Comparison in Therapeutic Outcome of Ultrasound-guided Botulinum Injections for Limb Spasticity Versus Dystonia.

Background: Botulinum toxin (BT) can alleviate limb dystonia, but limited insurance coverage hinders its utilization.

Objectives: To compare the therapeutic efficacy of BT injections for spasticity and dystonia of the limbs.

Methods: BT injections of hypertonic limbs were administered under ultrasound guidance between 2019 and 2024 for either limb dystonia or limb spasticity.

Results: Of 74 patients included, 57 were diagnosed with spasticity and 17 with dystonia. In total, 276 therapeutic cycles were administered. The dropout rates were 45.6% in the spasticity group and 41.2% in the dystonia group (P = 0.48). There was no significant difference in subjective motor improvement between dystonia and spasticity (P = 0.16). Dystonia patients reported significantly better pain relief (98.5 ± 4.9% vs. 72.4 ± 35.6% respectively, P < 0.001). Notably, 74.3% of dystonia treatments reported moderate or marked improvement, whereas only 54.0% of spasticity treatments did (P > 0.05), based on patient the global impression of change (PGI-C) scale. Side effects were infrequent.

Conclusions: BT injections for limb spasticity and dystonia are partially effective. Nonetheless, the dropout rate is high. While BT injections are more effective in relieving pain for dystonia compared to spasticity, disease severity gradually improves over time in treated patients with spasticity but not with dystonia.