title: Clinical and Cognitive Phenotype of Mild Cognitive Impairment Evolving to Dementia with Lewy Bodies.
abstract: OBJECTIVE
  The aim of this study was to determine which characteristics could better distinguish dementia with Lewy bodies (DLB) from Alzheimer's disease (AD) at the mild cognitive impairment (MCI) stage, with particular emphasis on visual space and object perception abilities.
  
  
  METHODS
  Fifty-three patients with mild cognitive deficits that were eventually diagnosed with probable DLB (MCI-DLB: n = 25) and AD (MCI-AD: n = 28) at a 3-year follow-up were retrospectively studied. At the first visit, the patients underwent cognitive assessment including the Qualitative Scoring Mini Mental State Examination Pentagon Test and the Visual Object and Space Perception Battery. The Neuropsychiatric Inventory Questionnaire, Unified Parkinson's Disease Rating Scale (UPDRS) and questionnaires for cognitive fluctuations and sleep disorders were also administered.
  
  
  RESULTS
  The best clinical predictor of DLB was the presence of soft extrapyramidal signs (mean UPDRS score: 4.04 ± 5.9) detected in 72% of patients, followed by REM sleep behavior disorder (60%) and fluctuations (60%). Wrong performances in the pentagon's number of angles were obtained in 44% of DLB and 3.7% of AD patients and correlated with speed of visual attention. Executive functions, visual attention and visuospatial abilities were worse in DLB, while verbal episodic memory impairment was greater in AD. Deficits in the visual-perceptual domain were present in both MCI-DLB and AD.
  
  
  CONCLUSIONS
  Poor performance in the pentagon's number of angles is specific of DLB and correlates with speed of visual attention. The dorsal visual stream seems specifically more impaired in MCI-DLB with respect to the ventral visual stream, the latter being involved in both DLB and AD. These cognitive features, associated with subtle extrapyramidal signs, should alert clinicians to a diagnostic hypothesis of DLB.
authors.affiliation: Department of Neurosciences, University of Padova, Padova, Italy ; IRCCS San Camillo Research Hospital, Venice, Italy.
authors.forename: Annachiara
authors.initials: A
authors.lastname: Cagnin
authors.affiliation: Department of Neurosciences, University of Padova, Padova, Italy.
authors.forename: Cinzia
authors.initials: C
authors.lastname: Bussè
authors.affiliation: Department of Neuroscience, University of Parma, Italy ; Center for Cognitive Disorders, AUSL of Parma, Parma, Italy.
authors.forename: Simona
authors.initials: S
authors.lastname: Gardini
authors.affiliation: Department of Neurosciences, University of Padova, Padova, Italy ; IRCCS San Camillo Research Hospital, Venice, Italy.
authors.forename: Nela
authors.initials: N
authors.lastname: Jelcic
authors.affiliation: Department of Neuroscience, University of Parma, Italy ; Center for Cognitive Disorders, AUSL of Parma, Parma, Italy.
authors.forename: Caterina
authors.initials: C
authors.lastname: Guzzo
authors.affiliation: Department of Neurosciences, University of Padova, Padova, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Gnoato
authors.affiliation: IRCCS San Camillo Research Hospital, Venice, Italy.
authors.forename: Micaela
authors.initials: M
authors.lastname: Mitolo
authors.affiliation: Department of Neurosciences, University of Padova, Padova, Italy.
authors.forename: Mario
authors.initials: M
authors.lastname: Ermani
authors.affiliation: Department of Neuroscience, University of Parma, Italy ; Center for Cognitive Disorders, AUSL of Parma, Parma, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Caffarra
keywords: Dementia with Lewy bodies; Mild cognitive impairment; Mini Mental State Examination; Visuoconstructional abilities