Intratympanic gentamicin treatment: preliminary results in two patients with Menière's disease.

Menière's disease is a vestibular disturbance characterized by episodic vertigo, tinnitus, and fluctuant hearing loss. The long-term effectiveness of available medical and nonablative surgical treatments has been variable, with frequent symptom recurrence. Vestibular neurectomy and labyrinthectomy, surgically ablative techniques, provide more permanent relief from vertiginous attacks. However, these procedures pose possible morbidity and cochlear risk. In this paper, preliminary results are presented for two patients who underwent intratympanic gentamicin application. Like surgical labyrinthectomy, intratympanic use of gentamicin is intended as an ablative procedure, but with potentially less risk to hearing. More vestibulotoxic than cochleotoxic, gentamicin initially disrupts the endolymph-secreting vestibular dark cells, thereby preventing endolymphatic hydrops development. Following gentamicin application, both patients demonstrated a significant change in peripheral vestibular function, as characterized by a reduction of caloric response, impaired posturography performance, and reduced low-frequency gain on rotary chair testing. Posturography performance subsequently improved, confirming functional compensation. Both patients reported relief from vertiginous attacks. However, word recognition ability was significantly worse in one of these two patients. Changes in pure-tone thresholds were minimal.