Assessing the neurophysiological effects of botulinum toxin treatment for adults with focal limb spasticity: a systematic review

Disabil Rehabil. 2012;34(2):91-100. doi: 10.3109/09638288.2011.591882. Epub 2011 Sep 27.


To examine effectiveness of botulinum toxin therapy (BoNT), accurate quantification of the neurological component of underlying spasticity is needed.

Purpose: Systematically identify and summarize literature on neurophysiological methods to test the effectiveness of BoNT, discuss methodological aspects, and recommend best techniques for clinical and research settings.

Methods: Electronic databases were searched using specific keywords. Reviews and reference lists were hand-checked to find relevant studies. Studies in adults with focal limb spasticity were included.

Results: Over 300 articles were scanned for relevance, and a list of 90 relevant articles was made. After excluding reviews and studies in healthy controls or non-spasticity related BoNT, 22 articles were reviewed. Neurophysiological techniques included electromyography (EMG; n = 11), electrical nerve stimulation (n = 13), transcranial magnetic stimulation (TMS; n = 1), functional magnetic resonance imaging (fMRI; n = 1), reflex threshold (n = 4), Achilles tendon reflex (n = 1), reflex latency (n = 1).

Discussion: Maximum M-wave amplitude (M-max) and stretch reflex threshold techniques were successfully used to measure the neurophysiological effects of BoNT and have high test-retest reliability. EMG techniques require effective magnitude normalization techniques and establishing test-retest reliability.

Conclusion: Serial electrical nerve stimulation can be incorporated into clinical practice to assist in follow-up. We recommend using M-max and stretch reflex threshold techniques to assess the neurophysiological effects.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review
  • Systematic Review

MeSH terms

  • Adult
  • Anti-Dyskinesia Agents / therapeutic use*
  • Botulinum Toxins / therapeutic use*
  • Electric Stimulation
  • Electromyography
  • Humans
  • Lower Extremity / physiopathology
  • Muscle Spasticity / drug therapy*
  • Muscle, Skeletal / drug effects
  • Muscle, Skeletal / innervation
  • Neurophysiology


  • Anti-Dyskinesia Agents
  • Botulinum Toxins