Vertigo doesn’t have to be a dizzying proposition in your ED.
Vertigo can be a scary topic for emergency physicians. If you have been in the business long enough, you have heard of a patient sent home with a non-serious vertigo diagnosis, only to return with a posterior circulation stroke (PSC), moribund in a coma.
One study showed up to 37% of patients with PCS were misdiagnosed in the ED.(1) Yet most patients who present to the emergency department with vertigo have benign, even highly treatable conditions.
As emergency physicians, we want to alleviate the suffering of patients and identify the most common and dangerous causes of their presentations.
Poor Training?
Has our training adequately prepared us to accomplish this with dizzy complaints? Sadly, the often-taught method of asking “what do you mean by dizzy?” and using characteristics of central vs. peripheral vertigo tables are not helpful when trying to make a diagnosis of the patient with vertigo in front of you.(2, 3) And it is by definitively diagnosing a benign cause of vertigo that you can rule out a dangerous cause of vertigo (usually a stroke).
Combine the fear of the worst possible outcome happening to your patient and approaches not easily leading to a diagnosis, a vicious cycle of dislike, avoidance and then further erosion of confidence occurs. This is the state many emergency physicians find themselves in.
When applied by a neuro-otologist to patients with Acute Vestibular Syndrome (AVS) the HINTS (Head Impulse test, Nystagmus, Test of Skew) exam has shown excellent sensitivity and specificity to identify patients with central causes of vertigo. Still, there is much skepticism about whether it could be used safely by emergency physicians.(4)
A patient with AVS has constant vertigo for hours or days that is worse with head movement, nausea/vomiting, difficulty walking and importantly, has spontaneous or gaze-evoked nystagmus.(5) A paper by one of the authors of this essay (R.O.) demonstrated that at one hospital, HINTS was being applied to patients who were not appropriate for the HINTS exam, and that nystagmus was rarely documented.(6)
Get a Clue
Does this poor use of the HINTS exam reflect that it is too difficult for emergency physicians to learn to use correctly? Or is it just an inevitable product of the vicious cycle of fear and outdated educational approaches as described above?
The answer may lie in a study conducted at the same institution by many of the same authors, that showed a similar poor application of the Dix-Hallpike Test (DHT).(7) This test should be applied to dizzy patients with typically 20- to 30-second episodes of vertigo initiated by head movements such as getting in/out of bed or rolling over in bed.
Importantly, these patients do not have spontaneous or gaze evoked nystagmus. During the DHT, the characteristic vertical upward/rotatory nystagmus towards the downward ear is seen. This is the gold standard for diagnosing posterior canal BPPV.
Unfortunately, in Ohle’s look at the DHT, many patients who might have benefited from it were not tested. Additionally, many patients who were tested had symptoms inconsistent with BPPV.
There is clearly confusion in vertigo education, which must be addressed, as the gold standard test for the most common and curable cause seen in the emergency department (BPPV) is misused to this extent.
Major Markers
The cornerstone of assessing a patient with dizziness is the history and physical exam. An often underemphasized point is that the differential diagnosis in acute vestibular syndrome is mostly vestibular neuritis vs. PCS.(8) Also, the first line of defense against missing a stroke is not, in fact, the HINTS exam.
All patients with vertigo — not just AVS patients — should first be screened for central features that bring into doubt the diagnosis of a benign cause of vertigo. Having any of the following: new significant headache or neck pain, inability to stand or walk unaided, focal weakness or paresthesia of face or limbs, dysarthria, diplopia dysmetria, dysphagia or dysphonia, or vertical nystagmus (not during the DHT) would mandate a search for a central cause of the vertigo.(8)
So in AVS, this means that the HINTS exam should not be applied to those with other neurologic signs or symptoms inconsistent with vestibular neuritis.
Most patients who present to the emergency department with constant, significant vertigo and nystagmus and no central features as outlined above, will have vestibular neuritis.(8)
The abnormal head impulse is seen when the head is turned rapidly in the opposite direction as the spontaneous unidirectional nystagmus. If there is no abnormal skew and the diagnosis of vestibular neuritis is confirmed, the patient can be safely discharged.
Can an emergency physician learn how to turn a head rapidly from 20 degrees off midline back to midline rapidly and observe the resulting eye findings? It would seem the motor skill required is easily within our capabilities. The difficult part is knowing who to perform it on, and how to interpret it.
And the good news is that by performing the HINTS exam on the more common vestibular neuritis patients, you will hone your skills for when you see the much less common patient with a PCS presenting with none of the central features outlined above. This is called “pseudo-vestibular neuritis,” and this is the raison d’être for the HINTS exam.
Conclusion
The question is not so much “can” or “should” emergency physicians be taught how to evaluate both BPPV and AVS better, but “how” to teach it. For that we need more vertigo champions to help lead the way.
No decision, rule or algorithm for assessment of any presenting complaint has 100% uptake by clinicians, or is 100% used and interpreted improperly.
The studies by Ohle show what we have suspected for decades. We are facing significant challenges when assessing vertigo. We also know both BPPV and vestibular neuritis can be definitely diagnosed by bedside assessment. Should we try and teach emergency physicians to properly use these techniques in order to diagnose and cure BPPV with the DHT and Epley maneuver respectively? What about reliably diagnosing vestibular neuritis by screening for central features, and then applying the HINTS exam to those who screen negative?
A quote from the Simpsons is “You gotta help us doc! We’ve tried nothing and we’re all out of ideas!”
For decades we have failed to diagnose and treat BPPV properly, and we miss PCS all too often.
We need to abandon the old methods of teaching vertigo, and from medical school onward, teach how to properly assess vertigo using the right bedside test on the right patient.
References
- Arch AE, Weisman DC, Coca S, Nystrom KV, Wira III CR, Schindler JL. Missed ischemic stroke diagnosis in the emergency department by emergency medicine and neurology services. Stroke. 2016;47(3):668-73.
- Johns P. What do you mean by dizzy? Youtube; 2019:https://www.youtube.com/watch?v=_sklwUilfg4.
- Johns P. Vertigo myth: Central vs peripheral tables help you make the diagnosis in vertigo. youtube; 2020:https://www.youtube.com/watch?v=0FL377pUIlA.
- Kattah JC, Talkad AV, Wang DZ, Hsieh YH, Newman-Toker DE. 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):3504-10.
- Ohle R, Montpellier RA, Marchadier V, Wharton A, McIsaac S, Anderson M, et al. Can Emergency Physicians Accurately Rule Out a Central Cause of Vertigo Using the HINTS Examination? A Systematic Review and Meta‐analysis. Academic Emergency Medicine. 2020;27(9):887-96.
- Dmitriew C, Regis A, Bodunde O, Lepage R, Turgeon Z, McIsaac S, et al. Diagnostic Accuracy of the HINTS Exam in an Emergency Department: A Retrospective Chart Review. Academic Emergency Medicine. 2021;28(4):387-93.
- Dmitriew C, Bodunde O, Regis A, Lepage R, Turgeon Z, Johns P, et al. The use and misuse of the Dix-Hallpike test in the emergency department. Canadian Journal of Emergency Medicine. 2021:1-4.
- Johns P, Quinn J. Clinical diagnosis of benign paroxysmal positional vertigo and vestibular neuritis. CMAJ. 2020;192(8):E182-E6.