Poststroke Postural Sway Improved by Botulinum Toxin: A Multicenter Randomized Double-blind Controlled Trial

Area of Science:

• Neurology
• Rehabilitation Medicine
• Biomedical Engineering

Background:

• Stroke survivors often experience hemiparesis, leading to lower limb spasticity and impaired postural control.
• Postural sway, a measure of balance, is significantly affected by spasticity in individuals post-stroke.

Purpose of the Study:

• To evaluate the impact of botulinum toxin injections into lower limb muscles on postural sway in hemiparetic individuals following a stroke.
• To determine the efficacy of botulinum toxin in managing post-stroke lower limb spasticity and its effect on balance.

Main Methods:

• A multicenter, randomized, double-blind, placebo-controlled trial involving 40 participants with chronic post-stroke lower limb spasticity.
• Participants received either botulinum toxin or placebo injections. Postural sway was assessed using center of pressure measurements under various conditions (eyes open, dual task, eyes closed) before and 4-6 weeks after injection.
• Spasticity was quantified using the Modified Ashworth Scale.

Main Results:

• Botulinum toxin treatment led to significant reductions in spasticity in the soleus and gastrocnemii muscles (P=.049 and P=.035, respectively).
• No significant difference in sway area was observed between groups pre-treatment.
• A significant decrease in sway area during the dual-task condition was noted in the botulinum toxin group compared to the placebo group (-3.11±6.92 vs +0.27±3.57, P=.005).

Conclusions:

• Botulinum toxin injections targeting lower limb spasticity in post-stroke hemiparetic individuals can improve postural sway.
• The dual-task assessment paradigm proved to be a sensitive and effective method for detecting improvements in postural control following botulinum toxin treatment.