Using Virtual Reality for Assessment and Rehabilitation of AD and MCI Patients: A Selective Overview

1. Introduction

Alzheimer disease (AD) is the primary cause of dementia worldwide (Ritchie & Lovestone, 2002). AD is defined by the National Institute on Aging-Alzheimer’s Association (NIAA; McKhann et al., 2011) as “evidence of progressive cognitive decline on subsequent evaluations based on information from informants and cognitive testing in the context of either formal neuropsychological evaluation or standardized mental status examinations.”

Currently, more than 35 million people are suffering from this disease around the globe (Brookmeyer, Johnson, Ziegler-Graham, & Arrighi, 2007). The basic pathological hallmarks of AD include widespread neuronal synaptic loss, excessive presence of astrocytes, aggregation of multiple proteinaceous deposits for instance β-amyloid plaques and neurofibrillary tangles (NFT) (Murph & LeVine, 2010).

People suffering from dementia are compromised in several cognitive domain (e.g., executive functions), to impede functioning in everyday life and social and occupational functioning. Impairment in the sense of orientation, and memory difficulties are related to the reduction of the temporal cortex volume, especially concerning the hippocampus, as well as the atrophy of the retro-splenial cortex. Serino and Riva (2013) claim that the translation between egocentric and allocentric frames, supported by the retro-splenial cortex, can be the basis of the spatial disorientation deficits. These deficits compromise the ability to link information between two landmarks (egocentric strategy) (Cushman, Stein, & Duffy, 2008). Patients with AD experience difficulties also when using an allocentric strategy (i.e., mental maps) or changing point of view between egocentric and allocentric views (Morganti, Stefanini, & Riva, 2015). These deficits are followed by a progressive decline in basic Activities of Daily Living (Millán-Calenti, Tubío,Pita-Fernández, Rochette, Lorenzo, & Maseda 2012).

Recently, several AD medical rehabilitation studies have shifted the focus to the field of virtual reality (VR) due to the rapid development of such technologies. To investigate everyday activities, virtual-reality offers the opportunity to bridge the gap between in situ approaches and laboratory settings. VR also demonstrates advantages in the treatment of dementia and reminiscence activities allowing experiences to be shared with family. These applications have an intuitive appeal but it remains unclear whether immersive virtual reality (IVR) can support the diagnosis or treatment of AD dementia (Johnson, 2018).

Until now, VR has been more employed in motor neurological disorders or in the treatment of mental health conditions, such as anxiety disorders or psychosis (Cogné et al., 2017). Researchers feared that patients would not tolerate the VR procedure (Flynn et al., 2003), but recently any danger was excluded (Laver et al., 2015). IVR has been utilized in public awareness campaigns allowing users to take reminiscence activities allowing experiences to be shared with family (Johnson, 2018). However, it remains unclear whether IVR can enhance the diagnosis or treatment of AD dementia. Moreover, VR applications are employed today as relevant experimental models of the real world to study how cognitive processes are embodied in complex and more natural behaviors (Rizzo, Schultheis, Kerns, & Mateer, 2004). Thus, immersive environment can easily stimulate the brain based on quantitative electroencephalogram (QEEG) analysis (Anopas & Wongsawat, 2014).