Relationship Of Neutrophil-To-Lymphocyte Ratio To Stroke Subtype And Functional Outcome In Intracranial Artery Dissection.

Background and Purpose: Spontaneous intracranial artery dissection (IAD) might be an underdiagnosed cause of stroke that is defined by the occurrence of a hematoma in the wall of an intracranial artery and develop either ischemic or hemorrhagic stroke, but it is not known about parameters to distinguish ischemic stroke from hemorrhagic stroke. Several studies demonstrated that the neutrophil-to-lymphocyte ratio (NLR) is associated with adverse outcomes in patients with stroke at the time of occurrence. We investigated (i) the association between NLR and stroke subtype, and (ii) the clinical impact of NLR on functional outcome at 3 months after IAD. Methods: We retrieved data on consecutive patients with IAD within one month from onset from prospective cohort databases from February 2011 to November 2016. All patients who were clinically diagnosed with IAD accompanying ischemic or hemorrhagic stroke, or headache alone were principally admitted. We measured WBCs subtype at admission, and examined the relationship between NLR, stroke subtype, and 3-months functional outcome (mRS 0-2 vs 3-6) using logistic regression analysis. Results: Of the total 105 patients with IAD (mean age, 52±2; 30% men), 6 with recurrent IAD and 6 with both hemorrhagic and ischemic stroke were excluded. One patient was also excluded because of missing blood data. Of the remaining 92 patients with IAD analyzed, 33 patients (36%) had ischemic stroke, 34 patients (37%) had hemorrhagic stroke, and 25 patients (27%) had headache alone. In univariate analyses, higher median admission NLR values were documented in patients with hemorrhagic stroke (4.76; IQR, 2.11-13.34) versus patients with headache alone (3.00; IQR, 1.67-4.95); P=0.015), and versus patients with ischemic stroke (3.02; IQR, 1.67-4.95; P=0.02). In multivariate analysis adjusting for age, sex and current smoking, NLR was associated with hemorrhagic stroke [odds ratio (OR) 2.29, 95% CI 1.32-4.00]. After adjustment for age and sex, NLR was independently associated with unfavorable functional outcome (mRS 3-6). Conclusions: NLR appears to be a potential predictor of stroke subtype, especially subsequent hemorrhagic stroke, in patients with IAD.