Stroke vision, aphasia, neglect (VAN) assessment—a novel emergent large vessel occlusion screening tool: pilot study and comparison with current clinical severity indices

Abstract

BackgroundIdentification of emergent large vessel occlusion (ELVO) stroke has become increasingly important with the recent publications of favorable acute stroke thrombectomy trials. Multiple screening tools exist but the length of the examination and the false positive rate range from good to adequate. A screening tool was designed and tested in the emergency department using nurse responders without a scoring system.MethodsThe vision, aphasia, and neglect (VAN) screening tool was designed to quickly assess functional neurovascular anatomy. While objective, there is no need to calculate or score with VAN. After training participating nurses to use it, VAN was used as an ELVO screen for all stroke patients on arrival to our emergency room before physician evaluation and CT scan.ResultsThere were 62 consecutive code stroke activations during the pilot study. 19 (31%) of the patients were VAN positive and 24 (39%) had a National Institutes of Health Stroke Scale (NIHSS) score of ≥6. All 14 patients with ELVO were either VAN positive or assigned a NIHSS score ≥6. While both clinical severity thresholds had 100% sensitivity, VAN was more specific (90% vs 74% for NIHSS ≥6). Similarly, while VAN and NIHSS ≥6 had 100% negative predictive value, VAN had a 74% positive predictive value while NIHSS ≥6 had only a 58% positive predictive value.ConclusionsThe VAN screening tool accurately identified ELVO patients and outperformed a NIHSS ≥6 severity threshold and may best allow clinical teams to expedite care and mobilize resources for ELVO patients. A larger study to both validate this screening tool and compare with others is warranted.

Predictive Value of Modifications of the Prehospital Rapid Arterial Occlusion Evaluation Scale for Large Vessel Occlusion in Patients with Acute Stroke

“…The RACE scale score was not detailed item-by-item in 16 cases and therefore we studied 341 patients (53.4% men; age (mean±SD) 70±13 years; NIHSS score at admission (median [interquartile range] 8 [3][4][5][6][7][8][9][10][11][12][13][14][15][16] had 85% sensitivity, 68% specificity and correctly classified 71% patients. The RACE and NIHSS scores were strongly correlated (r=0.78; p<0.001).…”

“…The Cincinnati Prehospital Stroke Severity Scale (CPSSS) was recently created to identify patients with severe AIS and LVO on the basis of a reasoned selection and modification of four NIHSS items (10). The VAN score has been recently designed to detect LVO and includes three cortical items, visual field, aphasia and neglect, added to the motor function (11). None of these scales have been designed based on systematic analysis of the NIHSS items most associated with LVO except the recently published PASS scale that includes level of consciousness, gaze palsy/deviation and arm weakness (12).…”

“…The RACE scale, NIHSS and the presence of LVO were assessed in a prospective cohort of patients admitted to the emergency department as detailed previously (11). RACE was assessed prehospital by EMS.…”

“…Other scales may identify these patients, but have not been validated prospectively or in the field (8)(9)(10)(11)(12). The RACE scale is simple and specifically designed to identify anterior circulation LVO patients (Table 1).…”

Pomona Large Vessel Occlusion Screening Tool for Prehospital and Emergency Room Settings

“…At present, there are several scales that use different clinical signs for identifying LVO patients; however, these scales are not widely used in clinical practice [5]. The most popular scales/scores are the Los Angeles Motor Scale (LAMS), the Cincinnati Prehospital Stroke Severity (CPSS) scale, the Rapid Arterial Occlusion Evaluation (RACE) scale, and the Vision Aphasia and Neglect Scale (VAN) [6-9]. We propose a simple screening tool that is easy to use in both prehospital and emergency room settings (the Pomona Scale).…”