Acute onset, continuous dizziness without focal neurological deficits is one of the most challenging symptoms in the emergency department (ED). Most patients with these complaints will have a benign disorder of the vestibular system. However, some patients will suffer from a central problem, mostly stroke. The challenge in distinguishing between these diagnoses lies in the identical presentation.
Acute onset, continuous dizziness is a very common symptom at the ED. It is assumed to represent 3% of all ED visits in the United States. To emphasize the difficulty we have in determining the correct diagnosis, approximately 130.000-200.000 strokes in all these patients are missed each year. Conventional neurologic examination is notoriously unreliable and CT imaging has a poor specificity and sensitivity. MRI of the brain is thought to be the gold standard, even though 12% of posterior circulation strokes could be missed if MRI is performed within 48 hours. This may even rise up to 23% if MRI is performed within 24 hours. The HINTS+ test (Head Impulse, Nystagmus, Test of Skew and Hearing Loss) has been proposed as a bedside test with an excellent sensitivity and specificity of around 100% and 90% respectively to discriminate between a central and peripheral cause. However, most of the studies regarding the HINTS+ test are small sized and are performed in a small number of specialized tertiary neuro-otology centers with highly selected patients. The external validation has yet to be performed. Further research with more inclusive selection paradigms is needed to validate the accuracy of the HINTS+ test and MRI in acute onset, continuous dizziness. Moreover, other diagnostic tests should be taken in to account (e.g. video assisted HINTS+ test and biomarker investigation) to further improve diagnostic accuracy in this patient population.