2025 American Academy of Neurology Abstract Website

Objective:

The USS aims to streamline LVO screening by utilizing multiple validated stroke scales simultaneously.

Background:

This study compares manual stroke scale calculations against e-calculated scores using the USS, a software designed to automate multiple large vessel occlusion (LVO) screening scales from a modified NIHSS.

Design/Methods:

We prospectively applied eight stroke screening scales (NIHSS, BE-FAST, VAN, LAMS, FAST-ED, EMS RACE, 3-ISS, and PASS) to 199 stroke activations between January 2021 and December 2023. In a prospective, external validation study, the scales were later recalculated using the USS with a modified NIHSS score that included hand grip strength. A Bland-Altman analysis was conducted to assess agreement between manual and USS-calculated scores.

Results:

PASS demonstrated the strongest agreement, with minimal bias (mean difference, M = -0.0402), a standard deviation (SD) of 0.315, and narrow Limits of Agreement (LoAs) (-0.657–0.576). BE-FAST and VAN also showed strong agreement, with minimal biases (M = -0.121 and M = -0.106), low SDs (0.369 and 0.367), and tight LoAs (-0.844–0.603 and -0.825–0.614). LAMS showed strong agreement with a small positive bias (M = 0.151), SD: 0.685, and LoAs: -1.19–1.49.

FAST-ED, 3-ISS, and EMS-RACE displayed moderate agreement. FAST-ED had a moderate bias (M = -0.151), SD: 0.991, and LoAs: -2.09–1.79, while 3-ISS had a moderate bias (M = -0.538), SD: 0.981, and LoAs: -2.47–1.39. EMS-RACE had a moderate bias (M = -0.387), SD: 1.43, and wider LoAs (-3.19–2.42).

NIHSS showed the weakest agreement, with the largest bias (M = -0.975), SD: 1.48, and LoAs: -3.87–1.92, reflecting expected discrepancies due to its modification.

Conclusions:

The USS demonstrates strong to moderate agreement with manual methods across tested stroke scales, with minimal biases and consistent performances. With further refinement and larger studies, the USS could become a valuable tool to expedite LVO screening.