British Tinnitus Association

The British Tinnitus Association - registered charity no: 1011145

Tinnitus Research: a vision of strategy and facilities

Tinnitus remains a scientific enigma. Whilst there are many theories regarding the generation of tinnitus, robust treatments have evaded the clinician. The numbers of individuals in the UK experiencing persistent and troublesome tinnitus are considerable (approximately 5 per cent of the adult population). These people have a variety of complaints associated with tinnitus including insomnia, concentration problems, irritability and depression. There is evidence to show that cognitive behavioural therapies facilitate habituation to tinnitus, evidence is emerging of the success of therapeutic approaches that combine directive counselling and sound therapy, the most well defined of these being Tinnitus Retraining Therapy. Hopes for a pharmacological treatment for tinnitus were raised by the discovery that the intravenous infusion of lignocaine temporarily reduced tinnitus intensity in two-thirds taking part in research trials. The failure, however, of similar substances to have the same effect, means these hopes remain unfulfilled to date.

The great variety, not only of causes, but also of perception of tinnitus amongst those experiencing the condition means that no one agent is likely to effect improvement in tinnitus for all patients. Tinnitus research, therefore, might usefully look at similar groups of patients when investigating both how tinnitus is generated and what therapies are best to treat it. It would also be worth exploring the prospect of combining available and future to better effect.

Recent research has advanced knowledge of tinnitus sufficiently to merit a more optimistic view of the chances of developing successful treatments and a major initiative at this point would greatly facilitate these developments. Recent important neurophysiological and neuro-imaging research has advanced this quest by establishing that persistent, troublesome tinnitus involves changes in the central nervous system rather than just problems in the hearing mechanism. Because of these findings there is now a consensus of opinion about the reason why tinnitus persists.

An effective tinnitus research strategy requires collaboration between disciplines, and at the present time interaction between clinical sciences (including audiology and otology), neuro-imaging, pharmacology, psychology and neurophysiology appears of particular importance. A research initiative in the UK that would encompass these disciplines and involve pre-existing groups with an interest in tinnitus could be of extraordinary value in identifying robust and effective therapies for this debilitating condition. There are a number of individuals and institutions that are actively involved in tinnitus research at present, and hence might form a useful core to such an initiative. These include David Baguley of the Audiology Department of Addenbrooke’s Hospital, Cambridge, and Laurence McKenna, Clinical Psychologist of the Royal National Throat Nose and Ear Hospital who have ongoing research collaborations undertaken in Cambridge, with Debbie Hall (Neuro-Imaging, MRC Institute of Hearing Research, Nottingham), Mr Don McFerran (Consultant Otolaryngologist, Essex County Hospital, Colchester), Ewart Davies and Nick Barnes (Pharmacologists, Birmingham) and Ian Winter (Department of Physiology, Cambridge University).

A collaborative and co-ordinated research programme involving these and/or other individuals and groups would have substantial advantages over isolated research in other parts of the world and indeed over the research that each group is now conducting on their own. Their present expertise in neuro-imaging, pharmacology and clinical research would provide a distinct impetus to tinnitus research in this country. Initial work would be undertaken to identify particular groups of patients (specifically those with noise induced cochlear dysfunction, Meniere’s disease and vestibular schwannoma), tinnitus characteristics and psychological attributes such as anxiety, depression, insomnia and cognitive measures of attention. Investigation of previously reported effects of various pharmacological substanceswould be undertaken with robust, randomised double blind controlled trial design. The effect of pharmacological, psychological and sound based interventions upon the reorganisation processes in the brain, as described above, would then be determined using the most up-to-date methods, including functional imaging and recordings of neural activity from the cochlea and central auditory pathways. The determination of the neurophysiological foundation of such changes would be a necessary adjunct to this clinical work.

The need for such collaboration and a multidisciplinary approach to tinnitus research would not necessarily require a physical Unit, though some central hub of research activity would be needed. There are already indications of such a hub emerging in Cambridge, which could be the starting point to speed up the process.

In summary, we now have the opportunity to proceed with strong, evidence based, multi-disciplinary and collaborative research to identify effective treatments for tinnitus in the United Kingdom.

This article has been specially edited from the original, which was collated by David Baguley, Head of Audiology, Addenbrooke's Hospital, Cambridge, for the Professional Advisers Committee of the British Tinnitus Association, December 2001.