Abnormalities of cortical thickness in postictal psychosis

Postictal psychosis (PIP), the occurrence of psychotic episodes following a seizure, is a common and serious comorbidity in patients with epilepsy. Yet, the anatomical correlates remain poorly defined. Here, we used quantitative MRI morphometry to identify structural abnormalities in the cortex of patients with PIP relative to patients with epilepsy without PIP and age- and gender-matched normal healthy controls. Comparison of patients with epilepsy and PIP with patients with epilepsy without PIP revealed increased cortical thickness in the right lateral prefrontal cortex, right anterior cingulate cortex, and right middle temporal gyrus. The PIP group was distinguished from the EC and NC groups by thicker cortex in the right rostral anterior cingulate cortex and thinner cortex in the right angular gyrus and the left middle temporal region. Findings indicate that PIP is associated with thickening of the right anterior cingulate cortex, which may serve as a marker for patients at risk for developing PIP.

Research highlights
► Previous findings of regional cortical thinning in epilepsy are confirmed.
► Cortex of patients with postictal psychosis is preserved or thickened relative to cortex of controls with epilepsy.
► Patients with postictal psychosis differed from both control groups in having thickened cortex in the rostral anterior cingulate cortex.