NEURO Flashcards
(73 cards)
1
Q
SYMPATHETIC -
effect
A
4 Fs: Flight, fright, freeze, fuck Increases heart rate Increases force of contractions in the heart Vasoconstriction BronchoDILATION Reduces gastric motility Sphincter contraction DECREASED gastric secretions Male ejaculation
2
Q
PARASYMPATHETIC -
effect
A
rest&digest CN 1973: Decreases heart rate Decrease force of contraction Vasodilation BronchoCONSTRICTION Increases gastric motility Sphincter relaxation INCREASED gastric secretions Male erection (both)
3
Q
SPINE & SPINAL CORD
Vertebral column - total + gps
A
33 in total: - 7 Cervical vertebra
- 12 Thoracic vertebra
- 5 Lumbar vertebra (fused) - 4 Coccyx vertebra (fused)
4
Q
Has x pairs of spinal nerves (segments): -
A
31
- Cervical - 8 nerves
- Thoracic - 12 nerves
- Lumbar - 5 nerves
- Sacral - 5 nerves
- Coccyx - 1 nerve
5
Q
Conus is the … and ends before …
A
end of spinal cord
L2
6
Q
Spinal nerve exit from cord:
A
- Cervical segments: around 1 vertebra HIGHER than their corresponding vertebra [EXCEPT C8 which exits below one 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
7
Q
Dermatome:
A
Area of skin supplied by a SINGLE SPINAL NERVE - SENSOR
8
Q
Sensory innervation of hand:
A
- Little finer (ulnar nerve) - C8
- Index finger (median nerve) - C7
- Thumb - C6 - The thumb is C6, always remember this!
9
Q
Sensory innervation key areas:
A
Clavicle - C4 Nipples - T4 Medial side of arm - T1 Umbilicus - T10 Knee - L4 Perianal area - S4 Anus - S5
10
Q
Myotome:
A
A volume of muscle supplied by a single spinal nerve Phrenic nerve: - C3,4,5 keeps the diaphragm alive! Small muscles of the hand - T1 Innervation of penis: - S2,3,4 keeps the penis off the floor!
11
Q
BROWN-SEQUARD SYNDROME:
A
Overall:
- Ipsilateral loss of; proprioception, motor & fine touch
- Contralateral loss of; pain, temperature & crude touch
12
Q
CN
A
- Olfactory - Some
- Optic - Say
- Oculomotor - Money - PARASYMPATHETIC
- Trochlear - Matters
- Trigeminal - But
- Abducens - My
- Facial - Brother - PARASYMPATHETIC
- Vestibulocochlear - Says
- Glossopharyngeal - Big - PARASYMPATHETIC
- Vagus - Boobs - PARASYMPATHETICS
- Accessory - Matter
- Hypoglossal - Most
OhOhOhTo TOuch And Feel A Girls Vagina Ah Heaven
13
Q
Cranial nerve brainstem nuclei location: -
A
3,4 - Midbrain
- 5,6,7,8 - Pons
- 9,10,11,12 - Medulla
14
Q
Vestibulocochlear nerve:
A
- Vestibular - Ipsilateral
- Cochlear - Contralateral
15
Q
Broca’s + Wernicke’s
A
Broca’s area is the language area of the DOMINANT FRONTAL LOBE (if left handed then Broca’s is still on the left side in 60%) responsible for the articulation of speech:
Wernicke’s area is the comprehension area in the DOMINANT (normally left if right handed) TEMPORAL LOBE and is responsible for understanding speech:
16
Q
External carotid supplies
Internal?
