Alternobaric oxygen therapy in long-term treatment of Ménière's disease.

Hyperbaric oxygen therapy (HBQ) has been used for several years as a treatment for Ménière's disease, particularly in Sweden. In this study continuous variations in pressure (from 1.7 to 2.2 ATA; alternobaric oxygen therapy: ABOT) were used to decrease endolymphatic hydrops, the typical histopathological substrate of Ménière's disease by increasing hydrostatic pressure and mechanical stimulation of the endolymphatic flow toward the duct and the endolymphatic sac, which produces a consequent increase in the dissolved O2 content in the labyrinth liquid, which should contribute to recovering cell metabolism and restoring cochlear electrophysiological function to normal. An experimental group of 20 patients suffering from unilateral Ménière's disease received a total of 15 ABOT treatment sessions during the acute episodes. Treatment foresaw two days without therapy every five days of application. Maintenance treatment consisted of one session per day for five consecutive days every month for one year. Thereafter, during the second, third, and fourth years of treatment, patients were submitted to one session per day for five consecutive days every three months. A control group of 18 patients suffering from Ménière's disease was treated with 10% glycerol i.v. (during the acute episodes) and with betahistine (8 mg x 3/day) in the periods in between. Mean pure tone average (PTA in dBHL) hearing thresholds at octave frequencies from 500 to 3,000Hz, and frequency of episodes of vertigo and tinnitus, both after 15 days of treatment and at the end of a four-year follow-up, were compared for both groups according to the 1995 Committee on Hearing and Equilibrium criteria. No statistically significant differences were found between the two groups at the end of the first 15 days of treatment. However, at the end of the follow-up period, patients treated with ABOT had significantly fewer vertiginous episodes and improved PTAs and tinnitus compared to the controls. The results support the use of ABOT as a valid alternative to drugs in the long-term treatment of Ménière's disease.