title: A review of the cognitive and behavioral sequelae of Parkinson's disease: relationship to frontostriatal circuitry.
abstract: BACKGROUND
  Parkinson's disease is a neurodegenerative hypokinetic movement disorder presenting with subcortical pathology and characterized by motor deficits. However, as is frequently reported in the literature, patients with Parkinson's disease can also exhibit cognitive and behavioral impairments. These impairments may be attributed to dysfunction of multiple systems associated with the disease process in Parkinson's disease that are not necessarily related to motor symptoms. In recent years, considerable attention has addressed the circuits connecting the frontal cortical regions and the basal ganglia (i.e., frontostriatal circuits) and how they mediate cognition and behavior in humans. It has been suggested that these same circuits are disrupted in Parkinson's disease and may be responsible for the frontal/executive deficits predominantly reported in this patient population.
  
  
  OBJECTIVE
  The current survey of the literature provides a critique and analysis of the neuropsychological profile of Parkinson's disease, including cognitive impairments, behavioral alterations, and emotional processing deficits. A special feature of this paper is to ascertain how frontostriatal circuitry might provide the substrate for the neuropsychological impairments exhibited in Parkinson's disease. In so doing, studies involving nonhuman subjects, neurologically healthy adults, brain-lesioned individuals, and patients with Parkinson's disease are reviewed to provide a novel perspective in conceptualizing and categorizing the cognitive and behavioral sequelae concomitant to specific frontostriatal circuit dysfunction in Parkinson's disease.
  
  
  CONCLUSIONS
  The current review suggests that the neuropsychological profile of Parkinson's disease, which predominantly reflects frontal/executive dysfunction, may be attributed to disruption of the frontostriatal circuitry. The information generated from this review can serve as a guide in the assessment of frontal/executive dysfunction in Parkinson's disease with suggestions for a clinical neuropsychological test battery.
authors.affiliation: Queens College and The Graduate Center of the City University of New York, Flushing, New York 11367, USA. neurodjz@juno.com
authors.forename: Dennis J
authors.initials: DJ
authors.lastname: Zgaljardic
authors.forename: Joan C
authors.initials: JC
authors.lastname: Borod
authors.forename: Nancy S
authors.initials: NS
authors.lastname: Foldi
authors.forename: Paul
authors.initials: P
authors.lastname: Mattis
mesh_terms: D000339:Affect; D000818:Animals; D001288:Attention; D003072:Cognition Disorders / Q000209:etiology / Q000503:physiopathology* / Q000523:psychology; D003342:Corpus Striatum / Q000502:physiology / Q000503:physiopathology*; D004644:Emotions; D005625:Frontal Lobe / Q000502:physiology / Q000503:physiopathology*; D006179:Gyrus Cinguli / Q000503:physiopathology; D006801:Humans; D007802:Language; D008568:Memory; D009483:Neuropsychological Tests; D010300:Parkinson Disease / Q000503:physiopathology* / Q000523:psychology*; D017397:Prefrontal Cortex / Q000503:physiopathology; D013028:Space Perception; D013060:Speech; D014796:Visual Perception