The study included 7 Russian research centers (41 patients). Sixteen patients (39%) received BoNT-A injections prior to entering the study. During the treatment, 29 patients (70.7%) received dysport injections; 2 (4.9%) botox injections, 8 (19.5%) xeomin injections and 2 (4.9%) other BoNT-A agents. The primary treatment goals were successfully attained in 87.8%, secondary treatment goals in 88.3%. An improvement in passive function as primary goal and as secondary goal were achieved in 100%, in the range of movement in 94.9%, pain reduction in 82.4%, improvement in active function of the upper limb in 76.5%, reduction in involuntary movements (associated reactions) in 83.3% of cases. Investigators' global assessment of benefits revealed that 97.6% of patients showed positive effects from BoNT-A injections. Pateitnts' assessment of global benefits was slightly lower - 90,2% of patients reported positive treatment effects When assessed by patients, the rate of global benefits was 90.2%. Botulinum-toxin therapy is an effective treatment option. In the vast majority of patients, it allows both for reduction in muscle tone and functional benefits that could improve quality of life of the patients.

In the Russian population, patients with a ≥ 25% improvement by TWSTRS scale at visit 2 (peak effect) accounted for 88.3%. Most of patients (81.6%) and physicians (81.7%) evaluated the efficacy of therapy as a «significant improvement» or «very significant improvement» by CGI. The criterion of the effect duration was achieved in 50% of cases. The BTA therapy was well tolerated (no severe AEs related to treatment) in 98.3% of patients. Overall, 40% of all patients met all the criteria for response to BTA treatment. According to the analysis of the general population, a high degree of response was observed for the effect size (73.6%), tolerability (97.5%) and patient-reported global clinical improvement (69.8%). Subjective assessment of the duration of the effect was achieved in 49.3% of patients, with 28.6% of patients considered as responders. Most patients met three of the four criteria. The proposed multifactorial definition of «response» may be of practical use for routine practice.