title: Neuropsychological profile in early Parkinson's disease: Comparison between patients with right side onset versus left side onset of motor symptoms.
abstract: OBJECTIVE
  Though impaired cognition in Parkinson's disease (PD) is well known, data in early PD is sparse. This study was designed to assess the cognitive profile in patients with early PD (motor symptoms <5 years and Hoehn and Yahr stage <2), and to compare the cognitive profile between these patients with right versus left side onset of motor symptoms.
  
  
  METHODS
  National Institute of National Health and Neurosciences (NIMHANS) neuropsychological battery was used to assess the cognitive profile in 50 patients with early PD and compared with 50 age-, education-, and gender-matched healthy controls. Within the PD group, the cognitive profile was also compared between patients with right side onset motor symptoms (RPD) versus those with left side onset (LPD). The neuropsychological tests assessed the executive functions, memory, attention, visuospatial functions, and psychomotor speed.
  
  
  RESULTS
  Among the 50 patients, 25 each were RPD and LPD. The two subgroups were matched for age, gender, education, age at disease onset, disease duration, and degree of motor disability. There was no significant difference between the groups on Hoehn and Yahr staging or Unified Parkinson Disease Rating Scale (UPDRS) motor score. Patients with early PD performed significantly worse in the tasks involving memory, executive functions, and attention compared to controls. However, there was no difference in the cognitive profile between RPD and LPD subgroups.
  
  
  CONCLUSIONS
  Patients with early PD have cognitive dysfunction with predominant involvement of frontal and temporal lobes. Side of onset of motor symptoms probably does not have significant role in future development or profile of cognitive dysfunction in PD.
authors.affiliation: Department of Neurology, National Institute of Mental Health and Neurosciences, Bangalore, Karnataka, India.
authors.forename: Sikandar
authors.initials: S
authors.lastname: Adwani
authors.affiliation: Department of Neurology, National Institute of Mental Health and Neurosciences, Bangalore, Karnataka, India.
authors.forename: Ravi
authors.initials: R
authors.lastname: Yadav
authors.affiliation: Department of Clinical Psychology, National Institute of Mental Health and Neurosciences, Bangalore, Karnataka, India.
authors.forename: Keshav
authors.initials: K
authors.lastname: Kumar
authors.affiliation: Department of Neurology, National Institute of Mental Health and Neurosciences, Bangalore, Karnataka, India.
authors.forename: S R
authors.initials: SR
authors.lastname: Chandra
authors.affiliation: Department of Neurology, National Institute of Mental Health and Neurosciences, Bangalore, Karnataka, India.
authors.forename: Pramod Kumar
authors.initials: PK
authors.lastname: Pal
keywords: Cognition; executive functions; laterality of motor symptoms; left side onse; memory; parkinson's disease; right side onset