Vestibular function after vestibular neuritis

Abstract

Objective: To measure horizontal semicircular canal function over days, weeks, and months after an acute attack of vestibular neuritis. Design: The video head impulse test (vHIT) was used to measure the eye movement response to small unpredictable passive head turns at intervals after the attack. Study sample: Two patients diagnosed with acute right unilateral vestibular neuritis. Results: There was full restoration of horizontal canal function in one patient (A) as shown by the return of the slow phase eye velocity response to unpredictable head turns, while in the other patient (B) there was little or no recovery of horizontal canal function. Instead this second patient generated covert saccades during head turns. Conclusion: Despite the objective evidence of their very different recovery patterns, both patients reported, at the final test, being happy and feeling well recovered, even though in one of the patients there was clear absence of horizontal canal function. The results indicate covert saccades seem a successful way of compensating for loss of horizontal canal function after unilateral vestibular neuritis. Factors other than recovery of the slow phase eye velocity are significant for patient recovery.