Primary dystonia, DYT4 type

Definition

A rare genetic dystonia characterized predominantly by laryngeal dystonia/spasmodic dysphonia, mostly followed by cervical and generalized dystonia. Upper and lower limb dystonia, with the latter leading to a "hobby horse" gait (with toe walking, stiff legs, and a skipping gait), craniofacial and/or oro-pharyngeal dystonia have been reported in some patients. Severity and rate of progression vary among affected individuals ; some patients may have laryngeal or cervical dystonia as a life-long isolated feature, however most patients present with dystonia in other body sites.