HINTs Exam for Acute Vestibular Syndrome (Continuous Dizziness): Stroke or Vestibular Neuritis?

Fauquier ENT
Fauquier ENT
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Published 2024-07-26
The HINTs examination, an acronym for Head Impulse, Nystagmus, and Test of Skew, is a cluster of 3 bedside tests used to evaluate a patient with acute onset dizziness that is continuously present, even when still. These tests can quickly differentiate between an inner ear vestibular problem versus central vertigo, which may be due to a stroke.

The head impulse test starts by flexing the patient’s head down slightly and moving their head slowly back and forth while having their eyes maintain fixed focus straight ahead. The head is then moved quickly and unexpectedly to one side while the patient tries to maintain straight target focus. The test is considered normal if the eyes stay focused on target without slippage.

However, if the eyes are dragged off the straight ahead target, even briefly, the test would be considered abnormal suggesting an inner ear vestibular problem. Please note that there needs to be a minimum 50% weakness of the inner ear vestibular system in order for this test to be positive.

Next, check the patient’s eyes for any nystagmus which are involuntary repetitive eye twitching. To evaluate for nystagmus, have the patient move the eyes in all the cardinal directions: left, right, up, and down.

Normally, nystagmus should be absent. However, if nystagmus is present, note which direction the eye is beating towards. The direction of nystagmus is defined by the direction of the quick phase.

An inner ear or vestibular cause for dizziness is suggested if the nystagmus is horizontal and the direction remains the same regardless of which direction the eye is looking.

A neurologic cause for dizziness is suggested if the nystagmus changes direction with eye movement. Neurologic cause for dizziness is also suggested if vertical or torsional nystagmus is present in any eye position.

The skew test, also known as the cover test, involves the patient focusing straight on a target while the clinician covers and uncovers each eye, observing for any vertical movement of the uncovered eye.

Normally, the uncovered eye remains steady. However, if it moves up or down, this indicates a vertical skew deviation, which can suggest a serious brain disorder involving the brainstem or cerebellum instead of a more benign cause due to an inner ear vestibular problem.

Collectively, when all 3 HINTs exams are performed in a dizzy patient, it is 95% accurate in identifying a central cause like stroke or peripheral origin like vestibular neuritis.

Accuracy is further increased when performing a HINTs-plus test when adding a fourth sign which is the presence of a one-sided, new-onset hearing loss which would suggest labyrinthitis.

• Intro (0:00)
• Head Impulse (0:29)
• Nystagmus (1:40)
• Test of Skew (3:10)
• HINTs Interpretation (3:46)

Video created by Dr. Christopher Chang:
www.FauquierENT.net/

References
Usage of the HINTS exam and neuroimaging in the assessment of peripheral vertigo in the emergency department. J Otolaryngol Head Neck Surg. 2018;47:54. www.ncbi.nlm.nih.gov/pmc/articles/PMC6131950/

HINTS to diagnose stroke in the acute vestibular syndrome: three-step bedside oculomotor examination more sensitive than early MRI diffusion-weighted imaging. Stroke. 2009 Nov;40(11):3504-10. www.ncbi.nlm.nih.gov/pmc/articles/PMC4593511/

H.I.N.T.S. to Diagnose Stroke in the Acute Vestibular Syndrome—Three-Step Bedside Oculomotor Exam More Sensitive than Early MRI DWI. Stroke. 2009 Nov; 40(11): 3504–3510. www.ncbi.nlm.nih.gov/pmc/articles/PMC4593511/

Actor Credit:
MJ Gordon ‪@marinjayden‬
Certified Yoga Alliance Instructor (RYP500, RPYT, Yin)
Certified Fitness Instructor NCEP
www.MJ-Gordon.com/

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All Comments (5)
  • @fauquierent
    Please Note! The info in this video ONLY applies if the dizziness has been CONTINUOUSLY present for hour(s) even when still. If the dizziness is triggered by movement, and disappears when still, you may have BPPV instead and information in this video does NOT apply!
  • @PeterJohns
    At the beginning you state the indications for the HINTS exam is acute onset dizziness, which is continuous, even when still”. You do not indicate that nystagmus must be present. Later, at 3:48, your slide indicates that no nystagmus, (as well as unidirectional nystagmus) indicates a peripheral cause. Neurologists would suggest that the finding of no nystagmus would be concerning for a central cause. I feel the truth is more complicated than either of the above statements. It is true that patients with BPPV sometimes complain of a continuous dizziness, and that a Dix-Hallpike test in those without nystagmus can show the classic nystagmus in posterior canal BPPV and make the diagnoses. And sometimes patients with vestibular neuritis after a day or two will have no nystagmus seen unless fixation is removed. But it is also true that patients who complain of persistent dizziness, have a new objective change in their gait, but have no nystagmus at rest have a significant increased risk of stroke, as much as 33-50% in Machner’s study. And it’s also true that many patients with a posterior circulation stroke do not have nystagmus at rest. 44% in Nham’s study. I can email you these studies. The approach I use in my HINTS videos is to only recommend performing the HINTS exam on patients with nystagmus at rest. But to look very carefully for nystagmus and remove fixation with a blank piece of paper placed beside the head. And that you should be very concerned about a patient who complains of constant dizziness, has a new objective change in their gait, and have NO nystagmus. Thanks for all you do for vertigo education. Peter Johns youtube.com/@PeterJohns/videos
  • @PeterJohns
    Nice job Christopher! I have to ask how your normal volunteer simulated left horizontal nystagmus so well.