Seventeen patients with vestibular neuronitis were followed up for the period ranging from 5 months to 6 years. The results obtained at the time of the follow-up examination were as follows:
1) Only one patient had a complaint of benign paroxysmal positional vertigo (BPPV) with positional rotatory nystagmus. Eight patients (47.1%) complained of unsteadiness when rising rapidly or walking in the dark. Two patients had had BPPV with positioning rotatory nystagmus during the course of illness.
2) Twelve patients (70.1%) presented spontaneous and positional nystagmus which had no relationship with the duration of their illness.
3) Twelve patients (70.1%) showed no response to caloric stimulation, while three (17.6%) showed slight and two (11.8%) normal response.
4) In the galvanic body sway test (GBST), five patients who were ill less than 3 years showed abnormal thresholds.
5) Of the nine patients, whose disease periods were more than 3 years, six complained of no symptoms, five showed slight or normal response to caloric stimulation and all the nine presented norma thresholds of the GBST.
These results suggest that complete compensation of the vestibular system and some recovery of the peripheral vestibular function may take more than 3 years after the first vertigo attack caused by vestibular neuronitis.