title: Prevalence study of primary dystonia in Iceland.
abstract: In Iceland, the crude prevalence for all types of primary dystonia was 37.1/10(5) (confidence interval, 30.4-44.9). Focal dystonia had the highest prevalence (31.2/10(5)), followed by segmental (3.1/10(5)), multifocal (2.4/10(5)) and generalized dystonia (0.3/10(5)). Cervical dystonia was the most common focal dystonia (11.5/10(5)), followed by limb dystonia (8.0/10(5)), laryngeal dystonia (5.9/10(5)), blepharospasm (3.1/10(5)), and oromandibular dystonia (2.8/10(5)). The male:female ratio for all patients was 1:1.9 (P=0.0007), and females outnumbered males in all subtypes except oromandibular dystonia. Mean age of onset for all patients was 42.7 years (range, 3-82 years). This prevalence of primary dystonia is higher than in most reported studies, possibly because of more complete ascertainment but the relative frequencies of dystonia subtypes is similar.
authors.affiliation: University of Iceland, Faculty of Medicine, Reykjavik, Iceland.
authors.forename: Hilmir
authors.initials: H
authors.lastname: Asgeirsson
authors.forename: Finnbogi
authors.initials: F
authors.lastname: Jakobsson
authors.forename: Haukur
authors.initials: H
authors.lastname: Hjaltason
authors.forename: Helga
authors.initials: H
authors.lastname: Jonsdottir
authors.forename: Sigurlaug
authors.initials: S
authors.lastname: Sveinbjornsdottir
mesh_terms: D000328:Adult; D017677:Age Distribution; D020821:Dystonic Disorders / Q000145:classification / Q000453:epidemiology* / Q000503:physiopathology; D005260:Female; D006801:Humans; D007055:Iceland / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D017678:Sex Distribution