Phantom Remodeling Effect of Dorsal Root Entry Zone Lesioning in Phantom Limb Pain Caused by Brachial Plexus Avulsion

Abstract

Background: Dorsal root entry zone (DREZ) lesioning has been reported to be effective for phantom limb pain caused by brachial plexus avulsion pain. Most reports on DREZ lesioning for brachial plexus avulsion pain have focused on the results of pain relief without a detailed description of phantom sensations following DREZ lesioning. Materials and Methods: Two patients (1 with amputation and the other nonamputated) with chronic intractable phantom limb pain caused by brachial plexus avulsion underwent DREZ lesioning on the avulsed segments of the cervical spinal cords. Changes of the phantom limb were observed. Results: Immediately following DREZ lesioning, the phantom limb pain disappeared in the amputee, the phantom arm was shortened and the phantom hand disappeared. The other patient with the nonamputated arm reported an immediate 50% reduction in the size of the phantom hand, and pain relief was up to 70% of the preoperative phantom limb pain. There was no further change in the phantom arm and hand during the follow-up of 1.5-2 years. Conclusions: The phantom arms and hands showed a prompt shortening and reduction in size, rather than a disappearance, following successful DREZ lesioning in patients with chronic phantom limb pain caused by brachial plexus avulsion.