Monogenik Parkinson Hastalarında Multimodal Görüntüleme ve Klinik Korelasyon

Abstract

Parkinson’s disease (PD) is a heterogeneous neurodegenerative disease. It has been suggested that idiopathic Parkinson’s disease (iPD) may have two subtypes as “body-first” and “brain-first” depending on α-synuclein pathology. However, monogenic PD (mPD) is mostly devoid of peripheral α-synuclein pathology. Therefore, phenotypic differences based on α-synuclein pathology may not be valid for monogenic forms. The aim of this study is to explore imaging biomarker(s) that can explain different clinical course between iPD and mPD (due to either Parkin or DJ-1 mutations) and study the physiopathological condition in these particular group of patients. We examined functional connectivity changes with resting state functional MRI and white matter changes with diffusion tensor imaging. For our purpose, dopaminergic innervation of striatum and myocardium were studied with 18F-DOPA PET/CT and cortical metabolic changes in the brain were examined with 18F-FDG PET/CT. In our study, functional connectivity between putamen and supplementary motor area was decreased in mPD compared to control group, and white matter changes was more widespread in mPD than in iPD. 18F-DOPA uptake in caudate corpus was significantly decreased in mPD group compared to iPD group and this is a prominent finding in our study. Myocardial 18F-DOPA uptake was decreased in iPD, but there was no difference in myocardial 18F-DOPA uptake between mPD and control group. Cortical hypometabolism pattern was demonstrated for both mPD and iPD, and no significant difference was found between two groups in terms of cortical glucose metabolism. Decreased 18F-DOPA uptake in the caudate corpus can be used as a biomarker in mPH patients. This is the first study which evaluated 18F-DOPA uptake in myocardium in this particular group of patients. We think that myocardial 18F-DOPA uptake might provide valuable information for etiological developmental pattern of the disease and support brain-first pathogenetic characteristic for mPD. 18F-FDG PET/CT is a valuable biomarker for the examination of cortical metabolic changes in the brain and reflects the physiopathological process not only in iPH but also mPH.