Chronic pain with beneficial response to electroconvulsive therapy and regional cerebral blood flow changes assessed by single photon emission computed tomography.

Abstract

Recent neuroimaging studies suggested that chronic neuropathic pain may be largely sustained by a complex neuronal network involving the thalamus. Although recent studies have demonstrated the efficacy of electroconvulsive therapy (ECT) in the treatment of a variety of types of chronic neuropathic pain, the effects of ECT on regional cerebral blood flow (rCBF) have not been studied. We present a 50-year-old female postsurgical chronic pain patient whose pain had failed to respond to standard pain treatment, but was resolved by ECT. To investigate the potential role of rCBF in ECT's analgesic effect, we measured significant changes in the rCBF in the thalamus before and after a course of bilateral ECT using technetium-99m ethyl cysteinate dimer (99mTc-ECD) single photon emission computed tomography (SPECT). 99mTc-ECD SPECT showed a significant bilateral decrease in the thalamus on the side of the pain, and this decreased rCBF in the thalamus increased after ECT. The results from the SPECT suggest that ECT increases abnormally decreased thalamus activity in chronic neuropathic pain.