Improvements in both psychosis and motor signs in Parkinson's disease, and changes in regional cerebral blood flow after electroconvulsive therapy

Abstract

Psychotic symptoms in Parkinson's disease (PD) are relatively common and, in addition to creating a disturbance in patients' daily lives, have consistently been shown to be associated with poor outcome. The use of anti-PD medications has been the most widely identified risk factor for PD psychosis (PDP). However, the pathophysiology of PDP remains unclear. Although the efficacy of electroconvulsive therapy (ECT) for PD had been pointed out, only one study has demonstrated the effectiveness of ECT on both psychotic symptoms and motor symptoms. The aim of this study was to examine the acute effectiveness of ECT on PD and to identify the brain areas associated with PDP. The study was conducted at Juntendo University Hospital in Tokyo. Eight patients with L-DOPA- or dopamine (DA) agonist-induced PDP, who were resistant to quetiapine treatment, were enrolled. Severity of PD was evaluated using the Hoehn and Yahr stage. Psychotic symptoms were evaluated using multiple measures from the Scale for the Assessment of Positive Symptoms (SAPS). Technetium-99m ethyl cysteinate dimer single photon emission computed tomography (99mTc ECD SPECT) was used to assess regional cerebral blood flow (rCBF) before and after a course of ECT. A voxel-by-voxel group analysis was performed using Statistical Parametric Mapping (SPM5). Our study clearly demonstrated that PDP was significantly less severe after ECT than before ECT, as indicated by change in mean SAPS total domain score (t=7.2, P=0.0002). Furthermore, the patients showed significant improvement in Hoehn and Yahr stage after ECT (t=11.7, P<0.0001). A further notable observation was significant increase in rCBF in the right middle frontal gyrus after ECT. We conclude that a course of ECT produced notable improvements not only in PDP but also in the severity of PD. The findings of change in rCBF suggest implications for dysfunction in the middle frontal region for patients with PDP.