Differences Between First and Second Electroconvulsive Treatments Given in the Same Session

For the first and second of two bilateral ECTs given under the same anesthesia, judgments were made of the durations of four seizure-induced phenomena: tonic-clonic motor activity, paroxysmal EEG activity, EEG spike waves, and tachycardia. A total of 36 pairs of treatments were given to 14 patients. Pearson correlation coefficients between each of six possible pairs of these four measures were higher for the first ECTs than for the second ECTs (p < 0.05 to p < 0.001). These results suggest that the seizure associated with the second ECT under the same anesthesia is physiologically different from that of the first ECT and is less well generalized through the brain.