CSF and plasma concentrations of free norepinephrine, dopamine, 3,4-dihydroxyphenylacetic acid (DOPAC), 3,4-dihydroxyphenylalanine (DOPA), and epinephrine in Parkinson's disease.

Abstract
To investigate endogenous cerebrospinal fluid catecholamines in Parkinson's disease. Basal concentrations of free norepinephrine (NE), dopamine (DA), epinephrine (E), 3,4-dihydroxyphenylacetic acid (DOPAC) and 3,4-dihydroxyphenylalanine (DOPA) in cerebrospinal fluid (csf) and plasma were measured using reverse-phase HPLC with electrochemical detection in 16 patients with Parkinson's disease and 21 control patients with low back pain. Parkinsonian patients had significantly decreased values of csf NE and DOPAC, the strong relationship between plasma and csf NE was disrupted and neither was there any age related increase of plasma NE. In l-DOPA treated patients plasma DA and DOPA concentrations were raised and csf DOPAC values were inversely related to severity of disease (Hoehn and Yahr score). Csf E concentrations were also reduced in parkinsonian patients whereas csf DA concentrations were unchanged. Csf DOPA concentrations were insignificantly decreased in parkinsonian patients. These results point towards a diffuse neuronal dysfunction in Parkinson's disease and indicate that lumbar csf NE and csf DOPAC are of central nervous origin.