Unfortunately, some people do not benefit from the phenomenon of habituation and come to consider their tinnitus as an inconvenience of nature that undermines their quality of life. “It is not unusual for the tinnitus to develop due to a pre-existing state of anxiety, stress or depression, which seems to result in a more negative perception of the problem”, says Audrey Maudoux. In other more frequent cases, its intensity is such that it becomes unbearable. Surgical sections of the auditory nerve have been attempted, but without worthwhile results. Initially, it was actually believed that tinnitus resulted exclusively from a problem localized in the ear, even though everything indicates today that the problem is essentially a neuronal one.

Chronic tinnitus is difficult to treat, all the more so because its etiology is often uncertain. When it is accompanied by loss of hearing, the wearing of a hearing aid can improve the situation substantially from both viewpoints. Why is this so? “Because the transmission of better sound information re-stimulates the processes of inhibition in the cerebral cortex”, explains Professor Lefebvre.

The unconscious route

Prescribed somewhat systematically in the first phase, corticoids are used for their anti-inflammatory properties in as much as tinnitus is quite frequently believed to occur following an initial problem with hearing- noise trauma, sudden deafness etc. These are practically the only medicines that have proved to be efficient with regard to tinnitus in the acute phase. Several other medicinal approaches are offered in the context of chronic tinnitus, but with limited success: magnesium, Ginkgo biloba, vasodilators, anticonvulsants or even anxiolytics or anti-depressants. As underlined by Professor Lefebvre, it would be necessary to identify sub-groups of patients in order to hope to obtain more conclusive results.

In addition, treatment by laser has been added to the list but the efficiency of this method has not been proved by any placebo-controlled scientific study.  Another technique which is invasive and reserved for rigorously selected cases, involves the implantation of electrodes in the brain. Practised in Belgium by Professor Dirk De Ridder’s group, from the University of Antwerp, this approach has resulted in positive results in two-thirds of patients treated. “The initial causes of tinnitus are often linked to a peripheral sensorineural problem that is affecting the ear and/or the auditory nerve (noise trauma, sudden deafness, ototoxicity...). When the brain no longer receives some sensitive information from the periphery (this is called deafferentation?), a functional reorganization is produced (principally hyperactivity) in the cerebral areas that, in this case, process sound information. In the context of tinnitus, the implanted electrodes stimulate the auditory cortex. This has two effects: firstly, to supply stimulation to the cerebral areas that no longer receive any stimulation from the periphery (reafferentation); secondly, to stop the pathological activity in the zones involved in the cause of tinnitus (neuromodulatory effect)”, comments Audrey Maudoux.