Treatment of refractory pain after brachial plexus avulsion with dorsal root entry zone lesions. (Medical School Hannover, Hannover, Germany) Neurosurgery. 2001;48:1269–1275.

Abstract

Forty‐seven patients with intractable pain after traumatic cervical root avulsions were treated with dorsal root entry zone coagulation between 1980 and 1998. The dorsal root entry zone coagulation procedure was performed 4 months to 12 years after the trauma, and patients were monitored for up to 18 years. Immediately after surgery, 75% of the patients experienced significant pain reduction; this value was reduced to 63% during long‐term follow‐up monitoring. Nine patients experienced major complications including subdural hematomas and motor weakness of the lower limb. Improved coagulation electrodes with thermistors that could produce smaller and more accurate lesion sizes, which were introduced in 1989, significantly reduced the number of complications. Conclude that long‐term follow‐up monitoring of patients who underwent the dorsal root entry zone coagulation procedure in the cervical cord indicated that long‐lasting satisfactory relief is possible for the majority of individuals with acceptable morbidity rates.Comment by Ron Pawl, M.D. This paper is important for several reasons. It provides a long‐term follow‐up on patients suffering intractable pain after cervical nerve root avulsion from the cord, and results of dorsal root entry zone lesioning using the thermocoagulation technique, where lesions are made at 1 mm intervals covering the length of the cord and one level above and one below the levels of the roots involved. Thirty‐nine of 47 patients had 63% reduction of pain in follow‐up of 2 to 18 years (14 year average). The authors also reported that 9 patients experienced major complications including subdural hematomas and lower extremity weakness, which they attribute to the electrodes used to make the lesions prior to 1989. Using an improved electrode since that time, they report fewer complications. Also, the authors note no correlation between the duration of the pain, the time between the trauma and the surgery, and the time of onset of the pain after trauma with the outcome of the surgery, indicating the procedure is effective, even when carried out years after the onset of the pain. This last concept puts a damper on the idea of centralized pain memory as the mechanism for the chronic pain.