry/grunt
- intense stiffening of body (tonic)
- stiffening not following by jerking
209
what is the clinical presentation of an atonic (akinetic) seizure?
sudden loss of muscle tone and cessation of movement resulting in a fall
210
what are types of partial/focal seizures?
- simple partial seizure
- complex partial seizure
- partial seizure with secondary generalisation
211
what is the clinical presentation of a simple partial seizure?
- not affecting consciousness or memory
- awareness is unimpaired with focal motor, sensory (olfactory, visual etc.), autonomic or psychic symptoms
- no post-ictal symptoms
212
what is the clinical presentation of a complex partial seizure?
- affecting awareness or memory before, during or immediately after the seizure
- most commonly arise from the temporal lobe
- post-ictal confusion is common with seizures arising from the temporal lobe, whereas recovery is rapid after seizures in the frontal lobe
213
what is the clinical presentation of a partial seziure with secondary generalisation?
in 2/3rds of patients with partial seizures, the electrical
disturbance, which starts focally (as either a simple or complex partial seizure), spreads widely causing a secondary generalised seizure which is typically convulsive
214
what are characteristics of a partial/focal seizure in the temporal lobe?
- aura (80%): deja-vu, auditory hallucinations, funny smells, fear
- anxiety or out of body experience, automatisms e.g. lip smacking, chewing, fiddling
215
what are characteristics of a partial/focal seizure in the frontal lobe?
- motor features such as posturing or peddling movements of the leg
- Jacksonian march; seizure “marches” up or down the motor homunculus starting in face or thumb
- post-ictal Todd’s palsy
216
what are characteristics of a partial/focal seizure in the parietal lobe?
sensory disturbances e.g. tingling/numbness
217
what are characteristics of a partial/focal seizure in the occipital lobe?
visual phenomena e.g. spots, lines or flashes
218
what are features of epilepsy vs syncope?
- epilepsy: tongue biting, head turning, muscle pain, loss of consciousness, cyanosis, post-ictal symptoms
- syncope is the loss of consciousness due to hypoperfusion to brain: caused by prolonged upright position, sweat prior to loss of consciousness, nausea, pre-syncopal symptoms
219
what is a non-epileptic seizure vs epileptic seizure?
* non-epileptic seizures are situational
* non-epileptic is longer, closed mouth/eyes during tonic-clonic movements, pelvic thrusting, do not result from sleep, no incontinence or tongue biting
* there are pre-ictal anxiety symptoms in non-epileptic seizure
220
what are differential diagnoses of epilepsy?
postural syncope, cardiac arrhythmia, TIA, migraine, hyperventilation, hypoglycaemia, panic attacks or non-epileptic seizure
221
what is used to diagnose epilepsy?
- EEG
- MRI (imaging of the hippocampus is used)
- CT head (used in emergency to look for space-occupying lesion and identify/exclude structural abnormalities)
- blood tests
- genetic testing e.g. in juvenile myoclonic epilepsy
222
how is EEG used to diagnose epilepsy? what can be seen on it?
* not diagnostic
* performed to support diagnosis of epilepsy when history suggests it
* may help determine seizure type and what epilepsy syndrome it is
* frequently it is normal between attacks and false-positive may be detected in non-epileptics
* typically a 3Hz spike and wave is seen in a absence seizure of the temporal lobe
223
how are blood tests used to diagnose epilepsy?
* FBC, electrolytes, Ca2+, renal function, liver function, urine biochemistry and blood glucose levels
* done to rule out metabolic causes and discover comorbidities
224
what are emergency measures for epilepsy?
* ensure patient harms themselves as little as possible (ABCDE)
* check glucose
* prolonged seizure (longer than 3 minutes) or repeated seizures are treated with rectal/IV diazepam or lorazepam; repeat twice
* IV phenytoin loading
* if still fitting then anaesthetist involvement for anaesthetics and ventilation
225
what should be done once epilepsy is confirmed?
make sure it's not syncope or non-epileptic seizure and decide whether it is partial or generalised seizures
226
what are features of drug treatment for epilepsy?
- generally drugs are not advised after just one fit unless the risk of recurrence is high e.g structural brain lesion or focal CNS deficit
- epilepsy is resistant to drug treatment in a 1/3rd of patients
227
what is the drug treatment of generalised tonic-clonic seizures (grand mal)?
- oral sodium volproate (weight gain, liver failure, teratogenic)
- oral lamotrigine (maculopapular rash, blurred vision, vomiting)
- oral carbamazepine (diplopia, rashes, leucopenia, impaired balance, drowsiness)
228
what is the drug treatment of absence seizures (petit mal)?
- oral sodium valproate
- oral lamotrigine
- oral ethosuximide (rashes, night tremors)
229
what is the drug treatment of a partial/focal seizures? what is the first line treatment?
- carbamazepine (first line)
- sodium valproate
- lamotrigine
230
what is the neurosurgical treatment of epilepsy? when is it used? what is the alternative to this?
* used if drugs are not working
* if a single defined cause if identified such as hippocampal sclerosis or low grade tumour then surgical resection can offer 70% chance of seizure freedom
* alternative is vagal nerve stimulation which can reduce seizure frequency and severity in 33%
231
what is status epilepticus?
* medical emergency
* continuous seizures without recovery of consciousness
* when grand-mal seizures follow one another, there is a risk of death from cardiorespiratory failure
* caused by stopping anti-epileptic treatment, alcohol abuse
232
what is the lifestyle advice for epilepsy patients?
avoid swimming alone, avoid dangerous sports e.g. rock climbing, leave door open when taking bath, cannot drive sometimes
233
what is SUDEP?
sudden unexpected death epilepsy
- more common in uncontrolled epilepsy
- can be related to nocturnal seizure-associated apnoea or asystole
234
what is the definition of dementia?
a syndrome caused by a number of brain disorders which causes memory loss, difficulties with thinking, problem-solving or language as well as difficulties with activities of daily living
235
what is the epidemiology of dementia? what is it caused by predominantly in males and females?
