Capsaicin 8% patch treatment for amputation stump and phantom limb pain: a clinical and functional MRI study

Abstract

PurposeThe aim of this study was to measure the efficacy of a single 60 min application of capsaicin 8% patch in reducing chronic amputation stump and phantom limb pain, associated hypersensitivity with quantitative sensory testing, and changes in brain cortical maps using functional MRI (fMRI) scans.MethodsA capsaicin 8% patch (Qutenza) treatment study was conducted on 14 patients with single limb amputation, who reported pain intensity on the Numerical Pain Rating Scale ≥4/10 for chronic stump or phantom limb pain. Pain assessments, quantitative sensory testing, and fMRI (for the lip pursing task) were performed at baseline and 4 weeks after application of capsaicin 8% patch to the amputation stump. The shift into the hand representation area of the cerebral cortex with the lip pursing task has been correlated with phantom limb pain intensity in previous studies, and was the fMRI clinical model for cortical plasticity used in this study.ResultsThe mean reduction in spontaneous amputation stump pain, phantom limb pain, and evoked stump pain were −1.007 (p=0.028), −1.414 (p=0.018), and −2.029 (p=0.007), respectively. The areas of brush allodynia and pinprick hypersensitivity in the amputation stump showed marked decreases: −165 cm2, −80% (p=0.001) and −132 cm2, −72% (p=0.001), respectively. fMRI analyses provided objective evidence of the restoration of the brain map, that is, reversal of the shift into the hand representation of the cerebral cortex with the lip pursing task (p<0.05).ConclusionThe results show that capsaicin 8% patch treatment leads to significant reduction in chronic pain and, particularly, in the area of stump hypersensitivity, which may enable patients to wear prostheses, thereby improving mobility and rehabilitation. Phantom limb pain (“central” pain) and associated brain plasticity may be modulated by peripheral inputs, as they can be ameliorated by the peripherally restricted effect of the capsaicin 8% patch.

Effects of Chronic Pain Treatment on Altered Functional and Metabolic Activities in the Brain: A Systematic Review and Meta-Analysis of Functional Neuroimaging Studies

“…We also summarized whether they monitored and reported adverse events caused by the treatments for chronic pain. Among 75 studies, we found that 12 studies monitored and reported treatment-related adverse events (Walitt et al, 2007 ; Gustin et al, 2010 ; Tillisch et al, 2012 ; Petzke et al, 2013 ; Boyer et al, 2014 ; Li et al, 2015 ; Zhao et al, 2015 , 2018 ; Zhang et al, 2016 ; Pinto-Sanchez et al, 2017 ; Privitera et al, 2017 ; Tetreault et al, 2018 ), and 7 studies monitored but did not report adverse events in the articles (Harris et al, 2013 ; Taylor et al, 2013 ; Jensen K. B. et al, 2014 ; Flodin et al, 2015 ; Sanders et al, 2015 ; Geha et al, 2016 ; Rogachov et al, 2019 ).…”

<p>Rational treatment of chemotherapy-induced peripheral neuropathy with capsaicin 8% patch: from pain relief towards disease modification</p>

“…The study involved hospital visits and telephone calls, as shown in Figure 1. Patients attended the hospital unit for study visits 1 to 3, and the application of the capsaicin 8% patches was carried out in the hospital as previously described in detail, with illustrations 67. The capsaicin 8% patches covered the feet and distal calf, including the region of the pretreatment baseline skin biopsies, after they had fully healed.…”

“…Capsaicin is an agonist which acts on TRPV1, the heat and capsaicin receptor, and recent advances in the understanding of its mechanism and site of action have been reviewed 66. Our recent study showed its effect and mechanisms in amputation stump pain and phantom limb syndrome 67…”

Capsaicin 8% dermal patch in clinical practice: an expert opinion

“…The therapeutic efficacy of the high-concentration 8% capsaicin dermal patch for the treatment of PNP has been assessed in patients with PDPN and in nondiabetic patients with PNP of various etiologies, including PHN and HIV-AN, both in large, randomized clinical trials (Tables 1 and 2) [35][36][37][38][39][40][41][42][43][44][45][46][47], and in 'fieldpractice' experiences (Tables 3-6) [8,[48][49][50][51][52][53][54][55][56][57][58][59][60][61][62][63][64][65][66][67].…”

“…d Mean change from baseline to week 2 [56], week 4 [51], week 8 [53], and week 52 [68]. If not otherwise specified: mean change in pain score from baseline to week 2 [49]; weeks 2-8 [53]; weeks 2-12 [55,56,58,61,62,; week 4 [51]; week 8 [54]; week 12 [59,63], and month 6 [68].…”