A
everything in head & neck EXCEPT the brain
brain only
17
Q
ischaemic stroke in
Anterior cerebral artery (ACA):
Middle cerebral artery (MCA):
Posterior cerebral artery (PCA):
A
lower limbs will be effected e.g. legs
majority of the outer surface of brain
If there is ischaemic stroke in MCA then the region affected will be from the chin to the hip
There may be limb sparing with an embolic stroke
results in peripheral vision loss but not macular vision
18
Q
if an emboli is present then it will most likely enter … artery
result in …
A
posterior inferior Cerebellar artery (PICA) is the 1st big artery to come off the
vertebral artery
lateral medullary syndrome:
• Dysphagia, slurred speech, ataxia, facial pain, nystagmus, loss of pain & sensation on opposite side of body
19
Q
(Berry anneurysms)
A
Most common at the ANTERIOR CEREBELLAR ARTERY (ACA) and ANTERIOR COMMUNICATING ARTERY JUNCTION
- Produces a subarachnoid haemorrhage - resulting in a thunderclap headache
20
Q
Aortic arch: bits
A
- Brachiocephalic trunk divides into the right common carotid & right subclavian artery
- Left common carotid
- Left subclavian artery
21
Q
The common carotid arteries BIFURCATE into
This bifurcation is at high risk of
A
the internal (larger than the external) & external carotid arteries at C4: atherosclerosis
22
Q
nternal carotid artery (ICA) segments:
bifurcates at .. into
A
After bifurcating at C4 ICA has segments, before terminating into the MIDDLE CEREBRAL ARTERY & ANTERIOR CEREBRAL ARTERY
23
Q
direct eye muscle innervations
A
To remember use: LR6SO4 - Lateral rectus = CN6 & Superior oblique = CN4, ALL THE REST are CN3
24
Q
ANALGESIA & EPIDURAL:where
A
SPINAL CORD FINISHED AT L1
25
Cavernous sinuses:
- Structures passing through it
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)
To remember think; O TOM CAT - say trochlear twice but it makes mnemonic work!
26
TRANSIENT ISCHAEMIC ATTACK (TIA):
def
Tx:
A brief episode of neurological dysfunction due to temporary focal cerebral ischaemia WITHOUT infarction
ABCD2 score risk of stroke after TIA:
-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
• 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
Antiplatelet drug:
• ASPIRIN IMMEDIATELY + DIPYRIDAMOLE (↑cAMP and ↓ thromboxane A2) for two weeks then lower dose
• P2Y12 inhibitor longterm e.g. CLOPIDOGREL
Anticoagulant if they have AF, mitral stenosis or recent big septal MI e.g. WARFARIN
Statin longterm e.g. SIMVASTATIN Control cardiovascular risk factors:
• Antihypertensives such as ACE-inhibitor e.g. RAMIPRIL or angiotensin receptor blocker e.g. CANDESARTAN
27
CEREBROVASCULAR ACCIDENT - STROKE (ISCHAEMIC & HAEMORRHAGIC): Definition:
Tx:
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
Give tissue plasminogen activator e.g. IV ALTEPLASE
• Then start antiplatelet therapy e.g. CLOPIDOGREL 24hrs after thrombolysis
If the time of onset is unknown and thus thrombolysis not suitable then give ASPIRIN DAILY for 2 weeks then lifelong CLOPIDOGREL
- In haemorrhagic:
• Antiplatelets contraindicated
• Any anticoagulants should be reversed 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
- Risk management for stroke prevention:
•Platelet treatment (lifelong if already had stroke) e.g. ASPIRIN + DIPYRIDAMOLE or CLOPIDOGREL
Cholesterol treatment like statins e.g. SIMVASTATIN
Atrial fibrillation treatment e.g. WARFARIN or new oral anticoagulants e.g. PIXIBAN
• Blood pressure treatment e.g. ACE-inhibitor e.g. RAMIPRIL
28
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SUBARACHNOID HAEMORRHAGE (SAH):
Def
```
- Spontaneous bleeding into the subarachnoid space - between the arachnoid layer of the meninges and the pia mater
- Can often be catastrophic
Seen as a ‘star shaped lesion’ due to blood filling in gyro patterns around the brain and ventricles
REFER ALL PROVED SAH TO NEUROSURGEON 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
29
SUBDURAL HAEMORRHAGE (SDH):
Diagnosis:
Tx:
- CT head:
• Diffuse spreading, hyperdense CRESCENT SHAPED collection of blood over 1 hemisphere:
SICKLE/CRESCENT SHAPE DIFFERENTIATES subdural blood from extradural haemorrhage!!
