Effect of intramuscular botulinum toxin injection on upper limb spasticity in stroke patients

Objective: To evaluate the therapeutic effect of intramuscular injection of botulinum toxin on spasticity of the upper limb, with emphasis on its influence over limb function. Design: An open-label, noncontrolled trial with a duration of 12 wk was designed to determine the safety and efficacy of intramuscular botulinum toxin A injection in the treatment of 16 patients with stroke with spastic hemiparesis. Electromyographically guided intramuscular botulinum toxin A injections were applied to the spastic limbs. A detailed scale system was used for the evaluation of muscle tone and functional changes induced by botulinum toxin A treatment. Results: No major side effect secondary to botulinum toxin A injection was reported. Statistically significant (P < 0.05) improvements of muscle tone, joint range of motion, hand muscle strength, and muscular pain were seen after the injection. The improvements lasted up to 8-12 wk after the treatment. However, there was no significant functional improvement except in two of the patients. Conclusions: Botulinum toxin A injection may help relieve upper limb spasticity and pain in patients with stroke. Its effect on function is probably determined by case selection.