The incidence of 6c/s spike and wave or wave and spike phantom(WSP) was examined by administration of diphenhydramine hydrochloride(DPHm). And the nature of 6c/s spike and wave or WSP was studied. 1. There were 787 subjects, all of whom were healthy young males with a mean age of 24.4years. The incidence of WSP in these subjects before administration of DPHm was 1.0% . Of these, 470 subjects were given DPHm. The incidence of WSP after DPHm administration was 16.4% . WSP incidence after DPHm administration was much higher than that of routine EEG recordings. 2. Dosage of DPHm were 0.5mg/kg(N=52), 1.0mg/kg(N=72), 1.5mg/kg(N=189), 2.0mg/kg(N=157). The incidence of WSP did not vary with the dosage. 3. Comparisons were made between the WSP positive and negative subjects in past histories, Cornell Medical Index results and in the basic activity of each EEG recordings. No significant differences were observed in these parameters. 4. Ninety-five subjects were injected first with DPHm 1.5mg/kg. Bemegride (Bg) was administered to the subjects showing WSP after DPHm injection. One hundred nine-teen other subjects were injected first with Bg 50mg. Subjects showing paroxysmal discharges with spike components after Bg were given DPHm 1.5mg/kg. The incidence after Bg and the incidence after DPHm were closely resembled each other. 5. These wave forms provoked by both DPHm and Bg administration were compared in the same individual. DPHm induced almost exclusively WSP form. Bg mainly showed atypical spike and wave form. Thus the author speculated that the WSP and the atypical spike and wave are the continuum. 6. Carefull attention should be given to the clinical diagnosis in cases where WSP has been demonstrated only by DPHm. 7. WSP after DPHm administration should be considered as a subclinical electrical manifestation. The incidence was very different according to age. 8. This study showed the possibility of DPHm having the property of the active activator.
wave and spike phantom(WSP)