P.079 Factors influencing HINTS exam usage by Canadian Emergency Medicine Physicians

Background: The HINTS examination is a sensitive and specific tool for determining whether a patient presenting with an acute vestibular syndrome has had a stroke. Despite its efficacy, it is often not used by Emergency Medicine (EM) physicians when assessing patients with vertigo. Methods: To ascertain why, we surveyed, by email, physicians registered with the Canadian Association of Emergency Physicians, to gather information on their practices when assessing patients with vertigo, and their utilization and perspectives concerning the HINTS examination. Results: 185 participants responded to our survey, demographically representative of Canadian EM physicians. The majority regularly use the HINTS exam in the appropriate setting, but significant minorities employ the exam inappropriately, such as in patients without nystagmus, with other neurological findings, or alongside tests for intermittent vertigo. Misapplication was associated with older age, years of practice, non-academic practice settings, and less residency training (p<0.05). The predominant reasons for not using this examination are lack of confidence in recalling and performing component exam techniques, particularly the head-impulse test, and doubts about the necessity, safety, or validity of this examination. Conclusions: HINTS examination use is limited by lack of provider skill, safety concerns, and doubts on its validity in excluding stroke when employed by EM physicians.

Video-Oculography-Assisted Head Impulse Test and Caloric Testing for Detecting Stroke in Acute Vertigo Patients via Modified HINTS Plus

Background: We assessed whether detection of stroke underlying acute vertigo using HINTS plus (head-impulse test, nystagmus type, test of skew, hearing loss) can be improved by video-oculography for automated head-impulse test (V-HIT) analysis. Methods: We evaluated patients with acute vestibular syndrome (AVS) presenting to the emergency room using HINTS plus and V-HIT-assisted HINTS plus in a randomized sequence followed by cranial MRI and caloric testing. Image-confirmed posterior circulation stroke or vertebrobasilar TIA were the reference standards to calculate diagnostic accuracy. We repeated statistical analysis for a third protocol that was composed post hoc by replacing the head-impulse test with caloric testing in the HINTS plus protocol. Results: We included 30 AVS patients (ages 55.4 ± 17.2 years, 14 females). Of these, 11 (36.7%) had posterior circulation stroke (n = 4) or TIA (n = 7). Acute V-HIT-assisted HINTS plus was feasible and displayed tendentially higher accuracy than conventional HINTS plus (sensitivity: 81.8%, 95% CI 48.2–97.7%; specificity 31.6%, 95% CI 12.6–56.6% vs. sensitivity 72.7%, 95% CI 39.0–94.0%; specificity 36.8%, 95% CI 16.3–61.6%). The new caloric-supported algorithm showed high accuracy (sensitivity 100%, 95% CI 66.4–100%; specificity 66.7%, 95% CI 41–86.7%). Conclusions: Our study provides pilot data on V-HIT-assisted HINTS plus for acute AVS assessment and indicates the diagnostic value of integrated acute caloric testing.

Acute Vestibular Syndrome in Cerebellar Infarction: A Case Report

Introduction: Acute vestibular syndrome (AVS) is characterized by rapid onset of vertigo, nausea and vomiting, and gait unsteadiness in association with head motion intolerance and nystagmus, lasting days to weeks. Although the majority of AVS patients have acute peripheral vestibulopathy, some may also have brainstem or cerebellar strokes. Cerebellar infarctions sometimes only cause vertigo. The Head Impulse Test, skew deviation, and nystagmus testing provide for great sensitivity and specificity in distinguishing between peripheral vestibular impairment and stroke. Case: A 41-year-old male patient suffered from acute-onset vertigo and dizziness about 5 hours before admission, which started when he started doing his morning routine. Patients also feel gait unsteadiness and almost fall to the left side. There was no weakness in extremities, skew face or slurred speech. Patient's neurological status showed the cerebellar examination was positive left dysmetria, left dysdiadochokinesia, the Romberg test open eye fell to the left, normal Head Impulse Test (HIT), with horizontal bidirectional nystagmus and negative skew deviation test. Cerebellum infarction was discovered using computed tomography imaging. After passing through the acute stroke period, patients are offered symptomatic therapy in the form of betahistine, antiplatelet medication, and vestibular rehabilitation planning. On the tenth day after the onset, the patient's symptoms began to improve. Conclusion: Proper diagnosis of acute vestibular syndrome will guide the necessary tests. The HINTS oculomotor test at the bedside can detect acute vestibular stroke. Keywords: acute vestibular syndrome, vertigo, cerebellum, HINTS

VESTIBULAR NEURONITIS

Vestibular neuronitis is an acute vestibular syndrome due to inflammation of the vestibular nerve characterized by the typical symptoms of acute rotatory vertigo accompanied by nausea, vomiting, and symptoms of balance disorders. The incidence of vestibular neuronitis is about 3.5 per 100,000 people. The exact etiology of this vestibular neuronitis is unknown. However, based on existing evidence, vestibular neuronitis is associated with viral infections of the upper respiratory tract and herpes zoster infection. The clinical manifestations of vestibular neuronitis are persistent rotatory vertigo accompanied by oscillopsia, horizontal-rotatory peripheral vestibular spontaneous nystagmus on the healthy side, and a tendency to fall on the affected side. Diagnosis of vestibular neuronitis can be made by clinical diagnosis, through history, physical examination, and special examinations. Through these examinations, the differential diagnosis of vestibular neuronitis should be excluded, such as Meniere's disease, labyrinthitis, benign paroxysmal positional vertigo, and vertigo due to central lesions such as cerebellar infarction. Management of vestibular neuronitis is in the form of symptomatic therapy with vestibular suppressants, antivertigo, and redirect to relieve the symptoms that arise, then causative therapy can be done by administering corticosteroids, and in patients, physiotherapy can be done to improve vestibular function.

A new ocular motor sign in acute vestibular syndrome: Is HINTS plus enough?

A 66-year-old hypertensive and diabetic male presented with acute vestibular syndrome for three days. HINTS plus examination was performed. The horizontal head impulse test was positive on the left side. Video oculography showed centripetal nystagmus on gaze testing in the dark and test of skew was negative. There was no new hearing loss on the finger rub test. On neurological examination, he had severe postural instability and saccadic smooth pursuit. Radio-imaging studies were conducted to rule out the possibility of stroke. CT brain showed infarction in the territory of the medial branch of the right posterior inferior cerebellar artery. MRI brain confirmed the diagnosis. Thus, posterior circulation stroke can present with acute vestibular syndrome mimicking acute unilateral vestibulopathy. However, the presence of associated neurological symptoms like gait ataxia, centripetal nystagmus and vascular risk factors pointed towards a central cause. Clinical evaluation suggesting a peripheral lesion should never be taken in isolation and needs to be correlated with other associated signs. We describe centripetal nystagmus without fixation as a new oculomotor sign in acute vestibular syndrome.

Vestibular vertigo in emergency neurology

The review deals with approaches to the differential diagnosis of the causes of vertigo in emergency neurology. The main causes of episodic and acute vestibular syndrome are discussed. Clinical diagnostic methods for acute vestibular syndrome (evaluation of nystagmus, test of skew, head-impulse test and neurological status) are considered. Clinical signs of “benign” acute vestibular syndrome and symptoms indicating a stroke in the vertebrobasilar system are presented. Differential diagnostic criteria for peripheral and central vestibular disorders are presented. Transient ischemic attacks, features of the otoneurologic status in vestibular neuronitis and different localizations of cerebral infarction focus are considered. Errors in the diagnosis of the vertigo causes are discussed.