– By Dr. Anirban Biswas
Introduction :-
Tinnitus is the perception of sound (s) in the ear (s) / head in the absence of any external or internal auditory stimulation, i.e., without any corresponding mechanical activity in the cochlea. It is now believed to result exclusively from some neural activity within the CNS. This abnormal neural activity in the brain causing the sensation of sound in the absence of any peripheral auditory stimulation, i.e. without any detectable physical sound may be induced by decreased / absent input from the auditory periphery (tinnitus with deafness) or may occur solely due to disorders in the higher auditory pathways without any dysfunction of the peripheral auditory system (tinnitus without deafness). The current consentious on the pathophysiology of tinnitus is that this abnormal perception of sound is caused by some obscure abnormality in the higher auditory pathways in the brain and is intimately linked with stress / anxiety / psychological trauma and various involvements of the limbic system. Tinnitus is now conceptualized as a phantom auditory perception caused by dysfunctional neuronal firing in large neuronal circuits in the brain that also include regions located outside the primary auditory cortex (area 41) particularly in the attentional and limbic systems of the brain. This is why psychic and psychological factors are intimately related to tinnitus. In tinnitus, the auditory cortex picks up signals within its own auditory circuits creating an endless loop of signaling. This results is a vicious cycle of perpetual firing of neurons in the higher auditory pathways and this firing spreads to involve the limbic system also. Breaking this perpetual loop of signaling is the objective of therapy in tinnitus.
Incidence :-
The incidence of tinnitus is very high. I in 7 of the general population of USA suffer from tinnitus and 1 in 30 are very severely affected. In UK, 1 in 10 of the general population suffers from tinnitus, and 1 in 30 are very severely affected.
Management :-
Numerous treatment options are available but results of treatment are not very effective. The currently advocated modalities are, e.g. Tinnitus Retraining Therapy (TRT), Tinnitus Maskers, Noise Generators, Psychotherapy, Behavioral Therapy, and of course drugs like Ginkgobiloba, Caroverene, Lidocaine, Alprazolam. Tocanide etc. A lot of many other procedures and drugs like neurotropic Vitamins have also been tried but have been proved to be totally ineffective. Of all the modalities of treatment used for tinnitus, Tinnitus Retraining Therapy has been found to be the most rational and beneficial, provided it is done properly, but it too has been several shortcomings viz.- a minimum period of 1½ to is 2 years of therapy which is rather too long for any patient to continue treatment, the involvement of a professional psychotherapist and the constant use of a noise generator which is a wearable device that looks very much like a hearing-aid. This makes the treatment costly and cumbersome and causes the drop-out-rate to be very high. Moreover, TRT is very improperly done in most clinics and what is done in the guise of TRT without a noise generator and without the services of an experienced and trained psychotherapist is basically a hoax and is a slur on our profession. Most ENTs are too ignorant on the methodology of the treatment of TRT and are incapable of monitoring the outcome of any tinnitus therapy. Quite a few unscrupulous persons offering TRT services capitalize on this ignorance of the ENTs and fraudulently earn money from the naive and hapless tinnitus suffers most of whom are prepared to go to any length for a cure. TRT though effective in many patients and currently one of the best options for tinnitus management yet is a rampantly abused modality and with its many shortcomings, is not always a very practical and viable solution.