Neuro-Surgery Delta Flashcards
(135 cards)
1
Q
What level does the spinal cord begin and end at?
A
Begins at the medulla oblongata and ends at L1-2 to form the cauda equina
2
Q
Describe the spinal cord in terms of where the white and grey matter is
A
Gray matter H-shape, surrounded by white matter
3
Q
Which horns receive somatosensory information
A
Dorsal (posterior) horns
4
Q
Which horns contain motor neurons for muscle innervation
A
Ventral (anterior) horns
5
Q
When are lateral horns present and what is their function
A
T1-L2
Contain autonomic sympathetic neurons
6
Q
What is the central canal
A
Cerebrospinal fluid-filled space that runs longitudinally through the length of the entire spinal cord
7
Q
What are the three main ascending tracts
A
Dorsal Column-Medial Lemniscus tract (DCML)
Spinothalamic tract
Spinocerebellar tract
8
Q
What information does the DCML pathway transmit
A
Fine touch, pressure, and vibration
9
Q
What information does the Spinothalamic tract transmit
A
Pain and temperature
10
Q
What information does the Spinocerebellar pathway transmit
A
Unconscious proprioceptive information to the cerebellum
11
Q
What is the function of the Spinocerebellar tract
A
To help coordinate posture and the movement of the lower limb and upper limb musculature.
12
Q
What is the gracile fasciculus
A
The part of the DCML pathway which transmits information from T6 and below
Lies medially
13
Q
What is the other fasciculus apart from gracile
A
Cuneate Fasciculus
Transmits information from upper trunk and arms (above T6)
Lies more laterally
14
Q
Where do the DCML fibres decussate
A
Medulla
decussate to the contralateral medial lemniscus
15
Q
Where do DCML fibres go after the medial lemniscus
A
Synapse at thalamus
Then signals are relayed via the internal capsule to the primary somatosensory cortex
16
Q
What is located at the precentral gyrus
A
Primary somatomotor cortex
17
Q
Where do spinothalamic tract fibres decussate
A
At a segmental level as they enter the spinal cord
18
Q
Which tract do spinothalamic fibres go through before synapsing at the dorsal horn
A
Tract of Lissauer
19
Q
What are the 2 main pyramidal tracts
A
Corticospinal tract
Corticobulbar tract
20
Q
Name the 4 main extra-pyramidal tracts
A
Vestibulospinal
Rubrospinal
Reticulospinal
Tectospinal
21
Q
What is the difference between the pyramidal and extrapyramidal tracts
A
Pyramidal tracts control voluntary movements and originate from the primary somatomotor cortex
Extrapyramidal tracts control involuntary movements and originate from the brainstem
22
Q
Where do all the corticospinal tract fibres decussate
A
85% of the corticospinal tract fibres decussate at the medullary pyramids where they become the lateral corticospinal tract
The other 15% travel down via the anterior corticospinal tract and decussate at a spinal level via the anterior white commissure
23
Q
What muscles does the lateral corticospinal tract innervate
A
The distal extremities
24
Q
What muscles does the anterior corticospinal tract innervate
A
Proximal and axial muscles
25
What is the function of the corticobulbar tracts
Contain the upper motor neurone of the cranial nerves, to provide innervation of the face, head and neck. They innervate cranial motor nuclei bilaterally
Two exceptions are the hypoglossal nuclei and lower facial nuclei which are innervated contralaterally only
26
What is the clinical significance of the corticobulbar tracts
An upper motor lesion affecting the facial nerve causes paralysis of the lower half of one side of the face only and the forehead muscles remain unaffected
a lower motor neurone lesion would cause a paralysis of the ipsilateral one-half of the face including the forehead (Bell's palsy)
27
Where does the vestibulospinal tract originate and what is it's function
Originates from the vestibular nucleus in the pons
| Controls balance and posture by innervating the anti-gravity muscles
28
What are the anti-gravity muscles
Extensors in the lower limbs and flexors in the upper limbs
29
Where does the reticulospinal tract originate
Originates from the reticular formation in the medulla and pons
30
What is the difference in function between the pontine and medullary reticulospinal tract
Pontine - facilitates reflexes + increases tone