IV MANNITOL to reduce ICP
30
```
EPILEPSY:
• Definition:
• Dx:
-Tx:
-Emergency
-Long term
```
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
Epileptic seizure:
• Paroxysmal/unprovoked event in which changes of behaviour, sensation or cognitive processes are caused by excessive, hypersynchronous (unusually synchronised) neuronal discharges in the brain
To make a clinical diagnosis, from history there needs to be at least 2 or more unprovoked seizures occurring > 24hrs apart to DIAGNOSE EPILEPSY
Emergency:
• Prolonged seizure (longer than 3 minutes) or repeated seizures are treated with RECTAL/IV DIAZEPAM or LORAZEPAM - repeat x2
• IV PHENYTOIN LOADING
```
Primary generalised:
• Generalised tonic-clonic seizures (grand-mal):
- ORAL SODIUM VOLPROATE: teratogenic
- ORAL LAMOTRIGINE:
- ORAL CARBAMAZEPINE:
```
• Absence seizure (petit mal):
- ORAL SODIUM VALPROATE
- ORAL LAMOTRIGINE
- ORAL ETHOSUXIMIDE:
Partial/focal seizure:
• CARBAMAZEPINE - 1ST LINE
• SODIUM VALPROATE
• LAMOTRIGINE
31
DEMENTIA DEF:
| Medication:
A syndrome caused by a number of brain disorders (e.g. Alzheimer’s) which cause memory loss, difficulties with thinking, problem-solving or language as well as difficulties with activities of daily living
• Acetylcholinesterase 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 e.g. RAMIPRIL
32
PARKINSON’S DISEASE: •
Characterised by the triad of:
Tx:
•Degenerative movement disorder caused by a REDUCTION IN DOPAMINE IN THE SUBSTANTIA NIGRA
- Rigidity
- Bradykinesia (slow to execute movement)
- Resting tremor
- Physical activity is beneficial and should be encouraged
- The GOLD STANDARD treatment is ORAL LEVODOPA given alongside a
decarboxylase inhibitor e.g. CO-CARELDOPA or CO-BENELDOPA:
33
-The basal ganglia is made up of the:
* Striatum (composed of the putamen & caudate nucleus)
* Globus pallidus (external & internal)
* Substantia nigra
* Subthalamic nucleus
34
Differential diagnosis of Parkinson's is...
| Tx:
- Benign essential tremor (more common) - worse on movement and rare
whilst at rest:
• Treat with beta-blockers e.g. PROPRANOLOL (contraindicated with
asthma/diabetes)
• PRIMIDONE (anti-seizure) or GABAPENTIN (anti-epileptic)
35
Parkinson's Tx explained:
Levodopa (L-dopa) is a precursor to dopamine, but dopamine CANNOT CROSS the blood brain barrier whereas L-dopa CAN
The decarboxylase inhibitor prevents peripheral conversion of L-dopa to dopamine and therefore reduces the peripheral side effects as well as maximising dose that crosses blood brain barrier
Once crossed, the L-dopa can be taken up by dopaminergic neurones and converted into dopamine and used
36
HUNTINGTON’S CHOREA:
Chorea: def
Chorea Tx:
Huntington’s is a cause of chorea and is a neurodegenerative disorder characterised by the LACK of the inhibitory neurotransmitter GABA
Chorea:
• A continuous flow of jerky, semi-purposeful movements, flitting from one part of the body to another
• They may interfere with voluntary movements but cease during sleep
Symptomatic management of chorea:
• BENZODIAZEPINES
• SULPIRIDE - neuroleptic - depresses nerve function
• TETRABENAZINE - dopamine depleting agent
- Antidepressants such as selective serotonin reuptake inhibitors (SSRI’s) e.g. SEROXATE
- Antipsychotic medication such as neuroleptics e.g. HALOPERIDOL
- To treat aggression use RISPERIDONE
37
Red flags for secondary headache
- HIV or immunosuppressed
- Fever
- Thunderclap headache (think subarachnoid haemorrhage!)
