Microcoagulation of Junctional Dorsal Root Entry Zone is Effective Treatment of Brachial Plexus Avulsion Pain: Long-term Follow-up Study

Aim: To analyze long-term clinical results of coagulation lesions of the dorsal root entry zone (DREZ) in patients with deafferentation pain due to brachial plexus avulsion and to correlate the pain relief after DREZ coagulation with pain duration before the DREZ coagulation. Methods: Twenty-six patients with intractable deafferentation pain after brachial plexus avulsion lesion were treated for pain at the Department of Neurosurgery. Junctional coagulation lesion was made with bipolar forceps along the DREZ. The patients assessed post-operative analgesic effect using a visual analog scale at 1 week, 1 year, 3 years, and 5 years after the surgery. Results: The greatest pain relief was reported immediately after the DREZ procedure. Over the 5-year follow-up period, the pain relief effect gradually and significantly decreased. There were no significant differences between the pain relief evaluated at 1 week and after 1 year and between the pain relief evaluated at 1 week and after 3 years. There was a correlation between the pain duration before the surgery and pain relief after the surgery, with best correlation found between pain duration before surgery and pain relief 5 years after DREZ procedure (r = 0.623, P = 0.007). Conclusion: The long-term follow up showed that the pain relief gradually decreased over 5 years after surgery. However, the pain relief still did not significantly decrease after 3 years