Evidence for a tinnitus subgroup responsive to somatosensory based treatment modalities.

Studies have established that the somatosensory system of the upper cervical region and head can be intimately involved in tinnitus. Tinnitus can arise directly from a disorder of the head and upper neck through activation of the somatosensory system. "Somatic testing" (a series of strong muscle contractions of the head and neck) can (1) modulate the tinnitus percept of approximately 80% of people with ongoing tinnitus, and (2) elicit a sound percept in approximately 50% of people with no tinnitus. These somatic phenomena are equally prevalent among people with or without functioning cochlea. Likely neural pathways underlying both the induction and modulation of tinnitus have been revealed in animal studies. Because somatic influences are fundamental to the operation of the auditory system, in general, and to tinnitus, in particular, somatic testing should be incorporated into all evaluations of tinnitus (1) to improve understanding of the role of the somatosensory system in any individual and (2) to identify subgroups of tinnitus patients who may respond to a particular treatment modality (as has already been shown for the tinnitus associated with temporomandibular disorder). Our clinical experience and review of reports of treatment modalities directed toward the somatosensory system supports the hypothesis that these modalities can benefit individuals with symmetric hearing thresholds but asymmetric widely fluctuating tinnitus. Treatment modalities involving the somatosensory system should be re-assessed by targeting this tinnitus subgroup.