- rare under 55 yrs
- prevalence rises with age
- AD is more common in females than males
- vascular and mixed dementias are more common in males than females
236
what are causes of dementia?
- Alzheimer's disease (50%)
- vascular dementia (25%)
- Lewy-body dementia (15%)
- fronto-temporal (Pick's) dementia
- Huntington's
- liver failure
- HIV
- prion diseases e.g. Creutzfeldt-Jakob
- vitamin B12/folate deficiency
237
how does Alzheimer's cause dementia?
* most common cause
* degeneration of the cerebral cortex, with cortical atrophy
* accumulation of beta-amyloid peptide, a degradation product of amyloid precursor protein, results in progressive neuronal damage, neurofibrillary tangles, increases in the number of amyloid plaques and the loss of ACh
238
how does vascular dementia cause dementia?
* brain damage due to cerebrovascular disease; either major stroke, multiple smaller unrecognised strokes or chronic changes in smaller vessels
* presents with signs of vascular pathology e.g. raised BP, past strokes and focal CNS signs
239
how does Lewy-body dementia cause dementia?
* 3rd most common cause of dementia
* deposition of abnormal protein within neurons in the brain stem and neocortex
* presents with fluctuating cognitive impairment, detailed visual hallucinations
* associated with Parkinsons
240
what are features of fronto-temporal (Pick's) dementia?
* specific degeneration/atrophy of the frontal and temporal lobes of the brain
* behavioural and personality change, early preservation of episodic memory and spatial orientation, emotional unconcern, lowers inhibitions
* mixed dementia
* Parkinson's dementia
241
what are risk factors for dementia?
- family history
- age
- Down's syndrome
- alcohol use
- obesity
- high BP
- hypercholesterolaemia
- diabetes
- atherosclerosis
- depression
- high oestrogen levels
242
what is the clinical presentation of Alzheimers's?
* insidious onset with steady progression over years
* short-term memory loss is usually the most prominent early symptom, but subsequently there is slow disintegration of the personality and intellect, eventually affecting all aspects of cortical function
* decline in language (difficulty naming and in understanding what is being said), visuospatial skills, apraxia (impaired ability to carry out skilled motor tasks and agnosia (failure to recognise objects e.g. clothing, people and places)
243
what is the clinical presentation of vascular dementia?
* stepwise deterioration with decline followed by short periods of stability
* history of TIAs and/or strokes
* evidence of atheropathy
244
what is the clinical presentation of dementia with Lewy bodies?
* fluctuating cognition with pronounced variation in attention and alertness
* prominent or persistent memory loss may not occur in the early stages
* impairment in attention, frontal, subcortical and visuospatial ability is often prominent
* depression and sleep disorders occur
* visual hallucinations
* Parkinsons is common
* loss of inhibitions
245
what are differential diagnoses of dementia?
substance abuse, hypothyroidism, space-occupying intracranial lesions, Huntington’s
246
what is used to diagnose dementia?
- history; assess cognitive functions by asking various questions
- MMSE used to screen for cognitive function
- exclude rare treatable causes of dementia (substance abuse, vitamin B12 deficiency, hypothyroidism)
- blood tests
- neuropsychology
- brain CT in younger patients or those with atypical presentation
- MRI to see extent of atrophy
- assess brain function (PET, SPECT, functional MRI)
247
what are the scores for MMSE?
score of 25+ out of 30 is normal, 18-24 = mild/moderate impairment and a score of 17 or below indicates serious impairment
248
what can be done to prevent dementia?
* healthy behaviours
* smoking cessation, good diet, physical activity and low alcohol
* engaging in more than 6 leisure activities lowers risk
* education, occupation, premorbid IQ and mental activities decreases risk
* changes in CSF amyloid-beta (Alzheimer’s) are seen 25yrs before onset of symptoms
249
what medication is used to treat dementia?
* ACE inhibitor in alzheimer’s to increase ACh e.g. oral donepezil or oral rivastigmine
* blood pressure control to reduce further vascular damage, particularly in vascular dementia such as ACE-inhibitors
250
what is Parkinson's disease?
degenerative movement disorder caused by a reduction in dopamine in the substantia nigra
251
what is the epidemiology of Parkinson's disease?
- increasing prevalence with age
- peak age of onset is 55-65 yrs
- more common in males than females
252
what is the aetiology of Parkinson's disease?
- idiopathic
- drug induced
- combination of: environmental factors, Parkinson's genes, oxidative stress and mitochondrial dysfunction
• environmental factors: pesticides, methyl-phenyl tetrahydropyridine found in illegal opiates
• mutation in parkin gene and alpha-synuclein gene
• oxidative stress and mitochondrial dysfunction
253
what are risk factors for Parkinson's?
- male
- increasing age
- family history
- being a non-smoker increases risk of parkinsons
254
what is the pathophysiology of Parkinsons?
```
this results in the progressive degeneration of dopaminergic neurons from the pars compacta of the substantia nigra in the midbrain that projects to
the striatum (caudate and putamen) of the basal ganglia
- loss of dopaminergic neurons leads to reduced striatal dopamine levels, leading to inhibition of the thalamus leading to decreased movement and symptoms of Parkinsons
- the extent of nigostriatal dopaminergic cell loss correlates with the degree of akinesia (muscle rigidity, stiffness and lack of responsiveness)
```
255
what do Lewy-bodies contain? how do they develop in Parkinsons?
- contain tangles of alpha synuclein and ubiquitin
- become gradually more widespread as the condition progresses, spreading from the lower brainstem to the midbrain then into the cortex
256
what is the onset of symptoms in Parkinson's what its common presentation? is it symmetrical or asymmetrical?