- Seizure and new headache
- Suspected meningitis
- Suspected encephalitis
- Red eye? acute glaucoma
- Headache + new focal neurology e.g. papilloedema
38
MIGRAINE: def
- 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 (black holes in visual field), but may also result in pins and needles (tingling), dysphasia and rarely weakness of limbs and motor function
39
MIGRAINE: No known specific cause but there are partial triggers:
CHOCOLATE:
1. Chocolate
2. Hangovers
3. Orgasms
4. Cheese
5. Oral contraceptives
6. Lie-ins
7. Alcohol
8. Tumult - loud noise
9. Exercise
40
Migraine Tx:
- Acute:
• DO NOT OFFER ERGOTS e.g.ergotamine or OPIODS
• Triptans e.g. SUMATRIPTAN:
• NSAIDs e.g. KETOPROFEN, NAPROXEN or ASPIRIN - good since less chance of developing medication overuse headache
- Avoid paracetamol or ibuprofen
• +/- anti-emetic e.g. PROCHLORPERAZINE
- Prevention:
• If more than 2 attacks a month, or acute treatment required more than 2x a week
• Beta blocker e.g. PROPRANOLOL (not for asthmatics)
• Tricyclic anti-depressant e.g. AMITRIPTYLINE ,
• Anti-convulsant e.g. TOPIRAMATE,
41
TENSION HEADACHE:
MOST CHRONIC DAILY & RECURRENT HEADACHES are tension headaches
42
Medication-overuse headaches:
| Eg:
Worsens whilst on regular analgesia especially on OPIOIDS
- Other causes are mixed analgesics e.g. paracetamol + codeine/opiates,
ergotamine and triptans
- Common reason for episodic headache becoming chronic daily headache
43
CLUSTER HEADACHES:
Most disabling of the primary headache disorders
- Acute attack:
• Analgesics are unhelpful
• 100% 15L O2 for 15mins via non-rebreathable mask (not if COPD)
• Triptan (selective serotonin (5HT) agonist) e.g. SC SUMATRIPTAN:
- Triptans are serotonin receptor agonists - this reduces vascular inflammation
- Prevention:
• Calcium channel blocker e.g. VERAPAMIL is first line prophylaxis • Avoid alcohol during cluster period
• Corticosteroids e.g. PREDNISOLONE may help during cluster
44
```
TRIGEMINAL NEURALGIA:
def and nerves
```
Tx:
- CN5.1 - OPTHALMIC
- CN5.2 - MAXILLARY
- CN5.3 - MANDIBULAR
Trigeminal neuralgia is described as a chronic, debilitating condition resulting in intense and extreme episodes of pain
UNILATERAL
Typical analgesics and opioids DO NOT WORK
Anticonvulsant e.g. ORAL CARBAMAZEPINE suppresses attacks in most
patients
Other, less effective options e.g. ORAL PHENYTOIN, GABAPENTIN and
LAMOTRIGINE
45
GIANT CELL ARTERITIS (GCA) aka TEMPORAL ARTERITIS:
tx:
Should be SUSPECTED in ALL >50yrs old with a HEADACHE that has LASTED A FEW WEEKS
- HIGH DOSE CORTICOSTEROIDS RAPIDLY e.g. ORAL PREDNISOLONE 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
- Polymyalgia rheumatica (PMR) presents in 50% of cases with giant cell arteritis
46
SPINAL CORD
| LP from?
Cord extends from C1 (junction with medulla) to L1/L2 (conus medullaris):
- Although the spinal cord ends around L1/L2 we still take lumbar puncture around L4 just to be safe!
Below L1 = lumbar & sacral nerve roots - grouped together to form the CAUDA EQUINA - this is the final point of the spinal cord
47
SPINAL CORD DISEASE:
| •Upper motor neurone signs:
signs are CONTRALATERAL to lesion
• Indicate that the lesion is above the anterior horn cell i.e. in the spinal
cord, brainstem and motor cortex
• Increased muscle tone - SPASTICITY:
- Velocity dependent and non-uniform i.e. the faster you move the patients muscle, the greater the resistance, until it finally gives way in a clasp-knife manner
• Weakness:
- Flexors are generally weaker than extensors in legs and reverse in
arms
• Increased reflexes, they are brisk - HYPERREFLEXIA
48
SPINAL CORD DISEASE:
| •Lower motor neurone signs:
Lower motor neurone signs: signs are IPSILATERAL to lesion
• 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) +/- FASCICULATIONS (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
• The level of the problem can be inferred from the accompanying
symptoms:
- Back pain & 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
49
Spondylolisthesis:
Spondylosis:
Myelopathy:
Radiculopathy:
* 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
- degenerative disc disease
* Caused by spinal cord compression
* Upper motor neurone signs e.g. spasticity, weakness, hyperreflexia
* Spinal cord disease
* Caused by spinal root compression
* Lower motor neurone signs e.g. decreased muscle tone, wasting, weakness and fasciculations
* 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
50
• Myotomes:
| key areas
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
51
Dermatomes
| key areas
```
Clavicle - C4
Nipples - T4
Medial side of arm - T1
Umbilicus - T10
- Anterior & inner leg - L2-3
- Knee - L4
- Posterior & outer leg - L5, S1-2
Perianal area - S4
```
52
SPINAL CORD COMPRESSION - MYELOPATHY:
| Tx:
If malignancy then give IV DEXAMETHASONE (reduces inflammation/ oedema around malignancy and improves outcome) and consider more specific therapy e.g. radiotherapy or chemotherapy
53
CAUDA EQUINE SYNDROME:
Clx:
Tx:
MEDICAL EMERGENCY
Flaccid & areflexic weakness
Bilateral sciatica
Saddle anaesthesia Bladder/bowel dysfunction Erectile dysfunction
Variable leg weakness that is FLACCID & AREFLEXIC (LMN signs)
Refer to neurosurgeon ASAP to RELIEVE PRESSURE or risk irreversible paralysis/sensory loss/incontinence!!!!:
• Microdiscectomy - removal of part of the disc - may tear dura!
