Background: The study of tinnitus mechanisms has increased tenfold in the last decade. The common
denominator for all of these studies is the goal of elucidating the underlying neural
mechanisms of tinnitus with the ultimate purpose of finding a cure. While these basic
science findings may not be immediately applicable to the clinician who works directly
with patients to assist them in managing their reactions to tinnitus, a clear understanding
of these findings is needed to develop the most effective procedures for alleviating
tinnitus.
Purpose: The goal of this review is to provide audiologists and other health-care professionals
with a basic understanding of the neurophysiological changes in the auditory system
likely to be responsible for tinnitus.
Results: It is increasingly clear that tinnitus is a pathology involving neuroplastic changes
in central auditory structures that take place when the brain is deprived of its normal
input by pathology in the cochlea. Cochlear pathology is not always expressed in the
audiogram but may be detected by more sensitive measures. Neural changes can occur
at the level of synapses between inner hair cells and the auditory nerve and within
multiple levels of the central auditory pathway. Long-term maintenance of tinnitus
is likely a function of a complex network of structures involving central auditory
and nonauditory systems.
Conclusions: Patients often have expectations that a treatment exists to cure their tinnitus.
They should be made aware that research is increasing to discover such a cure and
that their reactions to tinnitus can be mitigated through the use of evidence-based
behavioral interventions.
Key Words
Auditory cortex - cochlear nucleus - hyperacusis - tinnitus - tonotopy - spontaneous
activity
