Measurement of auditory brain stem potentials in Bell's palsy.

Auditory brain stem potentials (ABP) were recorded in 27 patients with Bell's palsy during the early phase of the disease and 1-3 months later. Pathological findings were observed in 6 patients, the dominant features being prolonged brain stem transmission time and diminished amplitude of the second wave. The extension of the pathological process in the so called idiopathic peripheral facial paralysis appears to vary. The observation of brain stem involvement in some patients with Bell's palsy may have important clinical implications.