Long-term treatment of cervical dystonia with botulinum toxin A: efficacy, safety, and antibody frequency

• DOI: 10.1007/s004150050345
• Publication Date: 2002-08-25T08:36:27Z
• Authors: Kirn R. Kessler; Michael Skutta; R. Benecke
• Keywords: Adult; Male; Adolescent; Middle Aged; 3. Good health; Dystonia; 03 medical and health sciences; Treatment Outcome; 0302 clinical medicine; Neuromuscular Agents; Neck Muscles; Humans; Female; Botulinum Toxins, Type A; Deglutition Disorders; Aged; Follow-Up Studies

Data from 616 patients suffering from idiopathic cervical dystonia were analyzed to determine the efficacy and safety of treatment with botulinum neurotoxin type A (BoNT/A). Since the specific purpose of this study was to determine the long-term effects of this treatment, the analysis focused specifically on the patients (n = 303) having received six or more injections. Statistical analysis of a standardized documentation showed sustained significant benefit as measured by a disease severity score independent of the type of cervical dystonia. Furthermore, pronounced individual differences were found in response to this treatment although initial clinical scores and doses of BoNT/A were similar. There was no indication of previously unknown adverse events, the only risk being the development of serum antibodies against the toxin. As in previous studies on short-term effects of BoNT/A treatment, the most frequent adverse event was dysphagia, which occurred on average 9.7 days after injection and lasted on average 3.5 weeks. While secondary nonresponse was seen in approx. 5% of patients, antibody tests revealed neutralizing serum antibodies in only 2%. On the basis of the present data, therapy of cervical dystonia with BoNT/A seems to be safe and yields good stable results even after 5 years of treatment.