- onset of symptoms is gradual and commonly presents with impaired dexterity or unilateral foot drop
- asymmetrical; one side always worse than the other
257
what is the clinical presentation of Parkinson's before motor symptoms develop?
* anosmia - reduced sense of smell
* depression/anxiety
* aches and pains
* REM sleep disorders
* urinary urgency
* hypotension and constipation
258
what is the classical triad of Parkinsons?
- tremor
- rigidity (since it's an extrapyramidal lesion)
- bradykinesia/hypokinesia
259
what is the clinical presentation of tremor in Parkinson's?
- worse at rest and often asymmetrical
- usually most obvious in the hands (pill-rolling of the thumb and fingers)
- improved by voluntary movements and made worse by anxiety
- 4-6 cycles/sec (slower than cerebellar tremor)
- only in Parkinson’s will you see issue with repetitive hand movements with worsening in rhythm the longer attempted
260
what is the clinical presentation of rigidity in Parkinson's? why does rigidity occur?
- occurs because Parkinson's is an extrapyramidal lesion
- increased tone in the limbs and trunk
- limbs resists passive extension throughout movement (lead-pipe rigidity or cogwheel when combined with tremor)
- this is opposed to the hypertonia of a UMN lesion, which is spasticity where resistance falls away as the movement continues (clasp-knife)
- increased tone and thus rigidity over entire radius of joint movement
- can cause pain and problems with turning in bed
261
what is the clinical presentation of bradykinesia/hypokinesia in Parkinson's?
```
- slow to initiate movement and slow, low-amplitude excursions in repetitive actions
• reduced blink rate
• monotonous hypophonic speech
• micrographia (writing smaller)
- gait
- expressionless face (hypomimesis)
```
262
what are features of gait in Parkinson's?
* asymmetrical, reduced arm swing
* narrow gait
* stooped posture and small shuffling steps
* festinance: shuffling steps, maybe dragging foot with flexed trunk
* difficulty initiating movement and turning
* poor balance
263
what is the general clinical presentation of Parkinson's?
- onset of symptoms is gradual and commonly presents with impaired dexterity or unilateral foot drop
- onset is asymmetrical
- before motor symptoms develop
- classic triad (tremor, rigidity, bradykinesia/hypokinesia)
- difficulty with fine movements e.g. problems doing up buttons
- Parkinsonian gait
- speech becomes quiet, indistinct and flat
- drooling of saliva and swallowing difficulty is a late feature (can lead to aspiration pneumonia as a terminal event)
- depression is common
- constipation is common
- increased urinary frequency
264
what are differential diagnoses of Parkinson's?
- benign essential tremor (more common); worse on movement and rare whilst at rest
- multiple cerebral infarcts, Lewy body dementia, drug-induced, Wilson’s disease, trauma and dopamine antagonists
265
what is treatment of benign essential tremor (differential diagnosis of Parkinson's)?
* treat with beta-blockers e.g. propanolol (contraindicated with asthma/diabetes)
* primidone (anti-seizure) or gabapentin (anti-epileptic)
266
what is used to diagnose Parkinson's?
- diagnosis is based on history and examination
- can confirm by response to levodopa
- MRI head (can show atrophy, used to exclude tumours or normal pressure hydrocephalus)
- dementia, incontinence, symmetry and early falls suggest that it's not Parkinsons
267
what is the pharmacological treatment of Parkinson's?
- the gold standard treatment is oral levodopa given alongside a decarboxylase inhibitor e.g. co-careldopa or co-beneldopa
- dopamine agonists e.g. oral ropinirole or oral pramiprexole
- monoamine oxidase B inhibitors e.g. oral selegiline or oral rasagiline
- catechol-O-methyltransferase inhibiors e.g. oral entacapone or oral tolcapone
- deep brain stimulation may help those who are partly-dopamine responsive
- surgical ablation of overactive basal ganglia circuits
268
what is the non-pharmacological treatment of Parkinson's?
- explain that the disease is slowly progressive and although incurable it's amenable to palliation
- balance problems, speech and gait disturbance do not respond to medication thus physiotherapy is the mainstay treatment for these
- physical activity is beneficial and should be encouraged
269
what is the gold standard treatment for Parkinson's? what is given alongside it?
oral levodopa given alonside a decarboxylase inhibitor e.g. co-careldopa or co-beneldopa
270
what is levodopa? how is it used to treat Parkinson's? what is given with it?
* levodopa (L-dopa) is a precursor to dopamine, but dopamine cannot cross the blood brain barrier whereas L-dopa can
* a decarboxylase inhibitor is given with it, prevents peripheral conversion of L-dopa to dopamine and therefore reduces the peripheral side effects as well as maximising the dose that crosses the BBB
* once crossed, the L-dopa can be taken up by dopaminergic neurones and converted into dopamine and used
271
what are the side effects of oral levodopa and a decarboxylase inhibitor? why are they started late?
- nausea, vomiting, arrhythmias, psychosis and visual hallucinations
- reduced efficacy over time even if dose is increased
• effect can wear off in 5-10yrs and won’t work for as long as before; L-dopa is usually avoided until very late or if symptoms have worsened
- the use of dopamine antagonists, MAO-B and COMT inhibitors can allow the delay in starting L-dopa
- on-dyskinesias
- off-dyskinesias
- freezing (unpredictable loss of mobility)
272
what are features of on-dyskinesias as a complication of long term L-dopa use?
hyperkinetic, choreiform movement whenever drugs work - repetitive, rapid, jerky well-coordinated involuntary movements (seen in Huntington’s)
273
what are features of off-dyskinesias as a complication of long term L-dopa use?
fixed, painful dystonic posturing (twisting and repetitive movements or abnormal fixed postures - caused by sustained repetitive muscle contractions)
274
what are examples of decarboxylase inhibitors?
co-careldopa or co-beneldopa
275
what are examples of dopamine agonists used in Parkinson's?
oral ropinorole or oral pramiprexole
276
what are side effects and contraindications of dopamine agonists?
