title: Longitudinal study of cognitive and cerebral metabolic changes in Parkinson's disease.
abstract: OBJECTIVE
  To investigate the cortical metabolic alterations that precedes longitudinal cognitive decline in Parkinson's disease (PD).
  
  
  METHODS
  We analyzed the data of 46 PD patients who did not have dementia at baseline and completed 3-year follow-up. Based on the results of general cognitive, memory and visuospatial tests, patients were classified into cognitively normal PD (PD-CogNL), PD with mild cognitive impairment (PD-MCI), and PD dementia (PDD). The regional cerebral glucose metabolism at rest was measured using18F-fluorodeoxyglucose positron emission tomography. Voxel-wise effect size analyses were performed to delineate abnormal metabolic patterns associated with changes in cognitive status in PD.
  
  
  RESULTS
  At baseline, 29 patients had PD-CogNL, and 17 patients had PD-MCI. At follow-up, 28 patients had PD-CogNL, 12 patients had PD-MCI, and 6 patients developed PDD. Seventeen of 29 PD-CogNL patients remained to be PD-CogNL, and 9 PD-CogNL patients converted to PD-MCI. Eleven PD-MCI patients reverted to normal cognition during follow-up. 3 PD-CogNL and 3 PD-MCI patients developed PDD. Cognitively stable PD-CogNL group had frontal predominant hypometabolism. PDD converters showed parieto-occipital hypometabolism at baseline regardless of whether a patient's initial cognitive status is PD-CogNL or PD-MCI.
  
  
  CONCLUSIONS
  Parieto-occipital hypometabolism is a good predictor of early dementia conversion in PD.
authors.affiliation: Department of Behavioral Neurology & Cognitive Neuroscience, Tohoku University Graduate School of Medicine, Japan. Electronic address: t-baba@med.tohoku.ac.jp.
authors.forename: Toru
authors.initials: T
authors.lastname: Baba
authors.affiliation: Department of Behavioral Neurology & Cognitive Neuroscience, Tohoku University Graduate School of Medicine, Japan.
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Hosokai
authors.affiliation: Department of Behavioral Neurology & Cognitive Neuroscience, Tohoku University Graduate School of Medicine, Japan.
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Nishio
authors.affiliation: Department of Neurology, Tohoku University Graduate School of Medicine, Japan.
authors.forename: Akio
authors.initials: A
authors.lastname: Kikuchi
authors.affiliation: Department of Occupational Therapy, Yamagata Prefectural University of Health Sciences, Japan.
authors.forename: Kazumi
authors.initials: K
authors.lastname: Hirayama
authors.affiliation: Department of Clinical Neuroscience, Yamagata University Graduate School of Medical Science, Japan.
authors.forename: Kyoko
authors.initials: K
authors.lastname: Suzuki
authors.affiliation: Department of Neurology, Tohoku University Graduate School of Medicine, Japan.
authors.forename: Takafumi
authors.initials: T
authors.lastname: Hasegawa
authors.affiliation: Department of Neurology, Tohoku University Graduate School of Medicine, Japan.
authors.forename: Masashi
authors.initials: M
authors.lastname: Aoki
authors.affiliation: Sendai Nishitaga National Hospital, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Takeda
authors.affiliation: Department of Behavioral Neurology & Cognitive Neuroscience, Tohoku University Graduate School of Medicine, Japan.
authors.forename: Etsuro
authors.initials: E
authors.lastname: Mori
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002540:Cerebral Cortex / Q000000981:diagnostic imaging / Q000378:metabolism*; D003072:Cognition Disorders / Q000000981:diagnostic imaging / Q000209:etiology*; D003430:Cross-Sectional Studies; D003704:Dementia / Q000209:etiology; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000378:metabolism; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D010300:Parkinson Disease / Q000150:complications* / Q000000981:diagnostic imaging / Q000473:pathology*; D049268:Positron-Emission Tomography; D012720:Severity of Illness Index
chemical_list: D019788:Fluorodeoxyglucose F18
keywords: Cognitive reversion; Cortical glucose metabolism; Dementia conversion; Longitudinal study; PD-MCI