Digital biomarkers from gaze tests for classification of central and peripheral lesions in acute vestibular syndrome.

Acute vestibular syndrome (AVS) is characterised by a sudden vertigo, gait instability, nausea and nystagmus. Accurate and rapid triage of patients with AVS to differentiate central (potentially sinister) from peripheral (usually benign) root causes is a challenge faced across emergency medicine settings. While there exist bedside exams which can reliably differentiate serious cases, they are underused due to clinicians' general unfamiliarity and low confidence interpreting results. Nystagmus is a fundamental part of AVS and can facilitate triaging, but identification of relevant characteristics requires expertise. This work presents two quantitative digital biomarkers from nystagmus analysis, which capture diagnostically-relevant information. The directionality biomarker evaluates changes in direction to differentiate spontaneous and gaze-evoked (direction-changing) nystagmus, while the intensity differential biomarker describes changes in intensity across eccentric gaze tests. In order to evaluate biomarkers, 24 sets of three gaze tests (left, right, and primary) are analysed. Both novel biomarkers were found to perform well, particularly directionality which was a perfect classifier. Generally, the biomarkers matched or eclipsed the performance of quantitative nystagmus features found in the literature. They also surpassed the performance of a support vector machine classifier trained on the same dataset, which achieved an accuracy of 75%. In conclusion, these biomarkers simplify the diagnostic process for non-specialist clinicians, bridging the gap between emergency care and specialist evaluation, ultimately benefiting patients with AVS.

Video head impulse test in stroke: a review of published studies.

Accurate and timely diagnosis of posterior circulation stroke in patients with acute dizziness is a challenge that can lead to misdiagnosis and significant harm. The present review sought to identify and describe published research on the clinical application of vHIT in posterior circulation stroke. vHIT, a portable device, has gained prominence in evaluating peripheral vestibular disorders and offers potential applications in diagnosing neurological disorders, particularly posterior circulation stroke. Several studies have shown that vHIT can differentiate between stroke and vestibular neuritis based on VOR gain values, with high sensitivity and specificity. The manuscript also discusses vHIT's performance in differentiating between types of posterior circulation stroke, such as PICA, AICA, and SCA strokes. While vHIT has demonstrated promise, the review emphasizes the need for further research to validate its use as a tool to rule out stroke in acute dizziness patients in the emergency department. In conclusion, the manuscript underscores the potential of vHIT as a valuable addition to the diagnostic arsenal for acute dizziness, particularly in the context of posterior circulation stroke. It calls for further research and wider adoption of vHIT in clinical settings to improve patient care and reduce unnecessary costs associated with misdiagnoses.

Application of motor learning theory to teach the head impulse test to emergency medicine resident physicians.

Objectives: The objective was to develop an innovative method of training emergency medicine (EM) resident physicians to perform the head impulse test (HIT) component of the HINTS (head impulse test, nystagmus, test of skew) examination using video-oculography (VOG) device feedback. Methods: Using principles from motor learning theory and Ericsson's framework for expertise, we developed a training innovation utilizing VOG device feedback to teach the degree (10°-20°) and velocity (>100°/s) of head turn required for the HIT. We assessed the technical ability of participants to perform the HIT using the VOG device, without feedback, to count the number of successful HITs out of 20 attempts before, immediately after, and 2 weeks after the training innovation. Participants rated their confidence on a 1 to 5 Likert scale before and 2 weeks after training. Results: Most participants (11 of 14, 78%) were unable to perform even one successful HIT in 20 attempts before training despite brief verbal and visual instruction regarding the head turn parameters. However, most participants achieved more than one success, in fact, all with at least five successes, immediately after training (13 of 14, 93%) and again 2 weeks after training (nine of 11, 82%). The median (interquartile range) number of successful HITs was 0 (0, mean 0.79) during baseline testing, 7.5 (5.8) immediately after training, and 10 (8.0) 2 weeks after training (p < 0.01, Kruskal-Wallis). The median confidence rating increased from 1.5 (1) before baseline testing to 3 (1.5) after follow-up testing (p = 0.02, Mann-Whitney U). Conclusions: Prior to motor training, most participants failed to properly perform the HIT. Feedback training with VOG devices may facilitate development of the skills required to properly perform the HIT. Further study is needed to assess the ability to train the interpretive aspect of the HIT and other components of the HINTS examination.

