Abstract Body: Both left hemisphere (LH) and right hemisphere (RH) stroke can cause contralesional viewer-centered neglect (VCN) or stimulus-centered neglect (SCN). Studies using perfusion imaging have shown that in acute stroke, hypoperfusion beyond the infarct contributes to deficits, including neglect. However, perfusion imaging is not always available. FLAIR hyperintense vessel (FHV; Fig. 1) number and site estimate the volume and site of hypoperfusion. We hypothesized that FHV rating in the right parietal cortex would contribute to VCN.

A series of 256 consenting acute stroke patients (82 LH and 174 RH) completed a neglect task with 30 ovals – 10 full, 10 with a gap on the left, and 10 with a gap on the right. Patients were asked to circle full ovals and cross out ovals with a gap on either side. We defined VCN as >10% of ovals unmarked after the most extreme mark (Fig. 2), and SCN as neglecting or incorrectly marking >10% of contralesional gaps (Fig. 3). On FLAIR sequences, we identified FHVs in 4 MCA regions: frontal, temporal, parietal, and insular, as well as ACA and PCA territories. Each region was scored from 0 to 2: 0 = no FHVs; 1 = 1-2 FHVs on 1-2 slices; 2 = 3 or more vessels on 1 slice or 3 or more slices with at least 1 FHV (total=0-12). Infarct volume was calculated after manual tracing of lesions on DWI. We used multivariable logistic regression, with the presence of VCN or SCN as the dependent variable, and FHV ratings in each territory, infarct volume, and age as independent variables. We used chi squared tests to test associations between dichotomous variables.

In LH stroke, SCN was more common than VCN (21% vs. 5%; X²= 9.3; p=0.002). VCN was more common in RH than LH stroke (13% vs 5%; X²= 4.1; p=0.04). In RH stroke, left VCN was independently predicted by age (p=0.005), volume of infarct (p<0.0001), and FHV score in the right parietal cortex (p=0.03). Together, these accounted for 40% of the variance in left VCN (pseudo r²= 40.2; p<0.00001). In LH stroke, right VCN was not independently predicted by any variable. However, together, age, infarct volume, and FHV in each region accounted for 52% of the variance in right VCN (pseudo r²= 51.8; p=0.008). SCN was not predicted by these variables.

In conclusion, we showed that left VCN in acute RH stroke can be predicted by age, infarct volume, and FHV score in the right parietal cortex. These results illustrate the usefulness of FHV in specific locations for estimating clinically significant hypoperfusion.