In this thesis, the consequences of Parkinson’s disease (PD) are studied using advanced approaches in neuroimaging, including structural as well as functional connectivity networks, examination of... Show moreIn this thesis, the consequences of Parkinson’s disease (PD) are studied using advanced approaches in neuroimaging, including structural as well as functional connectivity networks, examination of the role of aging in white matter degeneration in PD, and the use of machine learning classification models. Brain MRI features of PD patients are compared with healthy control subjects, and the relations between these features and patient characteristics, such as age, dopaminergic medication, motor and predominantly non-dopaminergic impairment, are described. Furthermore, brain features that may contribute to the differentiation of PD and Dementia with Lewy body dementia are described. Show less
Blood-brain barrier (BBB) leakage is considered an important underlying process in both cerebral small vessel disease (cSVD) and Alzheimer's disease (AD). The objective of this study was to examine... Show moreBlood-brain barrier (BBB) leakage is considered an important underlying process in both cerebral small vessel disease (cSVD) and Alzheimer's disease (AD). The objective of this study was to examine associations between BBB leakage, cSVD, neurodegeneration, and cognitive performance across the spectrum from normal cognition to dementia. Leakage was measured with dynamic contrast-enhanced magnetic resonance imaging in 80 older participants (normal cognition, n = 32; mild cognitive impairment, n 34; clinical AD-type dementia, n = 14). Associations between leakage and white matter hyperintensity (WMH) volume, hippocampal volume, and cognition (information processing speed and memory performance) were examined with multivariable linear regression and mediation analyses. Leakage within the gray and white matter was positively associated with WMH volume (gray matter, p = 0.03; white matter, p = 0.01). A negative association was found between white matter BBB leakage and information processing speed performance, which was mediated by WMH volume. Leakage was not associated with hippocampal volume. WMH pathology is suggested to form a link between leakage and decline of information processing speed in older individuals with and without cognitive impairment. (C) 2019 Elsevier Inc. All rights reserved. Show less
