title: Cognitive and cortical thinning patterns of subjective cognitive decline in patients with and without Parkinson's disease.
abstract: BACKGROUND
  Subjective cognitive decline (SCD) has gained attention as a predictor of future cognitive decline in neurodegenerative diseases. Based on the hypothesis that different pathologies may distinctly contribute to SCD, we investigated the cognitive profiles and cortical thickness of patients with SCD, with and without Parkinson's disease (PD).
  
  
  METHODS
  In total, 96 patients experiencing SCD were classified as having PD (SCD-PD(+), n = 49) or no neurological disease (SCD-PD(-), n = 47); cognitively normal subjects without SCD (n = 23) were included as controls. Neurocognitive profiles and cortical thickness were examined using standardized neuropsychological tests and magnetic resonance imaging-based analysis.
  
  
  RESULTS
  No significant differences in demographic characteristics were found among the three groups. Neuropsychological tests demonstrated that the SCD-PD(+) patients had lower semantic fluency than SCD-PD(-) patients and controls, and showed poorer performance in visual memory and confrontational naming than controls, whereas no significant difference in cognitive performance was observed between the SCD-PD(-) patients and controls. Cortical thickness analysis revealed that the SCD-PD(+) patients had focal cortical thinning in the dorsolateral prefrontal, orbitofrontal, parietal, and parahippocampal areas compared with controls. Compared with SCD-PD(-) patients, SCD-PD(+) patients had cortical thinning in the frontal, parahippocampal, and posterior cortical areas.
  
  
  CONCLUSIONS
  Our data show that cortical thinning and cognitive performance in patients with SCD may differ based on the presence of PD, suggesting that SCD in patients with PD reflects disease-related cortical thinning and cognitive dysfunctions more closely than SCD without PD.
authors.affiliation: Department of Neurology, Yonsei University Wonju College of Medicine, Wonju, Republic of Korea.
authors.forename: Jin Yong
authors.initials: JY
authors.lastname: Hong
authors.affiliation: Department of Biomedical Engineering, Hanyang University, Seoul, Republic of Korea.
authors.forename: Hyuk Jin
authors.initials: HJ
authors.lastname: Yun
authors.affiliation: Department of Neurology, Bundang Jesaeng General Hospital, Kwandong University College of Medicine, Seongnam, Republic of Korea.
authors.forename: Mun Kyung
authors.initials: MK
authors.lastname: Sunwoo
authors.affiliation: Department of Neurology and Brain Research Institute, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Jee Hyun
authors.initials: JH
authors.lastname: Ham
authors.affiliation: Department of Biomedical Engineering, Hanyang University, Seoul, Republic of Korea.
authors.forename: Jong-Min
authors.initials: JM
authors.lastname: Lee
authors.affiliation: Department of Neurology and Brain Research Institute, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Young H
authors.initials: YH
authors.lastname: Sohn
authors.affiliation: Department of Neurology and Brain Research Institute, Yonsei University College of Medicine, Seoul, Republic of Korea; Severance Biomedical Science Institute, Yonsei University College of Medicine, Seoul, Republic of Korea. Electronic address: phisland@chol.net.
authors.forename: Phil Hyu
authors.initials: PH
authors.lastname: Lee
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002540:Cerebral Cortex / Q000503:physiopathology; D003071:Cognition / Q000502:physiology*; D003072:Cognition Disorders / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology / Q000523:psychology*; D060825:Cognitive Dysfunction / Q000175:diagnosis / Q000503:physiopathology / Q000523:psychology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008568:Memory / Q000502:physiology*; D008875:Middle Aged; D009483:Neuropsychological Tests; D010300:Parkinson Disease / Q000150:complications / Q000175:diagnosis / Q000523:psychology*
keywords: Parkinson's disease; Semantic fluency; Subjective cognitive decline; cortical thickness