Late sequelae of cochlear infection.

Inflammatory reactions within the inner ear are deleterious to cochlear function and can result in server hearing loss that does not recover. This study investigated a guinea pig model of long-term cytomegalovirus infection. At high doses active inflammation was still present after 35 days. At lower doses some ears showed partial resolution while others were still inflamed. Hearing was totally lost in all cases of persistent inflammation. There was some residual hearing in the cases that had resolved. Cochlear structures including the organ of Corti, stria vascularis, and spiral ganglion were partially degenerated. Fibrotic matrix within scala tympani was ossified in many cases. These changes are consistent with those described for human cochleas following putative viral infections.