Classification of dystonia. Dystonia is currently classified according to two axes: clinical characteristics and aetiology. Clinical characteristics include age at onset, body distribution, temporal pattern and associated features. The aetiological axis refers to presence of nervous system pathology and whether these are inherited, acquired or idiopathic in nature (from Martino D, Espay AJ, Fasano A, Morgante F. Disorders of movement: a guide to diagnosis and treatment. Heidelberg: Springer-Verlag, 2016). MDS = movement disorders.