Thalamic deep brain stimulation for neuropathic pain after amputation or brachial plexus avulsion

Abstract

<jats:sec> <jats:title>Object</jats:title> <jats:p>Fifteen hundred patients have received deep brain stimulation (DBS) to treat neuropathic pain refractory to pharmacotherapy over the last half-century, but few during the last decade. Deep brain stimulation for neuropathic pain has shown variable outcomes and gained consensus approval in Europe but not the US. This study prospectively evaluated the efficacy at 1 year of DBS for phantom limb pain after amputation, and deafferentation pain after brachial plexus avulsion (BPA), in a single-center case series.</jats:p></jats:sec> <jats:sec> <jats:title>Methods</jats:title> <jats:p>Patient-reported outcome measures were collated before and after surgery, using a visual analog scale (VAS) score, 36-Item Short-Form Health Survey (SF-36), Brief Pain Inventory (BPI), and University of Washington Neuropathic Pain Score (UWNPS).</jats:p></jats:sec> <jats:sec> <jats:title>Results</jats:title> <jats:p>Twelve patients were treated over 29 months, receiving contralateral, ventroposterolateral sensory thalamic DBS. Five patients were amputees and 7 had BPAs, all from traumas. A postoperative trial of externalized DBS failed in 1 patient with BPA. Eleven patients proceeded to implantation and gained improvement in pain scores at 12 months. No surgical complications or stimulation side effects were noted. In the amputation group, after 12 months the mean VAS score improved by 90.0% ± 10.0% (p = 0.001), SF-36 by 57.5% ± 97.9% (p = 0.127), UWNPS by 80.4% ± 12.7% (p &lt; 0.001), and BPI by 79.9% ± 14.7% (p &lt; 0.001). In the BPA group, after 12 months the mean VAS score improved by 52.7% ± 30.2% (p &lt; 0.001), SF-36 by 15.6% ± 30.5% (p = 1.000), UWNPS by 26.2% ± 40.8% (p = 0.399), and BPI by 38.4% ± 41.7% (p = 0.018). Mean DBS parameters were 2.5 V, 213 microseconds, and 25 Hz.</jats:p></jats:sec> <jats:sec> <jats:title>Conclusions</jats:title> <jats:p>Deep brain stimulation demonstrated efficacy at 1 year for chronic neuropathic pain after traumatic amputation and BPA. Clinical trials that retain patients in long-term follow-up are desirable to confirm findings from prospectively assessed case series.</jats:p></jats:sec>

Deep brain stimulation of the dorsal anterior cingulate cortex for the treatment of chronic neuropathic pain

“…97,102 This theory, although now mostly supplanted by newer models such as the neuromatrix theory of pain, 96,98-100 was instrumental in establishing the central nervous system as an active partner in the development of chronic pain states. Over the past 3 decades, multiple neural targets have been explored for chronic stimulation, including the periaqueductal gray (PAG) region, 57 the ventral posterior lateral and medial thalamic nuclei (VPL/VPM), 114,123 the IC, 1 and, most recently, the dACC.…”

State of the Art: Novel Applications for Deep Brain Stimulation

“…In this small group, all of whom received VPL/PVG DBS, two out of four experienced more than 50% pain relief, but one of these did not want to keep the DBS system implanted. Better outcomes for DBS for phantom limb pain were reported in a case series of 11 patients implanted with VPL DBS for neuropathic limb pain (pain aetiology was either phantom limb pain after amputation or deafferentation pain after brachial plexus avulsion) . In this group, there was an improvement in visual analogue score of 69.6 ± 29.6% 12 months after surgery, which was statistically significant.…”

Neuropathic Pain and Deep Brain Stimulation

“…Comprehensive neuropsychologic evaluation forms best practice in patient selection to exclude psychoses, addiction and medically refractory psychiatric disorders, and to ensure minimal cognitive impairment [67][68][69][70]. Outcomes should be scored using both pain and health-related quality of life indices preoperatively and at regular follow-up; our methods are detailed elsewhere [49,50,71]. The specific etiology of the chronic pain appears less important to efficacy than its symptom history, which may involve hyperalgesia, allodynia, and hyperpathia.…”

“…In the last decade only 6 centers, to our knowledge, have published case series of >6 patients [42][43][44][45][46][47][48][49][50]. Only about 20 groups worldwide have reported long-term efficacy in up to 83 % of patients with follow-ups of up to 6 years (Table 1).…”