Spinal Cord Stimulation for Intractable Pain Following Limb Amputation

Objective: Spinal cord stimulation (SCS) by high-frequency electrical pulses has been used since the early 1970s for relief of chronic intractable pain following limb amputation. The long-term effectiveness of SCS for amputation-related pain with ongoing after-care is reviewed by assessment of all such cases managed over 20 years in the Neurostimulator Clinic at the Royal London Hospital. Materials and Methods: Twelve amputation-related pain patients had quadripolar paddle electrodes (Resume; Medtronic Inc., Minneapolis, MN, USA) inserted epidurally by laminectomy over the thoracic or cervical dorsal spinal cord and connected to remotely controlled subcutaneously implanted stimulators (Itrel2, Itrel3, Synergy; Medtronic). Results: Two of 12 patients had unsuccessful stimulation, one despite repeated electrode revisions. Two were subsequently lost to follow-up, one had delayed spontaneous resolution of phantom limb pain, one had a technical fault, and one had gradually waning benefit over 19 years. In the remaining five patients having ongoing follow-up, self-reported initial and final magnitudes of pain relief were unchanged, with a mean (SD) of 66% (18.2%). Benefits calculated from local and general visual analogue pain scores were similarly unchanged (initial local 48.8% [18.7%]; final local 50.0% [17.6%]; initial general 60.8% [10.9%]; final general 57.9% [12.3%]). Continued successful stimulation often required frequent changes of stimulating electrode contacts. Revision procedures for technical problems or pain at the battery site were universally successful. Conclusions: Successful SCS in some patients with amputation-related pain otherwise resistant to treatment indicates that the procedure merits continued use with further efforts to refine technique.