* side effects: drowsiness, nausea, hallucinations, compulsive behaviour
* avoid bromocriptine/cabergoline as they can cause cardiac valvulopathy
277
what are examples of monoamine oxidase B inhibitors?
oral selegiline or oral rasagiline
278
what are MAO-B inhibitors used for in Parkinson's?
* these inhibit MAO-B enzymes which breakdown dopamine, thus they result in a reduction of dopamine breakdown so dopamine remains for longer
* used to delay starting L-Dopa and to reduce the wearing off of L-Dopa
* side effects: postural hypotension and AF
279
what are some examples of COMT inhibitors?
oral entacapone or oral tolcapone
280
what are COMT inhibitors used for in Parkinson's? what are side effects?
- inhibit COMT, which breaks down dopamine
| - tolcapone can cause liver damage
281
what are some complications of Parkinson's treatment? what drugs can be used to treat these?
- neuropsychiatric complications e.g. depression, dementia and psychosis are common and reflect disease progression or drug side-effects
- SSRIs and anti-psychotics can be used
282
what surgical treatments are used to treat Parkinson's?
- deep brain stimulation may help those who are partly-dopamine responsive
- surgical ablation of overactive basal ganglia circuits e.g. subthalamic nuclei
283
what is Huntington's?
Huntington’s is a cause of chorea and is a neurodegenerative disorder characterised by the lack of the inhibitory neurotransmitter GABA
284
what is chorea?
* relentlessly progressive, jerky, explosive, semi-purposeful movements, rigidity, involuntary movements flitting from one part of the body to another; continuous flow
* can’t sit still
* may begin as general restlessness, unintentionally initiated movements and lack of coordination
* stops when sleeping
285
what is the epidemiology of Huntington's chorea?
- autosomal dominant condition with full penetrance; all gene carriers will develop disease
- incurable, progressive neurodegenerative disorder
- presents in middle age initially with a prodromal phase of mild symptoms e.g. irritability, depression and incoordination then progressing to psychiatric
and cognitive symptoms
- very rare, prevalence worldwide is 5 per 100000
286
what is the aetiology of Huntington's chorea? what is the genetic component?
mutation on chromosome 4 resulting in the repeated expression of CAG sequence
287
what are the risk factors for Huntington's chorea?
- family history
| - having a parent with Huntington’s; child has 50% risk of getting it
288
what is the pathophysiology of Huntington's chorea?
- repeated expression of CAG sequence leads to the translation of an expanded polyglutamine repeat sequence in the Huntington gene, the protein gene product the function is expansion is thought to be a toxic ‘gain-of-function mutation’
- progressive cerebral atrophy with marked loss of neurones in the caudate nucleus and putamen of the basal ganglia; there is specifically loss of the corpus striatum GABA-nergic and cholinergic neurons
- this results in decreased ACh and GABA synthesis in the striatum
- GABA is the main inhibitory neurotransmitter, loss of this will result in decreased inhibition of dopamine release and therefore result in excessive thalamic stimulation and thus excessive movements (chorea)
289
how does the number of CAG repeats present affect symptom onset in Huntington's chorea?
the more CAG repeats present, the earlier the symptom onset:
• most adult onset have 36-55 repeats
• early onset i.e. from childhood have over 60 repeats
290
what is the clinical presentation of Huntington's chorea?
- often prodromal phase of mild psychotic and behavioural symptoms, then chorea develops
- dysarthria (unclear speech), dysphagia and abnormal eye movements (behavioural change, depression/anxiety)
- psychiatric problems
- dementia
- associated with seizures
- eventually occurs until death; death usually occurs within 15yrs of diagnosis, usually from an intercurrent illness e.g. infection
291
what are differential diagnoses of chorea?
- Huntington’s is the commonest cause of chorea
- other causes or chorea:
• Sydenham’s chorea (Rheumatic fever)
• Creutzfeldt-Jakob Disease (prion)
• Wilson’s disease
• SLE
• stroke of basal ganglia
292
what is used to diagnose Huntington's chorea?
- diagnosis is mainly clinical
- genetic testing, shows many CAG repeats
- CT/MRI
293
what is seen on CT/MRI in Huntington's chorea?
* shows caudate nucleus atrophy and increased size of the frontal horns of the lateral ventricles (signs of brain matter destruction)
* imaging is not useful early on in disease process
294
what is the treatment of Huntington's chorea?
- there is no treatment to prevent progression
- counselling to patient and family, genetic counselling to any children of patients
- symptomatic management of chorea: benzodiazepines, sulpiride (neuroleptic, depresses nerve function), tetrabenzine (dopamine depleting)
- antidepressants such as SSRIs
- antipsychotic medication such as neuroleptics e.g. haloperidol
- to treat aggression use risperidone
295
what is primary headache? what are some examples?
* no underlying cause relevant to the headache
| * examples include; migraine (20% of population), cluster and tension headache (affect 99% in lifetime)
296
what is secondary headache?
there is an underlying cause
| - e.g. meningitis, SAH, giant cell arteritis, medication overuse headache
297
what are red flags for a secondary headache?
- HIV or immunosuppressed
- fever
- thunderclap headache (SAH)
- seizure and new headache
- suspected meningitis
- suspected encephalitis
- red eye? acute glaucoma
- headache + new focal neurology e.g. papilloedema
298
what is an example of a non-primary or secondary headache?
trigeminal neuralgia; a painful cranial neuropathy
299
what is the definition of migraine? what are some symptoms?
