[The severity of dementia and brainstem auditory evoked potentials--peak latency and interpeak latency].

We have examined the correlation of dementia severity and brainstem auditory evoked potentials. The subjects were 80 patients with dementia (20 males, 60 females) whose mean age was 80.7 years. Normal controls were 9 elderly subjects (2 males, 7 females) whose mean age was 80.4 years. The following parameters were measured: peak latencies (I, III and V), interpeak latencies (I-III, III-V and I-V) and interaural latency differences (V PLDs and I-V IPLDs). As for clinical items and sex differences; (1) There were sex differences recognized between peak latency of III and V, interpeak latency of III-V and I-V. (2) There was a significant difference in interaural differences of V PL Ds between vascular dementia and degenerative dementia (dementia of the Alzheimer's type and Parkinson's disease). Duration of illness had no correlation with latencies of BAEPs. Dividing the patients into three groups according to the severity of dementia which are mild, moderate and severe, (3) peak latency of III, V and interpeak latency of I-III, III-V, I-V and interaural latency differences of V PL Ds prolonged significantly with the increasing severity of dementia. From these results, it is suggested that brainstem dysfunction progresses with the increasing severity of the dementia.