Brain bioelectrical activity changes in patients with poststroke depression and apathy

Abstract

Objective: to study the specific features of brain bioelectrical activity in patents with poststroke apathy and depressive disorders. Patients and methods. The investigation enrolled 175 patients (84 men and 91 women) with new-onset cerebral stroke at different sites. A total of 107 (61%) patients of them were observed to have depressive disorders (n=41 (38%)) and apathy (n=66 (62%)) within a year after disease onset. A control group included 68 (39%) patients without poststroke affective disorders. The mean age of the study group patients was 66±10 years and that of the control patients was 68±11 years. The severity and magnitude of neurological deficit were evaluated using the U.S. National Institutes of Health Stroke Scale (NIHSS). The patients underwent electroencephalography (EEG), brain computed tomography and magnetic resonance imaging. The investigators used diagnostic and statistical manual of mental disorders (DSM-IV) criteria to diagnose depression and the Hamilton depression rating scale (HAM-D) and the mini-mental status examination (MMSE) to evaluate the mental status. The basic rhythmic power indices in the affected and unaffected hemispheres were calculated, as well as anteroposterior alpha rhythm distribution coefficient and interhemispheric asymmetry coefficient. Results and discussion. The computer EEG analysis was shown to identify the hallmark characteristics of brain bioelectric activity in patients with different types of affective disorders in the acute, early and late recovery periods of stroke. The patients with affective disorders were found to have brain bioelectrical activity changes predominantly in the rapid frequency sub-band on EEG, suggesting midbrain structural dysfunction. In the patients with poststroke depression, depressive disorder scale scores were related to the power of bioelectric activity in the slow and alpha frequency bands manly in the acute stroke period whereas those were correlated with the EEG beta band power in the delayed period.