title: Fluctuations in attention: PD dementia vs DLB with parkinsonism.
abstract: BACKGROUND
  Marked impairments in and fluctuation of attention are characteristic of dementia with Lewy bodies (DLB). The comparative impairment of these cognitive domains in PD and PD dementia (PD dementia) has not been studied, and is important to the conceptual understanding of parkinsonian dementias.
  
  
  METHODS
  Detailed evaluations of attention and fluctuating attention (Cognitive Drug Research computerized battery) were undertaken in 278 subjects (50 DLB, 48 PD dementia, 50 PD, 80 AD, 50 elderly controls) from the Newcastle dementia register and the Stavanger PD register (controls, PD, and PD dementia patients were recruited from both centers). DLB, AD, PD, and PD dementia were diagnosed using operationalized criteria.
  
  
  RESULTS
  Impairments in reaction time, vigilance, and fluctuating attention were comparable in patients with DLB and PD dementia, but were less substantially impaired in patients with DLB without parkinsonism. Patients with PD had significantly greater impairment of cognitive reaction time than elderly controls, and comparable impairments of cognitive reaction time to patients with AD. Patients with PD, however, did not exhibit fluctuation of attention.
  
  
  CONCLUSIONS
  The profile of attentional impairments and fluctuating attention is similar in PD dementia and DLB with parkinsonism. The current findings do not support the current arbitrary distinctions between these patient groups. Importantly, patients with PD do not experience fluctuating attention.
authors.affiliation: Institute for Ageing and Health, University of Newcastle, UK. c.g.ballard@ncl.ac.uk
authors.forename: C G
authors.initials: CG
authors.lastname: Ballard
authors.forename: D
authors.initials: D
authors.lastname: Aarsland
authors.forename: I
authors.initials: I
authors.lastname: McKeith
authors.forename: J
authors.initials: J
authors.lastname: O'Brien
authors.forename: A
authors.initials: A
authors.lastname: Gray
authors.forename: F
authors.initials: F
authors.lastname: Cormack
authors.forename: D
authors.initials: D
authors.lastname: Burn
authors.forename: T
authors.initials: T
authors.lastname: Cassidy
authors.forename: R
authors.initials: R
authors.lastname: Starfeldt
authors.forename: J-P
authors.initials: JP
authors.lastname: Larsen
authors.forename: R
authors.initials: R
authors.lastname: Brown
authors.forename: M
authors.initials: M
authors.lastname: Tovee
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001143:Arousal / Q000502:physiology; D001288:Attention / Q000502:physiology*; D003071:Cognition / Q000502:physiology; D003704:Dementia / Q000150:complications / Q000523:psychology*; D004569:Electroencephalography; D005260:Female; D006801:Humans; D020961:Lewy Body Disease / Q000150:complications / Q000523:psychology*; D008297:Male; D009483:Neuropsychological Tests; D010300:Parkinson Disease / Q000150:complications / Q000523:psychology*; D011930:Reaction Time / Q000502:physiology