Virtual reality-based cognitive-motor training in middle-aged adults at high Alzheimer's disease risk improves frontal cortex cerebral blood flow: A randomized controlled trial.

INTRODUCTION

Alzheimer's disease (AD) pathological processes begin decades before symptom onset. Early intervention in high-risk populations may be crucial for prevention. We investigated the effect of an intervention utilizing virtual reality (VR) cognitive-motor training on cerebral blood flow (CBF) and cognitive functioning in middle-aged adults at high AD risk due to parental history.

METHODS

In this randomized controlled trial, participants (n = 79) were randomly assigned to: VR cognitive-motor training while walking on a treadmill (VR+T, n = 24, treatment); VR cognitive training without treadmill (VR-T, n = 21, active control); treadmill walking while watching documentaries (TV+T, n = 20, active control); or no intervention (n = 14, passive control). Training consisted of 45-min sessions, twice weekly, for 12 weeks. CBF was measured at resting state using arterial spin labeling (ASL) at baseline, 3-month, and 6-month follow-up. Cognition was assessed using a comprehensive neuropsychological battery. We applied the intent-to-treat approach.

RESULTS

All groups improved in executive functions and memory over time (all p-values < 0.05), with no consistent between-group differences at follow-up. CBF of the VR+T group significantly increased at 3 months in the superior (p = 0.013, middle (p = 0.014), and inferior (p = 0.003) frontal gyri compared to the passive control group, which showed a decline in CBF over the same period. No significant differences in frontal CBF change were observed between VR+T and the TV+T active control group. This increase was sustained for 6 months in the superior (p = 0.035) and middle (p = 0.028) frontal gyri. In contrast, in the middle temporal gyrus, the VR+T group had lower CBF at 3 months, compared to the VR-T (p = 0.033) and to the passive control groups (p = 0.004).

DISCUSSION: Cognitive-motor VR training increased CBF in frontal regions susceptible to early AD-related changes in middle-aged adults at high AD risk. This intervention shows promise as a preventive approach and may be suitable for implementation as a home-based program for individuals at high risk.