the relationships between magnitude of response to orally administered carbidopa/levodopa ( cd/ld ) and serum/cerebrospinal fluid ( csf ) concentrations of levodopa ( ld ) , 3-o-methyldopa ( 3-o-md ) , and homovanillic acid ( hva ) were studied in 15 patients with chronic ld-treated parkinson disease .
C0023570
levodopa
C0030567
parkinson disease