Idiopathic sudden sensorineural hearing loss: Temporal bone histopathologic study

We microscopically examined the temporal bones of 12 ears with idiopathic s udden sensorineural hearing loss (iSSNHL), 10 ears with presbycusis, 11 ear s with normal hearing, and 8 unaffected contralateral ears of patients with iSSNHL. The degeneration of the spiral ligament, vascular stria, hair cell s, dendrites, and apical spiral ganglion cells was greater in ears with iSS NHL than in the other groups. The apical ganglion cells were significantly more affected than the basal ganglion cells, and the spiral ganglion cell l oss increased as a function of duration of iSSNHL. Cochlear ossification wa s found in 1 ear with iSSNHL, and hydrops in 2. These findings suggest a vi ral rather than a vascular or ruptured inner ear membrane origin for iSSNHL .