title: Virtual multiple errands test (VMET): a virtual reality-based tool to detect early executive functions deficit in Parkinson's disease.
abstract: BACKGROUND
  Several recent studies have pointed out that early impairment of executive functions (EFs) in Parkinson's Disease (PD) may be a crucial marker to detect patients at risk for developing dementia. The main objective of this study was to compare the performances of PD patients with mild cognitive impairment (PD-MCI) with PD patients with normal cognition (PD-NC) and a control group (CG) using a traditional assessment of EFs and the Virtual Multiple Errands Test (VMET), a virtual reality (VR)-based tool. In order to understand which subcomponents of EFs are early impaired, this experimental study aimed to investigate specifically which instrument best discriminates among these three groups.
  
  
  METHODS
  The study included three groups of 15 individuals each (for a total of 45 participants): 15 PD-NC; 15 PD-MCI, and 15 cognitively healthy individuals (CG). To assess the global neuropsychological functioning and the EFs, several tests (including the Mini Mental State Examination (MMSE), Clock Drawing Test, and Tower of London test) were administered to the participants. The VMET was used for a more ecologically valid neuropsychological evaluation of EFs.
  
  
  RESULTS
  Findings revealed significant differences in the VMET scores between the PD-NC patients vs. the controls. In particular, patients made more errors in the tasks of the VMET, and showed a poorer ability to use effective strategies to complete the tasks. This VMET result seems to be more sensitive in the early detection of executive deficits because these two groups did not differ in the traditional assessment of EFs (neuropsychological battery).
  
  
  CONCLUSIONS
  This study offers initial evidence that a more ecologically valid evaluation of EFs is more likely to lead to detection of subtle executive deficits.
authors.affiliation: Applied Technology for Neuro-Psychology Lab, IRCCS Istituto Auxologico Italiano Milano, Italy.
authors.forename: Pietro
authors.initials: P
authors.lastname: Cipresso
authors.affiliation: Division of Neurology and Neurorehabilitation, IRCCS Istituto Auxologico Italiano Oggebbio, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Albani
authors.affiliation: Applied Technology for Neuro-Psychology Lab, IRCCS Istituto Auxologico Italiano Milano, Italy.
authors.forename: Silvia
authors.initials: S
authors.lastname: Serino
authors.affiliation: Applied Technology for Neuro-Psychology Lab, IRCCS Istituto Auxologico Italiano Milano, Italy.
authors.forename: Elisa
authors.initials: E
authors.lastname: Pedroli
authors.affiliation: Applied Technology for Neuro-Psychology Lab, IRCCS Istituto Auxologico Italiano Milano, Italy.
authors.forename: Federica
authors.initials: F
authors.lastname: Pallavicini
authors.affiliation: Division of Neurology and Neurorehabilitation, IRCCS Istituto Auxologico Italiano Oggebbio, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Mauro
authors.affiliation: Applied Technology for Neuro-Psychology Lab, IRCCS Istituto Auxologico Italiano Milano, Italy ; Department of Psychology, Università Cattolica del Sacro Cuore Milano, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Riva
keywords: Parkinson’s disease; VMET; executive function; mild cognitive impairment; psychometric assessment; virtual reality