[Indicators of brain biogenic amine metabolism in various extrapyramidal disorders]

The authors describe the results of determinations of the main metabolites of dopamine (DA), serotonin (S) and noradrenaline (NA) in the cerebrospinal fluid (ventricular and lumbar) in patients with various extrapyramidal system diseases. A profound decrease was demonstrated in the concentration of homovanillic acid (HVA)--the end metabolite of DA in parkinsonism, reflecting damage to DA--containing pathways and reduced DA synthesis in basal ganglia. Treatment with L-DOPA raises considerably the HVA level in the cerebrospinal fluid evidencing increased DA metabolism in the brain during administration of its precursor L-DOPA. In torsion dystrophy a statistically significant difference was found in HVA concentrations in the ventricular fluid depending on the clinical manifestations of the disease. In the patients with local muscular rigidity HVA level was much lower than in patients with the hyperkinetic form of the disease. It is concluded that the character of changes in the cerebral dopaminergic systems differs phenotypically in the form of torsion dystonia. In hepatolenticular degeneration (Wilson's disease) the level of all studied metabolites was decreased, which could be an evidence of deficient cerebral metabolism of their precursors--amines. In cases of Huntington's chorea a low level of HVA was found in the ventricular fluid, reflecting decreased total amount of DA in the brain due to damage to the corresponding neurons. Absence of detectable changes in MHPG concentration (the main cerebral metabolite of NA) indicates that this amine plays a lower role than DA and S in the biochemical mechanisms of the pathogenesis of extrapyramidal motor disturbances. The obtained data are important for the understanding of the pathogenesis and for evolving therapeutic methods in extrapyramidal diseases.