The acute vestibular syndrome: prevalence of new hearing loss and its diagnostic value.

OBJECTIVES: To assess the prevalence of new hearing losses in patients with acute vestibular syndrome (AVS) and to start to evaluate its diagnostic value for the differentiation between peripheral and central causes. DESIGN: We performed a cross-sectional prospective study in AVS patients presenting to our Emergency Department (ED) from February 2015 to November 2020. All patients received an MRI, Head-impulse test, Nystagmus test and Test of skew ('HINTS'), caloric testing and a pure-tone audiometry. RESULTS: We assessed 71 AVS patients, 17 of whom had a central and 54 a peripheral cause of dizziness. 12.7% had an objective hearing loss. 'HINTS' had an accuracy of 78.9% to diagnose stroke, whereas 'HINTS' plus audiometry 73.2%. 'HINTS' sensitivity was 82.4% and specificity 77.8% compared to 'HINTS' plus audiometry showing a sensitivity of 82.4% and specificity of 70.4%. The four patients with stroke and minor stroke had all central 'HINTS'. 55% of the patients did not perceive their new unilateral hearing loss. CONCLUSIONS: We found that almost one-eighth of the AVS patients had a new onset of hearing loss and only half had self-reported it. 'HINTS' plus audiometry proved to be less accurate to diagnose a central cause than 'HINTS' alone. Audiometry offered little diagnostic accuracy to detect strokes in the ED but might be useful to objectify a new hearing loss that was underestimated in the acute phase. Complete hearing loss should be considered a red flag, as three in four patients suffered from a central cause.

Concordant GRADE-3 Truncal Ataxia and Ocular Laterodeviation in Acute Medullary Stroke.

Background: Severe truncal ataxia associated with an inability to sit up without assistance (STA grade 3) is frequent in patients with central acute vestibular syndrome (AVS) involving the brainstem or cerebellum. When these patients have nystagmus, central HINTS excludes peripheral lesions; however, additional localization and lateralization signs are helpful, not only to resolve the peripheral versus central vestibular lesion dilemma, but to zero in on a precise lesion localization/lateralization to the lateral medulla, the most common ischemic lesion localization associated with an initially false-negative stroke MRI. Methods: This is a study of AVS patients with additional inclusion criteria: grades 2 or 3 ataxia with an eventual diagnosis of medullary stroke (MS), either involving the lateral medulla (LMS) or the medial medulla (MMS), and horizontal (h) gaze paralysis was the main exclusion criteria. All patients sat on the side of the bed or stretcher, with assistance if needed. A general neurologic examination followed in the sitting position, the testing protocol included the head impulse, spontaneous nystagmus, and skew deviation (HINTS) tests, followed by observation of the effect of brief 3-5 sec eyelid closure on ocular position, and saccade and pursuit eye movement tests. If they could sit, the protocol included the ability to stand with a wide base, then a narrow base, the Romberg test, and tandem gait. Radiographic lesion localization and horizontal gaze deviation concluded the protocol. Results: A total of 34 patients met the entry criteria, 34 MS (13 in the lateral medulla, 12 previously described, and 1 new patient), and 1 new MMS. Among them, n = 10/12 had grade 3 ataxia, and 3 (1 new patient) had grade 2 ataxia. In addition, overt ocular laterodeviation (OLD) was present in thirteen of them (35.3%). All OLD patients had gaze deviation and ipsilateral saccade and truncal lateropulsion, 1 medial medulla stroke patient had grade 3 truncal contrapulsion and contralateral hemiparesis without OLD, n = 20/21 patients with LMS without OLD had grade 3 truncal ataxia, and 1 had grade 2 truncal ataxia. Discussion: AVS patients with severe truncal ataxia (inability to sit without assistance) potentially have brainstem, cerebellum, or subcortical lesions. All patients had central HINTS; however, simultaneous direction-concordant STA 3 and OLD provided greater lateral medulla localization specificity, affecting the ipsilateral medulla. Future work to explore a practical posterior circulation stroke scale that includes HINTS, STA, and OLD will potentially select cases for thrombolysis even in the event of initially false-negative imaging.

