Abstract
Several recent studies have been shown that central mechanisms such as abnormality of thalamic activity and hyperactivity of anterior cingulate cortex (ACC) and insula, are involved in the pathogenesis of CRPS type-1. A recent study has demonstrated the efficacy of electro-convulsive therapy (ECT) on neuropathic pain. Despite clinical reports of successful results, the effects of ECT on the regional cerebral blood flow (rCBF) have not been studied.
Purpose: The aim of the present study was to examine the efficacy of ECT in relieving pain in patients with CRPS and to characterize the effect of ECT on the rCBF in the thalamus, ACC and insula using Xenon-CT.
Methods: Three CRPS patients, who had failed to respond to standard pain treatment, received a course of ECT. We measured rCBF of thalamus, ACC, and insula of patients using Xenon-CT before and after ECT.
Results: ECT resulted in excellent resolution of pain in two patients. Both patients had significant decreases in rCBF of the thalamus ipsilateral to the side of pain and significant increases in rCBF of the ACC and the insula. Xenon-CT showed that significant left-right differences in rCBF of the thalamus were abolished after ECT in two responders.
Conclusion: This study suggested that normalization of significant left-right differences in rCBF of the thalamus is related to one of the analgesic mechanisms of ECT on CRPS type-1.