- recurrent throbbing headache often preceded by an aura and associated with nausea, vomiting and visual changes
- a migraine aura may affect the patients eyesight with visual phenomena such as fortification spectra (zig-zag lines), shimmering or scotomas, but may also result in pins and needles, dysphasia and rarely weakness of limbs and motor function
300
what is the epidemiology of migraine?
- most common cause of episodic headache (recurrent)
- more common in females than males
- in 90% onset if before 40yrs
- if onset >50 then pathology should be sought
- usually the severity of migraine decreases with advancing age
301
what are partial triggers of migraine? (CHOCOLATE)
CHOCOLATE:
- Chocolate
- Hangovers
- Orgasms
- Cheese
- Oral contraceptives
- Lie-ins
- Alcohol
- Tumult - loud noise
- Exercise
302
what are causes of migraine?
- CHOCOLATE (partial triggers)
- brain chemical imbalance may be cause
- may be caused by changes in the brainstem and its interactions with the trigeminal nerve
303
what are risk factors for migraine?
- family history
- female
- age; can occur at any age but majority have first migraine in adolescence
304
what is the pathophysiology of migraine?
- genetic and environmental factors play a role
- genetic factors play a role in causing neuronal-hyper-excitability
- changes in brainstem blood flow lead to an unstable trigeminal nerve nucleus and nuclei in the basal thalamus
- cortical spreading depression; self-propagating wave of neuronal and glial depolarisation that spreads across the cerebral cortex is thought to cause the aura of migraine and leads to the release of inflammatory mediators which impact on the trigeminal nerve nucleus
- this results in release of vasoactive neuropeptides including calcitonin-gene-related peptide and substance P; this results in neurogenic inflammation, vasodilation and plasma protein extravasation, leading to pain that propagates all over the cerebral cortex
305
what is the clinical presentation of migraine?
- there may be a prodrome that precedes the headache by hours/days (e.g. yawning, cravings, mood/sleep changes)
- migraine without aura
- symptoms during headache
- not attributable to another disorder
306
what are features of migraine headache without aura?
- attacks last 4-72 hours
- two of the following: unilateral, pulsing, moderade/severe pain in head, aggravated by routine physical actvity
- during headache at least one of: nausea and/or vomiting during headache, photophobia, sound sensitivity
- not attributable to another disorder
307
what is the clinical presentation of migraine with aura?
* at least 2 attacks
* aura precedes the attack by minutes and may persist during it
* unilateral, pulsatile headache
* chaotic cascading, jumbling, distorting lines, dots or zigzags
* scotoma (black hole in visual field)
* hemianopia
* paraesthesiae spreading from fingers to face
308
what general migraine features are there at least 2 of?
- unilateral pain
- throbbing-type pain
- moderate to severe intensity
- motion sensitivity (headache made worse with head movement of physical activity)
309
what general migraine features are there at least 1 of?
- nausea/vomiting
- photophobia/phonophobia
- normal examination with no other attributable cause
310
what are differential diagnoses of migraine?
- tension headache (bilateral, tight-band around head), cluster headache (excruciating, autonomic symptoms), medication over-use headache
- sudden migraine may resemble meningitis or subarachnoid haemorrhage
- the visual and hemisensory symptoms must be distinguished from thromboembolic TIAs (in TIAs the maximum deficit is present immediately and headache is unusual)
- brain tumour (rare cause of headaches) and temporal arteritis
311
what is used to diagnose migraine?
- mainly clinical diagnosis
- always examine eyes, BP, head and neck
- exclude other causes
312
how are other causes of migraine excluded?
- lab tests (CRP and ESR)
- indications for neuroimaging (CT/MRI)
- lumbar puncture
313
what are indications for neuroimaging (CT/MRI) in migraine diagnosis?
- worst/severe headache; thunderclap headache
- change in pattern of migraine
- abnormal neurological exam
- onset > 50 yrs
- epilepsy
- posteriorly located headache
314
what are indications for lumbar puncture in migraine diagnosis?
- worst headache of life; thunderclap headache
- severe rapid onset headache, progressive headaches, unresponsive headaches
- neuroimaging should precede lumbar puncture to rule out mass/lesion/raised ICP
315
what is the treatment of acute migraine?
- do not offer ergots e.g. ergotamine or opioids
- triptans e.g. sumatriptan
- NSAIDs e.g. ketoprofen, naproxen or aspirin (avoid paracetamol or ibuprofen)
- and/or anti-emetic e.g. prochlorperazine
316
what is the action of triptans? what are contraindications and side effects?
- e.g. sumatriptan
- selectively stimulate 5-hydroxytryptamine receptors in brain
- contraindicated in ischaemic heart disease, coronary spasm and uncontrolled high BP
- side effects: arrhythmias, angina, MI
317
what is done to prevent migraine?
* reduce triggers
* if more than 2 attacks a month, or acute treatment required more than twice a week
* beta blockers
* tricyclic anti-depressant; side effects: drowsiness, dry mouth and reduced vision
* anti-convulsant e.g. topiramate; side effects: reduced memory
318
what are features of tension headache?
- most common type of primary headache
- pain can radiate from lower back of the head, the neck, eyes or other muscle groups in the body, typically affecting both sides of the head
- most chronic daily and recurrent headaches are tension headaches
319
what is the epidemiology of tension headache?
- the commonest primary headache
- can be episodic (<15 days/month) or chronic (>15 days a month for at least 3 months)
- no organic cause
320
what is the aetiology/risk factors for tension headache?
- stress
- sleep deprivation
- bad posture
- hunger
- eyestrain
- anxiety
- noise
321
what is the clinical presentation of tension headaches?
