Primary focal or segmental dystonia is a rare clinical condition. The clinical features of dystonia have not been evaluated in China. We performed a study to investigate the epidemiology of primary dystonia and its clinical variants in an adult population.

A Botulinum Toxin Clinic-based study was conducted in the period 18 May through 8 October 2010 in East China. We identified 523 dystonia patients from the Movement disorders and Botulinum Toxin clinic Cases.

The most common focal dystonia were blepharospasm (59%), cervical dystonia (35%), limb dystonia (3%), oromandibular dystonia (2%) and laryngeal dystonia (1%). Males with primary dystonia were noted to have earlier age of onset. A female predominance was noted for most of the primary dystonias with a male to female ratio (M : F) ranging from 1 : 1.48 to 1 : 3.

The epidemiological features of dystonia in East China we collected were similar to the report in Japan which contrasts partly with that reported in Europe.