Neurology Formative

Question 1

what are the 2 divisions of the corticospinal tract?

Answer 1

lateral
- motor control of limbs and digits
- decussates in pyramids
ventral
- motor control of trunk and posture
- decussates segmentally

Question 2

function of corticobulbar tract?

Answer 2

type of descending pyramidal tract

controls muscles of face, head, neck (contains UMNs of CNs)

Question 3

how can a central/peripheral lesion affecting corticobulbar tract be differentiated?

Answer 3

central = forehead sparing

- corticobulbar tract gives bilateral innervation to CN nuclei apart from CNs 12 and lower 7 (which innervates forehead)

Question 4

what are the 2 non-pyramidal descending tracts?

Answer 4

rubrospinal

reticulospinal

Question 5

origin and function of rubrospinal tract?

Answer 5

originates in red nucleus of midbrain
excites flexor muscles of upper limb and inhibits extensor muscles
(doesn’t innervate lower limb)

Question 6

origin and function of reticulospinal tract?

Answer 6

originates in pons/medulla

excites flexors

Question 7

what is decorticate rigidity?

Answer 7

posture caused by damage to nerves between brain and spinal cord
flexed plantars, internally rotated legs, flexed arms and wrists
adducted arms

Question 8

what is decerebrate rigidity?

Answer 8

posture caused by midbrain lesion
flexed plantars
extended and pronated arms
flexed wrists
adducted arms

Question 9

what are the 2 divisions of the dorsal column and what does each carry?

Answer 9

cuneate fasciculus = from arm

gracile fasciculus = from leg

Question 10

neurones in dorsal column pathway?

Answer 10

1st = site of excitation > dorsal root ganglion
2nd = dorsal root ganglion > spinal cord > thalamus
3rd = thalamus > post central gyrus

Question 11

neurones in spinothalamic tract pathway?

Answer 11

1st = site of excitation > dorsal root ganglion
2nd = decussates and ascends spinal cord to thalamus
3rd = thalamus > post central gyrus

Question 12

what causes central cord syndrome?

Answer 12

damage to medial fibres in spinal cord
usually due to hyperflexion or extension in an already stenotic neck
common in elderly
can be due to syringomyelia (fluid filled cavity in spine) in younger people

Question 13

features of central cord syndrome?

Answer 13

loss of spinothalamic sensation in cape distribution
mainly upper limb signs
- distal weakness, tingling/numbness
normal lower limbs and dorsal column sensation

Question 14

what is anterior cord syndrome?

Answer 14

compression of anterior spinal artery causing anterior cord ischaemia

Question 15

features of anterior cord syndrome?

Answer 15

dorsal column intact

complete motor paralysis and loss of spinothalamic sensation below lesion level

Question 16

features of brown sequard syndrome?

Answer 16

ipsilateral dorsal column and corticospinal dysfunction

contralateral spinothalamic dysfunction

Question 17

common cause of brown sequard syndrome?

Answer 17

stab wound to back

Question 18

where is the circle of willis found?

Answer 18

subarachnoid space

Question 19

where are dural venous sinuses found?

Answer 19

between periosteal and meningeal dural layers

Question 20

main cause of extradural haemorrhage?

Answer 20

rupture of middle meningeal artery due to head trauma

common in younger people and boxers

Question 21

presentation of extradural haemorrhage?

Answer 21

punched on side of head, lost consciousness but was fine straight after but then unconscious 4 hours after
“lucid interval”

Question 22

imaging findings of extradural haemorrhage?

Answer 22

hyperdense biconvex lens appearance

Question 23

cause of chronic subdural haemorrhage?

Answer 23

rupture of cerebral bridging veins

common in elderly after a fall (low impact trauma)

Question 24

presentation of chronic subdural haemorrhage?

Answer 24

progressive headache and confusion weeks after a fall

Question 25

imaging findings in chronic subdural haemorrhage?

Answer 25

hypodense crescent shaped appearence

Question 26

cause of subarachnoid haemorrhage?

Answer 26

rupture of berry aneurysm in circle of willis due or severe head injury

Question 27

presentation of subarachnoid haemorrhage?

Answer 27

severe thunderclap headache meningeal irritation loss of consciousness

Question 28

imaging findings in subarachnoid haemorrhage?

Answer 28

hyperdense signal in subarachnoid space

Question 29

where does blood accumulate if each vessel ruptures? - bridging cerebral vein - posterior communicating artery - middle meningeal

Answer 29

bridging = subdural posterior communicating = subarachnoid middle meningeal = extradural

Question 30

general features of cerebral herniation?

Answer 30

extensor response UMN signs cushings triad unreactive pupils

Question 31

what is cushings triad?

Answer 31

hypertension bradycardia irregular breathing

Question 32

what type of herniation is most associated with unreactive, blown pupul?

Answer 32

uncal herniation | inner aspect of temporal lobe herniates, compressing CN III

Question 33

what is Hoffman's sign?

Answer 33

where flicking/tapping of the middle finger produces twitching/flexing of the index finger to thumb sign of UMN lesion

Question 34

Babinski reflex?

Answer 34

where stimulation of the sole of the foot causes upward flexion of the big toe indicates UMN lesion

Question 35

anterior circulation in brain?

Answer 35

internal carotid via carotid canal > ophthalmic (to eyes) > middle cerebral and anterior cerebral arteries - anterior communicating artery between anterior cerebral arteries

Question 36

posterior circulation in brain?

Answer 36

posterior inferior cerebellar artery, anterior inferior cerebellar artery and superior cerebellar artery supply cerebellum pontine artery branches off basillar artery posterior communicating artery forms edges of circle of willis

Question 37

features of total anterior circulation stroke?

Answer 37

all 3 of - higher cerebral dysfunction - homonymous visual field defect - contralateral motor and/or sensory deficit of at least 2 areas (face/arm/leg)

Question 38

partial anterior circulation stroke?

Answer 38

2 of: - higher cerebral dysfunction - homonymous visual field defect - motor and/or sensory deficit in at least 2 areas (face/arm/leg)

Question 39

features of posterior circulation stroke?

Answer 39

cerebellar dysfunction isolated homonymous visual field defect cranial nerve dysfunction

Question 40

features of lacunar stroke?

Answer 40

pure motor or pure sensory stroke | common in longstanding cerebrovascular disease and risk factors (Smoking etc)

Question 41

site and function of broca's area?

Answer 41

inferior frontal gyrus formulating language - expressive dysphasia if damaged

Question 42

site and function of wernickes area?

Answer 42

superior temporal gyrus language comprehension - receptive/Wernicke's dysphasia if damaged

Question 43

function of parietal lobes?

Answer 43

writing calculations dressing self

Question 44

where is the auditory complex?

Answer 44

superior temporal gyrus

Question 45

3 main features of cerebellar dysfunction?

Answer 45

nystagmus dysarthria intention tremor

Question 46

classic history of cerebellum tumour?

Answer 46

children progressive headache wide based ataxia difficulty speaking

Question 47

a lesion where cause left superior quadrantanopia?

Answer 47

right temporal lobe

Question 48

what is gerstmann syndrome?

Answer 48

specific symptoms caused by dominant parietal lobe lesion - inability to write - inability to do mathematics - inability to distinguish own from another person's fingers - inability to distinguish left from right side of body

Question 49

which types of hydrocephalus is most common in children and what usually causes this?

Answer 49

non-communicating | aqueduct stenosis

Question 50

how does non-communicating hydrocephalus present in children?

Answer 50

large head retracted eyes sunsetting of eyes impaired upward gaze