Question 1

Which cranial nerve is most commonly affected?

Accepted Answer

The facial nerve (CN VII) is most commonly paralysed, most often due to Bell's palsy, affecting 15-30 per 100,000 people per year.

Question 2

How do brainstem lesions cause crossed syndromes?

Accepted Answer

Brainstem lesions affect cranial nerve nuclei ipsilaterally and long tracts before decussation, producing ipsilateral cranial nerve deficit with contralateral hemiparesis.

Question 3

What are the key steps in a screening cranial nerve exam?

Accepted Answer

CN I (scent), CN II (visual acuity, fields), CN III, IV, VI (eye movements), CN V (facial sensation), CN VII (facial symmetry), CN VIII (hearing), CN IX, X (palate, gag), CN XI (shoulder shrug), CN XII (tongue).

Question 4

What is the mnemonic for the 12 cranial nerves?

Accepted Answer

On Old Olympus Towering Top, A Finn And German Viewed Some Hops (Olfactory to Hypoglossal).