Abstract W P319: Isolated National Institute of Health Stroke Scale Subscore Worsening is Predictive of Poor Outcomes in Acute Ischemic Stroke Patients

Abstract

Background and Objective: Neurological deterioration is common and contributes to poor outcome after acute ischemic stroke (AIS). The aim of this study is to determine if National Institutes of Health Stroke Scale (NIHSS) subscore changes, in the absence of an increase in total NIHSS score, are associated with poor outcomes. Methods: We conducted a retrospective analysis on patients with AIS who presented to our center (07/08-12/10). Two-point ND was defined as ≥2-point worsening on the total NIHSS within 24 hours of admission. NIHSS subscore neurologic deterioration (sND) was defined as a ≥1-point worsening on one or more individual NIHSS item, in the absence of 2-point ND, within 24 hours of admission. Poor functional outcome at the time of discharge (discharge mRS >2) was the primary outcome measure and was compared among patients who experienced sND, those who experienced 2-point ND, and patients with no worsening. Individual NIHSS worsening of particular items on the scale were analyzed. Results: A total of 522 patients met inclusion criteria. Patients with sND were at increased odds of poor functional outcome (discharge mRS >2, OR 2.08, 95% CI 1.33-3.25, p=0.001) even after adjusting for age, baseline NIHSS score, and glucose on presentation (Table 1). The association of sND with unfavorable discharge disposition was not maintained after covariate adjustment (OR 1.45, 95% CI 0.82-2.55, p=0.200). The odds of poor functional outcome and unfavorable discharge disposition were highest for isolated deterioration of level of consciousness (LOC) 1a followed by a worsening for motor in any limb (Table 2). Conclusion: In our population of patients with AIS, an isolated sND in the absence of 2-point ND was shown to be predictive of poor outcome. This suggests that sND, specifically for LOC 1a and motor limbs, should be included in the scope of the ND definition.