title: Decreased striatal D2 receptor density associated with severe behavioral abnormality in Alzheimer's disease.
abstract: OBJECTIVE
  Since patients manifesting behavioral and psychological symptoms of dementia (BPSD) are a burden for their families and caregivers, the underlying neurobiological mechanism of this condition should be clarified. Using positron emission tomography (PET), we previously reported that wandering behavior in dementia was associated with a disturbed dopaminergic neuron system. We herein investigated the relationship between the severity of BPSD and the striatal D2 receptor density in Alzheimer's disease (AD).
  
  
  METHODS
  Ten patients with probable AD as per the National Institute of Neurological and Communicative Disorders and Stroke (NINCDS) and the AD and Related Disorders Association (ADRDA) criteria and five normal subjects were examined with PET. The tracer used was [11C]raclopride (D2 antagonist). The uptake of [11C] raclopride was calculated as the estimation of binding potential (BP) of the striatum to the cerebellum. The AD patients were institutionalized in multiple nursing homes, and their BPSD were evaluated by the Behavioral Pathology in AD Frequency Weighted Severity Scale (BEHAVE-AD-FW) scale (Reisberg).
  
  
  RESULTS
  There was a significant inverse Spearman's correlation between BEHAVE-AD-FW score and the BP, especially between the score of the behavioral domain and the BP values. The BP was found to be lower in severer BPSD patients.
  
  
  CONCLUSIONS
  Patients with AD who manifest severe BPSD may have some dysfunction of striatal dopamine metabolism compared with those without BPSD.
authors.affiliation: Division of Neuropsychology, Department of Disability Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Tanaka
authors.forename: Kenichi
authors.initials: K
authors.lastname: Meguro
authors.forename: Satoshi
authors.initials: S
authors.lastname: Yamaguchi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ishii
authors.forename: Shoichi
authors.initials: S
authors.lastname: Watanuki
authors.forename: Yoshihito
authors.initials: Y
authors.lastname: Funaki
authors.forename: Keiichiro
authors.initials: K
authors.lastname: Yamaguchi
authors.forename: Atsushi
authors.initials: A
authors.lastname: Yamadori
authors.forename: Ren
authors.initials: R
authors.lastname: Iwata
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Itoh
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000150:complications / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000378:metabolism*; D003342:Corpus Striatum / Q000000981:diagnostic imaging* / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D001523:Mental Disorders / Q000000981:diagnostic imaging* / Q000209:etiology / Q000378:metabolism*; D020891:Raclopride / Q000493:pharmacokinetics; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D017448:Receptors, Dopamine D2 / Q000378:metabolism*; D013223:Statistics as Topic; D014055:Tomography, Emission-Computed / Q000379:methods
chemical_list: D019275:Radiopharmaceuticals; D017448:Receptors, Dopamine D2; D020891:Raclopride