ABSTRACT
INTRODUCTION Traditionally, the etiologic classifi cation of dystonia includes primary dystonia (a condition in which neurological fi ndings are limited to the sustained involuntary posture), secondary dystonia (due to exogenous cause), dystonia associated with degenerative disorders (i.e., Parkinson’s disease, multiple system atrophy, progressive supranuclear palsy, and corticobasal degeneration), and dystonia-plus syndromes (such as dopa-responsive dystonia, X-linked dystonia-parkinsonism, alcohol responsive myoclonus-dystonia, and heredodegenerative diseases such as Wilson’s disease and Huntington’s disease) (1).
