title: Long-term treatment response and fluorodopa positron emission tomographic scanning of parkinsonism in a family with dopa-responsive dystonia.
abstract: Dopa-responsive dystonia (DRD) is one form of childhood-onset idiopathic torsion dystonia. Adult-onset parkinsonism has appeared in several previously unaffected members in families with DRD suggesting that this may be an additional phenotypical expression of the disease. We report a family with DRD in which 2 women and 1 man, unaffected by dystonia, developed tremor-onset parkinsonism after age 50 years. The women continue on a low dosage of levodopa after 9 and 13 years of treatment, with a stable, nearly complete, symptomatic response. This contrasts to the typical long-term treatment complications observed in patients with Parkinson's disease. We assessed nigrostriatal dopaminergic function in the proband, with typical DRD, and the 2 women with parkinsonism using 6-[18F]fluoro-L-dopa positron emission tomography. All 3 had normal striatal 6-[18F]fluoro-L-dopa uptake. These observations provide compelling evidence that "benign" adult-onset parkinsonism may be an expression of the disease in some members of families with DRD and does not support consideration of the DRD gene as a risk factor for development of Parkinson's disease. There may be considerable clinical heterogeneity in DRD depending on the age at onset.
authors.affiliation: Department of Neurology, Columbia-Presbyterian Medical Center, New York, NY 10032.
authors.forename: T G
authors.initials: TG
authors.lastname: Nygaard
authors.forename: H
authors.initials: H
authors.lastname: Takahashi
authors.forename: G A
authors.initials: GA
authors.lastname: Heiman
authors.forename: B J
authors.initials: BJ
authors.lastname: Snow
authors.forename: S
authors.initials: S
authors.lastname: Fahn
authors.forename: D B
authors.initials: DB
authors.lastname: Calne
mesh_terms: D000328:Adult; D000368:Aged; D001921:Brain / Q000378:metabolism; D002648:Child; D002675:Child, Preschool; D004295:Dihydroxyphenylalanine / Q000031:analogs & derivatives / Q000493:pharmacokinetics; D004421:Dystonia / Q000150:complications / Q000000981:diagnostic imaging* / Q000188:drug therapy* / Q000378:metabolism; D005190:Family; D005260:Female; D005462:Fluorine Radioisotopes; D006801:Humans; D007980:Levodopa / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000000981:diagnostic imaging* / Q000188:drug therapy* / Q000209:etiology / Q000378:metabolism; D010375:Pedigree; D014055:Tomography, Emission-Computed
chemical_list: D005462:Fluorine Radioisotopes; C043437:fluorodopa F 18; D007980:Levodopa; D004295:Dihydroxyphenylalanine