Descending auditory system/cerebellum/tinnitus.

The cerebellum and the descending auditory system (DAS) are considered clinically significant for influencing the development of the clinical course of tinnitus of the severe disabling type. It is hypothesized that the SPECT of Brain perfusion asymmetries in cerebellum, demonstrated since 1993, reflect clinically the influence of an aberrant auditory stimulus i.e. tinnitus, on the activity and function of the descending auditory system highlighted by the cerebellum and the acousticomotor systems. SPECT of Brain perfusion asymmetries in the cerebellum have been demonstrated in 60-70% of tinnitus patients of the central type. Electrophysiologic support for this finding includes interference in ocular fixation suppression of the vestibulocular (VOR) with rotation and position testing. Abnormalities in cerebellar function are considered to reflect the psychomotor component of tinnitus. Support for the hypothesis is demonstrated with one patient with a predominantly central type tinnitus of the severe disabling type with cerebellar perfusion asymmetries and associated electrophysiologic evidence of interference in the VOR with rotation testing.