Effectiveness of botulinum neurotoxin type A injections in naïve and previously-treated patients suffering from Torti- or Laterocollis or -caput: Results from a German-Austrian open-label prospective post-marketing surveillance study.

AbobotulinumtoxinA (aboBoNT-A; Dysport®) is an effective treatment for cervical dystonia (CD) with a well-established safety profile. In this prospective, multicentre, non-interventional study (NCT01840462) the primary objective was effectiveness (Tsui score) of aboBoNT-A in botulinum neurotoxin type A (BoNT-A) treatment-naïve and previously-treated (>2 yrs) patients after two injection cycles (at visit 3). Secondary objectives included the effectiveness of aboBoNT-A overall visits and quality of life (CDQ-24) in different CD subtypes. Observation time was 12-16 months, including 5 visits and 4 injection cycles (each 3-4 months). In the analysis population 273 patients from 41 centres across Germany and Austria were included. At baseline, 62.6% were previously-treated with BoNT-A. The major primary components of CD were torticollis (64.5%) and torticaput (17.6%). Previously-treated patients showed a slight reduction of the Tsui scores, whereas BoNT-A-naïve patients had a more severe baseline Tsui score and improved much more over all cycles. Results were similar for CDQ-24. Interestingly, improvements mainly occurred in the Tsui subscore A (amplitude of sustained posture). Marked differences between CD subtypes regarding effectiveness could not be determined. To our knowledge this is the first large multi-centre study investigating the effectiveness of BoNT-A in different primary subtypes of CD over several injection cycles.