Dopamine sulfate in ventricular cerebrospinal fluid and motor function in Parkinson's disease

We measured sequential plasma and CSF levodopa and CSF dopamine sulfate levels following a single dose of levodopa/carbidopa in two patients with advanced Parkinson's disease (PD). We obtained CSF from an Ommaya reservoir implanted in the lateral ventricle several months earlier at the time of transplantation of adrenal medulla to caudate nucleus and could detect dopamine only in its sulfconjugated form. Peak CSF levodopa and dopamine sulfate levels occurred 1 to 1.5 hours after peak plasma concentration of levodopa. The time course of clinical improvement and worsening correlated precisely with the appearance and disappearance of both levodopa and dopamine sulfate in the CSF. The precise correlation between CSF dopamine sulfate and levodopa indicates that in patients with advanced PD the brain retains some capacity to convert levodopa to dopamine. The transient nature of the correlation between motor fluctuations, CSF levodopa, and CSF dopamine sulfate is consistent with suggestions that in patients with advanced PD there is a diminished capacity to store dopamine synthesized from exogenous levodopa. Dopamine sulfate appears to be a useful index of the availability of dopamine in the parkinsonian brain.