title: White matter hyperintensities do not impact cognitive function in patients with newly diagnosed Parkinson's disease.
abstract: The objective of this study was to investigate total volume and spatial distribution of white matter hyperintensities (WMH) in a large sample of newly diagnosed Parkinson's disease (PD) patients with and without mild cognitive impairment (MCI) compared to normal controls (NC). Furthermore, we aimed to examine the impact of the WMH on attention-executive performance in PD. MCI is regarded as a pre-dementia stage. Studies on MCI have found WMH associated with reduced cognitive function, especially in the attention and executive domains. The present study included 163 incident, drug-naïve PD patients (66.2+/-9.1 years and disease duration 27.1+/-19.8 months) and 102 age-matched NC (65.7+/-9.4 years). Thirty (30) subjects in the PD sample presented MCI, whereas 133 did not. MCI was classified based on tests for memory, attention-executive and visuospatial function compared to the NC group, taking age, sex and education into consideration. WMH were outlined on FLAIR scans using a semi-automated technique. Total WMH volumes were compared between the 3 study groups, and spatial distribution of normalized WMH masks in each group were compared using voxel-wise probability maps. Regression analysis examined the possible impact of WMH on attention-executive scores in the PD group. Analysis showed that there were no significant differences between the 3 groups in total volume or spatial distribution of WMH. In addition there was no significant relationship between total volume or spatial distribution of WMH and attention-executive functions in PD. We conclude that in this PD cohort, cognitive impairment seems to be independent of WMH damage.
authors.affiliation: Buffalo Neuroimaging Analysis Center, Department of Neurology, State University of New York at Buffalo, Buffalo, NY 14203, USA. datu@sus.no
authors.forename: Turi O
authors.initials: TO
authors.lastname: Dalaker
authors.forename: Jan P
authors.initials: JP
authors.lastname: Larsen
authors.forename: Michael G
authors.initials: MG
authors.lastname: Dwyer
authors.forename: Dag
authors.initials: D
authors.lastname: Aarsland
authors.forename: Mona K
authors.initials: MK
authors.lastname: Beyer
authors.forename: Guido
authors.initials: G
authors.lastname: Alves
authors.forename: Kolbjorn
authors.initials: K
authors.lastname: Bronnick
authors.forename: Ole-Bjorn
authors.initials: OB
authors.lastname: Tysnes
authors.forename: Robert
authors.initials: R
authors.lastname: Zivadinov
mesh_terms: D000368:Aged; D001921:Brain / Q000473:pathology*; D003071:Cognition; D003072:Cognition Disorders / Q000209:etiology* / Q000473:pathology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009413:Nerve Fibers, Myelinated / Q000473:pathology*; D010300:Parkinson Disease / Q000150:complications* / Q000473:pathology*