• Epidural steroid injection - more effective for leg pain
• Surgical spine fixation - if vertebra slipped
• Spinal fusion - reduces pain from motion and nerve root inflammation
54
CLINICAL SCENARIO:
- 50yr old nurse comes in with longstanding back pain and pain radiating
down right leg to sole of right foot - lesion?
- On examination there is weak plantar flexion, absent right ankle jerk,
decreased sensation over lateral edge and sole of right foot
SCIATICA (S1 LESION)
- WHERE IS LESION?
• Right S1 root lesion due to disc prolapse placing pressure on root • CALL NEUROSURGEON:
- Radiculopathy with neurological signs
- May need surgery
55
MULTIPLE SCLEROSIS (MS):
Plaques of demyelination are perivenular (occur around a VEIN) occur everywhere in the CNS but have a predilection for distinct CNS sites:
Chronic autoimmune, T-cell mediated inflammatory disorder of the CNS in which there are multiple plaques of demyelination within the brain and spinal cord, occurring sporadically over years
```
Optic nerves
Around ventricles of the brain
Corpus callosum
Brainstem and cerebellar connections
Cervical cord (corticospinal tract and dorsal columns
```
56
MS
Dx:
Tx:
Diagnosis requires TWO or more attacks affecting DIFFERENT PARTS of CNS; that is 2 CNS lesions disseminated in time and space i.e. cannot diagnose MS after one potential relapse
Acute relapse:
• IV METHYLPREDNISOLONE for less than 3 day
- Frequent relapse:
• SC INTERFERON 1B or 1A are anti-inflammatory cytokines and can help reduce relapses by 30% in active relapse-remitting MS and can reduce lesion accumulation
• Disease modifying agents:
- Monoclonal antibodies:
• IV ALEMTUZUMAB a CD52 monoclonal antibody that targets T cells
• IV NATALIZUMAB acts against VLA-4 receptors that allow immune cells to cross the blood-brain barrier. it reduces amount of immune cells that can enter CNS and cause damage
- DIMETHYL FUMARATE
- Symptomatic treatment:
• Spasticity - ALL anti-spasticity can result in WEAKNESS!
-Physiotherapy
BACLOFEN - GABA analogue that reduces Ca2+ influx,
-TIZANIDINE:
• Alpha 2 agonist
BOTOX INJECTION - reduces ACh in neuromuscular junction thus less spasticity
• Only has transient effect (2-12 weeks) and risk of dysphagia!
•self-catheterisation
• Incontinence - anti-cholinergic alpha-blocker drugs e.g. DOXAZOSIN
- Aggressive treatment is STEM CELL TRANSPLANT
57
MYASTHENIA GRAVIS (MG):
Def:
Tx:
Autoimmune disease against NICOTINIC ACETYLCHOLINE RECEPTORS (AChR) in the neuromuscular junction
Symptom control:
• Anti-cholinesterase so more ACh remains in neuromuscular junction e.g. ORAL PYRIDOSTIGMINE
- Immunosuppression:
if no response to pyridostigmine, start LOW STARTING DOSE e.g. ORAL PREDNISOLONE with dose increased per week - REDUCE DOSE on remission (may take months)!
