Cochlear degeneration in Leigh disease: Histopathologic features

Objective: To describe pathologic findings from temporal bones acquired from an infant with Leigh disease. Study Design: Retrospective case review. Materials and Methods: Temporal bones were taken at autopsy from an 8-month-old infant with Leigh disease. The right temporal bone was studied by microdissection. The middle ear was examined and the inner ear sensory organs dissected for study by light microscopy. The left temporal bone was embedded in celloidin, and sections were cut for microscopic examination. Results: Middle ear structures were normal bilaterally. There was, however, evidence of otitis media in both middle ears, which was more severe on the left side. Inner and outer hair cell loss, patchy degeneration of organ of Corti, and loss of nerve fibers in the osseous spiral lamina were found in the basal and middle turns of both cochleas. Basophilic deposits in the stria vascularis were observed in the apical portion of the left cochlea. Conclusions: Inner ear sensorineural degeneration may occur in Leigh disease. Possible cochlear dysfunction caused by the degenerative changes needs to be considered in the hearing assessment of patients with Leigh disease.