Video head impulse testing to differentiate vestibular neuritis from posterior circulation stroke in the emergency department: a prospective observational study.

Background and aims: Vertigo is a common presentation to the emergency department (ED) with 5% of presentations due to posterior circulation stroke (PCS). Bedside investigations such as the head impulse test (HIT) are used to risk stratify patients, but interpretation is operator dependent. The video HIT (v-HIT) provides objective measurement of the vestibular-ocular-reflex (VOR) and may improve diagnostic accuracy in acute vestibular syndrome (AVS). We aimed to evaluate the use of v-HIT as an adjunct to clinical assessment to acutely differentiate vestibular neuritis (VN) from PCS. Methods: 133 patients with AVS were consecutively enrolled from the ED of our comprehensive stroke centre between 2018 and 2021. Patient assessment included a targeted vestibular history, HINTs examination (Head Impulse, Nystagmus and Test of Skew), v-HIT and MRI>48 hours after symptom onset. The HINTS/v-HIT findings were analysed and compared between VN, PCS and other cause AVS. Clinical course, v-HIT and MRI findings were used to determine diagnosis. Results: Final diagnosis was VN in 40%, PCS 15%, migraine 16% and other cause AVS 29%. PCS patients were older than VN patients (mean age 68.5±10.6 vs 60.1±14.2 years, p=0.14) and had more cardiovascular risk factors (3 vs 2, p=0.002). Mean VOR gain was reduced (<0.8) in ipsilateral horizontal and (<0.7) anterior canals in VN but was normal in PCS, migraine and other cause AVS. V-HIT combined with HINTs was 89% sensitive and 96% specific for a diagnosis of VN. Conclusions V-HIT combined with HINTs is a reliable tool to exclude PCS in the ED.

Factors Associated with Stroke Misdiagnosis in the Emergency Department: A Retrospective Case-Control Study.

BACKGROUND: Failure to recognise acute stroke may result in worse outcomes due to missed opportunity for acute stroke therapies. Our study examines factors associated with stroke misdiagnosis in patients admitted to a large comprehensive stroke centre. METHODS: Retrospective review comparing 156 consecutive stroke patients misdiagnosed in emergency department (ED) with 156 randomly selected stroke controls matched for age, gender, language spoken and stroke subtype for the period 2014-2016. RESULTS: There were 141 ischemic and 15 hemorrhagic misdiagnosed strokes (median age: 77 years, male:female = 1.3: 1). Symptom resolution, altered mental status, nausea/vomiting, dizziness and vertigo favored misdiagnosis (p < 0.05). Hemiparesis and dysarthria favored an accurate diagnosis (p < 0.05). Misdiagnosed patients were more commonly triaged into a lower ED category (62 vs. 42%, p = 0.001), clinically assessed as Face, Arm, Speech and Time (FAST) - negative (78 vs. 22%, p < 0.001) and underwent delayed CT imaging (median 4.1 vs. 1.5 h, p < 0.001). Misdiagnosed patients were more likely to have posterior circulation stroke (PCS; 39 vs. 22%, p = 0.01) and be admitted under non-neurological services (35 vs. 11%, p < 0.001) with worse discharge outcomes including increased mortality. CONCLUSIONS: Patients with stroke misdiagnosis were commonly FAST-negative with nonspecific symptoms including altered mental status, dizziness and nausea/vomiting often associated with PCS. Improved diagnostic accuracy may increase access to acute therapies.