Auditory brainstem, middle-latency, and slow cortical responses in multiple sclerosis.

The efficacy of auditory brainstem responses (ABRs), middle-latency responses (MLRs), and slow cortical potentials (SCPs) has been evaluated in 40 patients with multiple sclerosis (MS). ABRs and MLRs were averaged to clicks and SCPs to 1-kHz tone bursts of 70-dB nHL intensity. ABR, MLR, and SCP abnormalities were detected in 65.0, 42.5, and 30.0% of the sample, respectively. The combined sensitivity of ABRs and MLRs amounted to 80.0%, of ABRs and SCPs to 75.0%, and of MLRs and SCPs to 60.0%. The joint aptitude of all three responses equalled 87.5%. All three responses were capable to detect MS in seven of nine patients, failing to display neurological signs of brainstem lesion. The responses were also abnormal in three of five subjects with negative magnetic resonance imaging. It is concluded that the combined application of ABRs, MLRs, and SCPs promotes both detecting and confirming MS loci.