Upper Limb Motor Function Affects the Outcome after Treatment with Botulinum Toxin A.

Background: Treatment with Botulinum toxin A (BoNT-A) is effective in decreasing upper limb spasticity.

Objective: This study aimed to determine the differences in the outcome based on the upper limb motor function before BoNT-A treatment.

Methods: The subjects were 61 patients who underwent BoNT-A treatment for upper limb spasticity. Limb function was evaluated using the Fugl-Meyer Assessment upper extremity (FMA-UE), modified Ashworth scale, passive range of motion and disability assessment scale before treatment as well as 2, 6, and 12 weeks after treatment. We divided the total and each subscale of FMA-UE before BoNT-A administration into beyond-the-mean-score group (higher score group) and below-the-mean-score group (lower score group).

Results: In both the higher and lower score groups of the FMA-UE total and modified Ashworth scale scores improved significantly after treatment. In FMA-UE, the higher score group of subscale A improved significantly, but subscale C decreased significantly at 2 and 6 weeks after the administration. The lower score group of total, subscale A, and B improved significantly. In the disability assessment scale, the self-dressing capability at 6 weeks and limb position at 2, 6 and 12 weeks after the administration improved significantly in the higher score group. In the lower score group, the hygiene capability at 2 weeks as well as the dressing capability and limb position improved significantly at 2, 6 and 12 weeks after administration.

Conclusions: The time course after administration of BoNT-A differed based on upper limb motor function before injection. When administering BoNT-A into the finger flexor muscles of a patient, we should carefully judge the indications for administration.