Saturday, February 26, 2011
Tinnitus is an auditory phantom sensation with ringing or hissing sounds. Up to 17% of the adult population experience tinnitus at least occasionally, and as many as 10% report unremitting tinnitus. However, the underlying pathomechanism has not yet been identified. As tinnitus often persists even subsequent to auditory nerve tanssection, processes in the central nervous system may play a major role in its development and maintenance. Several neuroimaging studies employing magnetoencephalography, positron emission tomography, and functional magnetic resonance imaging reported subcortical and cortical changes in tinnitus patients. Using the method of voxel-based morphometry, volumetric magnetic resonance tomography studies demonstrated tinnitus-related structural changes in the subcollosal region including the nucleus accumbens, and, withing the auditory pathway, at the level of the medial geniculate.