Acute Vertigo with an Abnormal Head Impulse Test in the Emergency Department

HINTS interpretation

• Head impulse test: normal (no corrective saccades) is the abnormal, peripheral-inconsistent finding. In vestibular neuritis the affected side shows an abnormal head impulse with corrective saccades.
• Nystagmus: direction-changing (right-beating on right gaze, left-beating on left gaze) and with a vertical component is central. Peripheral nystagmus is unidirectional and suppressed by fixation.
• Test of skew: a 2 mm vertical skew deviation is central.
• Any one central finding makes the examination 'HINTS dangerous', and this patient has all three. Combined with truncal instability and vascular risk factors, the diagnosis is a central lesion until proven otherwise, most likely posterior circulation infarction (posterior inferior cerebellar or lateral medullary). Acute vestibular syndrome with central HINTS has a stroke probability of roughly 1 in 5 or higher in this age group.

What the CT means

• A normal non-contrast CT in the first hours does not exclude posterior fossa infarction; sensitivity in this window is low (well under half).
• CT also poorly visualises the brainstem and cerebellum because of beam-hardening artefact. The report cannot be used to reassure or to label this as vestibular neuritis.

Immediate actions

• Activate the stroke pathway and request urgent MRI with diffusion-weighted imaging of brain and posterior fossa; if MRI is unavailable within the thrombolysis window, proceed with CT angiography to look for basilar or vertebral occlusion rather than waiting.
• Check blood glucose, electrolytes and ECG; treat vomiting with intravenous antiemetics and give cautious fluids.
• Assess swallowing and keep nil by mouth until screened; nurse with aspiration precautions.
• Control blood pressure according to the thrombolysis protocol, not to the general hypertensive target; do not lower it aggressively before the stroke team reviews.

Reperfusion decisions

• If imaging confirms acute infarction and there are no contraindications and the patient is within 4.5 hours, intravenous thrombolysis should be considered by the stroke team, with blood pressure below 185/110 mmHg.
• If there is a large vessel occlusion (e.g. basilar or vertebral), mechanical thrombectomy may be indicated within the appropriate window.
• Start aspirin after haemorrhage is excluded and 24 hours after thrombolysis; add statin and address vascular risk factors.
• Admit to a stroke unit, not to an ENT ward, and arrange vestibular rehabilitation only after the acute phase.

Management

• Short course (up to 3 days) of a vestibular sedative such as prochlorperazine or promethazine for severe vomiting, then stop to allow central compensation; avoid prolonged use.
• Consider a short tapering course of oral corticosteroids within 72 hours of onset, though evidence is modest; antivirals are not indicated.
• Encourage early mobilisation and refer for vestibular rehabilitation; explain that recovery takes weeks and is faster with graded movement rather than bed rest.
• Advise hydration and safety at home, and give a written warning of red flags (new weakness, diplopia, dysarthria, dysphagia, headache, hearing loss) requiring immediate return.

Prognosis

• Most patients recover substantially within 4–6 weeks, though a minority have persistent unsteadiness or positional vertigo from canal paresis.
• Recurrence is uncommon; if episodes recur, reassess for Ménière's disease, vestibular migraine or a central cause.
• Document that the initial presentation included central signs; if the final diagnosis is neuritis, this should be a documented discussion, since a normal MRI does not fully exclude small brainstem infarction and clinical follow-up matters.