[Myths and evidence on the use of botulinum toxin: neuropharmacology and dystonia].

INTRODUCTION: Botulinum toxin type A (BTA) is a bacterial endotoxin, whose therapeutic use has had a dramatic impact on different neurological disorders, such as dystonia and spasticity.

AIM: To analyze and summarize different questions about the use of BTA in our clinical practice.

DEVELOPMENT: A group of experts in neurology developed a list of topics related with the use of BTA. Two groups were considered: neuropharmacology and dystonia. A literature search at PubMed, mainly for English language articles published up to June 2016 was performed. The manuscript was structured as a questionnaire that includes those questions that, according to the panel opinion, could generate more controversy or doubt. The initial draft was reviewed by the expert panel members to allow modifications, and after subsequent revisions for achieving the highest degree of consensus, the final text was then validated. Different questions about diverse aspects of neuropharmacology, such as mechanism of action, bioequivalence of the different preparations, immunogenicity, etc. were included. Regarding dystonia, the document included questions about methods of evaluation, cervical dystonia, blepharospasm, etc.

CONCLUSION: This review does not pretend to be a guide, but rather a tool for continuous training of residents and specialists in neurology, about different specific areas of the management of BTA.