Neurocognitive Treatment Using Virtual Reality

Dear Editor

We read with great interest the recent study by White and Moussavi ¹ published in the Journal of Experimental Neuroscience. The authors used virtual reality navigation (VRN) to increase cognitive reserve in a patient with mild cognitive impairment (MCI) at the onset to develop Alzheimer disease (AD). Alzheimer disease is a dementia commonly found in the elderly that can cause cognitive impairment in memory and spatial navigation. ² This disease has phases with physical and cognitive impairments of different intensities and complexities that make treatment difficult. ³ The author’s hypothesis is that cognitive training and physical activities increase brain-derived neurotrophic factor, promoting cognitive reserve that may decrease or delay AD symptoms. ⁴ Virtual reality (VR) is a computerized 3-dimensional environment that responds in real time to the interaction of the individual. ⁵ The case report of White and Moussavi ¹ was focused on using their existing VRN task, ⁶ a type of VR, as a cognitive treatment for a patient with MCI and AD. In this environment, the participant had to develop a cognitive map in a building. Error scores and 2 types of training were used. The intervention was performed 3 sessions weekly, during 7 weeks, 2 hours per session. The results showed improvement on spatial navigation scores and decreased number of errors by trials in the VRN Building Assessment. ⁶ Some alteration in the VRN task, ⁶ such as different colors on floors, could standardize the intervention with less interference of the examiner. This could increase the difficulty of the task throughout the sessions leading to benefits to the patients. ⁷ The authors used the Montreal Cognitive Assessment to screen the cognition of the patient. For a clinical trial with larger sample, we suggest a neuropsychological assessment focused on visuospatial memory and navigation changes. Some possibilities are as follows: block design test (Wechsler Adult Intelligence Scale, fourth edition [WAIS-IV]), Corsi block-tapping test, complex figures of Rey, ⁸ Visual Object and Space Perception Battery,^9,10 and also ecological assessments, such as spatial planning task and maze tasks.

A strong point of this study was the development of a custom input system based on a wheelchair to make the navigation more natural for elderly patients without the need of previous training. Despite the interesting wheelchair input system, this can be hard to replicate and newer studies could use the HTC Vive and Oculus Rift (CV1) motion controllers to walk in the real world naturally. The use of physical motion in real life while immersive and moving with a head-mounted display can negate the symptoms of cybersickness. ¹¹ A negative point of this study was the lack of the Simulator Sickness Questionnaire ¹² to evaluate symptoms of cybersickness throughout the sessions. An interesting point in this study was the wife’s positive perception of the results of this treatment in the daily living of her husband. However, this is subjective to the wife and does not necessarily indicate the husband’s feelings about the effects of treatment. Therefore, they could have used Daily Living Scale Pfeffer ¹³ and Beck Depression Inventory ¹⁴ to have more reliable data. As described in this pilot study, the VRN task ⁷ shows promises as a possible treatment to delay or diminish the negative effects of AD. These small caveats, however, do not take away the main message raised by White and Moussavi. ¹

In this way, AD patients can benefit from the standardized and replicable virtual environments that VR can provide, ¹⁵ however, some variables that can be controlled in other to have a stronger evidence of the benefits of the VRN in MCI and AD population.