Résumé
Chronic low back pain is responsible for pathological patterns of prefrontal cortex activation enhancing pain perception and preventing prolonged physical exercise and therefore rehabilitation itself. Distraction is known to diminish pain intensity in chronic pain syndroms. The objective is to research the effect of virtual reality on dorsolateral and medial prefrontal cortex activation patterns using near infrared spectroscopy in chronic low back pain subjects during a physical exercise task (walking on a tilted treadmill) with and without distraction by a virtual reality simulation (BitGym). fNIRS is a brain imaging method using neuro-vascular coupling by measuring levels of oxyhemoglobin within brain cortex. Twelve subjects with non-specific chronic low back pain undergoing a physical rehabilitation program within the Nîmes city hospital were included in the study. Subjects underwent two identical sessions treadmill walk with and without distraction by a virtual reality simulation (BitGym) wearing functional near infrared spectroscopy (fNIRS) equipment in a random order. Oxyhemoglobin concentrations were measured in the dorsolateral and medial prefrontal cortex regions during each treadmill sessions and then compared. No effect of TV-broadcasted virtual reality distraction was demonstrated during this experiment, possibly due to a lack of immersion.