Long-Term Abobotulinumtoxin A Treatment of Cervical Dystonia

Botulinum toxin is considered as first-line therapy for cervical dystonia, but few papers have addressed these issues in the long term. Aim of this study was to investigate the long-term efficacy and safety of abobotulinumtoxin A (A/Abo) in patients with primary cervical dystonia. Consecutive patients who received at least six injections with A/Abo were included. Safety was assessed on patients' self-reports. Efficacy was assessed by recording the total duration of benefit, duration of maximum efficacy, disease severity measured by means of the Tsui score, and pain intensity evaluated by means of the visual analog scale (VAS). Thirty-nine patients with PCD were included. The mean dose injected was 701.5 ± 280.6 U. The mean duration of the clinical improvement was 93.0 ± 30.7 days, while the mean duration of the maximum clinical improvement was 77.1 ± 27.1 days. The mean VAS before and 4 weeks after injection was 4.4 ± 1.8 and 1.8 ± 1.6, respectively. The mean Tsui score before and 4 weeks after treatment was 5.7 ± 1.8 and 3.5 ± 1.5, respectively. Doses of A/Abo and duration of the maximum clinical improvement significantly increased over time, while the Tsui score and VAS displayed a tendency to decrease along time. Side effects occurred in 19.6% of all the treatments but were severe in only four injections. The results of our study confirm the effectiveness and safety profile of A/Abo for the long-term treatment of primary cervical dystonia.