Table 1.
Use of rating scales in pivotal clinical studies with BoNT treatment for cervical dystonia (studies listed in chronological order)
| References | Study design | BoNT | Number of CD patients | Efficacy outcome measure(s) | Results/remarks |
|---|---|---|---|---|---|
| Placebo-controlled studies | |||||
| Greene et al. (1990) | Randomized, double-blind, placebo-controlled, parallel groups | BoNT-A (Botox®) | 55 | GIR (+3 = markedly improved, −2 = definitely worse); VAS for functional capacity and for pain; degree of head turning; Columbia Torticollis Rating Scale | BoNT-A significantly improved the severity of CD, disability, pain and degree of head turning |
| Brans et al. (1996) | Randomized, double-blind, double-dummy, comparator-controlled, parallel groups | BoNT-A (Dysport®) | 66 | TWSTRS-Disability; TWSTRS-Pain; Tsui score; HRQoL scale | TWSTRS-Disability (primary outcome), Tsui score and HRQoL scale were significantly in favor of BoNT-A compared to trihexiphenidyl |
| Lew et al. (1997) | Randomized, double-blind, placebo-controlled, parallel groups | BoNT-B (Myobloc™/Neurobloc®) | 122 | TWSTRS-Total score; subscores for severity, disability and pain; VAS for pain; VAS for investigator and patient global assessment of change; Sickness Impact Profile scores | TWSTRS-Total score (primary outcome) improved for all treatment groups (including placebo), but BoNT-B was significantly superior. Improvement with BoNT increased with higher doses |
| Poewe et al. (1998) | Randomized, double-blind, placebo-controlled, parallel groups | BoNT-A (Dysport®) | 75 | Tsui score (modified version); pain on 4-point scale; global assessment of improvement post injection; global rating of efficacy; need for retreatment at week 8 | Magnitude of improvement was greatest after 1,000 U BoNT-A, but with significantly more AEs; lower start dose of 500 U BoNT-A is recommended |
| Brin et al. (1999) | Randomized, double-blind, placebo-controlled, parallel groups | BoNT-B (Myobloc™/Neurobloc®) | 77 | TWSTRS-Total score; subscores for severity, disability and pain; VAS for pain; VAS for investigator and patient global assessment of change | Significant difference in favor of BoNT-B for primary (TWSTRS-Total score) and all secondary outcome variables |
| Brashear et al. (1999) | Randomized, double-blind, placebo-controlled, parallel groups | BoNT-B (Myobloc™/Neurobloc®) | 109 | TWSTRS-Total score; subscores for severity, disability and pain; VAS for pain; investigator and patient global assessment of change | The mean improvement in TWSTRS-Total score (primary outcome) was significantly in favor of BoNT-B, but higher for the 10.000 U compared to the 5.000 U dose |
| Truong et al. (2005) | Randomized, double-blind, placebo-controlled, parallel groups | BoNT-A (Dysport®) | 80 | TWSTRS-Total score; subscores for severity, disability and pain; VAS for pain | Improvement in TWSTRS-Total score was the result of improvement in each of the three subscale scores. BoNT-A improved not only head position but also pain and disability |
| Comparator-controlled studies | |||||
| Benecke et al. (2005) | Randomized, double-blind, comparator-controlled, parallel groups | Xeomin® versus Botox® | 463 | TWSTRS-Severity; TWSTRS-Pain; VAS for pain; 9-point Global Response Scale; responder rates; investigator global assessment of efficacy | Improvement in TWSTRS-Severity score (primary outcome) 4 weeks after Xeomin® was non-inferior to Botox® |
| Pappert and Germanson (2008) | Randomized, double-blind, comparator-controlled, parallel groups | BoNT-A vs. BoNT-B | 111 | TWSTRS-Total score; subscores for severity, disability and pain; VAS for pain; investigator and patient global assessment | Improvement in TWSTRS-Total score (primary outcome) 4 weeks after BoNT-B was non-inferior to BoNT-A |
AEs adverse events; BoNT botulinum neurotoxin; GIR Global Improvement Rating; HRQoL health-related quality of life; TWSTRS Toronto Western Spasmodic Torticollis Rating Scale; U units; VAS Visual Analogue Scale