Hyperbaric oxygen therapy as a treatment for tinnitus ?

Treating tinnitus with hyperbaric oxygen therapy (HBOT) is considered very controversial. In some European countries, like Germany, many hyperbaric oxyten therapy centers had been very much focused on treating this disease. It was not uncommon to read "patient stories" and adverts in health magazines, advocating HBOT as a "miracle cure" for (even long-standing) tinnitus.

Despite the great numbers of patients having been treated for tinnitus, no single scientific report actually was published to demonstrate it's efficacy. Especially since the burden of tinnitus is extremely difficult to objectivate, and because there is a strong subjective "feel" to how patients cope with it, a reported positive effect of HBOT is often disputed as being "not objective". Even when urged to do so by the health insurers, no prospective randomised study has been produced by the HBOT centers in Germany up to this date, only retrospective reports. As a consequence of this (and of course other factors), all social security reimbursement of HBO treatment has been withdrawn for this and other indications as from September 2000.

For another disease entity, "sudden sensorineural deafness", a bit more scientific "proof" is available, although the final evidence, a randomised prospective study, is still running (see also: www.oxynet.org for more information about this study and HBOT in general). When started within one month after the onset of a sudden unilateral deafness where no clear cause could be identified, HBOT can result in a significant improvement in hearing or even a complete cure, even when "classical" drug treatment regimens have not yielded any effect before it.

Why HBOT is working in these cases, is not known. Most probably, a vasospasm or soft tissue swelling (edema) is at the origin of those cases that improve with HBOT. Most often, HBOT is only considered in those cases where a drug treatment has not given any or insufficient results. Several independent (retrospective) studies have clearly shown that even in these "refractory" cases, in about 50% of patients a significant improvement in hearing can be obtained (Desloovere et al. 1998). Many of these patients report a significant decrease of their tinnitus !

In conclusion, HBOT can be considered in those cases where:

• the tinnitus started concomitantly with an episode of sudden deafness
• which is caused by an inner ear disease process (i.e. not a disease of the auditory nerve or the brain tissue)
• for which no direct cause could be identified (by blood tests, brain auditory evoked potentials, magnetic resonance scanning)
• and where a treatment with (usually intravenous) drugs, often a combination therapy of cortisone, vasodilators and similar drugs in various dosages, has not given any effect

HBOT is usually administered in a series of 10 daily sessions of one and a half hour. After this, new earing tests will be performed to evaluate if there is any effect. Tinnitus can be evaluated using Visual Analog Scales for "loudness", "feeling of fullness" and "general bother" of the tinnitus. If there is no significant improvement, further HBOT treatment has no sense.