Comparison of treatment of tardive dystonia and idiopathic cervical dystonia with botulinum toxin type A

To compare clinical parameters of patients treated with botulinum toxin type A (BTX) for treatment of idiopathic cervical dystonia (ICD) and for tardive cervical dystonia (TCD), we studied 156 patients (149 with ICD and 7 with TCD) who were treated with serial injections of BTX over 5 years. We hypothesized thai patients with TCD and ICD would demonstrate similar improvement in severity-scores after treatment with BTX. The diagnosis, dates, dosages, and frequency of BTX injected and severity assessments were recorded into a computerized database, Nonparametric Wilcoxon rank sum and signed-rank tests were used to assess statistical significance. The change in severity scores between the first treatment and last treatment in both groups was not statistically significant (p = 0.4859), indicating similar improvement. The difference in BTX doses was significant (p = 0.0045). ICD patients (n = 149) received an average of 219.8 +/- 63.5 units and those with TCD (n = 7) were treated with an average dose of 287.4 +/- 60.3 units. The average number of days between treatments for individuals with ICD was 142.9 +/- 85.8, similar to that for persons with TCD (144.7 +/- 64.5) (p = 0.6075). Our analysis provides preliminary evidence that the improvement from the administration of BTX for patients with ICD and TCD is similar.