Comparing the real-world effectiveness of botulinum toxin type A injections across distinct poststroke muscle...

Post-stroke muscle hyper-resistance is produced by both neurogenic (spasticity) and non-neurogenic (contracture) factors. BoNT-A is the most effective intervention for post-stroke spasticity, yet whether concomitant contracture alters its therapeutic benefit remains unclear.

To compare BoNT-A effectiveness in plantar-flexor hyper-resistance stratified by contracture.

We retrospectively reviewed stroke survivors with spastic hemiplegia and ankle plantar-flexor hyper-resistance who received BoNT-A injections. Patients were stratified into two groups according to the presence of restricted passive ankle dorsiflexion: the spasticity group (PROM limitation <7°) and the spasticity-with-contracture group (PROM limitation ≥7°). Outcomes were assessed at baseline and at 2, 4 and 12 weeks post-injection, including the Modified Ashworth Scale (MAS) for plantar-flexors, Brunnstrom Recovery Stage (BRS), Fugl-Meyer Assessment (FMA) lower-extremity subscore and Barthel Index (BI).

A total of 107 patients were enrolled-54 in the spasticity group and 53 in the spasticity-with-contracture group. Baseline comparison revealed a significantly longer disease duration in the spasticity-with-contracture group; other characteristics were comparable. Both groups achieved improvements in MAS and BRS at all three follow-up visits. FMA and BI improved in the spasticity group at 4 and 12 weeks, whereas the spasticity-with-contracture group showed improvement only at 12 weeks. Between-group analyses indicated that MAS and BRS scores were consistently better in the spasticity group at each time point; although median FMA and BI were numerically higher in this group, the differences did not reach statistical significance.

BoNT-A markedly reduces post-stroke hyper-resistance and enhances motor function and activities of daily living; by contrast, concomitant contracture is associated with delayed and attenuated improvement in MAS and BRS.