Clinical Evolution of Acute Vestibular Syndrome: Longitudinal Retrospective Analysis of Epidemiological Data and Prognostic Factors for Recovery.

We evaluated the clinical features of patients admitted to the ED with acute vertigo, verifying symptoms after one month and one year to establish epidemiological factors and predictors of resolution. We reviewed 233 records of patients admitted to ED for acute vertigo (125 F and 85 M, mean age 56.12 years). We analyzed the correlation between time of resolution (at one month and one year) and symptoms duration (subjective and/or objective vertigo, instability, cervical pain, audiological, neurological, and neurovegetative symptoms), comorbidities, and therapies, the result of the clinical and instrumental vestibular examination. Resolution of acute vertigo occurred in 81.1%, while persistence of vertigo one year after ED access was reported in 18.8%. There were 135 patients who recovered in one month. The presence of instability, auditory and neurovegetative symptoms, and neck pain represents a significant factor for recovery within one year. Age over 65 and a history of hypertension are associated with a worst recovery. Patients with spontaneous Nystagmus or positive HIT showed a significant difference in symptoms recovery within one month and one year. Presence of positional Nystagmus represents a positive prognostic factor. Our findings emphasize the importance of clinical evaluation of the acute vertigo, helping the clinicians to define central or peripheral diagnosis and predict the resolution of vertigo.

Acute truncal ataxia without nystagmus in patients with acute vertigo.

BACKGROUND AND PURPOSE: Differentiating between peripheral and central aetiologies can be challenging in patients with acute vertigo, given substantial symptom overlap. A detailed clinical history and focused physical eye movement examination such as the HINTS eye examination appear to be the most reliable approach to identify acute cerebellar/brainstem stroke, outperforming even acute brain imaging. We have observed, however, that isolated vertigo of central cause may be accompanied by acute truncal ataxia, in the absence of nystagmus. METHODS: We explored the frequency of ataxia without concurrent nystagmus in a cross section of patients with acute vertigo who presented to the emergency department at two centres in Argentina (Group A) and the UK (Group B). Patients underwent detailed clinical neuro-otological assessments (Groups A and B), which included instrumented head impulse testing and oculography (Group B). RESULTS: A total of 71 patients in Group A and 24 patients in Group B were included in this study. We found acute truncal ataxia-without nystagmus-in 15% (n = 14) of our overall cohort. Lesions involved stroke syndromes affecting the posterior inferior cerebellar artery, anterior inferior cerebellar artery, and superior cerebellar artery, thalamic stroke, cerebral hemisphere stroke, multiple sclerosis, and a cerebellar tumour. Additional oculomotor deficits did not reliably identify a central cause in these individuals, even with oculography. CONCLUSIONS: We have identified a significant subpopulation of patients with acute vertigo in whom the current standard approaches such as the HINTS examination that focus on oculomotor assessment may not be applicable, highlighting the need for a formal assessment of gait in this setting.

Video head impulse testing in patients with isolated (hemi)nodular infarction.