| Medullary - inhibits reflexes + decreases tone
31
Where does the rubrospinal tract originate and what is its function
Originates from the red nucleus(in midbrain)
| Excites flexors and inhibits extensors
32
Where does the tectospinal tract originate and what is its function
Originates from the superior colliculus in the midbrain
| Co-ordinates movements of head and neck to vision stimuli (think *ecto*)
33
What are the 2 parts of the intervertebral discs called
Outer Annulus Fibrosus
| Inner Nucleus Pulposus
34
Which ligament connects the anterolateral aspects of vertebral bodies and IV discs
Anterior longitudinal ligament
35
Which ligament runs within the vertebral canal posterior to the vertebral bodies
Posterior longitudinal ligament
36
Which ligament helps maintain an upright posture and assists straighten the spine after flexion
Ligamentum Flavum
37
Where does the Ligamentum Flavum run
Runs vertically connecting the lamina of adjacent vertebrae
38
Where does the supraspinous ligament run
Along the tips of the spinous processes
39
Where does the interspinous ligament run
Between the spinous processes
40
What can occur when facet joints are hypertrophied
Patients get referred pain from the nerve supplying the facet joint that mimics sciatica
41
What is the difference between facet joint referred pain and sciatic pain
Facet joint referred pain does not spread below the knee
42
What are red flags for lower back pain
```
Age: >60 or <20 years old
Pain not improved by rest
Pain that wakes the patient up at night
Urinary retention/incontinence and faecal incontinence
Saddle anaesthesia
History of malignancy
Unexplained weight loss.
Fever, immunosuppression or IV drug abuse
```
43
Which nerve root is being compressed if there is pain along the posterior thigh with radiation to the heel
S1
44
Which nerve root is being compressed if there is weakness of dorsiflexion of the toe or foot
L5
45
Which nerve root is involved if there is wasting of the quadriceps muscle and a reduced knee-jerk
L4
46
What urgent investigations must be performed in suspected cauda equina
MRI lumbosacral spine
| PR exam to check anal tone
47
Which cord syndrome would cause a "cape-like” spinothalamic sensory loss
Central cord syndrome
48
Why is there predominantly bilateral upper limb weakness rather than lower limb weakness in central cord syndrome
Fibres supplying the upper limbs in the lateral corticospinal tracts are more medial to the fibres supplying the lower limbs
49
Which part of the body will lose its dorsal column input in central cord syndrome
None
| The DCML pathway is typically preserved in central cord syndrome
50
What might cause anterior cord syndrome
Cord infarction by the area supplied by the anterior spinal artery
51
What is the presentation of anterior cord syndrome
Paralysis and loss of pain and temperature below the level of injury with preserved proprioception and vibration sensation
52
What is the presentation of Brown-Sequard syndrome
Ipsilateral loss of motor function and proprioception below the lesion
Contralateral loss of pain and temperature below the lesion
53
Name the 6 lobes of the cerebral hemispheres
```
Frontal
Temporal
Parietal
Occipital
Insular
Limbic
```
54
Damage to which area results in expressive aphasia
Broca's area
55
What is expressive aphasia
When a patient can understand a language but cannot produce it properly
56
Where is Broca's area found
Inferior frontal gyrus
57
Which lobes contain the pre and postcentral gyri
Precentral gyrus --> Frontal lobe
| Postcentral gyrus --> Pareital lobe
58
Which structure separates the frontal and parietal lobes
Central sulcus
59
Which structure separates the parietal and temporal lobes
Lateral fissure (Sylvian fissure)
60
Which structure separates the frontal and temporal lobes
Lateral fissure (Sylvian fissure)
61
Which lobe contains the primary visual cortex
Occipital lobe
62
Which structure separates the parietal and occipital lobes
Parieto-occipital sulcus
63
Damage to Wernicke's area would cause which condition
Receptive aphasia
64
What is receptive aphasia
When a patient can produce words and sentences properly but has impaired comprehension of a language
65
Where is Wernicke's area located
