Histopathological changes of chorda tympani in chronic otitis media.

Abstract

To investigate whether histopathological changes of chorda tympani might exist in patients with chronic otitis media without facial paralysis. The study was designed as a prospective trial. Twenty of 107 patients with chronic otitis media, in whom the chorda tympani were injured inadvertently during middle ear surgery, were enrolled into the study. The cases were divided into two groups based on the activity of chronic infection at the time of surgery. Twelve cases with suppurative disease were included in group I, and 8 cases with dry ear in group II. Histopathological examinations of the specimens revealed findings such as thickening of perineural and epineural connective tissue, vacuolar degeneration of Schwann cells, and proliferation of fibroblasts in endoneurium. Disorganization of the axons of some nerve fibers was also determined. Based on the histopathological changes of chorda tympani in chronic middle ear disease, it is postulated that chronic otitis media may give rise to functional loss of the nerve.