Resting-state fMRI in Parkinson's disease patients with cognitive impairment: A meta-analysis

• Published in: Parkinsonism & related disorders 2019-05, Vol.62, p.16-27
• Main Authors: Wolters, Amée F., van de Weijer, Sjors C.F., Leentjens, Albert F.G., Duits, Annelien A., Jacobs, Heidi I.L., Kuijf, Mark L.
• Format: Article
• Language: English
• Subjects: Cognitive impairment; Functional connectivity; Functional MRI; Parkinson's disease; Resting-state network
• ISSN: 1353-8020; 1873-5126
• DOI: 10.1016/j.parkreldis.2018.12.016

Cognitive impairment is a common non-motor symptom in Parkinson's disease. So far, the underlying pathophysiology remains unclear. Several alterations in functional network connectivity have been described in Parkinson's disease patients with cognitive impairment which are probably the result of the heterogenous pathophysiology underlying this cognitive decline, including dopaminergic and cholinergic deficits. Accordingly, the reported resting-state connectivity patterns vary greatly among studies. To evaluate the localization and magnitude of functional connectivity patterns in resting-state brain networks in Parkinson's disease patients with cognitive impairment by pooling data from available studies. We searched PubMed, the Cochrane Library, MEDLINE, Embase and PsycINFO to identify functional MRI studies in Parkinson's disease patients with cognitive impairment. A voxel-based meta-analysis combined with quality statistics was performed, using the anisotropic effect-size version of the signed differential mapping method. Seventeen studies with cognitively impaired Parkinson's disease patients were included consisting of 222 Parkinson's disease patients with mild cognitive impairment, 68 patients with Parkinson's disease dementia, 289 cognitively unimpaired Parkinson's disease patients and 353 healthy controls. Parkinson's disease patients with cognitive impairment predominantly showed a reduced connectivity in specific brain regions that are part of the default mode network. Cognitive impairment in Parkinson's disease is associated with reduced connectivity in networks relevant to cognition, most prominently the default mode network. Specific alterations in functional connectivity may contribute to cognitive decline in Parkinson patients and may be a promising future biomarker. •Cognitive impairment (CI) is a common non-motor symptom in Parkinson's disease (PD).•Cognitive decline in PD is associated with changes in functional brain connectivity.•Alterations are predominantly seen in the default mode network.•Quantification of these network changes may be able to serve as a future biomarker.