Transient changes in mismatch negativity after two sessions of electroconvulsive therapy for atypical psychosis: A...

Cognitive abnormalities associated with electroconvulsive therapy (ECT) are limited to the first few days after treatment. Mismatch negativity (MMN) is an event-related potential that reflects an automatic auditory change detection process under nonattention conditions and cognitive function in psychotic disorders and may be trait- or state-dependent. This study aimed to report the changes in MMN and cognitive function after two ECT treatments in a female patient who underwent maintenance ECT for atypical psychosis.

A 67-year-old Japanese woman with atypical psychosis was admitted to our hospital for the maintenance of ECT. She received two ECT treatments. We measured her duration-MMN (MMN-D) at baseline, the day after two ECT treatments, and approximately 40 days after the two ECT treatments. After the two ECT treatments, the peak latency of the MMN on the following day was delayed compared with that before the first ECT treatment. Forty days after the two ECT treatments, the peak latency reverted to the baseline. The Brief Assessment of Cognition in Schizophrenia scores measured at the same time point also showed a similar temporary decrease in scores.

Peak latency prolongation in MMN-D may reflect transient cognitive abnormalities after ECT. MMN can be useful to evaluate cognitive dysfunction, one of the adverse events of ECT. However, future studies are needed to examine the reproducibility and to examine the results in diseases other than atypical psychosis.