Effects of electrode placement on symptoms, memory, and sustainment of results after electroconvulsive therapy- A comparative study

The memory-related side-effects rank among the strongest reasons for hostility against Modified Electroconvulsive Therapy (MECT). Most of the studies comparing the Unilateral v/s Bilateral Electrode placements on memory have been conducted on patients with depression while very few studies have been conducted on patients with psychosis in the Indian population. To compare the effects of right unilateral (RU/L) and bilateral (B/L) MECT on the severity of symptoms as well as memory in patients with psychosis after the fourth session and two weeks after the final session of the MECT. One hundred patients having a psychotic illness were randomized into either RU/L or B/L group. Comprehensive psychopathological rating scale (CPRS), clinical global impressions scale (CGI-S), and PGI-memory scale were applied before starting of MECT, after four sessions of MECT and two weeks after the last session of ECT. The results show similar symptomatic improvement in patients receiving RU/L and B/L MECT and the results persisted beyond the therapy sessions. But, in the case of RU/L-MECT group, the deterioration in memory was less as compared to the B/L-MECT group. Both groups had no significant difference in psychopathology and its severity (CPRS and CGI). Both groups were significantly different in memory side effects after the fourth session and two weeks after the last session. Both groups showed a consistent downward trend in psychopathology and its severity. The consistent fall in the total PGI scores remained even after two weeks of the final session in the B/L group (total of six points as compared to baseline) while it came to baseline levels in the RU/L group. Both groups differed significantly in total PGI scores after the fourth session and two weeks after the final session. This study points toward a favorable outcome in the case of therapeutic response with MECT without any significant difference between both types of electrode placements and even after stopping MECT, the improvement appears to be stable over time. Although, there was a side-effect of memory impairment, it appears to be for a shorter duration and it improves with time. The side-effect profile of RU/L electrode placement is lower as compared to bilateral placement. In the post-MECT period, the patients receiving MECT with RU/L electrode placement showed better improvement in memory functions.