Background and purpose: Conventional scales measure the effect of botulinum toxin (BT) therapy only at specific points in time. The Dystonia Discomfort Scale (DDS), a novel, easy-to-use, self-assessment scale to record temporal profiles of the effect of BT therapy in cervical dystonia (CD), is introduced and evaluated against the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS). Methods: Seventy-six patients with CD (age 54.4 AE 10.9 years, 34% male) receiving ≤5 cycles of incobotulinumtoxinA (Xeomin; Merz Pharmaceuticals, Frankfurt am Main, Germany) injections at intervals ≥10 weeks used DDS to record the severity of their symptoms daily. DDS data were compared with TWSTRS-Total scores and patients' subjective estimation (SE) of the onset (TO) and waning (TW) of the treatment effect. Results: The Toronto Western Spasmodic Torticollis Rating Scale À Total scores correlated significantly with DDS (P ≤ 0.028 at all visits evaluated). TO-DDS and TO-SE were 7.9 AE 8.6 and 7.1 AE 4.1 days, respectively; TW-DDS and TW-SE were 41.8 AE 19.2 and 45.1 AE 21.5 days, respectively. Conclusion: The Dystonia Discomfort Scale is a novel, easy-to-use, self-assessment scale for valid and sensitive monitoring of the temporal profile of the effect of BT therapy in patients with CD. DDS provides important additional information about onset, duration, waning, stability and reproducibility of the effects of BT therapy.
IntroductionLocal injections of botulinum toxin (BT) are effective and well tolerated in the symptomatic treatment of focal dystonias, including cervical dystonia (CD) [1][2][3]. The therapeutic effect of BT in CD follows a typical time course [4]. It builds up within 1-2 weeks, is maintained at a plateau for 6-8 weeks and then gradually fades over 2-6 weeks. Conventional scales such as the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) [5] or the Tsui Scale [6] are based on specific points in time measurements of the effect of BT therapy. Frequent measurements would allow construction of temporal profiles; however, as they require physicians' ratings, this would not be feasible. The Dystonia Discomfort Scale (DDS) (available at http://www.dds.iabnetz.de/) , a novel, easy-touse scale to monitor BT therapy in CD [7], is therefore introduced. Based on patients' daily self-assessments, DDS allows construction of temporal profiles which provide important additional information about onset, duration, waning, stability and reproducibility of the effects of BT therapy.To test the validity and sensitivity of DDS, it was evaluated against the TWSTRS and the patient's subjective estimation (SE). Data evaluated were collected as part of a clinical long-term study of incobotulinumtoxinA for the treatment of CD [8].
Methods
DesignThis prospective, open-label, single-arm, multicentre study (NCT00541905) was conducted at 17 centres in
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