- episodic (<15 days/month) or chronic (>15 days a month for at least 3 months)
- usually has one of the following: bilateral, pressing/tight non-pulsatile, mild/moderate intensity, scalp muscle tenderness
- without vomiting or sensitivity to head movement, no aura
- not aggravated by physical activity
- tight band-like sensation
- pressure behind eyes, mild-moderate pain
- headaches can last from 30 mins to 7 days
- not attributed to other disorder
322
what are differential diagnoses of tension headache?
migraine, cluster headache, giant cell arteritis, drug-induced headache
323
what is used to diagnose tension headache?
clinical diagnosis from history
324
what is used to treat tension headache?
- reassurance and lifestyle advice,avoidance of triggers
- stress relief e.g massage or acupuncture
- symptomatic treatment for episodes occurring >2 days a week
325
what is symptomatic treatment of tension headache that occurs more than 2 days a week?
* aspirin
* paracetamol
* NSAIDs e.g. ibuprofen
* no opioids
* limit the use of analgesia to no more than 6 days a month to reduce chance of medication-overuse headache
* consider tricyclic antidepressants e.g. amitriptyline
326
what are features of medication-overuse headaches?
- worsens whilst on regular analgesia, especially on opioids
- other causes are mixed analgesics e.g. paracetamol and codeine/opiates, ergotamine and triptans
- common reason for episodic headache becoming chronic daily headache
327
what are cluster headaches?
- neurological disorder characterised by recurrent severe headaches on one side of the head, typically around the eye
- most disabling primary headache
328
what is the epidemiology of cluster headaches?
- distinct from migraine
- much rarer than migraine; 1 per 1000
- more common in males than females
- affects adults, typically between 20-40 yrs
- commoner in smokers
329
what are the risk factors/aetiology for cluster headaches?
- smoker
- male
- autosomal dominant gene plays a role
330
what is the pathophysiology of cluster headaches?
- unknown
- may be due to superficial temporary artery smooth muscle hyper-reactivity to serotonin
- there are hypothalamic grey matter abnormalities too
- autosomal dominant gene has a role too
331
what is the clinical presentation of cluster headaches?
- abrupt onset
- rapid onset of excrutiating pain around one eye, temple or forehead
- ipsilateral cranial autonomic features
- pain is strictly unilateral and almost always affects the same side
- rises to crescendo over minutes and lasts 15-160mins, once or twice a day; usually at the same time
- often nocturnal/early morning - often wakes patient from sleep
- vomiting
- episodic; clusters last 4-12 weeks and are followed by pain-free periods of months or even 1-2 yrs before the next cluster
- can be chronic (attacks for more than 1yr without remission) instead of episodic
332
what are ipsilateral cranial autonomic features of cluster headaches?
* eye may become watery and bloodshot with lid swelling, lacrimation,
* facial flushing
* rhinorrhea (blocked nose)
* miosis (excessive pupil constriction) +/- ptosis (drooping or falling of upper eyelid), seen in 20% of attacks
333
what is used to diagnose cluster headaches?
- clinical diagnosis
| - at least 5 headache attacks fulfilling the clinical presentation criteria
334
what is the prevention and treatment of an acute cluster headache?
* calcium channel blocker is first line prophylaxis
* avoid alcohol during cluster period
* corticosteroids may help during cluster
* analgesics are unhelpful
* 100% 15L O2 for 15mins via a non-rebreathable mask (not if COPD)
* triptan e.g. SC sumatriptan
335
what is trigeminal neuralgia?
a chronic, debilitating condition affecting the trigeminal nerve, resulting in intense and extreme episodes of pain
336
what is the epidemiology of trigeminal neuralgia?
- peak incidence between 50-60yrs
- more common in females than males
- prevalence increases with age
- may be due to a genetic disposition
- almost always unilateral
337
what is the aetiology of trigeminal neuralgia?
- in most cases it is due to compression of the trigeminal nerve by a loop of vein or artery
- can be due to local pathology such as aneurysms, meningeal inflammation, tumours; local pathology is more common in younger people as a cause of compression
- a fifth nerve lesion is due to pathology
- hypertension is the main risk factor
- triggers: washing affected area, shaving, eating, talking and dental prostheses
338
what is a fifth nerve lesion often due to?
* within the brainstem - tumour, multiple sclerosis, infarction
* at the cerebellopontine angle - acoustic neuroma, other tumour
* within the petrous bone - spreading middle ear infection
* within the cavernous sinus - aneurysm of the internal carotid, tumour or thrombosis of the cavernous sinus
339
what is the pathophysiology of trigeminal neuralgia?
compression of the trigeminal nerve results in demyelination and excitation of the nerve resulting in erratic pain signalling
340
what is the clinical presentation of trigeminal neuralgia?
- almost always unilateral
- at least 3 attacks of unilateral facial pain
- facial pain occurs in one or more distributions of the
trigeminal nerve, with no radiation beyond the trigeminal distribution
- pain
341
what are features of trigeminal neuralgia pain?
pain has at least 3 of the following:
• reoccurring in paroxysmal (sudden and frequent) attacks from a fraction of a second to 2 minutes
• severe intensity
• electric shock like, shooting, stabbing or knife-like
• precipitated by innocuous (non-harmful) stimuli by the affected side of the face e.g. washing or shaving area
342
what are differential diagnoses of trigeminal neuralgia?
- giant cell arteritis/temporal arteritis should be excluded
| - dental pathology, temporomandibular joint dysfunction, migraine, cluster headaches
343
what is used to diagnose trigeminal neuralgia? what is the criteria?
- in order to diagnose, there need to be at least 3 attacks with unilateral facial pain
- clinical diagnosis based on criteria above and based on history
- MRI to exclude secondary causes or other pathologies
- not attributed to another disorder
344
what is the treatment of trigeminal neuralgia?
