Neuroimaging correlates of cognitive disorders secondary to electroconvulsive therapy: A systematic review

Electroconvulsive therapy is known as an efficient therapy, which is sometimes recommended for the management of severe and resistant depression. However, ECT is associated with cognitive adverse effects. The study of the neurobiological correlates of the cognitive adverse effects of ECT has been covered in few published reviews. However, these mechanisms have been investigated in an increasing number of studies in recent years, particularly in neuroimaging. This systematic review of the literature focuses on correlates between changes in structural or functional neuroimaging and impairment of cognitive functions during the ECT treatment.

We conducted a systematic review of the literature using PRISMA methodology. Searches were performed on the Medline and Web of Science databases using the following equation: "electroconvulsive therapy AND (MRI OR fMRI OR DTI OR neuroimaging) AND depression AND cogniti*".

This article highlights the significant heterogeneity of the results. In structural imaging, approximately 50% of the studies did not report any correlation between volumetric changes and neuropsychological changes. In studies that did highlight a correlation, the latter was mainly reported with changes in the hippocampus. From a functional perspective, we highlighted a correlation between changes in the connectivity of the hippocampal region and cognition.

These results demonstrate a growing interest in understanding the neurobiological mechanisms underlying cognitive disorders secondary to ECT treatment. The ultimate aim behind this understanding is to adopt a more effective prevention strategy vis-à-vis these adverse effects.