title: The long-term response to levodopa in dopa-responsive dystonia.
abstract: We report the long-term response to levodopa in 20 patients with dopa-responsive dystonia (DRD). We found an inverse correlation between the daily dose of levodopa and duration of treatment (r=-0.59, P<0.01). Mild dyskinesias were present in 20% of our patients. Dyskinetic patients were on a higher dose of levodopa than non-dyskinetics. Dyskinesias responded to a reduction in levodopa, with no deterioration in motor function. We propose that the dopamine turnover might decrease with time, which would lead to a decrease in the requirement for levodopa and the occurrence of dyskinesias late in the course of DRD.
authors.affiliation: Neurodegenerative Disorders Centre, Vancouver Hospital and Health Sciences Centre, British Columbia, Canada.
authors.forename: W J
authors.initials: WJ
authors.lastname: Hwang
authors.forename: D B
authors.initials: DB
authors.lastname: Calne
authors.forename: J K
authors.initials: JK
authors.lastname: Tsui
authors.forename: R
authors.initials: R
authors.lastname: de la Fuente-Fernández
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D004295:Dihydroxyphenylalanine / Q000502:physiology*; D015259:Dopamine Agents / Q000627:therapeutic use*; D004421:Dystonia / Q000188:drug therapy* / Q000503:physiopathology; D005260:Female; D006801:Humans; D007980:Levodopa / Q000008:administration & dosage / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013997:Time Factors; D016138:Walking
chemical_list: D015259:Dopamine Agents; D007980:Levodopa; D004295:Dihydroxyphenylalanine