Table 1.
Summary of studies of botulinum toxin (BTX) for central neuropathic pain.
| Author, Year | Study Design | Sample Size (N) | Diagnosis | Injection Site/Dose | Follow up | Pain Measure | Results |
|---|---|---|---|---|---|---|---|
| Jabbari, 2003 [55] | Case series | 2 | SCI | Subcutaneous injection at the site of allodynia/BTX-A 16–20 U/site | VAS | Pain was decreased; frequency of severe spontaneous pain was reduced | |
| Han, 2014 [56] | Case report | 1 | SCI | Subcutaneous injection in the painful foot/BTX-A | Week 4 | VAS | Pain severity and the frequency of burst was reduced |
| Han, 2016 [57] | Double-blind, randomized controlled study | 40 | SCI | Subcutaneous injection/BTX-A 200 U | Week 4, 8 | VAS (100 mm), McGill Pain Questionnaire | Pain was reduced significantly in BTX-A treated group |
| Yelnik, 2007 [58] | Double-blind, randomized controlled study | 20 | stroke | Subscapularis muscle/BTX-A 500 U/injection + physical therapy | Week 1, 2, 4 | verbal scale (10 point) | Pain improvement with BTX-A from first week |
| Marco, 2007 [59] | Double-blind, randomized controlled study | 31 | stroke | Pectoralis major muscle/BTX-A 500 U/injection + TENS for 6 weeks | Week 1, 4, 12, 24 | VAS (100 mm) | Significantly greater pain improvement from the first week in BTX group |
| Kong, 2007 [60] | Double-blind, randomized controlled study | 17 | stroke | Pectoralis major, biceps brachii muscles/BTX-A 500 U | Week 4, 8, 12 | VAS (0–10) | No difference in shoulder pain |
| Lim, 2008 [61] | Double-blind, randomized controlled study | 29 | stroke | Infraspinatus, pectoralis and subscapularis muscles + IA saline injection; IA triamcinolone (40 mg) injection + saline to the same muscles/BTX-A 100 U | Week 2, 6, 12 | NRS | Significantly greater pain improvement in the BTX-A–treated at 12 weeks |
| Boer, 2008 [62] | Double-blind, randomized controlled study | 22 | stroke | Subscapular muscle/BTX-A 50 U, twice | Week 6, 12 | VAS (vertical 100 mm) | No significant changes in pain |
| Shaw, 2011 [63] | Double-blind, randomized controlled study | 333 | stroke | Elbow, wrist and finger flexor muscles/ BTX-A, 4 times/injection + physical therapy 4 weeks | Week 4, 12, 48 | verbal scale, NRS | Significant decrease at 12 months in the BTX group |
| Castiglione, 2011 [8] | Pilot study | 5 | stroke | IA shoulder joint/BTX-A 500 or 100 units | Week 2, 8 | VAS | Decreased pain at 2 and 8 weeks after BTX-A injection |
| Marciniak, 2012 [64] | Double-blind, randomized controlled study | 21 | stroke | Pectoralis major ± teres major muscles/BTX-A 140–200 units | Week 2, 4, 12 | VAS | Decreased pain scores at 4 weeks |
| Choi, 2016 [65] | Retrospective, unblinded, uncontrolled study | 6 | stroke | Subscapularis muscle/BTX-A | Week 1, 2, 4, 8 | PI-NRS | Pain improvement with BTX-A injection |
| Carroll, 2009 [66] | Double-blind, randomized controlled study | 18 | CRPS | LSB/Bupivacaine 0.5% + 75 units of BTX-A | Week 4 | VAS (10 cm) | The rate of pain return was significantly lower after LSB with BTA |
| Safarpour, 2010 [67] | Double-blind, randomized controlled study Uncontrolled, unblinded, open-label study | 14 (6 control) | CRPS | Intradermally and subcutaneously into the allodynic area/ 5 units per site (total 40–200 units) | Week 3, 8 | Brief pain inventory, PIQ, McGill pain questionnaire, QST, patients satisfaction scale | No significant response after injection; study terminated prematurely because of intolerance |
| Kharkar, 2011 [68] | Retrospective, unblinded, uncontolled study | 37 | CRPS | Upper limb girdle muscles/BTX-A 10–20 units per muscle (total 100 units) | Week 4 | Likert scale (11 point) | 43% decrease in local pain scores |
| Safarpour, 2010 [69] | Case series | 2 | CRPS | Trigger point in the proximal muscle/BTX-A 20 units per site | □ | VAS (1–10) | Alleviate both myofascial pain syndrome and the distal allodynia, discoloration and, tissue swelling |
| Birthi, 2012 [70] | Case report | 1 | CRPS | Subcutaneous injection on the dorsum of the hand/BTX-A 5 units per site (total 100 units) | weekly, 12 weeks | McGill Pain Questionnaire | Able to decrease daily opioid medication by 20% at 8th week; pain returned to baseline at 12th week |
| Choi, 2015 [71] | Case series | 2 | CRPS | Lumbar sympathetic block/levovupivacaine 0.25% + 5000 units of BTX-B | Week 8 | VAS, LANSS | Pain intensity and LANSS score were significantly reduced |
| Buonocore, 2017 [72] | Case report | 1 | CRPS | TP, FDL, FHL muscles, tibial nerve around the tarsal tunnel/BTX-A 120 units per muscle, twice | Week 36 | □ | Significant decrease in the frequency of acute dysesthesias |
SCI: Spinal cord injury; CRPS: Complex regional pain syndrome; VAS: Visual analog scale; NRS: Numeric rating scale; IA: Intra-articular; LANSS: Leeds assessment of neuropathic symptoms and signs; LSB: Lumbar sympathetic block; TP: Tibialis posterior; FDL: Flexor digitorum longus; FHL: Flexor hallucis longus.