Prolongation of brainstem auditory-evoked responses in Autistic probands and their unaffected relatives

Maziade, M. et al. (2000). Prolongation of brainstem auditory-evoked responses in Autistic probands and their unaffected relatives. Arch Gen Psychiatry, 57, 1077-1083.

Genetic factors play a major role in autism, with heritability greater than 90%. As the search for biological markers of autism continues, electrophysiological markers have been considered more and more. Early EEG studies comparing autistic subjects to control subjects revealed differences in early brain auditory-evoked responses (BAER). Prolonged BAERs indicate a slowing in nerve conduction within the early auditory system. This study confirmed slow latencies between consecutive sequential waves in autistic individuals, and went further to show that first degree relatives also show significantly longer interpeak latencies (IPLs) than matched controls. Although no significant prolongation was found in second and third degree relatives, resemblance of the IPL trait was found within families. While autism is a complex disorder, perhaps a combination of many neurophysiological deficits, IPL prolongation could be a marker of one of these deficits.