Multiple sclerosis as the cause of sudden 'pontine' deafness.

Sudden deafness is rarely ascribed to multiple sclerosis (MS). Sudden deafness and tinnitus were the initial symptoms of MS for the two patients described in this paper. A sensorineural hearing loss was present in one ear in both patients. Brainstem responses (BSRs) showed only the first three waves for the first patient, and only wave I for the second. Magnetic resonance imaging showed focuses of demyelination in the pons (case 1) and on the borderline between medulla and pons (case 2). The placement of plaques and the involvement of the BSR-generating acoustic afferent pathways are discussed. The hearing level measured by tonal audiometry recovered after 1 month in both patients and remained stable during 1 year. BSRs remained pathological after 1 month as well as after 1 year. Sudden hearing loss and tinnitus might be the initial symptoms of MS.