title: A systematic review of cognitive decline in dementia with Lewy bodies versus Alzheimer's disease.
abstract: BACKGROUND
  The aim of this review was to investigate whether there is a faster cognitive decline in dementia with Lewy bodies (DLB) than in Alzheimer's disease (AD) over time.
  
  
  METHODS
  PsycINFO and Medline were searched from 1946 to February 2013. A quality rating from 1 to 15 (best) was applied to the included studies. A quantitative meta-analysis was done on studies with mini mental state examination (MMSE) as the outcome measure.
  
  
  RESULTS
  A total of 18 studies were included. Of these, six (36%) reported significant differences in the rate of cognitive decline. Three studies reported a faster cognitive decline on MMSE in patients with mixed DLB and AD compared to pure forms, whereas two studies reported a faster decline on delayed recall and recognition in AD and one in DLB on verbal fluency. Mean quality scores for studies that did or did not differ were not significantly different. Six studies reported MMSE scores and were included in the meta-analysis, which showed no significant difference in annual decline on MMSE between DLB (mean 3.4) and AD (mean 3.3).
  
  
  CONCLUSIONS
  Our findings do not support the hypothesis of a faster rate of cognitive decline in DLB compared to AD. Future studies should apply recent diagnostic criteria, as well as extensive diagnostic evaluation and ideally autopsy diagnosis. Studies with large enough samples, detailed cognitive tests, at least two years follow up and multivariate statistical analysis are also needed.
authors.affiliation: Section of Mental Health Research, Clinic of Psychiatry, Helse-Fonna HF Haugesund Hospital, Haugesund, 5504, Norway ; Old Age Department, Clinic of Psychiatry, Helse-Fonna HF Haugesund Hospital, Haugesund, 5504, Norway.
authors.forename: Monica H
authors.initials: MH
authors.lastname: Breitve
authors.affiliation: Section of Mental Health Research, Clinic of Psychiatry, Helse-Fonna HF Haugesund Hospital, Haugesund, 5504, Norway ; Neurological Department, Clinic of Medicine, Helse-Fonna HF Haugesund Hospital, Haugesund, 5504, Norway.
authors.forename: Luiza J
authors.initials: LJ
authors.lastname: Chwiszczuk
authors.affiliation: Department of Clinical Psychology, University of Bergen, Christies gate 12, Bergen, 5015, Norway ; NKS Olaviken Hospital for Old Age Psychiatry, Ulriksdal 8, Bergen, 5009, Norway.
authors.forename: Minna J
authors.initials: MJ
authors.lastname: Hynninen
authors.affiliation: Section of Mental Health Research, Clinic of Psychiatry, Helse-Fonna HF Haugesund Hospital, Haugesund, 5504, Norway ; Old Age Department, Clinic of Psychiatry, Helse-Fonna HF Haugesund Hospital, Haugesund, 5504, Norway ; Faculty of Medicine, University of Bergen, Bergen, 5020, Norway.
authors.forename: Arvid
authors.initials: A
authors.lastname: Rongve
authors.affiliation: TIPS, Regional Centre for Clinical Research in Psychosis, Stavanger University Hospital, Stavanger, 4068, Norway ; Network for Medical Sciences, Stavanger University Hospital, Stavanger, 4068, Norway.
authors.forename: Kolbjørn
authors.initials: K
authors.lastname: Brønnick
authors.affiliation: Centre for Age Related Medicine, Stavanger University Hospital, Stavanger, 4068, Norway.
authors.forename: Carmen
authors.initials: C
authors.lastname: Janvin
authors.affiliation: Centre for Age Related Medicine, Stavanger University Hospital, Stavanger, 4068, Norway ; Department NVS, Center for Alzheimer Research, Division for Neurogeriatrics, Karolinska Institutet, Huddinge, 14157, Sweden.
authors.forename: Dag
authors.initials: D
authors.lastname: Aarsland