Kastytis Dapšys1, Aldona Šiurkutė2, 3, Jūratė Lengvenienė2, Valentinas Mačiulis2, 3
1Republican Vilnius Psychiatric Hospital, Department of Electrophysiological Research and Treatment Methods, Vilnius, Lithuania
2Republican Vilnius Psychiatric Hospital, Vilnius, Lithuania
3Vilnius University Medical Faculty Psychiatric Clinic, Vilnius, Lithuania
Objectives: Recording and analysis of event-related potentials (ERP) can reflect a range of different cognitive processes. ERP P300 is a sensitive indicator of disturbances of attentional and working memory processes. As the study of effect of electroconvulsive therapy (ECT) on non-memory cognitive functions has been relatively neglected, aim of this work was to examine the effect of course of ECT on auditory ERP P300.
Methods: Auditory “oddball” paradigm was applied to elicit P300 potential in 32 patients. 20 patients had schizophrenia spectrum disorders and 12 patients had various mood disorders. Mean age of patients was 42±12 years (from 22 to 72 years). ERPs were recorded before the first ECT procedure and the next day after the last ECT. Recordings were made at Fz, Cz and Pz electrode sites. Peak-to-peak (N2-P3) amplitude and latency of P300 wave were analysed. Correlation between P300 parameters, clinical symptoms (measured using PANSS, MADRS, HAM-D scales) and parameters of ECT procedure – delivered energy, seizure energy index (SEI) and duration of seizure – were evaluated.
Results: There was statistically significant increase in P300 amplitude after the course of ECT. Increase was greater in the young patients (20–39 years old) group. Decrease in P300 latency was insignificant. Correlation between P300 latency and amplitude and qualitative parameters of evoked seizures was more reliable in the mood disorders group. After ECT main clinical symptoms have improved. According to HAM-D the improvement of depression symptoms correlates with the decreased latency and increased amplitude of the P300 potential.
Conclusions: ECT may have beneficial effect on some non-memory cognitive functions in patients with treatment-resistant schizophrenia spectrum disorders and mood disorders as assessed by event-related potential P300.