- typical analgesics and opioids do not work
- anticonvulsant suppresses attacks in most patients
- other, less effective options e.g. oral phenytoin, gabapentin and lamotrigine
- may spontaneously remit after 6-12 months
- if drugs fail then surgery may be necessary: microvascular decompression (anomalous vessels are separated from the trigeminal root) or gamma knife surgery (done directly at the trigeminal nerve ganglion or nerve root), stereotactic radiosurgery
345
what are features of time in migraine, tension type, cluster headache vs trigeminal neuralgia?
migraine
- 4-72 hours
- varies
tension type
- minutes to days
- varies
cluster headache
- 15-80mins
- ECH vs CCH
trigeminal neuralgia
- seconds
- bouts
- many/day
346
what are features of pain in migraine, tension type, cluster headache vs trigeminal neuralgia?
migraine
- moderate/severe
- throbbing
- uni/bilateral
tension type
- mild/moderate
- pressing/tight
- uni/bilateral
cluster headache
- severe/very severe
- boring/hot poker
- unilateral
trigeminal neuralgia
- severe/very severe
- electric/lightening/stabbing
- unilateral
347
what is giant cell arteritis/temporal arteritis? what is it associated with?
- inflammatory disease of large blood vessels
• systemic immune-mediated vasculitis affecting medium to large size arteries of the aorta and its extra cranial branches
• associated with polymyalgia rheumatica (PMR) and can occur in 50% of cases with GCA
348
what is the epidemiology of temporal arteritis?
- primarily in those over 50yrs
- most common in caucasians
- more common in females than males
349
what are risk factors for temporal arteritis?
- caucasian
- common in elderly women (>60)
- polymyalgia rheumatica and giant cell arteritis have a familial component
- incidence increases with age
350
what is the pathophysiology of temporal arteritis?
- there is granulomatous arteritis of unknown aetiology affecting in particular the extra-dural arteries and the large cerebral arteries
- arteries become inflamed, thickened and can obstruct blood flow
- cerebral arteries affected in particular e.g. temporal artery
- opthalmic artery can also be affected potentially resulting in permanent or temporary vision loss
351
what is the clinical presentation of temporal arteritis?
- severe headaches (temporal pulsating)
- tenderness of scalp (combing hair can be painful) or temple
- claudication of the jaw (pain in jaw) when eating
- tenderness and swelling of one or more temporal or occipital arteries
- sudden painless vision loss (emergency); arteritic anterior ischaemic optic neuropathy - optic disc is very pale/swollen
- malaise, lethargy, fever
- associated symptoms of PMR
- dyspnoea, morning stiffness and unequal or weak pulses
352
what are differential diagnoses of temporal arteritis?
migraine, tension headache, trigeminal neuralgia, polyarteritis nodosa
353
what is the diagnosic criteria of temporal arteritis?
diagnostic criteria - 3 or more of:
• over 50
• new headache
• temporal artery tenderness or decreased pulsation
• ESR raised
• abnormal artery biopsy - inflammatory infiltrates present
354
what is used to diagnose temporal arteritis? what is CRP and biochemistry like?
- diagnostic criteria
- normocytic normochromic anaemia
- ESR raised
- ANCA negative
- CRP very high
- serum alkaline phosphatase may be raised
- temporal artery biopsy
355
what is done for a temporal artery biopsy in temporal arteritis?
- definitive diagnostic test
- should be taken before or within 7 days of starting high dose corticosteroids
- lesions are patchy so take a big chunk
356
what are histological features of temporal arteritis on temporal artery biopsy?
- cellular infiltrates of CD4+ T lymphocytes, macrophages and giant cells (may not be visible in all cases) in the vessel wall
- granulomatous inflammation of the intima and media
- breaking up of the internal elastic lamina
357
what is the treatment of temporal arteritis?
- high dose corticosteroids to stop vision loss; gradual reduction of steroids over 12-18 months
- if visual symptoms persist then give IV methylprednisolone for 3 days
- used long-term so give GI and bone protection (to prevent osteoporosis due to steroid use) e.g. lansoprazole and alendronate and Ca2+ and
vitamin D
- monitor treatment progress by looking at ESR/CRP (should fall)
- polymyalgia rheumatica (PMR) presents in 50% of cases with giant cell arteritis
358
where does the spinal cord extend from and to?
C1 (junction with medulla) to L1/L2 (conus medullaris)
359
what is the conus medullaris?
- lumbar and sacral nerve roots are below L1
- grouped together to form the cauda equina (final point of the spinal cord)
- L1/L2
360
what is paraplegia?
paralysis of both legs; always caused by spinal cord lesion
361
what is hemiplegia?
paralysis of one side of the body caused by lesion of the brain
362
are signs of an UMN ipsilateral or contralateral?
contralateral to lesion
363
are LMN lesion signs ipsilateral or contralateral to the lesion?
ipsilateral to the lesion
364
what are LMN lesion signs? what do they indicate?
* indicate that the lesion is either in the anterior horn cell or distal to the anterior horn cell i.e. in anterior horn cell, plexus or peripheral nerve
* decreased muscle tone
* wasting (atrophy) +/- fasiculations (spontaneous involuntary twitching)
* weakness that corresponds to those muscles supplied by the involved cord segment, nerve root, part of plexus or peripheral nerve
* reflexes are reduced or absent
365
what can the level of the LMN lesion be inferred from?
- can be inferred from the accompanying symptoms
- back pain and sciatica suggests a root problem
- weakness of the biceps with absence of the biceps reflex, with UMN signs in the legs suggests cord disease e.g. a disc prolapse at C5/C6 - LMN at that level, and UMN below
366
what does weakness of the biceps with absence of the biceps reflex suggest?
weakness of the biceps with absence of the biceps reflex, with UMN signs in the legs suggests cord disease e.g. a disc prolapse at C5/C6 - LMN at that level, and UMN below
367
what is spondylolisthesis?
* slippage of one vertebra over the one below
* nerve root comes out above the disc, therefore root affected will be the one below the disc herniation e.g. L4/L5 herniation leads to L5 nerve root compression
368
what is spondylosis?
degenerative disc disease
369
what is myelopathy?
