Pain and brachial plexus lesions: evaluation of initial outcomes after reconstructive microsurgery and validation of a new pain severity scale

Background Peripheral nerve lesions usually are associated with neuropathic pain. In the present paper, we describe a simple scale to quantify pain after brachial plexus injuries and apply this scale to a series of patients to determine initial outcomes after reconstructive surgery. Methods Fifty-one patients with traumatic brachial plexus avulsion injuries were treated over the period of one calendar year at one center by the same surgical team. Of these, 28 patients who were available for follow-up reported some degree of neuropathic pain radiating towards the hand or forearm and underwent reconstructive microsurgery and direct pain management, including trunk and nerve neurolysis and repair. A special pain severity rating scale was developed and used to assess patients' pain before and after surgery, over a minimum follow-up of 6 months. An independent researcher, not part of the surgical team, performed all pre- and postoperative evaluations. Findings Of the 28 patients with brachial plexus traction injuries who met eligibility criteria, 93% were male, and most were young (mean age, 27.6 years). The mean preoperative severity of pain using our scale was 30.9 out of a maximum of 37 (±0.76 SD), which fell to a mean of 6.9 (±0.68 SD) 6 months post-procedure. On average, pain declined by 78% across the whole series, a decline that was statistically significant (p<.001). Subset analysis revealed similar improvements across all the different parameters of pain. Conclusions We have designed and tested a simple and reliable method by which to quantify neuropathic pain after traumatic brachial plexus injuries. Initial surgical treatment of the paralysis—including nerve, trunk and root reconstruction, and neurolysis—comprises an effective means by which to initially treat neuropathic pain. Ablative or neuromodulative procedures, like dorsal root entry zone, should be reserved for refractory cases.