title: Neural substrates of cognitive subtypes in Parkinson's disease: a 3-year longitudinal study.
abstract: BACKGROUND
  The neuropsychological features and neuropathological progression patterns associated with rapidly evolving cognitive decline or dementia in Parkinson's disease (PD) remain to be elucidated.
  
  
  METHODS
  Fifty-three PD patients without dementia were recruited to participate in a 3-year longitudinal cohort study. The patients were grouped according to the Clinical Dementia Rating (CDR). Group-wise comparisons were made with regard to demographic characteristics, motor symptoms, neuropsychological performances and 18F-fluorodeoxyglucose positron emission tomography.
  
  
  RESULTS
  Patients who had memory-plus cognitive impairment (patients whose CDR was 0 at baseline and 0.5 in memory and other domains at follow-up, and those whose baseline CDR was 0.5 in memory and other domains) exhibited higher age at onset, visuoperceptual impairment, non-tremor-dominant motor disturbance, rapid symptomatic progression and posterior neocortical hypometabolism. In patients who were cognitively unimpaired and those who had memory-dominant cognitive impairment (patients whose CDR was 0 at baseline and 0.5 only in memory domain at follow-up, and those whose baseline CDR was 0.5 only in memory domain), the posterior neocortex was relatively unaffected until a later stage of the disease.
  
  
  CONCLUSIONS
  These results suggest that visuoperceptual impairment and the early involvement of the posterior neocortex may be risk factors for rapid symptomatic progression and dementia in PD.
authors.affiliation: Department of Behavioral Neurology and Cognitive Neuroscience, Tohoku University School of Medicine, Sendai, Japan.
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Shoji
authors.affiliation: Department of Behavioral Neurology and Cognitive Neuroscience, Tohoku University School of Medicine, Sendai, Japan.
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Nishio
authors.affiliation: Department of Behavioral Neurology and Cognitive Neuroscience, Tohoku University School of Medicine, Sendai, Japan.
authors.forename: Toru
authors.initials: T
authors.lastname: Baba
authors.affiliation: Department of Behavioral Neurology and Cognitive Neuroscience, Tohoku University School of Medicine, Sendai, Japan; Department of Speech, Language and Hearing Sciences, Niigata University of Health and Welfare, Niigata, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Uchiyama
authors.affiliation: Department of Behavioral Neurology and Cognitive Neuroscience, Tohoku University School of Medicine, Sendai, Japan.
authors.forename: Kayoko
authors.initials: K
authors.lastname: Yokoi
authors.affiliation: Department of Occupational Therapy, Saitama Prefectural University, Koshigaya, Japan.
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Ishioka
authors.affiliation: Department of Diagnostic Image Analysis, Tohoku University School of Medicine, Sendai, Japan.
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Hosokai
authors.affiliation: Department of Behavioral Neurology and Cognitive Neuroscience, Tohoku University School of Medicine, Sendai, Japan; Department of Occupational Therapy, Yamagata Prefectural University of Health Science, Yamagata, Japan.
authors.forename: Kazumi
authors.initials: K
authors.lastname: Hirayama
authors.affiliation: Department of Radiology and Nuclear Medicine, Institute of Development, Aging, and Cancer, Tohoku University, Sendai, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Fukuda
authors.affiliation: Department of Neurology, Tohoku University School of Medicine, Sendai, Japan.
authors.forename: Masashi
authors.initials: M
authors.lastname: Aoki
authors.affiliation: Department of Neurology, Tohoku University School of Medicine, Sendai, Japan.
authors.forename: Takafumi
authors.initials: T
authors.lastname: Hasegawa
authors.affiliation: Department of Neurology, Sendai Nishitaga Hospital, Sendai, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Takeda
authors.affiliation: Department of Behavioral Neurology and Cognitive Neuroscience, Tohoku University School of Medicine, Sendai, Japan.
authors.forename: Etsuro
authors.initials: E
authors.lastname: Mori
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003072:Cognition Disorders / Q000145:classification / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology; D003704:Dementia / Q000145:classification / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology; D018450:Disease Progression; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D019579:Neocortex / Q000000981:diagnostic imaging / Q000503:physiopathology; D010300:Parkinson Disease / Q000145:classification / Q000150:complications / Q000000981:diagnostic imaging / Q000503:physiopathology; D049268:Positron-Emission Tomography; D011859:Radiography