Regional blood flow in herniparkinsonism

Abstract

Positron emission tomography was used to measure global and local blood flow in 11 patients with hemiparkinsonism (before and after an acute oral dose of L-dopa) and in 26 normal subjects. Global hemispheric blood flow was not significantly different between the patients [45 ± 11 ml/(min. 100 g)] and the controls [49 ± 8 ml/(min. 100 g)]. After L-dopa, the patients' mean global hemispheric flow did not change. Measurements of local blood flow from specific, anatomically defined cortical and basal ganglia regions were performed using a newly developed stereotactic localization technique. Before L-dopa, mesocortical blood flow contralateral to the patients' symptoms was significantly less than controls (p < 0. 003), suggesting a specific abnormality in the (cortical dopaminergic projection from the ventral tegmental area. In addition, right and left pallidal blood flow were significantly less tightly coupled in patients than controls (p = 0. 0312). After L-dopa, the mesocortical blood flow remained below normal, whereas pallidal blood flow was no longer significantly different from controls (p > 0. 05).