Cranial Nerves

Question 1

what can cause loss of smell

Answer 1

damage to CN I olfactory:
head injury
tumours 
parkinsons
seizures

Question 2

upper quadrantinopia indicates a problem in

Answer 2

temporal lobe

Question 3

lower quadrantinopia indicates a problem in

Answer 3

parietal lobe

Question 4

where is problem if homonymous hemianopia

Answer 4

optic tract (after chiasm)

Question 5

common cause of homonymous hemianopia

Answer 5

posterior cerebral artery infarct

Question 6

what do retinal/local eye lesions cause

Answer 6

scotoma (blind spot)

peripheral vision loss (‘tunnel vision’)

Question 7

hallmark of optic nerve lesion

Answer 7

unilateral visual loss
central or paracentral scotoma
loss of papillary light reflex

Question 8

what part of autonomic nervous system causes pupil dilatation

Answer 8

sympathetic

‘running in the dark’

Question 9

what part of autonomic nervous system causes pupil constriction

Answer 9

parasympathetic

Question 10

what nerve causes pupillary constriction

Answer 10

short ciliary nerve

Question 11

what is Leber’s hereditary optic neuropathy

Answer 11

unilateral/bilateral optic nerve neuropathy developing over several weeks in young healthy men

Question 12

mode of inheritance of leber’s hereditary optic neuropathy

Answer 12

mitochondrial DNA mutations

Question 13

optic disc pallor

Answer 13

optic atrophy

Question 14

causes of optic atrophy

Answer 14

nerve infarction follows papilloedema inflammation (MS, syphilis, LHON)

Question 15

clinical manifestations of pupillary defect

Answer 15

illuminated pupil not reacting to light

loss of contralateral consensual reflex

Question 16

Triad of:
unilateral pupillary constriction
ptosis + enophthalmosis (sunken eye)
ipsilateral anhidrosis (loss of sweating)

Answer 16

horner’s syndrome - interruption of sympathetic supply in face

Question 17

causes of horner’s syndrome

Answer 17

demyelination
vascular disease
tumour

Question 18

what does diplopia indicate

Answer 18

weakness to one or more extraocular muscles

Question 19

signs of CN III nerve palsy

Answer 19

unilateral complete ptosis
eye facing DOWN and OUT
fixed, dilated pupil (if pupil spared, parasympathetics not affected)

Question 20

signs of CN IV nerve palsy

Answer 20

supplies superior oblique muscle
torsional diplopia when attempting to look down (descending stairs)
head tilted away form that side

Question 21

signs of CN VI palsy

Answer 21

supplies lateral rectus

convergent squint with diplopia when looking to the side of the lesion

Question 22

sign of CN V lesion

Answer 22

diminution of corneal reflex (don’t blink when eye touched)
unilateral sensory loss to face, toungue
jaw deviates to side of lesion as mouth opens

Question 23

paroxysms of knife like/electric shock pain lasting seconds and triggered by touch (washing, shaving, cold wind, eating)

Answer 23

trigeminal neuralgia

Question 24

treatment for trigeminal neuralgia

Answer 24

carbamazepine

Question 25

signs of UMN lesion of facial nerve

Answer 25

weakness on lower part of face on opposite side (forehead spared)

Question 26

signs of LMN lesion of fcial nerve

Answer 26

ipsilateral weakness of all facial expression muscles

Question 27

most common cause of CN VII nerve palsy

Answer 27

Bell's palsy

Question 28

other causes of CN VII nerve palsy

Answer 28

``` trauma otitis media ramsay-hunt syndrome (herpes zoster) brain stem lesion acoustic neuroma parotid tumours ```

Question 29

bell's palsy is acute/chronic

Answer 29

acute

Question 30

what virus is associated with bell's palsy

Answer 30

herpes simplex

Question 31

treatment of bell's palsy

Answer 31

``` steroids within 72 hours onset protect eye (dark glasses, artificial tears) ```

Question 32

hallmark of ramsay-hunt syndrome

Answer 32

painful vesicular rash on auditory canal, pinna, tongue, palate or iris

Question 33

treatment for ramsay-hunt syndrome

Answer 33

prednisolone (if <72 hours onset) | acyclovir

Question 34

nystagmus on performing hallpike manoeuvre

Answer 34

benign positional vertigo

Question 35

Meniere's disease clinical manifestations

Answer 35

vertigo >20mins (possible nausea/vomiting) sensorineural hearing loss tinnitus

Question 36

what drugs can cause vertigo and hearing loss

Answer 36

gentamycin furosemide cisplatin

Question 37

in hypoglossal lesion, tongue deviates towards/away from lesion

Answer 37

towards