Serotonergic decompensation in the akinetic expression of Parkinson's disease.

The current diagnostic and treatment paradigm for the akinetic form of Parkinson's disease asserts that the majority of symptoms and treatment phenomena arise from a dysfunctional dopaminergic system. Recent studies have attempted to determine the roles of other biogenic amine neurotransmitters such as serotonin and norepinephrine. Metabolic breakdown product studies of Parkinsonian and non-Parkinsonian cerebrospinal fluid (CSF) samples indicate significant differences in the levels of serotonin and norepinephrine in addition to the levels of dopamine. Such changes may suggest that current pharmacologic therapies that attempt to restore only dopamine are inadequate, and require accompanying therapies to elevate serotonin and norepinephrine levels.