Improving botulinum toxin efficiency in treating post-stroke spasticity using 3D innervation zone imaging

Chuan Zhang, Yen Ting Chen, Yang Liu, Elaine Magat, Monica Gutierrez-Verduzco, Gerard E. Francisco, Ping Zhou, Sheng Li, Yingchun Zhang

Research output: Contribution to journalArticlepeer-review

11 Scopus citations


Spasticity is a common post-stroke syndrome that imposes significant adverse impacts on patients and caregivers. This study aims to improve the efficiency of botulinum toxin (BoNT) in managing spasticity, by utilizing a three-dimensional innervation zone imaging (3DIZI) technique based on high-density surface electromyography (HD-sEMG) recordings. Stroke subjects were randomly assigned to two groups: the control group (n = 6) which received standard ultrasound-guided injections, and the experimental group (n = 6) which received 3DIZI-guided injections. The amount of BoNT given was consistent for all subjects. The Modified Ashworth Scale (MAS), compound muscle action potential (CMAP) and muscle activation volume (MAV) from bilateral biceps brachii muscles were obtained at the baseline, 3 weeks, and 3 months after injection. Intra-group and inter-group comparisons of MAS, CMAP amplitude and MAV were performed. An overall improvement in MAS of spastic elbow flexors was observed during the 3-week visit (p < 0.01), yet no statistically significant difference found with intra-group or inter-group analysis. Compared to the baseline, a significant reduction of CMAP amplitude and MAV were observed in the spastic biceps muscles of both groups at 3-week post-injection, and returned to approximate baseline value at 12-week post injection. A significantly higher reduction was found in CMAP amplitude (34.71±5.42% versus 20.92±6.73%, p < 0.01) and MAV (71.51±8.20% versus 44.33±21.81%, p < 0.05) in the experimental group compared to the control group. The study has demonstrated preliminary evidence that precisely directing BoNT to the innervation zones (IZs) localized by 3DIZI leads to a significantly higher treatment efficiency improvement in spasticity management. Results have also shown the feasibility of developing a personalized BoNT injection technique for the optimization of clinical treatment for post-stroke spasticity using proposed 3DIZI technique.

Original languageEnglish (US)
Article number2150007
Pages (from-to)2150007
JournalInternational Journal of Neural Systems
Issue number4
StatePublished - Apr 2021


  • 3D source imaging
  • Stroke
  • botulinum toxin
  • high-density surface electromyography
  • innervation zone
  • spasticity
  • Stroke/complications
  • Muscle Spasticity/diagnostic imaging
  • Humans
  • Treatment Outcome
  • Neuromuscular Agents/therapeutic use
  • Botulinum Toxins, Type A/therapeutic use
  • Electromyography

ASJC Scopus subject areas

  • Computer Networks and Communications


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