Effective Treatment of Neurological Symptoms with Normal Doses of Botulinum Neurotoxin in Wilson's Disease: Six Cases and Literature Review.

Background: Recent cell-based and animal experiments have demonstrated an effective reduction in botulinum neurotoxin A (BoNT/A) by copper.
Aim: We aimed to analyze whether the successful symptomatic BoNT/A treatment of patients with Wilson's disease (WD) corresponds with unusually high doses per session.
Methods: Among the 156 WD patients regularly seen at the outpatient department of the university hospital in Düsseldorf (Germany), only 6 patients had been treated with BoNT/A during the past 5 years. The laboratory findings, indications for BoNT treatment, preparations, and doses per session were extracted retrospectively from the charts. These parameters were compared with those of 13 other patients described in the literature.
Results: BoNT/A injection therapy is a rare (<4%) symptomatic treatment in WD, only necessary in exceptional cases, and is often applied only transiently. In those cases for which dose information was available, the dose per session and indication appear to be within usual limits.
Conclusion: Despite the evidence that copper can interfere with the botulinum toxin in preclinical models, patients with WD do not require higher doses of the toxin than other patients with dystonia.