Effects of 3 Cycles of Increasing Botulinum Toxin Doses on Functional Parameters of Post-stroke Spastic Gait: A Prospective Cohort Study

BackgroundSingle botulinum toxin type A (BT-A) injections reduce spasticity, but the effects of repeated injections on walking activities remain unclear.ObjectivesTo demonstrate cumulative effectiveness of progressively higher doses of BT-A on walking activities (primary outcome) and spasticity reduction.Methods32 individuals with lower-limb spasticity impairing gait post-stroke were included in this prospective cohort study. Participants received 3 injections of increasing doses of Inco BT-A (400-600-800 U) in both upper and lower limbs and were followed for 7 months. Activity evaluations included the 10 MWT, 6MWT, TUG, and a timed stairs test (TST). Spasticity was assessed using the Modified Ashworth (MAS) and Modified Tardieu (MTS) scales.ResultsActivities remained stable after the 1st injection but improved after the 2nd and 3rd cycles on the 6MWT (+0.07 and +0.12 m/s, respectively, p < 0.05) and TST (-13.7 s and -14.8 s, respectively, p < 0.05). Spasticity significantly reduced after each injection cycle, with greater reductions after the 2nd and 3rd cycles.ConclusionsRepeated, progressively higher doses of Inco BT-A in lower-limb spasticity post-stroke improved walking activities and reduced spasticity, more so after successive cycles and higher doses. This could suggest cumulative effects, better effects due to higher doses, or both. This supports the use of progressively higher doses to thoroughly treat spasticity patterns.clinicaltrials.gov : NCT04544280.