On the Shoulders of Giants
Take a HINTS
HINTS stands for Head-Impulse-Nystagmus-Test-of-Skew. This 3-part test of vestibular function was able to distinguish vertigo caused from posterior stroke vs. a peripheral cause. HINTS performed better than MRI. MRI diffusion was false negative in 12% of patients ultimately diagnosed with posterior stroke, but these cases were not missed with HINTS, which was 100% sensitive and 96% specific. I have no problem with this study, but I am a little nervous about putting this into practice and performing and interpreting the HINTS exam properly. A great way to start is to watch this video by the senior author, Dr. Newman-Toker.
HINTS is a 3-part exam that is a powerful bedside discriminator of vertigo caused by a peripheral insult vs. posterior stroke that outperformed MRI.
Stroke. 2009 Nov;40(11):3504-10. doi: 10.1161/STROKEAHA.109.551234. Epub 2009 Sep 17.
1Department of Neurology, The University of Illinois College of Medicine at Peoria and the Illinois Neurological Institute at OSF Saint Francis Medical Center, Peoria, Ill, USA.
BACKGROUND AND PURPOSE:
Acute vestibular syndrome (AVS) is often due to vestibular neuritis but can result from vertebrobasilar strokes. Misdiagnosis of posterior fossa infarcts in emergency care settings is frequent. Bedside oculomotor findings may reliably identify stroke in AVS, but prospective studies have been lacking.
The authors conducted a prospective, cross-sectional study at an academic hospital. Consecutive patients with AVS (vertigo, nystagmus, nausea/vomiting, head-motion intolerance, unsteady gait) with >or=1 stroke risk factor underwent structured examination, including horizontal head impulse test of vestibulo-ocular reflex function, observation of nystagmus in different gaze positions, and prism cross-cover test of ocular alignment. All underwent neuroimaging and admission (generally <72 hours after symptom onset). Strokes were diagnosed by MRI or CT. Peripheral lesions were diagnosed by normal MRI and clinical follow-up.
One hundred one high-risk patients with AVS included 25 peripheral and 76 central lesions (69 ischemic strokes, 4 hemorrhages, 3 other). The presence of normal horizontal head impulse test, direction-changing nystagmus in eccentric gaze, or skew deviation (vertical ocular misalignment) was 100% sensitive and 96% specific for stroke. Skew was present in 17% and associated with brainstem lesions (4% peripheral, 4% pure cerebellar, 30% brainstem involvement; chi(2), P=0.003). Skew correctly predicted lateral pontine stroke in 2 of 3 cases in which an abnormal horizontal head impulse test erroneously suggested peripheral localization. Initial MRI diffusion-weighted imaging was falsely negative in 12% (all <48 hours after symptom onset).
Skew predicts brainstem involvement in AVS and can identify stroke when an abnormal horizontal head impulse test falsely suggests a peripheral lesion. A 3-step bedside oculomotor examination (HINTS: Head-Impulse-Nystagmus-Test-of-Skew) appears more sensitive for stroke than early MRI in AVS.
PMCID: PMC4593511 Free PMC Article
PMID: 19762709 [PubMed – indexed for MEDLINE]