Video-oculography findings in patients with otosclerosis.

OBJECTIVE: To evaluate the existence of vestibular irritation with video-oculography before and after stapes surgery and to examine whether there would be signs of specific end-organ irritation. STUDY DESIGN: A prospective study of preoperative and postoperative nystagmus, vertigo, and hearing thresholds. SETTING: University hospital, tertiary referral center. PATIENTS: Thirty-three patients (mean age, 47 yr) with otosclerosis. INTERVENTION: Stapedotomy/stapedectomy with laser or microdrill. MAIN OUTCOME MEASURES: Spontaneous, gaze-evoked, and head-shaking nystagmus was measured preoperatively and approximately 1 week, 1 month, and 3 months after the operation. Three dimensions of nystagmus were identified and their slow-phase velocities were calculated. RESULTS: Spontaneous horizontal nystagmus was found preoperatively in 18% (slow-phase velocities, 1.3-3.3 deg/s) and postoperatively in 11 to 19% of the patients (slow-phase velocities, 1.3-3.8 deg/s). Head-shaking nystagmus was not detected preoperatively. After the operation, 11 to 15% of the patients had head-shaking nystagmus (slow-phase velocities, 6.6-17.8 deg/s), but this prevalence did not differ statistically significantly from the preoperative level (p = 0.18). Vertical nystagmus was found equally pre- and postoperatively. Torsional nystagmus was not found. One week after the operation, nine patients (27%) had some sensation of vertigo, but it lasted over 1 month in only one patient. We found no significant correlation with vertigo and the types of nystagmus. CONCLUSION: Nystagmus with a low slow-phase velocity can occur in patients with otosclerosis. However, according to the video-oculographic findings and subjective symptoms, significant vestibular dysfunction seems to be rare and temporary after stapes surgery.