The Deutsche Tinnitus-Liga e.V. (German tinnitus league) assumed a total of three million tinnitus patients in Germany already in 1999. Those people experience more or less permanent noises in their ears – the quota similar to diabetes. Every fourth person has already made experience with tinnitus. Back then 1.5 million people suffered medium to strong from the either returning or permanent noise nuisance and thus needed therapeutic help.
The list of potential causes is long. For diagnosis, physicians concentrate on proving suspicious physical and psychological causes: But stress, labyrinthine deafness, acute hearing loss, tumors, ear disorders, disorders of the metabolism, high blood pressure, circulatory disorders, injuries of the cervical spine, mal position of the teeth, different drugs and muscle tensions sometimes cannot just be nailed down or according therapies don’t help.
Tunes made by the brain
And until recently, those tunes nobody else hears were hardly provable. But now more and more hints indicate that the cause has to be sought in the brain itself – similar to phantom limb pains. Michael Seidman at the otolaryngology department at the Henry Ford Hospital in Detroit/USA was able to show that – and how – tinnitus changes the brain waves. In 2009 he published results of his study on the occasion of the AAO-HNSF – the annual meeting of the American Academy for Otolaryngology in San Diego/USA. By using magneto encephalography (MEG) he was able to identify weak magnetic fields which result from the electric activities of the brain. This method allows to locate active brain regions more precisely than other imaging methods. The brain waves of 15 tinnitus patients and ten healthy people showed in those with bilateral ear noises brain activities in the hearing center on both sides of the brain. With patients suffering from ringing only in one ear MEG detected brain activities only on the opposite side of the brain.
Such findings can be used in therapy, because the increased activity in the responsible brain areas can be reduced. A new therapy procedure for patients with chronic tinnitus is TMS – transcranial magnetic stimulation. Repeated treatment with low frequency inhibits excessive neuronal arousal previously identified by PET (positron emission tomography).
Acoustic stimuli against the chaos in the brain
The tinnitus stimulator T30CR, just recently licensed in Europe for treatment of chronic, subjective, tone-like tinnitus, is based on the same principle. The therapy goes back to the research work of Professor Peter Tass, director of the Institute for Neurosciences and Medicine in the Juelich Research Center in Germany. Targeted acoustic stimuli are supposed to fight tinnitus. The basis for this therapy is the assumption that deregulations in the brain cause the bugging tone and nerve cells firing signals excessively and synchronized. The neurostimulator interrupts the common mode with acoustic stimuli and disturbs the overactive, highly synchronous nerve cells. The result is a “healthy chaos” as described in their press release.
Basis of the therapy is the Coordinated-Reset technology (CR) developed by Tass. CR stands for a mathematical-physical stimulation algorithm which sends weak, individually adjusted impulses to the synchronic nerve cells for various lengths off time thus “bringing them out of step”. Effect: Nerve networks rebuild themselves again and the tinnitus reduces. Interim results of a study with 45 patients show that the volume of ear noises and the subjectively experienced nuisance continuously reduced with the treatment. After twelve weeks reductions of about up to 40 percent were observed, but with placebo only about a max of nine percent. The frequency of the tinnitus tone changes as well: It was deeper and more pleasant. ENT doctors are participating in first trainings. You can find specialists providing this therapy in the internet at Forschungszentrum Jülich.
Music: Tone against tone
Christo Pantey and a team of researchers in Muenster/Germany is using a special music therapy to reorganize misguided nerve cells. Pantey applies individual profiles of ear noises to rewrite patients’ favorite music pieces in a way where he filters tinnitus frequencies out of the tune. Patients listening daily to this music for a period of one year perceived their tinnitus in a lower volume. At the same time, the activities in areas of the auditory cortex were reduced.
Hearing defect plus tinnitus: Cochlea-implant and stem cells
Noise as a hearing impairing influence participates in the development of tinnitus. Thus is doesn’t come as a surprise that tinnitus occurs frequently in combination with hearing impairment including deafness. A cochlea-implant can be a potential treatment for tormenting tinnitus with unilateral deafness as Katrien Vermeire from Antwerp explains in her presentation during the ‘Jahrestagung der Deutschen Gesellschaft für Audiologie’ (DGA) 2008 (Annual Meeting of the German Association for Audiology). At the same time, a cochlea-implant should be declined for adults with unilateral deafness if it is only meant to improve hearing because the improvement is rather minor. At that point of time, 22 tinnitus patients suffering from unilateral deafness were treated with a cochlea-implant. All of them showed a significant improvement of their tinnitus after one year. The Deutsche Cochlear Implant Gesellschaft e.V. (German Cochlea-Implant Association) published a congress report.
Stem cell therapy might be promising against deafness and tinnitus. Recently scientists succeeded to isolate human auditory stem cells from fetal cochlea. Those stem cells were capable of differentiating into sensorial hair cells and neurons. Stem cell therapy in the inner ear of mice was successful. It remains debatable though whether this therapy could improve tinnitus.