体性感覚誘発電位(SEP)，視覚性誘発電位(VEP)と脳波に対するcaffeineの効果

The effects of caffeine on central nervous system were investigated with SEP and VEP (EPs). The subjects were 25 healthy male volunteers aged 24-44 with a mean caffeine consumption of 251.4 mg/day, and were divided into the light and heavy consumer groups according to DSM-IV criteria for caffeine intoxication. They were given 3 mg/kg of body weight of caffeine or placebo in a double-blind cross-over design. EEGs containing SEPs evoked by electric stimuli to the right median nerve and VEPs by flash stimuli were recorded before, 30, 60, 90 minutes after dosing. The consecutive changes in EPs and EEG power% were studied and the following results were obtained.
1. Overall subjects had few components with significant changes in latencies and amplitudes of SEP and VEP after administration of caffeine.
2. EEGs recorded together with EPs showed a significant increase in α1 power% and a significant decrease in δ, θ and β２ power%.
3. There were also no significant differences in EPs measures and EEGs between the light and heavy consumer groups, except for EEG power% of VEP with the heavy costumer group showing an earlier appearance of changes.
In conclusion, 3 mg/kg of body weight of caffeine administered in the present study did not effect on SEP and VEP as well as EEGs.