Factors affecting the health-related quality of life of patients with cervical dystonia and impact of treatment with abobotulinumtoxinA (Dysport): results from a randomised, double-blind, placebo-controlled study

OBJECTIVE To describe the health-related quality of life (HRQOL) burden of cervical dystonia (CD) and report on the HRQOL and patient perception of treatment benefits of abobotulinumtoxinA (Dysport). DESIGN The safety and efficacy of a single injection of abobotulinumtoxinA for CD treatment were evaluated in a previously reported international, multicenter, double-blind, randomised trial. HRQOL measures were assessed in the trial and have not been previously reported. SETTING Movement disorder clinics in the USA and Russia. PARTICIPANTS Patients had to have a diagnosis of CD with symptoms for at least 18 months, as well as a total Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) score of at least 30; a Severity domain score of at least 15; and a Disability domain score of at least 3. Key exclusion criteria included treatment with botulinum toxin type A (BoNT-A) or botulinum toxin type B (BoNT-B) within 16 weeks of enrolment. INTERVENTIONS Patients were randomised to receive either 500 U abobotulinumtoxinA (n=55) or placebo (n=61). PRIMARY AND SECONDARY OUTCOME MEASURES Efficacy assessments included TWSTRS total (primary end point) and subscale scores at weeks 0, 4, 8, 12; a pain visual analogue scale at weeks 0 and 4; and HRQOL assessed by the SF-36 Health Survey (SF-36; secondary end point) at weeks 0 and 8. RESULTS Patients with CD reported significantly greater impairment for all SF-36 domains relative to US norms. Patients treated with abobotulinumtoxinA reported significantly greater improvements in Physical Functioning, Role Physical, Bodily Pain, General Health and Role Emotional domains than placebo patients (p≤0.03 for all). The TWSTRS was significantly correlated with Physical Functioning, Role Physical and Bodily Pain scores, for those on active treatment. CONCLUSIONS CD has a marked impact on HRQOL. Treatment with a single abobotulinumtoxinA injection results in significant improvement in patients' HRQOL. TRIAL REGISTRATION NUMBER The trial is registered at ClinicalTrials.gov, numbers NCT00257660 and NCT00288509.