Clinical effectiveness of spinal cord stimulation in managing refractory upper-extremity pain

Spinal cord stimulation (SCS) is an effective therapy for intractable pain, but it is used less frequently for upper extremity than for lower limb pain. Evidence supporting SCS for the upper extremity remains limited. This study evaluated the efficacy of SCS for severe refractory upper extremity pain. Thirteen patients with refractory upper extremity pain underwent a trial of SCS. Eleven patients, who achieved marked pain relief during the trial, proceeded to permanent implantation. We collected clinical characteristics and outcomes, including numeric pain rating scale (NPRS) measurements. We then compared pain reduction among subgroups: neural versus non-neural lesions, and complex regional pain syndrome (CRPS) versus non-CRPS. In the 11 implanted patients, the mean NPRS score decreased from 9.5 of 10 preoperatively to 3.6 of 10 postoperatively (p < 0.001). Analysis showed significant pain improvement in each subgroup (p < 0.05). At last follow-up, the NPRS scores remained below baseline levels in 10 of 11 patients. However, the magnitude of the NPRS score reduction did not differ significantly between neural and non-neural lesions (p = 0.350), or CRPS and non-CRPS (p = 0.245). One participant with CRPS type 2 experienced treatment failure during long-term follow-up. This study demonstrated that SCS effectively alleviates refractory upper extremity pain caused by various etiologies. No single pain etiology, including CRPS, conferred a superior response, suggesting broad potential benefits of SCS in these patients.