First Author / Year | Hand Muscles Affected | Intervention/Type of Dose of BTX-A | Type of Assessments/Outcome Measures | Main Results |
---|---|---|---|---|
Tsui (1993) [10] | FDS, FCR, FCU, FPL, EDC, ECU, PT, PQ |
BTX-A injection – dose range 25–50 MU |
1. Self-report assessment of participant writing on a four-point scale 2. Speed and accuracy of pen control 3. Gibson’s maze 4. Copying a standard passage (readability scoring by “blind” physician) |
Self-reported results were modest: 4/20 had definite improvement, 2/20 had slight improvement. 8/12 participants described pain relief after BTX-A. For speed, significant mean change in velocity from baseline to 2 weeks for BTX-A was recorded for horizontal movement (0.17 cm/sec, p < 0.05); for vertical movement (0.9 cm/sec, p < 0.01); and for descending movement (0.39 cm/sec, p < 0.05). Mean time to complete Gibson’s maze significantly improved by 3.23 sec (p < 0.01) at 2 weeks, and by 3.63 sec (p < 0.01) at 6 weeks for participants on BTX-A. |
Cole (1995) [11] | FCR, APL, EPL, FDS, FPL, FCU, FDP, EDC | BTX-A injection – dose range 5–30 MU |
1. Self-report response about improvement and weakness 2. Functional performance testing using: a. MRC scales for muscle power b. Timing of writing sample c. Counting errors of writing “off-the-line” for WC d. Counting the number of errors for a standard transcription for SC e. MC participants played a standard piece of music which was recorded on videotape and assessed by five professors of music |
4/10 participants had major improvement, 5/10 had moderate improvement and 1/10 had no improvement to BTX-A. From MRC testing, 7/10 participants were weaker with BTX-A, 3/10 had no difference in strength after BTX-A, 2/10 had weakness after placebo. 4/6 participants with WC wrote faster after BTX-A. 2/2 participants with SC did not show any improvement in BTX-A compared to placebo. 2/2 participants with MC improved on BTX-A compared to placebo. |
Kruisdijk (2007) [12] | FPL, FDP, EIP | BTX-A injection – 178 MU (range 30–240) Placebo – volume equal to 224 MU (20–280) |
1. Self-response to the question about benefit of treatment 2. Secondary outcome measures included: a. Visual analogue scale (VAS) for handwriting b. Symptom severity scale (SSS) c. Functional status scale (FSS) d. Writer’s cramp rating scale (WCRS) e. Writing speed |
Primary outcome – In the BTX-A group, 14/20 participants wished to continue treatment versus 6/19 participants in the placebo group. Secondary outcome – The mean difference comparing placebo to BTX-A from baseline to 8 weeks of the objective measures were: VAS: 1.32 cm (95% CI, 0.33 to 2.3, p = 0.01) in favor of BTX-A. SSS: -2.44 points (95% CI, -4.52 to -0.37, p = 0.02) in favor of BTX-A. FSS: 2.07 points (95% CI, -0.4 to 4.54, p = 0.1). WCRS: -1.51 points (95% CI, -2.55 to -0.47, p < 0.01) in favor of BTX-A. Writing speed: 1.14 lines (95% CI, 0.07 to 2.20, p = 0.04) in favor of BTX-A. |