Vol 54, No 6 (2020)
Research Paper
Published online: 2020-10-12

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Botulinum toxin type A for hand tremor: a meta-analysis of randomised controlled trials

Xiaoyan Zheng1, Wenjing Wei1, Peidong Liu1, Chunxiao Wu1, Liming Lu1, Chunzhi Tang1
Pubmed: 33047784
Neurol Neurochir Pol 2020;54(6):561-567.


Background. Tremor is one of the most common movement disorders. It does not usually respond to first-line drug treatments (e.g. propranolol, primidone, anticholinergics, gabapentin and clonazepam) due to side effects and frequent dose limitations. Botulinum toxin type A (BoNT-A) has been widely used to treat tremor, but its efficacy and safety are uncertain.

Aims. To evaluate the efficacy and safety of BoNT-A in the treatment of hand tremor.

Methods. We searched the MEDLINE, EMBASE, PsycINFO and Cochrane Library databases for relevant randomised controlled trials of the effects of BoNT-A injections on tremors, up to 20 February 2020. A meta-analysis of comparative effects was performed using R studio software, and publication bias was examined using Egger’s test.

Results. Six studies examining a total of 245 participants with tremor were included in the meta-analysis. The primary outcome of meta-analysis showed no difference in clinical tremor scale scores between the BoNT-A group versus the placebo group (standardised mean difference (SMD): -0.42, 95% confidence interval (CI): -1.94 to 1.10; I2 = 96%). For clinical tremor scale scores, subgroup analyses suggested that the BoNT-A group may differ in terms of multiple sclerosis (MS) related tremor (SMD: -1.10; 95% CI: -2.17 to -0.04; I2 = 79%) compared to a placebo, but the difference did not exist in the outcome of essential tremor (ET) or hand tremor (MD: -1.31; 95% CI: -3.39; 1.31; I2 = 97%). Grip strength (MD: -1.25, 95% CI: -5.99 to 3.50, I2 = 97%) was slightly lower in the BoNT-A group, but the difference was not significant. The incidence of adverse events (AEs), including hand weakness (RR: 2.96, 95% CI: 1.40 to 6.24, I2 = 37%), was significantly greater in the BoNT-A group than in the placebo group. Two studies were assessed as having an overall low risk of bias.

Conclusions. Our study confirms that BoNT-A injections are unlikely to have an impact on patients with hand tremors. However, subgroup analysis suggested that BoNT-A injections could have possible benefits in MS-related tremor. While moderate to severe hand weakness AEs often limits their use in clinical practice, additional well-designed double-blind, placebo-controlled trials are needed to provide more robust conclusions.

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  1. Elias WJ, Shah BB. Tremor. JAMA. 2014; 311(9): 948–954.
  2. Liu HC, Wang SJ, Fuh JL, et al. The Kinmen Neurological Disorders Survey (KINDS): A Study of a Chinese Population. Neuroepidemiology. 1997; 16(2): 60–68.
  3. Larsson T. Sjogren T, Essential tremor: a clinical and genetic population study. Acta Psychiatr Scand Suppl, 1960. 36(144): p. : 1–176.
  4. Louis ED, Ferreira JJ. How common is the most common adult movement disorder? Update on the worldwide prevalence of essential tremor. Mov Disord. 2010; 25(5): 534–541.
  5. Pringsheim, T., , The prevalence of Parkinson's disease: a systematic review and meta-analysis. Mov Disord, 2014. 29(13): p. : 1583–90.
  6. Labiano-Fontcuberta A, Benito-León J. Understanding Tremor in Multiple Sclerosis: Prevalence, Pathological Anatomy, and Pharmacological and Surgical Approaches to Treatment. Tremor and Other Hyperkinetic Movements. 2012; 2(0): 02.
  7. Lyons KE, Pahwa R. Pharmacotherapy of essential tremor : an overview of existing and upcoming agents. CNS Drugs. 2008; 22(12): 1037–1045.
  8. Baizabal-Carvallo JF, Jankovic J. Movement disorders induced by deep brain stimulation. Parkinsonism Relat Disord. 2016; 25: 1–9.
  9. Schneider SA, Deuschl G. The treatment of tremor. Neurotherapeutics. 2014; 11(1): 128–138.
  10. Koller WC, Vetere-Overfield B. Acute and chronic effects of propranolol and primidone in essential tremor. Neurology. 1989; 39(12): 1587–1588.
  11. Wasielewski PG, Burns JM, Koller WC. Pharmacologic treatment of tremor. Mov Disord. 1998; 13 Suppl 3: 90–100.
  12. Atuah, K.N., D. Hughes and M. Pirmohamed, Clinical pharmacology: special safety considerations in drug development and pharmacovigilance. Drug Saf, 2004. 27(8): p. : 535–54.
  13. Niemann N, Jankovic J. Botulinum Toxin for the Treatment of Hand Tremor. Toxins (Basel). 2018; 10(7).
  14. Savović J, Weeks L, Sterne JAC, et al. Evaluation of the Cochrane Collaboration's tool for assessing the risk of bias in randomized trials: focus groups, online survey, proposed recommendations and their implementation. Syst Rev. 2014; 3: 37.
  15. Brin MF, Lyons KE, Doucette J, et al. A randomized, double masked, controlled trial of botulinum toxin type A in essential hand tremor. Neurology. 2001; 56(11): 1523–1528.
  16. Jankovic J, Schwartz K, Clemence W, et al. A randomized, double-blind, placebo-controlled study to evaluate botulinum toxin type A in essential hand tremor. Mov Disord. 1996; 11(3): 250–256.
  17. Mittal S, Machado D, Richardson D, et al. Botulinum Toxin in Parkinson Disease Tremor. Mayo Clinic Proceedings. 2017; 92(9): 1359–1367.
  18. Van Der Walt A, Sung S, Spelman T, et al. A double-blind, randomized, controlled study of botulinum toxin type A in MS-related tremor. Neurology. 2012; 79(1): 92–99.
  19. Mittal SOm, Machado D, Richardson D, et al. Botulinum toxin in essential hand tremor - A randomized double-blind placebo-controlled study with customized injection approach. Parkinsonism Relat Disord. 2018; 56: 65–69.
  20. Boonstra FMC, Evans A, Noffs G, et al. OnabotulinumtoxinA treatment for MS-tremor modifies fMRI tremor response in central sensory-motor integration areas. Mult Scler Relat Disord. 2020; 40: 101984.
  21. Ferreira J, Costa J, Coelho M, et al. The management of cervical dystonia. Expert Opinion on Pharmacotherapy. 2007; 8(2): 129–140.
  22. Zakin E, Simpson D. Botulinum Toxin in Management of Limb Tremor. Toxins (Basel). 2017; 9(11).
  23. Safarpour Y, Jabbari B. Botulinum Toxin Treatment of Movement Disorders. Curr Treat Options Neurol. 2018; 20(2): 4.
  24. Wood L, Egger M, Gluud LL, et al. Empirical evidence of bias in treatment effect estimates in controlled trials with different interventions and outcomes: meta-epidemiological study. BMJ. 2008; 336(7644): 601–605.