in this study , concentrations of homovanillic acid ( hva ) , a principal metabolite of dopamine ( da ) , in the cerebrospinal fluid ( csf ) were measured in 17 patients with parkinson 's disease ( pd ) who had been effectively treated with l-dopa and in 8 patients clinically diagnosed as having striatonigral degeneration ( snd ) and for whom treatment with l-dopa had proved ineffective .
C0030567
parkinson 's disease
C0023570
l-dopa