Histopathologic features of the temporal bone in usher syndrome type I.

Temporal bones of 2 patients with Usher syndrome type I were examined using light microscopy. In both patients, findings from histopathologic examination of the cochlea were characterized by degeneration of the organ of Corti, which was most marked in the basal turn, atrophy of the stria vascularis, and a decrease in the number of spiral ganglion cells. The cochlear nerve appeared to be diminished. The sensory epithelium of the saccular and utricular maculae of patient 1 was normal for age. The left temporal bone of patient 2, classified as Usher syndrome genetic subtype USH1D or USH1F, demonstrated the typical signs of severe cochleosaccular degeneration. Present cases and cases from the literature were reviewed in search of an explanation for the above-described differences in histologic findings.