Intramuscular botulinum toxin-A reduces hemiplegic shoulder pain: a randomized, double-blind, comparative study...

Shoulder pain is frequent after stroke and interferes with the rehabilitative process and outcome. However, treatments used for hemiplegic shoulder pain are limited and largely ineffective. This prospective, randomized, double-blind controlled study was conducted to compare the efficacies of botulinum toxin type A (BoNT-A) and triamcinolone acetonide (TA) on hemiplegic shoulder pain and their effects on arm function in patients with stroke.

Twenty-nine hemiplegic stroke patients with shoulder pain (duration or=6/10) were randomized into 2 groups. One group received intramuscular injections of BoNT-A (BOTOX 100 U total) during one session to the infraspinatus, pectoralis and subscapularis muscles in conjunction with an intraarticular injection of normal saline to painful shoulder joint, whereas the other group received an intraarticular injection of TA (40 mg) and an intramuscular injection of normal saline to the same muscles. Outcome measures were pain (measured using a numeric rating scale), physician's global rating scale, shoulder range of motion (ROM) in 4 directions, arm function measured using Fugl-Meyer score, and spasticity measured using the modified Ashworth scale. Measurements were made at baseline and 2, 6, and 12 weeks after injection.

At 12 weeks after treatment mean decrease in pain was 4.2 in the BoNT-A-treated group versus 2.5 in the TA-treated group (P=0.051), and improvements in overall ROM were 82.9 degrees versus 51.8 degrees in these groups (P=0.059), showing a strong trend toward there being less pain and better ROM among those treated with BoNT-A than with TA. However, no significant differences were observed between the 2 groups in terms of improvement in physician global rating, Fugl-Meyer score or modified Ashworth scales. No adverse effect was observed in either group.

Results from this study suggest that injection of BoNT-A into selected muscles of the shoulder girdle might provide more pain relief and ROM improvement than intraarticular steroid in patients with hemiplegic shoulder pain. A larger clinical trial needs to be undertaken to confirm the benefits of this approach.