- osteoporosis prophylaxis: bisphosphonates e.g. ALENDRONATE
• Steroids may be combined with ORAL AZATHIOPRINE or ORAL METHOTREXATE as the disease become more general
Myasthenic crisis:
• Weakness of the respiratory muscles during a relapse can be life- threatening
• Monitor FVC
• Treat with PLASMAPHERESIS (antibody removal) + IV IMMUNOGLOBULIN and identity and treat trigger of relapse e.g. infection, medications
58
MOTOR NEURONE DISORDERS:
| Signs and symptoms:
Weakness or paresis:
Paralysis:
Ataxia or incoordination:
- Willed movements are clumsy, ill-directional or uncontrolled
Involuntary movements:
- Spontaneous movement of a body part, independently of will
Apraxia:
- Disorder of consciously organised pattern of movement or impaired ability to recall acquired motor skills e.g. brushing teeth or striking a match
59
Organisation of movement:
1. Idea of the movement - association areas of cortex
2. Activation of upper motor neurones in the pre central gyrus
3. Impulses travel to lower motor neurones and their motor units (a alpha motor neurone and all the skeletal fibres it innervates) via the corticospical tract
4. Modulating activity of the cerebellum and basal ganglia
5. Further modification of movement depending on sensory feedback
60
Regulation of muscle tone:
- Stretch receptors in muscle (MUSCLE SPINDLES) innervated by GAMMA MOTOR NEURONES
- Muscle stretched → afferent impulses FROM muscle spindles → reflex partial contraction of muscle
- Disease states e.g. spasticity and rigidity ALTER MUSCLE TONE by altering the sensitivity of this reflex
61
MOTOR NEURONE DISORDERS: NOT JUST THE DISEASE
Upper motor neurone signs:
- everything goes up!:
- Spasticity (increased muscle tone)
- Brisk reflexes - tendon & jaw reflexes
- Plantars are upturned on stimulation (see picture) - positive Babinski sign
- Characteristic pattern of limb muscle weakness (pyramidal pattern):
• Upper limbs extensor muscles are weaker than flexors
• Lower limbs flexor muscles are weaker then extensors
• Finer more skilful movement are impaired
62
MOTOR NEURONE DISORDERS: NOT JUST THE DISEASE
Lower motor neurone signs:
- everything goes down!:
- Muscle tone reduced - FLACCID
- Muscle wasting
- Fasciculation - visible spontaneous contraction of motor units
- NOT ENOUGH TO DIAGNOSE LMN, NEED WEAKNESS TOO!
- Reflexes depressed or absent
63
MOTOR NEURONE DISEASE (MND):
4 main clinical patterns:
Amyotrophic lateral sclerosis (ALP) - UMN + LMN:
Tx:
Cluster of major degenerative diseases characterised by selective loss of neurones in motor cortex, cranial nerve nuclei and anterior horn cells
Sometimes referred to as Amyotrophic lateral sclerosis (ALS) in other countries
Amyotrophic lateral sclerosis (ALP) - UMN + LMN:
Progressive muscular atrophy (PMA) - LMN ONLY:
Progressive bulbar pasty (PBP) - LMN ONLY:
Primary lateral sclerosis (PLS) - UMN ONLY:
- Antiglutamatergic drugs:
• ORAL RILUZOLE - Na+ channel-blocker: inhibits glutamate release
• Prolongs life by 3 months
• Raises LFT’s so monitor these!
- Drooling - due to bulbar palsy (wasting of muscles of mastication):
• ORAL PROPANTHELINE or ORAL AMITRIPTYLINE
Spasms:
• ORAL BACLOFEN
- Analgesia e.g. NSAIDs - DICLOFENAC or opioids
64
- GUILLAIN-BARRE SYNDROME (GBS):
Tx:
An acute inflammatory demyelinating ascending polyneuropathy affecting the PERIPHERAL NERVOUS SYSTEM (SCHWANN CELLS TARGETED) following an upper respiratory tract infection of GI infection
IV IMMUNOGLOBULIN for 5 days:
• Decreases duration and severity of paralysis
• Contraindicated when IgA deficient!! - in whom it can cause a severe allergic reaction - screen for deficiency BEFORE treatment
Plasma exchange
Low-molecular weight heparin e.g. SC ENOXAPARIN
65
MONONEUROPATHIES:
MONONEURITIS MULTIPLEX:
mnemonic
the MOST COMMON MONONEUROPATHY...
