Quality of life in long-term botulinum toxin treatment of cervical dystonia: Results of a cross sectional study

Introduction: Patients' rating of the effectiveness of and quality of life after long-term botulinum toxin (BoNT) injection therapy up to 22 years and treating physician's rating of the therapy effect in patients with idiopathic cervical dystonia (CD) are analysed in a large monocentric cross-sectional study.

Patients and methods: Patients (n = 221) who received uninterrupted, long-term treatment for CD (≥10 BoNT injection cycles) in a BoNT outpatient clinic underwent detailed clinical investigation, Tsui scoring, rated post-treatment CD severity as a percentage of CD severity prior to BoNT injection (patient's subjective scoring of the treatment effect (PSSTE)), and completed the CDQ-24 quality of life (QoL) questionnaire. Correlations between demographics, treatment-related data and QoL were analysed by linear regression, analysis of variance and pairwise single comparisons.

Results: Treating physicians and patients rated mean ongoing treatment effect as >50%. There was high variability of duration of treatment, PSSTE, Tsui score and CDQ-24 across all patients. PSSTE was significantly correlated with Tsui score (p < .001) and all CDQ-24 subscores (p < .003). Tsui score and CDQ-24 were significantly correlated (p < .001), but the correlation was lower than between PSSTE and total CDQ24. CDQ-24 revealed a significant improvement with duration of therapy. PSSTE and Tsui score did not change with duration of BoNT treatment.

Conclusion: Patients with CD who receive up to 22 years' continuous BoNT treatment experience a >50% mean reduction of symptoms and a significant improvement of QoL with duration of treatment. A highly significant correlation exists between patients' and physicians' rating of treatment effectiveness.