Sensitivity of a Qualitative 5-Element Cortical Sign Screen for Detecting Acute Basilar Artery Occlusion

Large vessel occlusion stroke screens primarily identify anterior circulation large vessel occlusion ischemic strokes. Our primary objective was to assess the sensitivity of FANG-D, which screens for visual Field deficit, Aphasia, Neglect, Gaze preference, and Dense limb weakness, to detect basilar artery occlusion (BAO).

We conducted a retrospective study of BAO strokes (May 2018-February 2024) to assess sensitivity of the FANG-D screen to detect acute BAO. BAO site (proximal, mid, or distal) was confirmed by a neuroradiologist, and occlusions were classified as total or subocclusive. FANG-D was performed by the treating physician; National Institutes of Health Stroke Scale Score (NIHSSS) was performed by neurology consultants.

Of 204 patients with BAO identified, 121 had FANG-D documented. Patients without FANG-D had significantly lower Glasgow Coma Scale (GCS) scores (11 [5-15] and 14 [8-15], respectively). Among BAO patients with FANG-D, sensitivity for detecting subocclusive or total occlusive BAO was 81.8% (74.0%-87.7%). FANG-D negative BAO cases had significantly higher GCS scores (15, IQR: 15-15) and lower NIHSSS (3, IQR: 1-4) than FANG-D positive cases (13, IQR: 7-15 and 12, IQR: 5-25, respectively). The sensitivity of NIHSSS ≥ 6 for detecting BAO in all patients with an NIHSSS (n = 197) was 64.2% (57.4%-70.5%).

A qualitative screen composed of cortical signs lacks sufficient sensitivity to be used alone to screen for acute BAO. Our findings support the importance of considering acute BAO in patients presenting with NIHSSS < 6.