Diagnostic and therapeutic dilemmas in rapidly progressive sensorineural hearing loss and sudden deafness. A reappraisal of immune reactivity in inner ear disorders.

Sera from 76 patients with a clinical diagnosis of idiopathic rapidly progressive sensorineural hearing loss (SNHL) (n = 15), sudden deafness (n = 31) and with other etiologies of their hearing loss (n = 30) were analysed by western blot assay. Seventy-three percent of the cases with rapidly progressive SNHL had cross-reacting antibodies (27, 45, 50, 68 kD). The overall response to immunoprogressive therapy was effective in only 50% of cases. Sixty-five percent of the patients with sudden deafness also had cross-reacting antibodies (27, 45, 50, 80 kD). In these cases steroid therapy was more effective in re-establishing the hearing than no treatment, regardless of the western blot outcome. Spontaneous recovery occurred in approx. 50% of cases, but only in those with a positive assay. The antigenic epitopes detected with immunoblotting were not cochlea specific; they were also found in protein extracts of other organs (cranial nerves, kidney, brain).