Aging and CSF hydroxylase cofactor.

The level of cerebrospinal fluid (CSF) hydroxylase cofactor activity was measured in 34 neurologically normal patients and analyzed according to age. Levels declined by approximately one-third over a 40-year span, probably reflecting loss of aminergic neurons. Fourteen patients with Parkinson disease all tended to have lower values than age-matched controls. Among Parkinson patients with the same order of disability, younger cases had higher CSF concentratons of hydroxylase cofactor than older patients.