Background: Isolated (hemi)nodular strokes as underlying cause of acute dizziness are rare, thus there are still gaps of knowledge in the clinical presentation of affected patients. Clinical and experimental evidence has suggested that lesions involving the nodulus lead to various vestibulo-ocular deficits including prolonged velocity-storage, periodic-alternating nystagmus, positional nystagmus, abolished suppression of post-rotatory nystagmus by head-tilt and impaired verticality perception. At the bedside, the angular vestibulo-ocular reflex (aVOR), as assessed by the horizontal head-impulse test (HIT), has been reported to be normal, however quantitative assessments of all six semicircular canals are lacking. Objective: The primary aim of this case series was to characterize the spectrum of clinical presentations in isolated (hemi)nodular strokes. Furthermore, based on preliminary observations, we hypothesized that the aVOR is within normal limits in isolated nodular strokes. Methods: We retrospectively included patients with isolated (hemi)nodular stroke on diffusion-weighted MR-imaging from a prospective stroke-registry. All patients received a standardized bedside neuro-otological assessment and quantitative, video-based HIT (vHIT) of all six semicircular canals. Overall ratings of vHIT (normal vs. abnormal function) were performed independently by two reviewers and disagreements were resolved. Results: Between January 2015 and December 2021 six patients with isolated nodular (n = 1) or heminodular (n = 5) ischemic stroke were included. Clinical presentation met diagnostic criteria for acute vestibular syndrome (AVS) in 5/6 patients and for episodic vestibular syndrome (EVS) in 1/6 patients. Ocular motor abnormalities observed included the presence of spontaneous horizontal nystagmus (n = 2), positional nystagmus (5/6), head-shaking nystagmus (3/6), skew deviation (n = 1), and moderate or severe truncal ataxia (5/6). Bedside HIT was normal in all patients and no gaze-evoked or periodic alternating nystagmus was observed. aVOR-gains were within normal range in all patients and overall aVOR-function as assessed by vHIT was rated as normal in all six patients. Conclusions: Using quantitative, video-based testing of the horizontal and vertical aVOR, preserved integrity of the aVOR in (hemi)nodular strokes was confirmed, extending preliminary findings at the bedside. Furthermore, widespread deficits of both ocular stability, postural control and volitional eye movements were observed in our study cohort, being consistent with findings reported in previous studies.

Incidence, characteristics, and neuroanatomical substrates of vestibular symptoms in supratentorial stroke.

The incidence and characteristics of acute vestibular symptoms, responsible structures, and lateralization of the causative lesions in supratentorial stroke remain unknown. This study aimed to determine the incidence, clinical features, and anatomical correlation of acute vestibular symptoms in supratentorial stroke. We performed a prospective, multicenter, observational study that had recruited patients with supratentorial stroke from the neurology clinics of referral-based four university hospitals in Korea. All patients received a constructed neuro-otological evaluations, and neuroimaging. We analyzed the incidence of acute vestibular symptoms, abnormal ocular motor and vestibular function tests, and stroke lesions. Of 1301 patients with supratentorial stroke, 48 (3.7%) presented with acute vestibular symptoms, and 13 of them (1%) had the vestibular symptoms in isolation. In patients with acute vestibular symptoms, abnormal findings included spontaneous nystagmus (5%), impaired horizontal smooth pursuit (41%), and abnormal tilt of the subjective visual vertical (SVV) (20%). Video head impulse and caloric tests were normal in all the patients. There was no clear correlation between acute vestibular symptoms and involvement of specific vestibular cortex. In patients with unilateral stroke, there was also no lateralization of the causative lesions of acute vestibular symptoms (left vs. right; 52 vs. 48%), even in patients with vertigo (left vs. right; 58 vs. 42%). This study demonstrates that the incidence of acute vestibular symptoms in supratentorial stroke is 3.7%, with being isolated in 1%. The widespread lesions responsible for acute vestibular symptoms implicate diffuse multisensory cortical-subcortical networks in the cerebral hemispheres without a lateralization.

Virtual-reality-enhanced mannequin to train emergency physicians to examine dizzy patients using the HINTS method.

Introduction: Acute vertigo is a frequent chief complaint in the emergency departments, and its efficient management requires thorough training. The HINTS protocol is a valid method to screen patients in the emergency room, but its application in routine is hindered by the lack of training. This study aimed to evaluate the training of emergency physicians for the HINTS method based on a mannequin-based virtual reality simulator (MBVRS). Methods: We conducted a monocenter, prospective, longitudinal, and randomized cohort study in an Emergency Department at a regional university hospital. We included 34 emergency physicians randomized into two equal groups matched by age and professional experience. The control group attended a theoretical lesson with video demonstrations and the test group received a simulation-based training in addition to the lecture. Results: We showed that the test group had a higher diagnosis performance for the HINTS method compared to the control group as evaluated by the simulator at 1 month (89% sensitivity versus 45, and 100% specificity versus 86% respectively, p < 001, Fisher's exact test). Evaluation at 6 months showed a similar advantage to the test group. Discussion: The MBVRS is a useful pedagogic tool for the HINTS protocol in the emergency department. The advantage of a unique training session can be measured up to 6 months after the lesson.

