FOURTEEN AND SIX PER SECOND POSITIVE SPIKES —A Further Consideration of the Clinical Significance of This Pattern and Some Comments for Recording and Interpretation—

Abstract

SummaryFrom the analysis of 230 cases with 14 and 6 per second positive spikes, the following was found:1) Fourteen per second positive spikes were commonly found in young individuals, whereas 6 per second positive spikes were commonly found in aged individuals. Unusually fast frequency components of positive spikes (18–28 per second) were seen in 9 cases, all less than 17 years of age.2) The appearance of positive spikes was more common over the right hemisphere (84 cases) than over the left hemisphere (46 cases). Focal EEG abnormalities other than positive spikes tended to appear in the hemisphere where positive spikes were not seen. Two out of 10 cases which showed consistent lateralized positive spikes in serial records had hemiparesis and showed voltage suppression over the hemisphere where positive spikes were not seen.3) Epilepsy (93 cases), particularly autonomic epilepsy (51 cases) was most frequently found.4) The frequent occurrence of a history of head trauma (95 cases) was presumed to be the most common etiology of positive spikes.5) Mecholyl tests done in the 24 cases showed 15 S‐type, 8 N‐type and 1 P‐type. The above results were discussed. In addition, some techniques for recording positive spikes were also presented and the interpretation of positive spikes was described.