[Homovanillic acid content in the cerebrospinal fluid as an index of dopamine cerebral metabolism before and after a stereotaxic operation in patients with extrapyramidal hyperkinetic syndromes].

The level of homovanillic acid (HVA) in the cerebrospinal fluid (CSF) as an indicator of the cerebral metabolism of dopamine was examined prior to and after the stereotaxic operation on the basal ganglia in 13 patients with extrapyramidal hyperkinetic syndromes. The HVA levels in the lumbar CSF decreased significantly (P less than 0.01) following the operation. The data obtained suggest that a decrease in the activity of the central dopaminergic systems secondary to the destruction of the ventrolateral nucleus of the thalamus affects the biochemical mechanisms underlying the therapeutic effect of stereotaxic operations on extrapyramidal hyperkineses. A possible relationship of the ventrolateral nucleus of the thalamus with dopaminergic and other neurotransmitter systems involved in the regulation of extrapyramidal motor functions is discussed. The findings obtained are important for the understanding of the role of the dopaminergic systems in the pathogenesis of extrapyramidal hyperkinetic syndromes and for the identification of the biochemical mechanisms underlying the therapeutic effect of stereotaxic operations.