Gentamicin perfusion vestibular response and hearing loss.

OBJECTIVE: To compare hearing results as a function of vestibular ablation in the treatment of Ménière's Disease, using gentamicin perfusion.

STUDY DESIGN: A retrospective review of patients with Ménière's Disease treated by gentamicin perfusion of the inner ear via the MicroWick device.

SETTING: A tertiary otologic referral center.

PATIENTS AND INTERVENTIONS: The charts of patients treated with gentamicin perfusion via the MicroWick between the years 1998 and 2000 were reviewed. The results for patients with functional hearing in the affected ear were analyzed and were compared with the results in patients without functional hearing.

MAIN OUTCOME MEASURES: Audiologic and vestibular test results as well as subjective symptoms.

RESULTS: There were 45 patients who met the inclusion criteria. The averages for speech discrimination score and pure tone average before treatment were 92% and 38 dB, and after treatment were 82% and 47 dB. Patients were divided into two groups: Group 1 (20 patients), less than 75% ice air caloric reduced vestibular response (RVR); Group 2 (25 patients), those who reached greater than 75% ice air caloric RVR. There were 8 patients (17.6%) with persistent vertigo; 7 were from Group 1, and 1 was from Group 2, which was statistically significant (p = 0.007)wwww. The pure tone average dropped an average of 3 dB for Group 1 and 15 dB for Group 2. The difference in hearing loss between the two groups was statistically significant (p = 0.01).

CONCLUSION: This study suggests that there is a correlation between the degree of vestibular ablation, the control of vertigo, and the risk of hearing loss. Patients with functional hearing seem to have a similar success rate for vertigo control, compared with patients who already had lost functional hearing before treatment. Future investigation may determine if less than 100% RVR, but greater than 75% RVR, is an alternative end point with adequate vertigo control and reduced risk of hearing loss.