Diagnosing and localizing the acute vestibular syndrome - Beyond the HINTS exam.

When assessing the acutely dizzy patient, the HINTS 'Plus' (Head Impulse, Nystagmus, Test of Skew, 'Plus' a bedside assessment of auditory function) exam is a crucial component of the bedside exam. However, there are additional ocular motor findings that can help the clinician distinguish peripheral from central etiologies and enable accurate localization, especially when the patient has acute dizziness, vertigo and/or imbalance but without spontaneous nystagmus. We will review the literature on these findings which are 'beyond HINTS' and include saccades/ocular lateropulsion, smooth pursuit, and provocative maneuvers including head-shaking and positional testing (not part of the HINTS exam). Additionally, we will expound on the localizing value of nystagmus, ocular alignment and the ocular tilt reaction (parts of the HINTS exam). The paper has been organized neuroanatomically, based on brainstem and cerebellar structures that have been reported to cause the acute vestibular syndrome.

A prospective study on the application of HINTS in distinguishing the localization of acute vestibular syndrome.

BACKGROUND: Acute vestibular syndrome (AVS) is a common clinical syndrome in neurology clinics and emergency department. Canonical standard for AVS diagnosis requires the presence of persistent vertigo for more than 24 h. HINTS (head impulse-nystagmus-test of skew) is an emerging scheme in the diagnosis of AVS. In this prospective study, we evaluated the specificity and sensitivity of HINTS in distinguishing between central and peripheral AVS. METHODS: A cohort of 239 cases with complete clinical record was recruited in the study. All patients completed emergency brain CT examination to exclude hemorrhagic stroke. HINTS examination was conducted to distinguish between central AVS and peripheral AVS, and all patients completed head MRI, BAEP and vestibular function examinations within one week. Patients diagnosed as central AVS were subject to angiography (CTA/MRA/DSA), and patients with peripheral AVS were considered for a 3-month follow-up to correct the initial diagnosis. RESULTS: Patients with central AVS were associated with an elder age, higher incidences of hypertension, atrial fibrillation, family history of stroke and previous history of stroke. Posterior circulation cerebral infarction, vestibular migraine and cerebellitis were the dominant diseases associated with central AVS. The sensitivities of HIT, GE, and TS in the diagnosis of central AVS were 73.5%, 61.2%, and 26.5%, and the specificities were 97.9%, 92.6%, and 93.2% respectively. CONCLUSIONS: The sensitivity of HINTS for central AVS diagnosis is 89.8% and the specificity is 84.2%. HINTS is an easy-to-operate, low-cost, high-sensitivity and specific examination technique, which is practical in neurology outpatient clinics and emergency departments.

Positive horizontal-canal head impulse test is not a benign sign for acute vestibular syndrome with hearing loss.

Background: Diagnosis of acute vestibular syndrome (AVS) with hearing loss is challenging because the leading vascular cause-AICA territory stroke-can appear benign on head impulse testing. We evaluated the diagnostic utility of various bedside oculomotor tests to discriminate imaging-positive and imaging-negative cases of AVS plus hearing loss. Method: We reviewed 13 consecutive inpatients with AVS and acute unilateral hearing loss. We compared neurologic findings, bedside and video head impulse testing (bHIT, vHIT), and other vestibular signs (including nystagmus, skew deviation, and positional testing) between MRI+ and MRI- cases. Results: Five of thirteen patients had a lateral pontine lesion (i.e., MRI+); eight did not (i.e., MRI-). Horizontal-canal head impulse test showed ipsilateral vestibular loss in all five MRI+ patients but only in three MRI- patients. The ipsilesional VOR gains of horizontal-canal vHIT were significantly lower in the MRI+ than the MRI- group (0.56 ± 0.11 vs. 0.87 ± 0.24, p = 0.03). All 5 MRI+ patients had horizontal spontaneous nystagmus beating away from the lesion (5/5). One patient (1/5) had direction-changing nystagmus with gaze. Two had skew deviation (2/5). Among the 8 MRI- patients, one (1/8) presented as unilateral vestibulopathy, four (4/8) had positional nystagmus and three (3/8) had isolated posterior canal hypofunction. Conclusion: The horizontal-canal head impulse test poorly discriminates central and peripheral lesions when hearing loss accompanies AVS. Paradoxically, a lateral pontine lesion usually mimics unilateral peripheral vestibulopathy. By contrast, patients with peripheral lesions usually present with positional nystagmus or isolated posterior canal impairment, risking misdiagnosis as central vestibulopathy.

