Research News About Tinnitus
From the e-mail rolf-forum, 5 May 1998
as most of you know TINNITUS (perception of disturbing sounds in the ear) is on a drastic increase (in so-called First World countries). Most of us have worked with it, often had some temporary improvements, yet according to statistics, the chances for complete healing are quite low (below 20%) once the condition has been there for over 3 months.
The most common theories about the causes are
a) oxygen lack in inner ear, due to constraints of local blood circulation there
b) trauma to acoustic nerve or sensory organs in inner ear
c) theory that the sounds are not produced in ear, but only in brain itself
d) refectory disturbances from TMJ, AO, or cervical joint receptors
In our field of manual therapy most successes have been reported (published) in relation to work on
- and (other) cranial manipulations.
In the last few months the question of how these sounds are produced have been finally solved by several scientific studies. It is now clear that - at least most of the time - these sounds are NOT created in the ear or even the acoustic nerve. Rather theses sound perceptions are caused and created within the CORTEX itself. Tinnitus is now seen as a similar neural mechanism as phantom limb pain. (Often tinnitus goes together with a partial hearing loss for high frequencies. Apparently the then unused brain regions rewire themselves with other brain regions in their vicinity which leads to these mis-interpretations).
My suggested consequences of this new research for our work:
- Rolfing can still be helpful. Often it helps to diminish the symptoms for some time. The rational is that by lowering the general STRESS level of theautonomic nervous system, the brain then creates less tinnitus sounds (Anatomically the acoustic cortex has a very strong connection with the limbic system, which is greatly affected by stress). For many patients work on the jaw, neck, etc. is the most effective way to de-stress - just as much as a warm herbal bath, a relaxing meditation, or a foot massage might be to others.
- Same for cranial manipulations: if they are helpful it is less on a mechanical rational (e.g. of opening blood flow to the inner ear or getting the acoustic nerve free of any entrapments, etc.), but via the same relaxation influence to the limbic system as the other approaches just listed before.
- If clients ask for treatment advice, I suggest to refer them to training approaches in which the brain learns to pay attention again to external sounds rather than to their own ones. Most promising approach is currently the so-called 'Tinnitus Retraining Therapy' which uses some miniature sound masking and training devices, coupled with psychological and relaxation training. Preliminary data from a study by J.Hazellb & R.Coles speak about considerable improvements and even complete healing within 2-3 years of training.
For those interested in details:
In a study with humans they did PET scans on tinnitus patients. It was shown that when the sounds appeared only brain regions on one side of the brain were activated. This was convincing proof that the acoustic nerve was not involved, since the acoustic nerve would stimulate regions on both hemispheres. Neurology, Vol.50, p.114, 1998.
In another study they trained mice to become allergic to silence. Based on the knowledge that high amount of ASS (aspirin) can create tinnitus, they treated them with ASS plus some acoustic shock trauma until they tested positive for tinnitus symptoms. After killing those poor animals, they studied their brains (which they had dyed before for cellular activity). Result: The pathways of the acoustic nerve did not show any signs of increased activity in relation to tinnitus, yet the acoustic cortex did. (Langner G, Wallhaeuser-Franke E, Neuroreport 7:1585-8, 1996).