To determine the impact of neurovascular injury in childhood on cerebral visual impairment (CVI) as evaluated by visual-spatial processing using bedside virtual reality testing.

CVI, characterized by functional vision deficits, is not assessed in standard ophthalmological exams and can delay diagnosis and interventions. Multisystemic Smooth Muscle Dysfunction Syndrome (MSMDS), caused by R179H mutation in the ACTA2 gene is associated with diffuse white matter injury and arterial ischemic strokes. Pediatric strokes are commonly caused by focal disruption of blood flow to the brain affecting grey and white matter.

Using a virtual-reality dynamic visual search task, requiring searching for on-screen targets with increasing complexity, we prospectively characterized metrics of higher-order visual processing in pediatric stroke subjects (n=19), and MSMDS patients (n=4) as compared to healthy controls (n=13). Metrics – reaction time, gaze error, shifted ellipse area, success rate, and pursuit saccade ratio – were analyzed using Kruskal-Wallis and ANOVA tests and significant if p<0.05. An off-screen count metric confirmed task compliance.

While all cohorts had similar success rates, both MSMDS and pediatric stroke subjects showed longer reaction times to identify the target and higher gaze error than controls. Additionally, MSMDS subjects exhibited a larger shifted ellipse area and lower pursuit saccade ratios than controls. Perinatal and pediatric stroke subjects showed no differences, leading us to combine their results as one cohort.

Deficits exhibited by MSMDS and pediatric stroke subjects, despite similar success rates to controls, highlight the compensatory energy used to complete tasks. While plasticity and focality of pediatric stroke injury protect against CVI, globality in MSMDS injury correlates with increasingly more severe CVI. This highlights the need for clinical tools that can assess these difficulties with quantitative methods to guide therapies and improve functional outcomes.