A 31-year-old teacher presents with 5 days of severe rotational vertigo, nausea, and oscillopsia, having woken with the symptoms after a recent flu-like illness. Hearing is preserved. Caloric testing shows a 78% left canal paresis. Head-impulse test is positive to the left.

Investigations

Which division of the vestibular nerve is affected?

• ALeft superior division (utricle + horizontal canal)
• BLeft inferior division (saccule + posterior canal)
• CTotal left vestibular neuritis
• DRight superior division