Acoustic reflex dynamics and auditory brain stem responses in multiple sclerosis.

Onset latency, rise time, and amplitude measures of the acoustic reflex and auditory brain stem responses (ABRs) to clicks were elicited from normal subjects and subjects with multiple sclerosis (MS). The results indicated that MS subjects exhibited response abnormalities including prolonged rise times of the acoustic reflex and prolonged absolute latencies, interwave latencies and interaural latencies, and poor response stability of the ABR. The results of this study indicate that measurement of acoustic reflex dynamics can add to the diagnostic value of the test beyond measurement of acoustic reflex threshold and decay. The combination of complete acoustic reflex and ABR tests is a valuable contribution to the diagnosis of patients with MS who have no auditory symptoms.