Changes in Cortical Activity in Stroke Survivors Undergoing Botulinum Neurotoxin Therapy for Treatment of Focal Spasticity.

Very small sample size of nine stroke participants limits the generalizability of the findings. The observed improvement in arm function was below the minimal clinically important difference, suggesting the clinical benefit may be negligible for individual patients. Physical therapy was prescribed but largely not completed, making it impossible to separate the effects of the injection from any potential therapy effects. Hand movement was not measured during the MRI scan, so differences in movement quality between sessions could have influenced brain activation patterns. Participants were not in their first course of treatment, which may have minimized the potential for significant functional improvement compared to naive patients.

Funding was provided by the Strategic Fund at the Medical College of Wisconsin. The authors declared no commercial or financial conflicts of interest.

Do not interpret the increased brain activation as evidence that botulinum toxin restores hand function. The functional improvement was statistically significant but clinically trivial, and the study was too small to determine if the brain changes are a cause or consequence of the limited recovery.