title: Parkinson's disease beginning before age 40.
authors.affiliation: Seccion Enfermedades Extrapiramidales, Centro Neurologico-Hospital Frances, Buenos Aires, Argentina.
authors.forename: O S
authors.initials: OS
authors.lastname: Gershanik
authors.forename: T G
authors.initials: TG
authors.lastname: Nygaard
mesh_terms: D000328:Adult; D000367:Age Factors; D006801:Humans; D002479:Inclusion Bodies / Q000648:ultrastructure; D009460:Neurologic Examination; D010300:Parkinson Disease / Q000175:diagnosis* / Q000473:pathology; D013378:Substantia Nigra / Q000473:pathology