Abstract:

Tinnitus, the phenomenon of ringing or buzzing in the ears without an external sound source has evolved into one of the most common symptoms in otorhinolaryngology. It affects about 10 to 15% of the general population. There are now plausible models for neural basis of tinnitus, its pathogenesis and its consequences on mental health: Peripheral sensory deprivation due to cochlear damages may prompt increased neuronal activity in the central auditory system in order to adapt the neural sensitivity to the reduced sensory inputs. This central gain could over amplify the “neural noise” and thus trigger a homeostatic down-regulation of inhibitory synapses in the auditory cortical map leading to specific reorganization of the cortical representation of the tinnitus percept. Dysfunctional feedback connections from limbic regions to auditory brain areas, interacting at the thalamic level, may account for the psychological impairment.