title: Juvenile Huntington disease exacerbated by methylphenidate: case report.
abstract: The authors describe the case of an 8-year-old boy, otherwise healthy, who presented with symptoms consistent with attention-deficit hyperactivity disorder (ADHD) and was started on a trial of methylphenidate. Within 4 weeks, he experienced a rapid decline in fine motor skills, with dysarthria, intention tremor, motor impersistence, and diffusely increased tone. Symptoms persisted despite cessation of methylphenidate. At that time, a paternal history of Huntington disease was disclosed. Molecular analysis revealed an expansion in CAG repeats to 75 copies, within the range characteristic of juvenile Huntington disease. This report raises the possibility that use of dopaminergic agonists in patients with a family history of Huntington disease may lead to clinical exacerbation of motor symptoms and/or unwitting diagnosis in an unprepared family.
authors.affiliation: Department of Pediatrics, Children's Medical Center of Dallas, Texas, USA. michael.dowling@utsouthwestern.edu
authors.forename: Jeff L
authors.initials: JL
authors.lastname: Waugh
authors.forename: Van S
authors.initials: VS
authors.lastname: Miller
authors.forename: Robert S
authors.initials: RS
authors.lastname: Chudnow
authors.forename: Michael Morgan
authors.initials: MM
authors.lastname: Dowling
mesh_terms: D017668:Age of Onset; D001289:Attention Deficit Disorder with Hyperactivity / Q000150:complications* / Q000175:diagnosis / Q000188:drug therapy; D002648:Child; D042622:DNA Repeat Expansion / Q000235:genetics; D018765:Dopamine Uptake Inhibitors / Q000009:adverse effects*; D006801:Humans; D006816:Huntington Disease / Q000139:chemically induced / Q000150:complications / Q000175:diagnosis* / Q000235:genetics; D008297:Male; D008774:Methylphenidate / Q000009:adverse effects*
chemical_list: D018765:Dopamine Uptake Inhibitors; D008774:Methylphenidate