The pharmacological treatment of acute vestibular syndrome.

Acute vestibular syndrome (AVS) represents a clinical picture that involves urgent management due to the important procession of symptoms accompanying the event, which can be positively or negatively influenced by therapeutic choices and intervention timing. This forces a differential diagnosis and therapeutic choices to be made in conditions that are not always favorable and often not in the specialist field. In this work, we will examine in detail the pharmacological therapeutic possibilities, correlating them to the differential and, as far as possible, to the etiological diagnosis. In particular, the pharmacological possibilities for the two main conditions we can face will be investigated, namely, vestibular neuritis and posterior circulation stroke.

Role of incubitus truncal ataxia, and equivalent standing grade 3 ataxia in the diagnosis of central acute vestibular syndrome.

INTRODUCTION AND OBJECTIVES: acute vestibular syndrome is a diagnostic challenge, requiring a rapid and precise diagnosis to take therapeutic actions. Truncal ataxia, inability to sit still, and Babinski flexor dysergy were evaluated. Material anf methods: 52 patients with central pathology (stroke in aica and pica territory) and vestibular neuritis were prospectively studied. MRI of the brain was used as the gold standard. RESULTS: A combination of grade 2-3 ataxia to differentiate patients with vestibular neuritis from patients with stroke resulted in a 92% sensitivity (95% CI 79-100%), a 67% specificity (95% CI 47-86%). Flexion asynergy had a 70% sensitivity (95% CI 47-92%), and an 88% specificity (95% CI 69-100%). The inability to sit still correlated well with truncal ataxia. CONCLUSIONS: vestibulospinal signs are useful in the differential diagnosis of acute vestibular syndromes, and the inability to sit is a good substitute for truncal ataxia when it cannot be evaluated.

Case report: Acute vestibular syndrome and cerebellitis in anti-Yo paraneoplastic syndrome.

Background: We define acute vestibular syndrome (AVS) as a sudden onset vertigo, nausea, vomiting, and head motion intolerance, more frequently associated with an acute peripheral and unilateral vestibulopathy. About 10-20% of all cases with central vestibulopathy are secondary to stroke. We report three patients evaluated over the past decade with an acute AVS along with subtle downbeat nystagmus (DBN), followed by dysarthria and progressive truncal and limb ataxia, as well as increasing DBN intensity. Methods: All patients underwent neurologic examination, video-oculography, MRI, serum cancer markers, spinal fluid examination, paraneoplastic panel testing, and oncologic workup. With a consolidated diagnosis of cancer/paraneoplastic syndrome, we treated with plasma exchange (PLEX), high-dose steroids, surgery, and oncologic investigation. We additionally provided oncotherapy in one out of three patients. Results: All three patients had an acute AVS, downbeat nystagmus DBN, and inability to perform tandem gait. Two of three patients had a normal head impulse test (HIT). As acute vertigo, nausea, and vomiting subsided, a progressive cerebellar syndrome ensued characterized by persistent DBN, impaired horizontal and vertical pursuit, impaired VOR suppression, truncal and limb ataxia, and dysarthria. All patients had normal MRI brain studies excluding stroke. CSF studies demonstrated lymphocytic pleocytosis and elevated protein. One patient had confirmed ovarian cancer with high CA-125 serum levels; another had undifferentiated cancer of unknown primary with high CA-125 and one patient with esophageal cancer. All had a positive PCA-1 antibody titer, also known as anti-Yo antibody. In one patient with expeditious immunosuppression, the ataxia progression slowed for 18 months, whereas the other two patients with delayed initiation of treatment had more rapidly progressive ataxia. Discussion: Paraneoplastic encephalitis related to PCA-1 antibody (Anti-Yo) targets Purkinje cells and cells in the granular layer of the cerebellar cortex. Clinically, our patients had a central AVS characterized by DBN and followed with progressive ataxia and unremarkable neuroimaging studies. Rapid initiation of treatment may offer a greater chance to prevent further neurologic decline. Any patient with an AVS as well as DBN and normal MRI should have an expeditious workup to rule out metabolic, toxic, and infectious causes just prior to considering prompt treatment with high-dose steroids and plasma exchange (PLEX) to mitigate the risk of rapidly progressive and irreversible neurologic decline.

