Quantitative analysis of correlation between smooth pursuit and vertebrobasilar hemodynamics.

The cerebellar arterial system is derived from the vertebrobasilar system. However, the relation between cerebellar function and vertebrobasilar hemodynamics remains poorly understood. In this study on patients with vertebrobasilar insufficiency symptoms we examined the relation between magnetic resonance angiography (MRA) abnormalities in the vertebrobasilar system and smooth pursuit function, which is a sensitive parameter of cerebellar function. MRA abnormality was quantitatively assessed on the basis of the severity of stenosis in the vertebral arteries and basilar artery, and on the visualization of the superior cerebellar arteries. Smooth pursuit dysfunction was quantified by the combined amplitude of spikes on an electronystagmograph. A significant correlation was found between MRA abnormality and smooth pursuit dysfunction. This suggests that smooth pursuit dysfunction is closely related to static factors of dysregulation of vertebrobasilar blood flow. Therefore, smooth pursuit can be valued as a sensitive parameter to dysfunction of vertebrobasilar blood flow.