title: The impact of silent vascular brain burden in cognitive impairment in Parkinson's disease.
abstract: OBJECTIVE
  White matter hyperintensities (WMHs) detected by magnetic resonance imaging (MRI) of the brain are associated with dementia and cognitive impairment in the general population and in Alzheimer's disease. Their effect in cognitive decline and dementia associated with Parkinson's disease (PD) is still unclear.
  
  
  METHODS
  We studied the relationship between WMHs and cognitive state in 111 patients with PD classified as cognitively normal (n = 39), with a mild cognitive impairment (MCI) (n = 46) or dementia (n = 26), in a cross-sectional and follow-up study. Cognitive state was evaluated with a comprehensive neuropsychological battery, and WMHs were identified in FLAIR and T2-weighted MRI. The burden of WMHs was rated using the Scheltens scale.
  
  
  RESULTS
  No differences in WMHs were found between the three groups in the cross-sectional study. A negative correlation was observed between semantic fluency and the subscore for WMHs in the frontal lobe. Of the 36 non-demented patients re-evaluated after a mean follow-up of 30 months, three patients converted into MCI and 5 into dementia. Progression of periventricular WMHs was associated with an increased conversion to dementia. A marginal association between the increase in total WMHs burden and worsening in the Mini Mental State Examination was encountered.
  
  
  CONCLUSIONS
  White matter hyperintensities do not influence the cognitive status of patients with PD. Frontal WMHs have a negative impact on semantic fluency. Brain vascular burden may have an effect on cognitive impairment in patients with PD as WMHs increase overtime might increase the risk of conversion to dementia. This finding needs further confirmation in larger prospective studies.
authors.affiliation: Clínica Universidad de Navarra, Pamplona, Spain.
authors.forename: R
authors.initials: R
authors.lastname: González-Redondo
authors.forename: J
authors.initials: J
authors.lastname: Toledo
authors.forename: P
authors.initials: P
authors.lastname: Clavero
authors.forename: I
authors.initials: I
authors.lastname: Lamet
authors.forename: D
authors.initials: D
authors.lastname: García-García
authors.forename: R
authors.initials: R
authors.lastname: García-Eulate
authors.forename: P
authors.initials: P
authors.lastname: Martínez-Lage
authors.forename: M C
authors.initials: MC
authors.lastname: Rodríguez-Oroz
mesh_terms: D000368:Aged; D001921:Brain / Q000098:blood supply / Q000473:pathology*; D003072:Cognition Disorders / Q000209:etiology* / Q000473:pathology*; D060825:Cognitive Dysfunction / Q000473:pathology; D003430:Cross-Sectional Studies; D003704:Dementia / Q000473:pathology; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009483:Neuropsychological Tests; D010300:Parkinson Disease / Q000150:complications* / Q000473:pathology*