Superior temporal gyrus
66
What is a pneumonic for remembering the parts of the limbic system
Hippo with a HAT
67
What does Hippo with a HAT stand for
Hippocampus
Hypothalamus
Amygdala
Thalamus
68
What are the 3 components of the cerebellum
Vestibulocerebellum
Spinocerebellum
Cerebrocerebellum
69
What is the function of the Vestibulocerebellum
Receives input from the vestibular organs for the maintenance of balance and coordinating vestibule-ocular reflexes
70
What is the function of the Spinocerebellum
Maintains muscle tone and participates in posture and gait
71
What is the function of the Cerebrocerebellum
Coordination of voluntary motor activity and correct any error in the movements
72
Name the parts of the basal ganglia
```
Caudate nucleus
Putamen
Globus pallidus
Subthalamic nucleus
Substantia nigra
```
73
What are the 3 layers of the cerebellum
Molecular layer (outer)
Purkinje cell layer (middle)
Granule cell layer (inner)
74
Where do afferent projections come into the cerebellum
Granule cell layer
75
Where do efferent projections from the cerebellum originate from
Purkinje cell layer
76
Which common disease affects the pars compacta of the sunstantia nigra
Parkinson's
77
What is the triad associated with Parkinson's
Rigidity (cogwheel)
Brady/Akinesia
Resting (pill rolling) tremor
78
What are the three main arteries supplying the brain's anterior circulation
Internal carotid
Anterior cerebral
Middle Cerebral
79
Where does the internal carotid artery originate
Bifurcates from the common carotid
80
Where does the internal carotid terminate
Terminates into a bifurcation as the middle cerebral artery and anterior cerebral artery
81
Which artery is larger, the anterior cerebral or the middle cerebral
Middle cerebral
82
Where do the anterior and middle cerebral arteries originate
From the bifurcation of the internal carotid
83
How are the right and left anterior cerebral arteries connected
Via the anterior communicating artery
84
Which 4 arteries make up the posterior circulation
Vertebral artery
Basilar artery
Posterior cerebral artery
Posterior communicating artery
85
Where does the vertebral artery originate
Arises from the subclavian artery and extends through the transverse foramen of the cervical vertebrae
86
What do the right and left vertebral arteries join to make
The basilar artery
87
What is the origin of the basilar artery
Arises from the two vertebral arteries joining
88
What is the origin of the posterior cerebral artery
Arises from the termination of the basilar artery
89
What is the origin of the posterior communicating artery
Arises from the internal carotid artery
90
What is the function of the posterior communicating artery
Connects the anterior and posterior circulations
91
What are the 2 divisions of the venous system of the brain
Cerebral veins
| Dural venous sinuses
92
What are the dural venous sinuses
Large venous channels that are contained within the dura which contain arachnoid granulations, allowing CSF to be absorbed
93
What is the function of the cerebral veins
Cerebral veins drain blood into the sinuses
94
What is the difference between the superficial and deep cerebral veins
Superficial veins mainly drain into the superior sagittal sinus
Deep veins mainly drain into the straight sinus
95
What is a typical presentation of a subarachnoid haemorrhage
Sudden onset of a thunderclap headache
96
Which symptoms may be present due to any cause of meningeal irritation
Neck stiffness
| Photophobia
97
A third nerve palsy would suggest an aneurysm in which vessel
Posterior communicating artery
98
How is the diagnosis of subarachnoid haemorrhage made
CT scan
99
What would a lumbar puncture, performed a few hours after a subarachnoid haemorrhage, show
Xanthochromia
| A yellow discolouration of the CSF
100
What is the most common electrolyte disturbance which can occur after a subarachnoid haemorrhage
Hyponatraemia
101
What are the 4 types of stroke
Lacunar infarct
Total Anterior Circulation Infarct
Partial Anterior Circulation Infarct
Posterior Circulation Infarct
102
How is a lacunar infarct defined
A pure motor or pure sensory stroke or an ataxic hemiparesis
103
Which 3 symptoms must be present to classify a stroke as a Total Anterior Circulation Infarct
