title: Apathy and striatal dopamine defects in non-demented patients with Parkinson's disease.
abstract: BACKGROUND
  Apathy is a common, disabling symptom in Parkinson's disease (PD). The mechanisms underlying apathy in PD are still unclear, although they may be related to dysfunction in the meso-cortico-limbic circuit, including the ventral striatum. Thus, we performed this study to investigate whether dopamine depletion in the ventral striatum contributes to apathy in PD.
  
  
  METHODS
  We conducted a survey of the degree of apathy (using the Korean version of the Apathy Evaluation Scale, AES-S) in 108 non-demented patients with PD who underwent dopamine transporter (DAT) positron emission tomography scans as an initial diagnostic work-up. Patients with AES-S scores of 37 or higher were defined as having apathetic PD. The Beck Depression Inventory (BDI) was administered to assess the severity of depression. Patients with BDI scores of 15 or higher were regarded as having depression.
  
  
  RESULTS
  Apathetic patients (n = 34) tended to exhibit higher BDI scores than non-apathetic patients (n = 74); however, other clinical variables were comparable between the two groups. DAT activity in the striatal sub-regions was also similar between the two groups. Selecting only non-depressed patients, including 20 apathetic and 47 non-apathetic patients, did not alter the results.
  
  
  CONCLUSIONS
  This study demonstrated that the pattern of striatal dopamine depletion does not contribute to the degree of apathy in early PD. Apathy in PD may be associated with extra-striatal lesions that accompany PD rather than striatal dopaminergic deficits.
authors.affiliation: Department of Neurology, Yonsei University College of Medicine, Seoul, South Korea.
authors.forename: Su Jin
authors.initials: SJ
authors.lastname: Chung
authors.affiliation: Department of Neurology, Yonsei University College of Medicine, Seoul, South Korea.
authors.forename: Jae Jung
authors.initials: JJ
authors.lastname: Lee
authors.affiliation: Department of Neurology, Yonsei University College of Medicine, Seoul, South Korea.
authors.forename: Jee Hyun
authors.initials: JH
authors.lastname: Ham
authors.affiliation: Department of Neurology, Yonsei University College of Medicine, Seoul, South Korea; Severance Biomedical Science Institute, Yonsei University College of Medicine, Seoul, South Korea.
authors.forename: Phil Hyu
authors.initials: PH
authors.lastname: Lee
authors.affiliation: Department of Neurology, Yonsei University College of Medicine, Seoul, South Korea. Electronic address: yhsohn62@yuhs.ac.
authors.forename: Young H
authors.initials: YH
authors.lastname: Sohn
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D057565:Apathy / Q000502:physiology*; D003342:Corpus Striatum / Q000000981:diagnostic imaging / Q000378:metabolism*; D004298:Dopamine / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D010300:Parkinson Disease / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000523:psychology*; D049268:Positron-Emission Tomography
chemical_list: D004298:Dopamine
keywords: Apathy; Dopamine; PET; Parkinson's disease; Striatum