Advanced radiological investigation of levodopa- induced dyskinesia in Parkinson's disease patients: assessment of blood brain barrier function

Background: The purpose of this study is to explore changes in blood-brain barrier (BBB) function and volumetry associated with Parkinson's disease (PD) levodopa-induced-dyskinesia (LID). Methods: Twenty-six PD patients [matched pairs, 13 with LID (LID+) and 13 without (LID-)], performed high resolution 3D FSPGR MRI, applying a novel methodology developed for calculating delayed -enhancement-subtraction-maps, representing BBB function. Segmentation software calculated volumes of pre-determined brain structures and the mean BBB function was calculated for each structure. Comparisons between the LID+ and LID-paired patients and within patient, between the more and less affected hemisphere (MAH, LAH) and correlation tests with lateralized UPDRS motor scores were performed. Results: There were no significant differences in volumetric or BBB map characteristics between the matched LID+ and LID-patients regarding most brain areas except for the inferior parietal cortex (IPC) of the MAH that displayed a higher BBB disruption in LID+ vs. LID-patients. A positive correlation was found with the motor score of the side contralateral to the MAH(r = 0.58, p<0.038) among the LID+ patients. Conclusions: We demonstrated an association between slight BBB disruption in the IPC and LID in patients with PD using a new MRI methodology. As currently there is no known straightforward biological explanation for this positive finding, it might be genuine and novel, or spurious. Further studies to explore BBB functioning in the various stages of PD and its motor complications are needed, as well as further investigation of the IPC clinical importance and correction for epiphenomenon.