Abstract WP178: Evaluation of Low NIHSS Subitems Association With LVO Detection in Large Telestroke Database

Abstract

Background: The benefits of mechanical thrombectomy in low NIHSS score (<6) is unclear and undergoing investigation. Current acute stroke guidelines do not address the utilization of computed tomography angiography (CTA) in low NIHSS largely due to a paucity of data leading to great variation in clinical practice. Understanding the predictive value of NIHSS subitems for LVO may help guide imaging selection. Methods: Acute stroke consultations seen in the emergency department in 227 facilities (27 states) from July 1, 2021 to December 31, 2021 were extracted from the TeleCare by TeleSpecialists TM database. The encounters with CTA performed were reviewed for LVO detected, and NIHSS score with individual subitems. Logistic regression analysis was performed on the NIHSS subitems in total and at NIHSS cutoff points of ≤6, ≤4, and ≤2. Results: A total of 12,668 patients had complete NIHSS subitems available with 1,459 (11.5%) having an LVO and 11,209 without an LVO were extracted. There is a significant difference in the ORs for each subitem. The ORs for patients with NIHSS ≤6 subitems: Level of Consciousness 1.11 (p=0.626), Consciousness Questions 1.36 (p<0.001), Consciousness Commands 1.94 (p<0.001), Best Gaze 1.61 (p=0.061), Visual Field 1.65 (p<0.001), Facial palsy 1.71 (p <0.001), Motor Arm-left 1.43 (p <0.001), Motor arm-right 1.03 (p=0.840), Motor leg-left 0.97 (p=0.758), Motor leg-right 0.83 (p=0.103), Limb ataxia 1.09 (p=0.545), Sensory 0.67 (p=0.001), Language 1.92 (p<0.001), Dysarthria 1.81 (p<0.001), and Neglect 5.78 (p<0.001). Trends in subitems with each lower cutoff were increased odds of LVO with Consciousness Commands, Visual Fields, Language, and Neglect, and lower odds of LVO with Sensation. Conclusions: This analysis shows the limitations of the NIHSS subitems to predict LVO. Despite the trend of lower odds of LVO for Sensation, even with the NIHSS cutoff of ≤2 there would have been 7 LVOs missed. There are 6 subitems showing statistical significance at an NIHSS cutoff of ≤2 which suggests that an NIHSS cutoff, even with these identified subpoints, is not a good CTA candidate selection tool for the detection of all LVOs.