Low-dose treatment of cervical dystonia, blepharospasm and facial hemispasm with albumin-diluted botulinum toxin type A under EMG guidance. An open label study

Abstract

Several studies support the hypothesis that low-dose botulinum toxin treatment may be as beneficial as high-dose regimen. Therefore, we studied 115 patients (aged 27-84; mean 58.0, SD = 12.9 years; 68% females, 32% males) suffering from cervical dystonia (n = 66), blepharospasm (n = 28), and facial hemispasm (n = 21) over a period of 2 years in an open label, non-controlled pilot study. Patients received low-dose treatment with botulinum toxin type A (Dysport((R))). The toxin was diluted in 20 ml of 0.1% albumin solution to arrive at a concentration of 25 MU/ml and injected under EMG control. Patients responded to the treatment about 1 week after injection (mean 7.3 days, SD = 4.6). The mean duration of beneficial effects was 11.7 weeks (SD = 5.6). Patients evaluated the clinical global improvement on a scale ranging from 0 to 4. For the whole population, the mean was 2.7 points (SD = 1.1). In none of the subjects could antibodies to botulinum toxin type A be detected, and only a few side effects were observed. In conclusion, low-dose therapy with botulinum toxin A merits further controlled studies.