What guides decision-making on intravenous thrombolysis in acute vestibular syndrome and suspected ischemic stroke in the posterior circulation?

Abstract

Intravenous thrombolysis (IVT) is rarely performed in dizzy patients with acute vestibular syndrome (AVS) or acute imbalance (AIS) even if posterior circulation stroke (PCS) is suspected. Decision-making may be affected by uncertainties in discriminating central from peripheral vestibulopathy or concerns of IVT-related harm, particularly intracerebral hemorrhage (ICH), but related studies are missing. Using an in-house register of dizzy patients coming to the emergency room, we identified 29 AVS/AIS patients who presented within 4.5 h after onset, revealed clinical signs indicative of PCS (central oculomotor signs, mild focal abnormalities), and had non-contrast computed tomography (NCCT). Patients treated with IVT (n = 15) were compared to NoIVT patients (n = 14) with regard to clinical and imaging (including perfusion computed tomography, CTP) parameters, occurrence of ICH and short-term clinical outcome (NIHSS improvement; ability to walk independently). IVT and NoIVT patients did not differ in baseline characteristics, central oculomotor signs, or clinical outcome. IVT patients more often exhibited disabling vestibular symptoms (severe dizziness/vertigo, inability to stand unsupported) and focal abnormalities than NoIVT patients. There was no ICH in either group. CTP was performed in 0% of NoIVT versus 80% of IVT patients, seven of twelve revealing posterior circulation hypoperfusion. Comparison of initial hypoperfusion (CTP) and final stroke (NCCT) revealed IVT-related benefit (smaller lesion) in three of seven IVT patients. In AVS/AIS patients with suspected PCS, disabling vestibular symptoms, focal neurological deficits, and hypoperfusion on CTP seem to direct decision-making pro IVT. In our small cohort, there were no significant IVT-related clinical benefits, no IVT-related ICHs, and salvage of brain tissue in some patients.

Usability of the head impulse test in routine clinical practice in the emergency department to differentiate vestibular neuritis from stroke

“…Similar to the latter study, nonexperts revealed high sensitivity (88%) for VN but at the cost of low specificity (64%), reflected by many false‐abnormal bHITs in PCS. Although this may constitute only a minor problem in an elective outpatient visit, it represents a major fault in the emergency setting where a stroke must not be missed, as early treatment and monitoring is mandatory [25,26].…”

A Simple Gain-Based Evaluation of the Video Head Impulse Test Reliably Detects Normal Vestibulo-Ocular Reflex Indicative of Stroke in Patients With Acute Vestibular Syndrome

“…As shown by our additional analysis, a higher cutoff (0.8) can indeed increase the algorithm's sensitivity for peripheral vestibulopathy but at the same time reduces its specificity, thereby increasing the risk to falsely classify a stroke patient's VOR as abnormal/peripheral. Especially when evaluating AVS patients in an emergency setting, identification of stroke is most critical for clinical decision-making on diagnostics, monitoring and therapy (35). For this population and clinical setting, we [and others (25)] suggest to use the 0.7 as a more conservative cutoff gain for pathological VOR.…”

“…If the VOR gain of at least one side is equal or below 0.7, patients should be stratified to the suspected diagnosis of peripheral vestibulopathy and not undergo further stroke-related diagnostics, as this can save imaging and monitoring resources or even unnecessary hospitalization. In contrast, those with a bilateral VOR gain above 0.7 should be assigned to "suspected PCS" and accordingly receive the necessary stroke assessment including brain imaging, monitoring on a stroke unit and where appropriate antiplatelet/anticoagulatory medication, and in severe cases should also be evaluated for potential eligibility for intravenous thrombolysis (35).…”

Pitfalls in the Diagnosis of Posterior Circulation Stroke in the Emergency Setting

“…Studies suggest that the sensitivity of CT for the detection of acute PCS is low (52) and that a negative CT may lead to false reassurance and missed stroke diagnoses in the emergency setting, especially in patients with less severe or inconclusive symptoms (53). To some extent, this disadvantage is attenuated when multimodal CT-imaging (CT angiography and CT perfusion) is employed, as reported for patients with acute vestibular syndrome who received intravenous thrombolysis triggered by information supplied by these procedures (54). One study found that while there were lower rates of early ischemic signs on admission CT and overall arterial pathology in PCS than in ACS, intracranial arterial pathology was more prevalent in the former (49).…”