Factors influencing HINTS exam usage by Canadian Emergency Medicine Physicians.

OBJECTIVES: The HINTS examination (head impulse, nystagmus, test of skew) is a bedside physical examination technique that can distinguish between vertigo due to stroke, and more benign peripheral vestibulopathies. Uptake of this examination is low among Emergency Medicine (EM) physicians; therefore, we surveyed Canadian EM physicians to determine when the HINTS exam is employed, and what factors account for its low uptake. METHODS: We designed and tested a 26-question online survey, and disseminated it via email to EM physicians registered with the Canadian Association of Emergency Physicians (CAEP), with 3 and 5-week reminder emails to increase completion. This anonymous survey had no incentives for participation, and was completed by 185 EM physicians, with post-graduate medical training in either Emergency Medicine or Family Medicine. The primary outcomes were the frequencies of various responses to survey questions, with secondary outcomes being the associations between participant characteristics and given responses. RESULTS: 88 respondents (47.8%) consistently use the HINTS examination in the work-up of vertigo, and 117 (63.7%) employ it in scenarios where its clinical utility is limited. The latter is more common among physicians working in non-academic settings, without 5-year EM residency training, and with greater years of practice (p < 0.01). The most frequent explanations for non-use were a lack of need for the HINTS examination, the lack of validation of the exam among EM physicians, and concerns surrounding the head-impulse test. CONCLUSIONS: Though HINTS exam usage is common, there is a need for education on when to apply it, and how to do so, particularly as concerns the head-impulse test. Our attached rubric may assist with this, but quality-improvement initiatives are warranted. Low uptake is partly due to the lack of validation of this examination among EM physicians, so effort should be made to conduct well-designed HINTS trials exclusively involving EM physicians.

RéSUMé: OBJECTIFS: L'examen HINTS (head impulse, nystagmus, test of skew) est une technique d'examen physique au chevet du patient qui permet de distinguer les vertiges dus à un accident vasculaire cérébral des vestibulopathies périphériques plus bénignes. Cet examen est peu pratiqué par les médecins en médecine d'urgence (MU). Nous avons donc mené une enquête auprès des médecins d'urgence canadiens afin de déterminer quand l'examen HINTS est utilisé et quels sont les facteurs qui expliquent sa faible utilisation. MéTHODES: Nous avons conçu et testé une enquête en ligne de 26 questions, et l'avons diffusée par courriel aux médecins urgentistes inscrits à l'Association canadienne des médecins d'urgence (ACMU), avec des courriels de rappel de trois et cinq semaines pour augmenter le taux de réponse. Cette enquête anonyme, qui ne comportait aucune incitation à la participation, a été remplie par 185 médecins de médecine d'urgence ayant suivi une formation médicale postuniversitaire en médecine d'urgence ou en médecine familiale. Les résultats primaires étaient les fréquences des diverses réponses aux questions de l'enquête, les résultats secondaires étant les associations entre les caractéristiques des participants et les réponses données. RéSULTATS: 88 répondants (47,8 %) utilisent systématiquement l'examen HINTS dans l'évaluation des vertiges, et 117 (63,7 %) l'emploient dans des scénarios où son utilité clinique est limitée. Cette dernière est plus fréquente chez les médecins travaillant dans des établissements non universitaires, n'ayant pas suivi une formation de 5 ans en résidence en médecine d'urgence et ayant un plus grand nombre d'années de pratique (p < 0,01). Les explications les plus fréquentes de la non-utilisation étaient le manque de nécessité de l'examen HINTS, le manque de validation de l'examen parmi les médecins de médecine d'urgence et les préoccupations concernant le test d'impulsion de la tête. CONCLUSIONS: Bien que l'utilisation de l'examen HINTS soit courante, il existe un besoin d'éducation sur le moment où il faut l'appliquer et sur la manière de le faire, en particulier en ce qui concerne le test d'impulsion de la tête. Notre rubrique ci-jointe peut vous aider à cet égard, mais des initiatives d'amélioration de la qualité sont justifiées. Le faible taux d'utilisation est en partie dû au manque de validation de cet examen parmi les médecins de la médecine d'urgence. Il faut donc s'efforcer de mener des essais HINTS bien conçus impliquant exclusivement des médecins de la médecine d'urgence.

