Use of immersive virtual reality to detect unilateral spatial neglect in chronic stroke

Introduction/Background Unilateral spatial neglect (USN) is a neuropsychological syndrome in which patients fail to pay attention to and represent the contralesional part of the space. Standard assessment of USN is carried out with paper-and-pencil tests, which do not capture the full range of deficits (i.e., not sensitive enough; no evaluation of “far” space) or detect compensatory learning effects in chronic patients. Here we explore interactive and ecological assessments within immersive virtual reality (IVR) to overcome these limitations. Material and method Twelve chronic stroke patients (58 ± 9.4 years; 5 female; time from stroke: 15.8 ± 7.7 months) completed a battery of paper-and-pencil neuropsychological tests (line bisection, cancellation, reading, drawing, functional scales) and a IVR-based assessment for extra-personal USN. In the IVR tasks, participants were presented with a virtual environment representing a forest, via head-mounted display ( Fig. 1 ). The tasks consisted of finding static objects (level 1) or moving rabbits (levels 2–4) in the scene. Difficulty was modulated with the presence of distractors and an additional auditory dual task. Participants used the embedded head tracker in the HMD to control a pointer to select the targets in the scene, and the space bar of the computer to validate the selected item. Results Four patients presented USN in both paper-and-pencil and IVR tasks. Interestingly, two other participants showed signs of neglect in the IVR assessment without being classified as neglect patients in the paper-and-pencil tests. These patients did not show signs of USN in the items of the Catherine Bergego Scale that assesses their ability to explore the extra-personal space. Conclusion This preliminary data suggests that IVR-based assessments represent an easy-to-use and consistent tool to investigate USN, can extend its evaluation to the far space, and can detect USN in chronic patients who do not show sign of neglect in standard assessments.