Long-Term Results of Cortical Motor Stimulation for Neuropathic Peripheral and Central Pain: Real-World Evidence From Two Independent Centers.

Background And Objectives: Cortical motor stimulation (CMS) is used to modulate neuropathic pain. The literature supports its use; however, short follow-up studies might overestimate its real effect. This study brings real-world evidence from two independent centers about CMS methodology and its long-term outcomes.

Methods: Patients with chronic refractory neuropathic pain were implanted with CMS. The International Classification of Headache Disorders 3rd Edition was used to classify craniofacial pain and the Douleur Neuropathique en 4 Questions Scale score to explore its neuropathic nature. Demographics and clinical and surgical data were collected. Pain intensity at 6, 12, and 24 months and last follow-up was registered. Numeric rating scale reduction of ≥50% was considered a good response. The Clinical Global Impression of Change scale was used to report patient satisfaction.

Results: Twelve males (38.7%) and 19 females (61.3%) with a mean age of 55.8 years (±11.9) were analyzed. Nineteen (61.5%) were diagnosed from painful trigeminal neuropathy (PTN), and seven (22.5%) from central poststroke pain. The mean follow-up was 51 months (±23). At 6 months, 42% (13/31) of the patients were responders, all of them being PTN (13/19; 68.4%). At last follow-up, only 35% (11/31) remained responders (11/19 PTN; 58%). At last follow-up, the global Numeric rating scale reduction was 34% ( P = .0001). The Clinical Global Impression of Change scale punctuated 2.39 (±0.94) after 3 months from the surgery and 2.95 (±1.32) at last follow-up ( P = .0079). Signs of suspicious placebo effect were appreciated in around 40% of the nonresponders.

Conclusion: CMS might show long-term efficacy for neuropathic pain syndromes, with the effect on PTN being more robust in the long term. Multicentric clinical trials are needed to confirm the efficacy of this therapy for this and other conditions.