RETURNCorrelation between the Severity of Dementia and Brainstem Transmission Time (BTT)
Ryuzo Kawahara, Hisayoshi Takeshita and Hidebumi Hazama
Department of Neuro-Psychiatry, Faculty of Medicine, Tottori University, Yonago 683, Japan
In order to examine the correlation between the severity of dementia and the brainstem transmission time (BTT), brainstem auditory evoked potentials (BAEPs) were measured. This study was conducted on 60 female patients with dementia, aged 80.7 ± 6.6 years on average. The normal control group consisted of 7 normal elderly women without dementia, whose mean age was 78.6 ± 4.9 years. The measured parameters of BAEPs included the interpeak latencies (IPLs) of I-III, III-V and I-V. The results are outlined as follows: (a) The IPLs of I-III became longer as dementia became severer. There were significant differences, in particular, between the normal group and severe dementia group, and between the mild dementia group and the severe dementia group (P < 0.05). (b) The IPLs of III-V also became longer as dementia became severer. The values in the 3 dementia groups were significantly higher than those in the normal group (P < 0.05). (c) The IPLs of I-V became longer as dementia became severer. Especially, the differences between the normal group and the 3 dementia groups, and between the mild and the severe groups were significant (P < 0.05–0.01). There was a significantly negative correlation between the IPLs of I-V and the scores obtained on the dementia rating scale (r=–0.354227, P < 0.01). Based upon the above results, the BTT became loner as dementia became severer suggesting that the brainstem dysfunction might progress with the severity of dementia.
Key words: brainstem auditory evoked potentials; severity of dementia; brainstem transmission time