Background: While spasticity is commonly treated with oral agents or botulinum neurotoxin (BoNT) injection, these treatments have not been systematically compared.
Methods: We performed a randomized, double-blind, placebo-controlled trial to compare injection of BoNT-Type A into spastic upper limb muscles versus oral tizanidine (TZD), or placebo, in 60 subjects with upper limb spasticity due to stroke or traumatic brain injury (TBI). Wrist flexors were systematically injected, while other upper limb muscles were injected as per investigator judgment. Participants were randomized into three groups: 1: Intramuscular BoNT plus oral placebo; 2: Oral TZD plus intramuscular placebo; 3: Intramuscular placebo plus oral placebo. The primary outcome was the difference in change in wrist flexor modified Ashworth score (MAS) between groups. Other outcome measures included MAS at elbow and finger joints, disability assessment scale (DAS), and adverse events (AE).
Results: BoNT produced greater tone reduction than TZD or placebo in finger and wrist flexors at week 3 (p < 0.001 vs TZD; p < 0.02 vs placebo) and 6 (p = 0.001 vs TZD; p= 0.08 vs placebo), and greater improvement in the cosmesis domain of the DAS at week 6 (p < 0.01). TZD was not superior to placebo in tone reduction at either time point (p ≥ 0.09). The incidence of AE related to study treatment was higher with TZD than in the BoNT (p <0.01) or placebo groups (p=0.001).
Conclusions: BoNT is safer and more effective than TZD in reducing tone and disfigurement in upper extremity spasticity, and may be considered as first line therapy for this disorder.