Blood-Brain Barrier Leakage Is Increased in Parkinson's Disease.

BACKGROUND: Blood-brain barrier (BBB) disruption has been noted in animal models of Parkinson's disease (PD) and forms the basis of the vascular hypothesis of neurodegeneration, yet clinical studies are lacking. OBJECTIVE: To determine alterations in BBB integrity in PD, with comparison to cerebrovascular disease. METHODS: Dynamic contrast enhanced magnetic resonance images were collected from 49 PD patients, 15 control subjects with cerebrovascular disease [control positive (CP)] and 31 healthy control subjects [control negative (CN)], with all groups matched for age. Quantitative maps of the contrast agent transfer coefficient across the BBB (K trans) and plasma volume (v p ) were produced using Patlak analysis. Differences in K trans and v p were assessed with voxel-based analysis as well as in regions associated with PD pathophysiology. In addition, the volume of white matter lesions (WMLs) was obtained from T2-weighted fluid attenuation inversion recovery (FLAIR) images. RESULTS: Higher K trans, reflecting higher BBB leakage, was found in the PD group than in the CN group using voxel-based analysis; differences were most prominent in the posterior white matter regions. Region of interest analysis confirmed K trans to be significantly higher in PD than in CN, predominantly driven by differences in the substantia nigra, normal-appearing white matter, WML and the posterior cortex. WML volume was significantly higher in PD compared to CN. K trans values and WML volume were similar in PD and CP, suggesting a similar burden of cerebrovascular disease despite lower cardiovascular risk factors. CONCLUSION: These results show BBB disruption in PD.