title: Functional improvement with long-term levodopa therapy.
mesh_terms: D000368:Aged; D004295:Dihydroxyphenylalanine / Q000627:therapeutic use*; D006801:Humans; D008875:Middle Aged; D010300:Parkinson Disease / Q000188:drug therapy*; D013997:Time Factors
chemical_list: D004295:Dihydroxyphenylalanine