Do ictal EEG characteristics predict treatment outcomes in schizophrenic patients undergoing
electroconvulsive therapy?
Sammanfattning
Objective: The aim of this study is to investigate the relationship between features of
electroencephalography (EEG), including seizure time, energy threshold level and post-ictal
suppression time, and clinical variables, including treatment outcomes and side-effects, among
schizophrenia inpatients undergoing electroconvulsive therapy (ECT). Method: This is a naturalistic
follow-up study on schizophrenia patients, diagnosed using DSM-IV-TR criteria, treated by a
psychosis inpatient service. All participants completed the Brief Psychiatric Rating Scale (BPRS), the
Global Assessment of Functioning (GAF) scale, the Frontal Assessment Battery (FAB) and a Data
Collection Form. Assessments were made before treatment, during ECT and after treatment. Findings:
Statistically significant improvements in both clinical and cognitive outcome were noted after ECT in
all patients. Predictors of improvement were sought by evaluating electrophysiological variables
measured at three time points (after the third, fifth and seventh ECT sessions). Logistic regression
analysis showed that clinical outcome/improvement did not differ by seizure duration, threshold
energy level or post-ictal suppression time. Discussion and conclusion: We found that ictal EEG
parameters measured at several ECT sessions did not predict clinical recovery/outcomes. This may
be because our centre defensively engages in "very specific patient selection" when ECT is
contemplated. ECT does not cause short-term cognitive functional impairment and indeed improves
cognition, because symptoms of the schizophrenic episode are alleviated.