Botulinum toxin physiology in focal hand and cranial dystonia.

Barbara Illowsky Karp

doi:10.3390/toxins4111404

Abstract

The safety and efficacy of botulinum toxin for the treatment of focal hand and cranial dystonias are well-established. Studies of these adult-onset focal dystonias reveal both shared features, such as the dystonic phenotype of muscle hyperactivity and overflow muscle contraction and divergent features, such as task specificity in focal hand dystonia which is not a common feature of cranial dystonia. The physiologic effects of botulinum toxin in these 2 disorders also show both similarities and differences. This paper compares and contrasts the physiology of focal hand and cranial dystonias and of botulinum toxin in the management of these disorders.

Highlights

Focal hand dystonia and cranial dystonia share the phenotypic features of uncontrolled involuntary muscle contraction leading to abnormal postures characteristic of all dystonias
They differ, in the anatomic distribution of focal dystonia symptoms, and in age of onset, prevalence, gender predilection, and pathways implicated in their pathophysiology
While the safety and efficacy of botulinum toxin for the treatment of these focal dystonias have been established through controlled clinical trials and over 20 years of use [2], their response to botulinum toxin treatment reveals both shared features and divergent features

Summary

Introduction

Focal hand dystonia and cranial dystonia share the phenotypic features of uncontrolled involuntary muscle contraction leading to abnormal postures characteristic of all dystonias. While the safety and efficacy of botulinum toxin for the treatment of these focal dystonias have been established through controlled clinical trials and over 20 years of use [2], their response to botulinum toxin treatment reveals both shared features and divergent features. Toxins 2012, 4 yet overlapping disorders may provide clues to the nature of the dystonia and the action of botulinum toxin in their treatment

Physiology of Focal Hand Dystonia and Cranial Dystonias

Findings

Conclusions