Neuro-otological study of positional vertigo caused by head injury.

A neuro-otological examination was given to 22 patients with paroxysmal positional vertigo within 1 week of head injury. In all cases, reverse rotatory positional nystagmus accompanied by a vertiginous sensation was observed in the positional nystagmus test. No relationship between the affected side and the direction of eye movement in the head-hanging position was found in the positional nystagmus test. From the prognosis and the nystagmus findings, the cause of the vertigo was thought to be partial damage to the inner ear. The clinical course was generally favorable, but recovery was slower in the 11 cases with neuro-otologically demonstrated central nervous system disorders than in the other 11 cases.