Title: HINTS to diagnose posterior circulation stroke in patients with acute vertigo
Funder: Health Education England

Abstract: Background: Acute vertigo is the commonest presenting symptom of Posterior Circulation (PC) stroke. However, the acute vertigo presentation in patients with PC stroke can mimic acute peripheral vestibular disorders. More than a third of PC strokes are misdiagnosed in emergency settings. Unrecognised PC stroke on initial assessment could increase the risk of death. A careful eye movement assessment may be the only method to identify PC stroke in the hyperacute stage in these patients. The HINTS-plus, a four-step bedside evaluation encompasses a clinical assessment of Head Impulse test (HI), Nystagmus (N), and Test of Skew deviation (TS), plus a bedside hearing assessment, has been shown to outperform early Diffusion-Weighted MRI, but if it is performed by specialists. We recently surveyed UK frontline clinicians' perspectives on the use of the HINTS assessment for the diagnosis of PC stroke and our results demonstrated a lack of awareness and low confidence in the performance and interpretation of the HINTS-plus assessment in emergency settings. Training emergency and stroke clinicians to perform and interpret the HINTS-plus assessment could lead to earlier stroke diagnosis and more efficient testing and triage decisions for patients with vertigo. But these methods need validation. Furthermore, the diagnostic accuracy of HINTS-plus assessment has never been evaluated in a UK hyperacute setting. Aim: To introduce the HINTS-plus assessment in the high-risk emergency setting of hyperacute and emergency stroke units (HASU and ESU) and analyse factors influencing the contribution of HINTS-plus to accurate diagnosis of PC stroke in patients presenting with vertigo. Objectives To provide structured training in clinical HINTS-plus assessment to stroke and emergency clinicians To validate the diagnostic accuracy of the HINTS-plus assessment after the training programme To conduct a qualitative evaluation with the trained clinicians to identify feasibility and acceptability factors to perform the clinical HINTS-plus assessment in hyperacute stroke units Methods:Stage 1: I will train stroke and emergency clinicians (University College London Hospitals) to perform, document and interpret the HINTS-plus assessment correctly and confidently.Stage 2: Two hundred and sixty patients with acute vertigo will be recruited. All patients will undergo the HINTS-plus assessment (index test) and then a delayed DW MRI scan 24-72 hours after their first symptom (reference standard).Stage 3: I will then invite trained clinicians to discuss factors that might prevent or encourage their HINTS-plus assessment usage in the future. Anticipated impact and dissemination: It is anticipated that the full study output will inform guidelines and be used to develop a planned diagnostic pathway for patients with acute vertigo with an impact on NHS practice. This research's potential impact will go beyond the hospital emergency settings, and over the longer term will benefit other services such as paramedics, ambulance, or primary care settings. First, this work will be submitted as national and international conference abstracts and posters during my research plan. The findings will also be disseminated in peer-reviewed journals, patient education brochures, health-related lay journals, and contribute to patient and consumer information sections on relevant websites concerned with health issues.

Lay abstract: Aim: To look at whether a test called HINTS can spot a stroke in patients with severe dizziness. Background: 'Vertigo' or 'dizziness' is a common symptom of many conditions. While some of these conditions are harmless, others may be life-threatening, such as stroke. Strokes presenting with vertigo are often missed. Doctors find them difficult to detect because they might not be seen on a brain scan in the first 24 hours after they happen. Because of this, some stroke patients will miss out on early treatment, meaning they are more likely to die or be severely disabled. Delayed diagnosis also increases costs to the NHS. So, it is important that we are able to tell immediately when people with vertigo are having a stroke. Stroke patients presenting with vertigo often have abnormal eye movements. Research shows a bedside test called HINTS (which carefully measures eye movements) is better than an early brain scan at telling whether patients with vertigo have had a stroke. However, our recent survey showed that many stroke doctors in the UK do not feel confident that they can understand HINTS test results. We do not know the test's value in emergency stroke settings. Study design: First, I will use online and in-person teaching to train stroke clinicians to perform and understand the HINTS test. I will look at how well training works to see which approach works best. Second, I will study 260 patients with acute vertigo. Trained clinicians will run the HINTS test on these patients. All patients will have a brain scan 48 hours after their first symptom. A specialist will then confirm the final diagnosis. I will study how good the HINTS test is at spotting who has had a stroke. I will also use video goggles to record and interpret the HINTS test in the same patients. I will look at whether the HINTS test carried out with the video goggles is better at spotting strokes than the HINTS test performed by the clinicians. Finally, I will invite the clinicians to discuss what might prevent or help them use this test in the future. My findings will tell us how best to use this test in stroke services. Our team includes experts in vertigo, stroke, analysing video and audio data, and teaching healthcare staff. Future: I plan to develop a bigger study looking at whether HINTS can work in different NHS hospitals. I will also look at the effect of HINTS on how well patients do and its value for money. Patient and public involvement (PPI): I have worked with four patients with vertigo, including two patients whose vertigo caused by a stroke. They felt the study could help improve patient care. They commented on the methods. They suggested improvements to how we get patients' consent to take part in the study. I wrote this plain English summary with the help of PPI members. They agreed to continue to help with all stages of this research. One panel member has already volunteered to take on the PPI lead role and will be part of the study advisory board. Sharing findings:With the PPI group, I will share findings with: Patients, the public, and relevant charities. NHS staff who provide stroke care. Researchers who are interested in how healthcare services work.We will publish our findings in medical journals and NHS training programmes. Impact: This study will help patients with vertigo avoid brain scans and hospital stays that they do not need. It should free up time in stroke wards so that staff can treat patients who need urgent stroke care more quickly.

Research activity codes: 4.2 EVALUATION OF MARKERS AND TECHNOLOGIES
Health categories: STROKE