Catechol metabolites in the cerebrospinal fluid as possible markers in the early diagnosis of Parkinson's disease.

This paper is a preliminary report of work aiming to elucidate the possible use of 5-S-cysteinyl metabolites of catechols in the cerebrospinal fluid as markers in the early diagnosis of Parkinson's disease (PD). The rationale for this approach is the hypothesis that this disorder is caused by a failure of antioxidative mechanisms to prevent the excessive autoxidation of dopamine and other catechols that yields highly reactive and cytotoxic semiquinones and quinones. 5-S-cysteinyl adducts of these quinones have been detected in human brains, analyzed postmortem, and appear to be formed at an increased rate in elderly individuals, who show an increased loss of dopaminergic neurons.