1. Higher cerebral dysfunction (e.g. dysphasia).
2. Homonymous visual field defect
3. Ipsilateral motor and/or sensory deficit of at least two areas (out of the face, arm and leg)
104
What is the difference between a Total and Partial Anterior Circulation Stroke
Partial only requires 2 out of 3 of:
1. Higher cerebral dysfunction (e.g. dysphasia).
2. Homonymous visual field defect
3. Ipsilateral motor and/or sensory deficit of at least two areas (out of the face, arm and leg)
105
A Posterior Circulation Infarct must have one of which four symptoms
1. Ipsilateral cranial nerve palsy with contralateral motor and/or sensory deficit
2. Bilateral motor and/or sensory deficit
3. Cerebellar dysfunction
4. Isolated homonymous visual field defect
106
Where is the oculomotor nucleus located
In the dorsal midbrain at the level of the superior colliculus
107
Where is the trochlear nucleus located
In the midbrain at the level of the inferior colliculus
108
Which nerve travels through the cavernous sinus and where is its nucleus located
Abducens nerve
| The nucleus is in the pontine tegmentum
109
What is the pathophysiology of optic neuritis
Inflammation of the optic nerve
110
Which two types of diseases can cause optic neuritis
Infective or demyelinating
111
What is Charcot's triad with regard to Multiple Sclerosis
Nystagmus
Intention tremor
Staccato speech
112
What is L'Hermitte's sign
Electrical shock sensation on neck flexion
113
What is the Uhthoff phenomenon and which disease is it seen in
Worsening of symptoms due to increase in temperature, such as exercising or hot shower
Seen in MS
114
What is a treatment for optic neuritis
Intravenous methylprednisolone followed by oral prednisolone
115
What 3 drugs can be used for MS (not symptomatic treatment)
Interferon beta
Copaxone
Tecfidera
116
What is the pathophysiology of Myasthenia gravis
Autoimmune disease of acetylcholine receptors at post-synaptic neuromuscular junctions
117
How can myasthenia gravis typically present
Muscle fatiguability of:
Extraocular muscles
Facial muscles
Bulbar muscles
118
What is the Cogan Lid twitch and which disease is it seen in
Brief upshoot of the lid elicited by making patient look downwards then upwards
Seen in ocular myasthenia gravis
119
What is the ice test and what disease is it used to check for
Ptosis improve after applying ice to upper eyelid for 2 mins
| Myasthenia gravis
120
How does the ice test work in Myasthenia Gravis
The cold decreases the acetylcholinesterase break-down of acetylcholine at the NMJ, allowing more to accumulate and increasing muscle contraction
121
What is the treatment of Myasthenia Gravis
Pyridostigmine (anticholinesterase)
122
Hyperplasia of which body part is associated with Myasthenia Gravis
Thymus
123
What does decorticate posturing suggest
Indicates severe brain damage where the midbrain is spared
124
What is decorticate posturing
The patient presents with abnormal flexion of his arms, the hands are clenched into fists, and the legs extended and feet turned inward
125
How does decorticate posturing occur
Lateral corticospinal tracts are disrupted so the rubrospinal tracts take over causing the abnormal flexion to the upper extremities and the reticulospinal tracts take over causing the extension of the legs
126
What is decerebrate posturing
The patient presents with his head arches back and both arms and legs extended
127
What does decerebrate posturing suggest
Indicates an even more severe brain damage and brainstem damage, specifically at a level below the red nucleus in the midbrain
128
How does decerebrate posturing occur
Both the lateral cortical spinal tract and rubrospinal tract are damage so the reticulospinal tract takes over and causes extension of the whole body
129
Which type of haematoma is the accumulation of blood in a space between the dura and the bone
Extradural Haematoma
130
What is the most common source of bleeding in an extradural haematoma
Middle Meningeal artery
131
What appearance will an extradural haematoma have on a CT scan
A lens-shaped appearance
132
Which vessels rupture during a Subdural Haematoma
```
Bridging veins
(veins which drain the cortex and empty into dural sinuses)
```
133
How can chronic subdural haematomas occur
Brain atrophy due to alcoholism, age or dementia
134
How do acute subdural haematomas show up on CT
A crescent-shaped hyperdensity representing acute blood products
135
How do chronic subdural haematomas show up on CT
A hypodense crescent-shaped appearance
