Role of Non-Perfusion Factors in Mildly Symptomatic Large Vessel Occlusion Stroke.

Introduction: Uncertainty regarding reperfusion of mildly-symptomatic (minor) large vessel occlusion (LVO)-strokes exists. Recently, benefits from reperfusion were suggested. However, there is still no strong data to support this. Furthermore, a proportion of those patients don't improve even after non-hemorrhagic reperfusion. Our study evaluated whether or not non-perfusion factors account for such persistent deconditioning.

Methods: Patients with identified minor LVO-strokes (NIHSS ≤ 8) from our stroke alert registry between January-2016 and May-2018 were included. Variables/ predictors of outcome were tested using univariate/multivariate logistic and linear regression analyses. Three month-modified ranking scale (mRS) was used to differentiate between favorable (mRS = 0-2) and unfavorable outcomes (mRS = 3-6).

Results: Eighty-one patients were included. Significant differences between the two outcome groups regarding admission-NIHSS and discharge-NIHSS existed (OR = 0.47, 0.49 / p = 0.0005, <0.0001 respectively).The two groups had matching perfusion measures. In the poor outcome group, discharge-NIHSS was unchanged from the admission-NIHSS while in the good outcome group, discharge-NIHSS significantly improved.

Conclusion: Admission and discharge NIHSS are independent predictors of outcome in patients with minor-LVO strokes. Unchanged discharge-NIHSS predicts worse outcomes while improved discharge-NIHSS predicts good outcomes. Unchanged NIHSS in the poor outcome group was independent of the perfusion parameters. In literature, complement activation and pro-inflammatory responses to ischemia might account for the progression of stroke symptoms in major-strokes. Our study concludes similar phenomena might be present in minor-strokes. Therefore, discharge-NIHSS may be useful as a clinical marker for future therapies.