Abstract WMP55: Up-front Ct Angiography Of The Head And Neck Imaging For Patients With Low NIH Stroke Scale: Is There Utility?

Abstract

Background: Current guidelines encourage early vascular imaging to assess for large vessel occlusions (LVO) in patients presenting with NIHSS ≥ 6 to establish candidacy for mechanical thrombectomy (MT). In patients with low NIHSS, the benefit of early vascular imaging is uncertain. Cortical signs such as aphasia, neglect or visual field deficits on the exam have been used to identify patients with LVO. Still, the utility of these clinical signs in low NIHSS is unknown. Methods: This is a retrospective analysis of all acute ischemic stroke patients who presented directly to our comprehensive stroke center (CSC) from December 1, 2020-May 31, 2021. All patients had CT angiography (CTA) or MR angiography (MRA) of the head and neck with timing at the discretion of the treating neurologist. Results: Of the 167 patients [median age 70 IQR (58-78), 50% female, 64% African-American], 85 (51%) presented with NIHSS of 0-5. Compared to patients with NIHSS ≥ 6, patients with NIHSS of 0-5 were younger (median age 66 vs. 70, p= 0.039) and had less congestive heart failure (0.6% vs. 4.8%, p=.014). Upfront CTA with initial non-contrast CT head was done less in patients with NIHSS 0-5 (65% vs. 85%, p=.002). Patients with NIHSS 0-5 had fewer LVO (13% vs. 44%, p<.001), less IV tPA administration (7.1% vs. 22%, p=.006), less MT (2.4% vs. 27%, p<.001), and more posterior circulation strokes (42% vs. 13%, p<.001). Of the 11 patients with NIHSS 0-5 and an LVO, 4 (36%) had no cortical signs (aphasia, extinction, or visual field deficit) on the exam. Conclusions: The absence of cortical signs on exam in ischemic stroke patients presenting with NIHSS 0-5 does not exclude LVO. Our cohort with NIHSS 0-5 were less likely to have upfront CTA despite having LVO in 13% of cases. Early upfront vascular imaging should be considered to assess for LVO in all suspected acute ischemic stroke patients regardless of the presence of cortical signs.