The Relationship Between Middle Latency Auditory Evoked Responses(MLRs)and Neurobehavioral Functions in Patients with Asymptomatic & Silent Brain Stroke(infarction)

Abstract

The human Pb middle latency auditory evoked responses (MLRs) is postulated to be generated in the thalamus by a cholinergic component of the ascending reticular activating system (ARAS). To test the hypothesis that Pb and its generator substrate are abnormal in asymptomatic & silent brain stroke (infarction), recordings of MLRs to click stimuli, were carried out. Comparison among the silent brain infarction (SBI), vascular dementia (VD) and agematched hospital control subjects indicated normal auditory brain-stem and Pa responses but a significant decrease in Pb amplitude of the VD group. This Pb abnormality suggests that the midbrain cholinergic cells may not be dysfunctional in SBI but in VD, and the current status of SBI to development of VD.