The Dystonia Discomfort Scale (DDS): a novel instrument to monitor the temporal profile of botulinum toxin therapy in cervical dystonia

Background and purposeConventional 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). MethodsSeventy-six patients with CD (age 54.410.9years, 34% male) receiving 5 cycles of incobotulinumtoxinA (Xeomin((R)); Merz Pharmaceuticals, Frankfurt am Main, Germany) injections at intervals 10weeks 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. ResultsThe Toronto Western Spasmodic Torticollis Rating Scale - Total scores correlated significantly with DDS (P0.028 at all visits evaluated). TO-DDS and TO-SE were 7.9 +/- 8.6 and 7.1 +/- 4.1days, respectively; TW-DDS and TW-SE were 41.8 +/- 19.2 and 45.1 +/- 21.5days, respectively. ConclusionThe 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.