* caused by spinal cord compression
* UMN signs
* spinal cord disease
370
what is radiculopathy? what are signs of it?
* caused by spinal root compression
* LMN signs
* pain down dermatome supplied by root
* weakness in myotome supplied by root
* no UMN signs
* acute - no LMN signs - since fasciculations and wasting take time to develop
371
what are the C5, C6, C7, L3/4, L5 and S1 myotomes?
- C5 - shoulder abduction/biceps jerk
- C6 - elbow flexion/supinator jerk
- C7 - elbow extension/triceps jerk
- L3/4 - knee extension/knee jerk
- L5 - ankle dorsiflexion (upwards)
- S1 - ankle plantar flexion (downwards)/ankle jerk
372
what are the C4, T4, T1, T10, L2-3, L4, L5, S1-2, S4 dermatomes?
- clavicle - C4
- nipples - T4
- medial side of arm - T1
- umbilicus - T10
- anterior and inner leg - L2-3
- knee - L4
- posterior and outer leg - L5, S1-2
- perianal area - S4
373
what is myelopathy?
compression of the spinal cord resulting in upper neurone signs and specific symptoms dependent on where compression is
374
what are aetiology/risk factors for myelopathy?
- vertebral body neoplasms (most common cause of acute compression) caused by secondary malignancy commonly from lung, breast, prostate, myeloma, lymphoma
- spinal pathology (disc herniation and prolapse)
375
what is vertebral disc herniation?
when centre of disc (nucleus pulposus) has moved out through the annulus (outer part of disc) resulting in pressure on nerve root and pain
376
what is vertebral disc prolapse?
- when nucleus pulposus moves and presses against the annulus but it doesn't escape outside the annulus
- can produce a bulge in the disc which, sometimes, can result in pressure (less pressure than herniation) on nerve root resulting in pain
377
what are rarer causes of myelopathy?
* infection e.g. epidural abscess
* haematoma e.g. warfarin
* primary spinal cord tumour e.g. glioma, neurofibroma
378
what is the clinical presentation of myelopathy?
- spinal or root pain may precede leg weakness and sensory loss
- there is progressive weakness of the legs with UMN signs
- onset may be acute (hours to days) or chronic (weeks to months) depending on cause
- arm weakness if often less severe e.g. cervical cord lesion
- bladder (and anal) sphincter involvement is late and manifests as hesitancy, frequency and later as painless retention
- there is sensory loss below the level of the lesion
- look for a motor, reflex and sensory level with normal findings above the level of the lesion
- LMN signs at the level (especially in cervical cord compression) and UMN below the level - but remember that tone and reflexes are usually reduced initially in acute compression; takes time to develop
- depends on the level of the lesion
379
what is the sensory loss in myelopathy?
* sensory loss below the level of lesion
* this is known as the sensory level
* sensation abruptly diminishes one/two cord segments below the level of the actual anatomical level of spinal cord compression
380
what are features of sciatica in myelopathy?
- L5/S1 lesion = S1 nerve root compression
| - sensory loss/pain in back of thigh/leg/lateral aspect of little toe (essentially in the sciatic nerve distribution)
381
what are features of L4/L5 lesions in myelopathy?
L4/L5 = L5 nerve root compression:
| • sensory loss/pain in lateral thigh/lateral leg and medial side of big toe
382
what are differential diagnoses of myelopathy?
transverse myelitis, multiple sclerosis, cord vasculitis, trauma, dissecting aneurysm
383
what is used to diagnose myelopathy?
- do not delay imaging, since irreversible paraplegia may follow if the cord is not decompressed
- speed of imaging should parallel the rate of clinical progression
- MRI (gold standard; identifies cause and site of cord compression)
- biopsy/surgical exploration may be required to identify the nature of any mass
- screening blood tests: FBC, ESR, B12, U+E’s, syphilis serology, LFT, PSA
- CXR (looks for TB or malignancy)
384
what is the treatment of myelopathy?
- if malignancy then give IV dexamethasone and consider more specific therapy e.g. radiotherapy or chemotherapy
- epidural abscess must be surgically decompressed and antibiotics given
- refer to neurosurgeons
385
what is neurosurgical treatment of myelopathy?
* epidural steroid injection - effective for leg pain
* surgical decompression of cord:
* laminectomy - removal of the lamina/spongy tissue between discs to relieve pressure and thus symptoms
* microdiscectomy - removal of herniated tissue from disc
386
what is cauda equina syndrome?
- condition that occurs when the bundle of nerves below the end of the spinal cord
- medical emergency
- cauda equina is formed by the nerve roots caudal (distal) to the level of the termination of the spinal cord at L1/L2
- spinal damage at or caudal to L1
- flaccid and areflexic weakness
387
what is the caudal equina?
a bundle of spinal nerves and spinal nerve rootlets, consisting of the second through fifth lumbar nerve pairs, the first through fifth sacral nerve pairs and the coccygeal nerve, all of which arises from theh lumbar enlargement and the conus medullaris of the spinal cord
388
what is the conus medullaris?
tapered, lower end of the spinal cord. occurs near lumbar vertebral levels 1 and 2, occasionally lower
389
what is the filum terminale?
delicate strand of fibrous tissue, about 20cm in length, proceeding downward from the apex of the conus medullaris
- consists of the filum terminale internum and externum
390
what is the reticulospinal tract?
- medial reticulospinal tract arises from the pons; it facilitates voluntary movements and increases muscle tone
- lateral reticulospinal tract arises from the medulla; inhibits voluntary movements and reduces muscle tone
- ipsilateral
391
what does the striatum consist of?
caudate nucleus and putamen
392
what does the corpus striatum consist of?
caudate nucleus, putamen, nucleus accumbens, globus pallidus