The Spectrum of Vestibular Disorders Presenting With Acute Continuous Vertigo.

Objective: To explore the composition of vestibular disorders presenting with the acute vestibular syndrome (AVS). Methods: We performed a case analysis of 209 AVS patients between January 2016 and December 2020. These patients were grouped into different disorder categories according to the relevant diagnostic criteria. Results: We classified the 209 patients into 14 disorder categories, including 110 cases of vestibular neuritis, 30 of idiopathic sudden sensorineural hearing loss with vertigo, 17 of the first attack of continuous vertigo with migraine, 15 of Ramsay Hunt syndrome, 11 of acute labyrinthitis secondary to chronic otitis media, 8 of vestibular schwannoma, 6 of posterior circulation infarction and/or ischemia, 3 of cerebellar abscess secondary to chronic otitis media, 3 of AVS caused by trauma or surgery, 2 of AVS with down-beating nystagmus, 1 of multiple sclerosis of the medulla oblongata, 1 of epidermoid cyst of the posterior cranial fossa, 1 of a probable acute otolithic lesion, and 1 of AVS without measurable vestibular dysfunction. Conclusion: When a group of disorders present with AVS, characteristic clinical manifestations and imaging help with an accurate diagnosis.

Topography and etiologies of cerebellar infarcts presenting as isolated acute vestibular syndrome.

BACKGROUND AND PURPOSE: To investigate the topography and etiologies of acute cerebellar infarcts (ACIs) that presented as isolated acute vestibular syndromes (AVSs). METHODS: ACI was ascertained on magnetic resonance diffusion-weighted imaging combined with apparent diffusion coefficient sequence and was categorized into the simple (territory and small infarct) and the complicated (concomitant infarcts in territories of posterior circulation besides cerebellum). Infarct topography and etiologies were compared between ACI patients with isolated AVS and non-isolated AVS (general and/or local neurological symptoms and/or signs with or without AVS). RESULTS: We enrolled 129 ACI patients, and 53 patients (53/129, 41.1%) had isolated AVS. In isolated AVS, the infarct lesions could be territory infarcts, small infarcts involving cortical, subcortical, and areas directly related to vestibular structures, and the primary etiologies were of large artery atherosclerosis and small vessel disease. Compared with the patients with non-isolated AVS, those with isolated AVS had more prevalence of small vessel disease (OR 6.30, 2.16-18.39; p = 0.001) and more probability of small infarcts (OR 6.04, 95%CI 2.31-15.76; p < 0.0001). In isolated AVS patients, the small infarct located more frequently in cerebellar hemispheres than the areas directly related to vestibular structures (27/35 vs 8/35), and the territory infarct located more frequently in the area supplied by posterior inferior cerebellar artery than the other areas (9/13 vs 4/13). CONCLUSION: Our study found that ACI could be presented as isolated AVS, which occurred more frequently in patients with small hemisphere infarct or infarct in the territory supplied by posterior inferior cerebellar artery.