title: White Matter Hyperintensities and Mild Cognitive Impairment in Parkinson's Disease.
abstract: OBJECTIVE
  The clinical implications of white matter hyperintensities (WMH) in non-demented Parkinson's disease (PD) have not been thoroughly examined. To address this, we investigated the spatial distribution of WMH and their regional predilection in non-demented patients with mild PD.
  
  
  METHODS
  Cognitive assessments classified the sample into patients with mild cognitive impairment (PD-MCI, n = 25) and patients with no cognitive impairment (PD-NCI, n = 65) based on the recent formal Movement Disorder Task Force diagnostic criteria. The mean age was 65.1 ± 7.7 years, disease duration was 5.3 ± 3.9 years, and Hoehn and Yahr stage was 1.9 ± .4. WMHs were outlined on T2-weighted imaging using a semi-automated technique. The spatial distribution of WMHs were compared between PD-MCI and PD-NCI using voxel-wise lesion probability maps (LPM). General linear models examined the associations between spatially specific WMHs and cognitive domains.
  
  
  RESULTS
  LPM analyses showed significant differences in the spatial distribution of WMH in PD-MCI compared to PD-NCI in widespread regions of the brain (P < .05). PD-MCI demonstrated significantly greater total and periventricular WMHs compared to PD-NCI (P ≤ .02). Spatial distribution of WMHs was also significantly associated with global cognition, performance on the Frontal Assessment Battery and Fruit Fluency (P < .05).
  
  
  CONCLUSIONS
  Voxel-wise LPM analysis revealed differences in the spatial distribution of WMH between PD-MCI and PD-NCI patients, particularly in the periventricular regions. A more widespread extent of WMH might be indicative of cognitive deterioration. Our findings warrant further longitudinal investigation into the importance of WMH spatial distribution as a predictor for conversion from PD to PD with dementia.
authors.affiliation: Buffalo Neuroimaging Analysis Center, Department of Neurology, School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, Buffalo, NY.|Department of Neurology, National Neuroscience Institute, Singapore.
authors.forename: Elijah
authors.initials: E
authors.lastname: Mak
authors.affiliation: Buffalo Neuroimaging Analysis Center, Department of Neurology, School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, Buffalo, NY.
authors.forename: Michael G
authors.initials: MG
authors.lastname: Dwyer
authors.affiliation: Buffalo Neuroimaging Analysis Center, Department of Neurology, School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, Buffalo, NY.
authors.forename: Deepa P
authors.initials: DP
authors.lastname: Ramasamy
authors.affiliation: Department of Neurology, National Neuroscience Institute, Singapore.|Duke-NUS Graduate Medical School, Singapore.
authors.forename: Wing Lok
authors.initials: WL
authors.lastname: Au
authors.affiliation: Department of Neurology, National Neuroscience Institute, Singapore.|Duke-NUS Graduate Medical School, Singapore.
authors.forename: Louis C S
authors.initials: LC
authors.lastname: Tan
authors.affiliation: Buffalo Neuroimaging Analysis Center, Department of Neurology, School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, Buffalo, NY.|MR Imaging Clinical Translational Research Center, School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, Buffalo, NY.
authors.forename: Robert
authors.initials: R
authors.lastname: Zivadinov
authors.affiliation: Department of Neurology, National Neuroscience Institute, Singapore.|Duke-NUS Graduate Medical School, Singapore.
authors.forename: Nagaendran
authors.initials: N
authors.lastname: Kandiah
mesh_terms: D000368:Aged; D060825:Cognitive Dysfunction / Q000209:etiology* / Q000473:pathology*; D056324:Diffusion Tensor Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods; D008297:Male; D010300:Parkinson Disease / Q000150:complications* / Q000473:pathology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D066127:White Matter / Q000473:pathology*
keywords: Parkinson's disease; White matter hyperintensities; cognitive impairment; mild cognitive impairment; neuroimaging