title: Significance of visual hallucinations and cerebral hypometabolism in the risk of dementia in Parkinson's disease patients with mild cognitive impairment.
abstract: BACKGROUND
  Mild cognitive impairment (MCI) and visual hallucinations (VH) are common co-morbidities and risk factors for dementia in Parkinson's disease (PD). The relative value of each of them in the progression to dementia is unknown. We investigated cognitive impairment and cerebral hypometabolism in PD-MCI patients with VH (VH-positive) and without (VH-negative).
  
  
  METHODS
  Twenty-one PD-MCI patients (12 VH-negative, nine VH-positive) and 19 controls were studied using a comprehensive neuropsychological battery and [18F]-Fluorodeoxyglucose positron emission tomography (FDG-PET). The neuropsychological assessment was repeated after 30 months. Regional FDG uptake was analyzed using statistical parametric mapping.
  
  
  RESULTS
  VH-positive patients had lower FDG uptake bilaterally in the occipital, and parietal cortex, right temporal lobe and in the left cingulum compared with VH-negative patients. The two groups showed no significant differences in clinical characteristics and cognitive status at baseline. After 30 months of follow-up, three (25%) and four (50%) of the VH-negative and VH-positive patients, respectively, had progressed to dementia.
  
  
  CONCLUSIONS
  Even in the absence of significant cognitive differences, PD-MCI patients with VH exhibit more severe cerebral hypometabolism and had a higher rate of progression to dementia than VH-negative patients, supporting the importance of VH and cerebral hypometabolism in establishing the risk of dementia in PD-MCI.
authors.affiliation: Department of Neurology and Neurosurgery, Neurosciences Area, CIMA, Clínica Universidad De Navarra, University of Navarra, Pamplona, Spain.|Centro De Investigación Biomédica en Red Sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain.
authors.forename: Carmen
authors.initials: C
authors.lastname: Gasca-Salas
authors.affiliation: Department of Neurology and Neurosurgery, Neurosciences Area, CIMA, Clínica Universidad De Navarra, University of Navarra, Pamplona, Spain.
authors.forename: Pedro
authors.initials: P
authors.lastname: Clavero
authors.affiliation: Department of Neurology and Neurosurgery, Neurosciences Area, CIMA, Clínica Universidad De Navarra, University of Navarra, Pamplona, Spain.|Centro De Investigación Biomédica en Red Sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain.|Department of Neurology, University Hospital Donostia; Neuroscience Unit BioDonostia Research Institute, San Sebastian; Ikerbasque, Basque Foundation for Science, Bilbao, Spain.
authors.forename: David
authors.initials: D
authors.lastname: García-García
authors.affiliation: Department of Neurology and Neurosurgery, Neurosciences Area, CIMA, Clínica Universidad De Navarra, University of Navarra, Pamplona, Spain.|Centro De Investigación Biomédica en Red Sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain.
authors.forename: José A
authors.initials: JA
authors.lastname: Obeso
authors.affiliation: Department of Neurology and Neurosurgery, Neurosciences Area, CIMA, Clínica Universidad De Navarra, University of Navarra, Pamplona, Spain.|Centro De Investigación Biomédica en Red Sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain.|Department of Neurology, University Hospital Donostia; Neuroscience Unit BioDonostia Research Institute, San Sebastian; Ikerbasque, Basque Foundation for Science, Bilbao, Spain.
authors.forename: María C
authors.initials: MC
authors.lastname: Rodríguez-Oroz
mesh_terms: D000368:Aged; D001921:Brain / Q000000981:diagnostic imaging / Q000378:metabolism*; D001931:Brain Mapping; D060825:Cognitive Dysfunction / Q000150:complications* / Q000000981:diagnostic imaging / Q000378:metabolism; D015897:Comorbidity; D018450:Disease Progression; D005260:Female; D019788:Fluorodeoxyglucose F18; D005500:Follow-Up Studies; D006212:Hallucinations / Q000150:complications* / Q000000981:diagnostic imaging / Q000378:metabolism; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests; D010300:Parkinson Disease / Q000150:complications* / Q000000981:diagnostic imaging / Q000378:metabolism / Q000523:psychology; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D012307:Risk Factors
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18
keywords: FDG-PET; Parkinson's disease; cerebral metabolism; dementia; mild cognitive impairment; visual hallucinations