EBQ:HINTS Exam

Under Review Journal Club Article

Kattah, J. et al. "HINTS to Diagnose Stroke in the Acute Vestibular Syndrome: Three-Step Bedside Oculomotor Examination More Sensitive Than Early MRI Diffusion-Weighted Imaging". Stroke. 2009. 40(11):3504–3510.
PubMed Full text PDF

Clinical Question

Is the HINTS exam (Head-Impulse—Nystagmus—Test-of-Skew) more sensitive for diagnosing stroke than early MRI diffusion-weighted imaging in Acute Vestibular Syndrome?

Conclusion

A negative HINTS examination can rule out a stroke better than a negative MRI with DWI in the first 24 to 48 hours after symptom onset with a specificity of 96%.

Major Points

• The 3 components of the HINTS exam include: head impulse test of vestibulo-ocular reflex function; observation for nystagmus in primary, right, and left gaze; alternate cover test for skew deviation.

• Skew deviation is a fairly specific predictor of brainstem involvement in patients with acute vestibular syndrome. The presence of skew may help identify stroke when a positive head impulse test falsely suggests a peripheral lesion.

• Initial MRIs are falsely negative in 12% and can prove misleading out to 48 hours after symptom onset.

Inclusion Criteria

At least one stroke risk factor: smoking, hypertension, diabetes, hyperlipidemia, atrial fibrillation, eclampsia, hypercoagulable state, recent cervical trauma, prior stroke or myocardial infarction.

Exclusion Criteria

A history of recurrent vertigo with or without auditory symptoms

Interventions

Patients presenting with symptoms of acute vestibular syndrome underwent neurological and vestibular examination according to a standard protocol:

• head impulse test
• prism cross-cover test for ocular alignment
• observation of nystagmus in different gaze positions

All patients underwent neuroimaging, generally after bedside evaluation, otherwise the examiner was masked to these results at the time of clinical assessment.

All patients were admitted for observation and underwent serial daily examinations for evolution of clinical findings.

Outcome

Primary Outcomes

• A positive HINTS exam: 100% sensitive and 96% specific for the presence of a central lesion.
• The HINTS exam was more sensitive than general neurological signs: 100% versus 51%.
• The sensitivity of early MRI with DWI for lateral medullary or pontine stroke was lower than that of the HINTS examination (72% versus 100%, P=0.004) with comparable specificity (100% versus 96%, P=1.0).

Funding

the National Institutes of Health and the Agency for Healthcare Research and Quality