Association of vascular parkinsonism with impaired neuronal integrity in the striatum

The purpose of this study is to identify the underlying differences between patients with white matter lesions (WMLs) who manifested gait disturbance suggestive of vascular parkinsonism (VaP) and those who did not, using the PET scan. Fourteen patients with extensive WMLs, as determined by MRI, were divided into two groups - 7 with gait disturbance and 7 without it. Neuronal integrity was evaluated with a PET scan using [(11)C]flumazenil (FMZ) by calculating the distribution volume of FMZ (FMZ-V(d)) in various regions of interest by non-linear curve fitting. Additionally, tracer kinetic analysis was applied for voxel-by-voxel quantification of FMZ-V(d) and data analysis was performed using statistical parametric mapping. The striatal FMZ-V(d) values were inversely correlated with the motor UPDRS scores (r = 0.70, p < 0.005), and their reductions were associated with the presence of gait disturbance. Therefore, differences in neuronal integrity in the striatum may determine whether patients with WMLs develop VaP or not.