Medizinische Universität Graz Austria/Österreich - Forschungsportal - Medical University of Graz

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Gewählte Publikation:

Pichler, J.
Functional connectivity and memory in Parkinson’s disease
Humanmedizin; [ Diplomarbeit ] Graz Medical University; 2019. pp. 111 [OPEN ACCESS]


Autor*innen der Med Uni Graz:
Koini Marisa

Background and Objectives: Parkinson’s disease (PD) is the second most common neurodegenerative disorder after Alzheimer’s disease. Clinical presentations vary from slight motor impairment to akinesia, progressive neuropsychiatric disorders and cognitive decline. Resting state functional imaging is a rapidly developing research area, and its usage in PD brings major advances, not only in the diagnostic process, but also for understanding the pathophysiology. The aim of this review is to present the current state of research concerning functional connectivity (especially resting state connectivity) alterations measured through functional magnetic resonance imaging (fMRI) in PD. A special focus is given on functional connectivity changes due to cognitive dysfunctions. Methods: Literature search was conducted via PubMed, Cochrane library (CENTRAL), and Google Scholar in May 2018. Only studies in English language, published between 2008 and 2018, were included for further screening. Overall 44 manuscripts have been included in the review. Results: The results show a high heterogeneity, due to different resting state approaches used to analyse FC alterations. Medication status and different subtypes of PD also lead to heterogeneous FC results. A variety of approaches was used in the selected manuscripts to examine resting state connectivity: Seed-based approach, independent component analyses, principal component analyses, graph-based approaches, amplitude of low-frequency fluctuation approaches, voxel-mirrored homotopic connectivity approaches, regional homogeneity approaches and multivariate pattern analyses. This variety of approaches is causative for the fact that comparability of individual studies is poor. The number of PD patients, examined in the selected studies, varies between 16 and 106 subjects. Principally, alterations in resting state connectivity were detected in cortico-striatal-thalamic networks, mostly ascribed to dopaminergic depletion. Considering cognitive decline, alterations were reported within the default mode network, dorsal attention network, fronto-parietal network and ventral attention network, among many other divergent changes. Discussion and Conclusion: Even if the comparability of studies concerning resting state fMRI data is poor, future studies can lead to a better understanding of the ongoing processes within the brain in PD patients.

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