Cranial nerves Exam

Question 1

3 causes of anosmia

Answer 1

Head trauma: shearing of olfactory nerve fibres

Genetic: Kallmanns syndrome

Parkinsons disease

Question 2

Assess pupils for…

Answer 2

Size
Shape
Symmetry (asymmetry = anisocoria)

Question 3

3 causes of reduced VA

Answer 3

Refractive errors
Cataract
Optic neuritis

Question 4

Snellen chart recording

Answer 4

Numerator: distance from chart
Denominator: distance at which someone with normal vision can see that line

Question 5

3 causes RAPD

Answer 5

Optic neuritis
CRAO
Compression due to tumour

Question 6

2 causes of colour vision deficiency

Answer 6

Optic neuritis
Vit A deficiency

Question 7

Cause of bitemporal hemianopia

Answer 7

Optic chiasm compression e.g. pituitary adenoma

Question 8

Cause of homonymous VF defects

Answer 8

Stroke
Tumour
Abscess
(Pathology affecting visual pathways posterior to optic chiasm)

Question 9

2 causes of scotoma

Answer 9

MS
DM

Question 10

Use of fundoscopu

Answer 10

Assess optic disc for signs of pathology e.g. papilloedema

Question 11

CNIII palsy

Answer 11

Unopposed action of LR + SO
Down + out
Can also cause ptosis + mydiasis

Question 12

CN IV palsy

Answer 12

Vertical diplopia when looking inferiorly

Question 13

CN VI palsy

Answer 13

Horizontal diplopia, worsened when attempt to look towards affected side
Convergent squint

Question 14

Reflexes of CNV

Answer 14

Jaw jerk
Corneal

Question 15

Questions in CNVII assessment

Answer 15

Change in sense of taste? (anterior 2/3 tongue)
Change in hearing? (stapedius)

Question 16

CNVII palsy variation

Answer 16

LMN: forehead affected
UMN: forehead spared

Question 17

Rinne’s test positive

Answer 17

Air > Bone
= normal

Question 18

Conductive hearing loss Rinne and Webers test

Answer 18

R: Bone > Air
W: Louder in affected side

Question 19

Sensorineural hearing loss Rinne + Webers test

Answer 19

R: Air > Bone
W: Louder in normal ear

Question 20

Gag reflex nerve

Answer 20

Afferent limb: CN IX
Glossopharyngeal

Efferent limb: CN X
Vagus

Question 21

CN IX and X questions

Answer 21

Any issues with swallowing?
Any change to voice/ cough?

Question 22

Vagus nerve lesion effect on uvula

Answer 22

Uvula deviates AWAY from lesion

Question 23

Vagus nerve lesion effect on cough

Answer 23

Weak, non-explosive sounding bovine cough
Due to inability to close glottis

Question 24

Hypoglossal nerve palsy

Answer 24

Atrophy of ipsilateral tongue
Deviation of Tongue TOWARDS side of lesion
(over-action of functioning genioglossus)