Oral Zinc Supplementation to Enhance Botulinum Neurotoxin Response

Botulinum neurotoxin (BoNT) is injected into muscles for treatment of dystonia. BoNTs are zinc proteases, and their enzymatic effect is reduced in the setting of low zinc. The study hypothesis is that a large enough fraction of unselected dystonia patients receiving BoNT injection have suboptimal zinc concentration in their tissues, and will experience improved response to BoNT if the injection is preceded by oral zinc supplementation (OZS). OZS consists of 50 mg of zinc acetate oral tablet each day for 7 days before injection. This is a double blind placebo controlled cross-over study, randomized order placebo and OZS, in patients at a neurology clinic on stable dose of BoNT.