Comparative Effectiveness of Botulinum Toxin Injections and Extracorporeal Shockwave Therapy for Post-Stroke Spasticity: A Systematic Review and Network Meta-Analysis

BACKGROUND: The anti-spasticity efficacy of botulinum toxin (BoNT) injection has been well established for patients with chronic stroke; however, extracorporeal shock wave therapy (ESWT), i.e. focused shockwave (FSW) and radial shockwave (RSW), has recently been applied. We aimed to investigate the comparative effectiveness of BoNT vs. ESWT in the reduction of spasticity among stroke survivors. METHODS: PubMed, EMBASE, MEDLINE and Cochrane CENTRAL were searched from the earliest record to September 2021 for randomized controlled trials. Weighted mean differences (WMDs) on the reduction of the Modified Ashworth Scale before or at the 6th post-treatment week (short-term) and between the 7th and 12th weeks (mid-term) after the intervention were calculated. Ranking probabilities of the WMD were simulated to determine which treatment had the potential to possess the best effectiveness. inplasy.com registration: INPLASY202170018. FINDINGS: A total of 33 studies comprising 1,930 patients were enrolled. The network meta-analysis revealed that BoNT injections, FSW and RSW were better in spasticity reduction than the control treatment(s) at the short term, with WMDs of -0.69 (95% CI, -0.87 to -0.50), -0.36 (95% CI, -0.69 to -0.03) and -0.62 (95% CI, -0.84 to -0.40), respectively. Likewise, mid-term effects of BoNT injections, FSW and RSW also revealed superiority, with WMDs of -0.44 (95% CI, -0.62 to -0.26), -0.74 (95% CI, -1.26 to -0.23) and -0.79 (95% CI, -1.07 to -0.51), respectively. Ranking probability analysis revealed that RSW had the highest probability of being the best treatment for spasticity reduction at the short-term (62.2%) and mid-term (72.3%) periods during the follow up. INTERPRETATION: BoNT injections and ESWT are effective in alleviating post-stroke spasticity at the mid-term. The effectiveness of ESWT was comparable to BoNT injections, and RSW had the potential to be the best treatment for spasticity reduction among the three treatment options. More prospective trials incorporating head-to-head comparisons of BoNT injections vs. ESWT are needed to validate the role of ESWT in reducing post-stroke spasticity. FUNDING: The current research project was supported by (1) National Taiwan University Hospital, Bei-Hu Branch; (2) Ministry of Science and Technology (MOST 106–2314-B-002–180-MY3 and 109–2314-B-002–114-MY3); 3) Taiwan Society of Ultrasound in Medicine.