title: Cognitive profile of Parkinson's disease patients: a comparative study between early-onset and late-onset Parkinson's disease.
abstract: OBJECTIVE
  To investigate the influence of onset age on the occurrence and progression of cognitive dysfunction using neuropsychological tests and the electrophysiological component P300 in both early-onset Parkinson's disease (EOPD) and late-onset Parkinson's disease (LOPD) patients.
  
  
  METHODS
  A cohort of 76 EOPD patients and 166 LOPD patients was recruited for this study. Demographic information and clinical features, including age, disease duration, education level, family history, the Unified Parkinson's Disease Rating Scale, the Hoehn and Yahr stage, and depression scores were documented for each patient. The Mini-Mental State Examination, Montreal Cognitive Assessment (MoCA), Wechsler Adult Intelligence Scale - Revised, Chinese version (WAIS-RC) and Wechsler Memory Scale - Revised, Chinese version (WMS-RC) were used. In addition, P300 was also examined to assess cognitive function.
  
  
  RESULTS
  Although EOPD patients had longer disease duration, their cognitive dysfunction progressed more slowly. The MoCA tests revealed that EOPD patients had higher scores in visuospatial function, attention, delayed recall, and orientation than the LOPD patients. The difference between the two groups on the WMS-RC test did not reach significance, whereas the scores in executive function, visuospatial function and attention as measured on the WAIS-RC test were significantly lower in the LOPD group. In addition, P300 latencies were markedly delayed and P300 amplitudes were reduced in the LOPD group.
  
  
  CONCLUSIONS
  The current findings demonstrated that cognitive dysfunction progressed more slowly in the EOPD group. Although the LOPD patients exhibited shorter disease durations, their cognitive abilities, including executive function, visuospatial function and attention, may have been impaired.
authors.affiliation: a Southern Medical University , Guangzhou , Guangdong Province , China.|b Department of Neurology, Guangdong Neuroscience Institute , Guangdong General Hospital and Guangdong Academy of Medical Sciences , Guangzhou , Guangdong Province , China.
authors.forename: Hongmei
authors.initials: H
authors.lastname: Tang
authors.affiliation: b Department of Neurology, Guangdong Neuroscience Institute , Guangdong General Hospital and Guangdong Academy of Medical Sciences , Guangzhou , Guangdong Province , China.
authors.forename: Jing
authors.initials: J
authors.lastname: Huang
authors.affiliation: b Department of Neurology, Guangdong Neuroscience Institute , Guangdong General Hospital and Guangdong Academy of Medical Sciences , Guangzhou , Guangdong Province , China.
authors.forename: Kun
authors.initials: K
authors.lastname: Nie
authors.affiliation: b Department of Neurology, Guangdong Neuroscience Institute , Guangdong General Hospital and Guangdong Academy of Medical Sciences , Guangzhou , Guangdong Province , China.
authors.forename: Rong
authors.initials: R
authors.lastname: Gan
authors.affiliation: b Department of Neurology, Guangdong Neuroscience Institute , Guangdong General Hospital and Guangdong Academy of Medical Sciences , Guangzhou , Guangdong Province , China.
authors.forename: Limin
authors.initials: L
authors.lastname: Wang
authors.affiliation: b Department of Neurology, Guangdong Neuroscience Institute , Guangdong General Hospital and Guangdong Academy of Medical Sciences , Guangzhou , Guangdong Province , China.
authors.forename: Jiehao
authors.initials: J
authors.lastname: Zhao
authors.affiliation: b Department of Neurology, Guangdong Neuroscience Institute , Guangdong General Hospital and Guangdong Academy of Medical Sciences , Guangzhou , Guangdong Province , China.
authors.forename: Zhiheng
authors.initials: Z
authors.lastname: Huang
authors.affiliation: b Department of Neurology, Guangdong Neuroscience Institute , Guangdong General Hospital and Guangdong Academy of Medical Sciences , Guangzhou , Guangdong Province , China.
authors.forename: Yuhu
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: b Department of Neurology, Guangdong Neuroscience Institute , Guangdong General Hospital and Guangdong Academy of Medical Sciences , Guangzhou , Guangdong Province , China.
authors.forename: Lijuan
authors.initials: L
authors.lastname: Wang
mesh_terms: D017668:Age of Onset; D000368:Aged; D001288:Attention / Q000502:physiology*; D003071:Cognition / Q000502:physiology*; D056344:Executive Function / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D010300:Parkinson Disease / Q000175:diagnosis / Q000523:psychology*
keywords: Parkinson's disease; age of onset; cognitive function; early-onset Parkinson's disease (EOPD); late-onset Parkinson's disease (LOPD)