```
MONONEURITIS MULTIPLEX is used if 2 or more peripheral nerves are affected, when causes tend to be systemic - WARDS PLC:
Wegener’s granulomatosis
Aids/Amyloid
Rheumatoid arthritis
Diabetes mellitus Sarcoidosis
Polyarteritis nodosa
Leprosy
Carcinoma
```
Carpal tunnel syndrome is
66
MEDIAN NERVE
myotomes + mnemonic
```
(C6-T1):
• The median nerve is the nerve of precision grip - muscles involved are easier to remember if you use your ‘LOAF’:
2 Lumbricals
Opponens pollicis
Abductor pollicis brevis
Flexor pollicis brevis
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RADIAL NERVE
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(C5-T1) -opens fist
Muscles involved:
Brachioradialis
Extensors
Supinator
Triceps
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PRIMARY BRAIN TUMOURS:
signs
DDx:
If they might have this remember!!!...
Tx:
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Cardinal sign is PAPILLOEDEMA:
• Swelling of the optic disc due to obstruction of venous return
from the retina due to the raised ICP
• Loss of crisp optic nerve head margins
• Venous engorgement
• Retinal oedema
• Haemorrhages
• NOTE: this can take DAYS to become apparent
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Other causes of space-occupying lesion:
• Aneurysm
• Abscess
• Cyst
• Haemorrhage
• Idiopathic intracranial hypertension
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LUMBAR PUNCTURE CONTRAINDICATED when any possibility of a mass lesion since withdrawing CSF may PROVOKE IMMEDIATE CONING - that is herniation of the brain through the foramen magnum resulting in BRAINSTEM COMPRESSION as it passes through foramen magnum and POTENTIAL DEATH
- Chemotherapy for glioma: TEMOZOLOMIDE
Not all tumours are sensitive - some have high Methyl-Guanine-Methyl-Transferase (MGMT) - an enzyme that reverses the therapeutic effect of temozolomide
•if it has METHYLATED MGMT (essentially enzyme is silenced) then it will be sensitive- give ORAL DEXAMETHASONE:
• Most powerful synthetic steroid
• Rapidly improves brain performance in all tumours: Reduces tumour inflammation/oedema
- Can give anticonvulsants for epilepsy e.g. ORAL CARBAMAZEPINE
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Commonest neoplasms to metastasise to CNS in order:
- Non small cell LUNG - MOST COMMON
- Small cell LUNG
- Breast
- Melanoma
- Renal cell
- GI
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MENINGITIS
| Tx:
IF SUSPECT BACTERIAL MENINGITIS - START ANTIBIOTICS BEFORE TESTS COME BACK!!
- Bacterial meningitis:
• IV CEFOTAXIME or IV CEFTRIAXONE - 3rd generation Cephalosporin
- Can give IV CHLORAMPHENICOL if severe anaphylaxis with penicillin (beta-lactams)
• If over 50/immunocompromised then add IV AMOXICILLIN to cover Listeria
• Consider steroids e.g. ORAL DEXAMETHASONE to reduce cerebral oedema
• Consider IV VANCOMYCIN in return travellers
• Prophylaxis for contacts:
- ORAL CIPROFLOXACIN STAT - for all ages and pregnancy
- Or can give ORAL RIFAMPICIN - for all ages but NOT PREGNANCY
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ENCEPHALITIS:
Tx:
- If viral e.g. herpes simplex or varicella zoster then IMMEDIATE TREATMENT with anti-viral e.g. IV ACICLOVIR - even BEFORE the investigation results available
Early treatment can reduce mortality and long neuro damage
- Anti-seizure medication e.g. PRIMIDONE
- If meningitis is suspected then EMERGENCY IM BENZYLPENICILLIN
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SHINGLES:
Tx:
Complications:
Oral antiviral therapy begun WITHIN 72HRS OF RASH ONSET:
• ORAL ACICLOVIR X5 DAILY
• Or; ORAL VALICICLOVIR X2 DAILY or ORAL FAMCICLOVIR X2 DAILY
• Rapid treatment start to minimise risk of peripheral herpetic neuralgia (PHN)
- Topical antibiotic treatment for secondary bacterial infection - Analgesia e.g. IBUPROFEN for pain
Post herpetic neuralgia (PHN):
- Pain lasting for more than 4 months AFTER developing shingles - 10% of patients - often elderly
- Burning, intractable pain
- Responds poorly to analgesics
- Treat with:
• Tricyclic antidepressant e.g. ORAL AMITRIPTYLINE
• Anti-epileptic e.g. ORAL GABAPENTIN
• Anti-convulsant e.g. ORAL CARBAMEZAPINE
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CEREBELLAR DISEASE:
| The most important layer is
the PURKINJE LAYER as this is the only output of the cerebellum. Its degeneration results in dysfunction & ATAXIA
