EEG spindle bursts from hippocampus

Abstract

Abstract This paper reports the case of an epileptic patient who underwent memory testing (delayed matching to sample and paired associates) during electrical recording and stimulation from depth electrode arrays placed for lateralization and localization of seizure onset. EEG recordings from the left, but not right, depth electrodes in mid hippocampus (anterior-posterior) showed an unusual pattern of four bursts of high-voltage spindle activity associated with verbal responses required during the recognition phase of delayed matching to sample tasks on 48 of 51 trials. No such pattern of bursts was observed on longer delayed (180 s) visual-verbal paired associate tasks. Spindle bursts occurred in distinct grouping patterns, only when minimal overt verbal response to object recognition was required, but not under other dissociating situations.