You make me dizzy, Miss Lizzy: HINTS for assessing acute dizziness

The evaluation of the dizzy patient in the Emergency Department can be very complicated. The differential diagnosis is broad and misdiagnosis carries with it the potential for a high degree of morbidity and mortality. This summary will focus on patients with acute vestibular syndrome—patients with acute onset, continuous dizziness—and differentiating peripheral and central causes. We are not going to discuss vertigo or other causes of dizziness (see Table 1).

Screen Shot 2016-01-29 at 11.22.23 PM

Table 1: Timing and Trigger Approach to dizziness (from TiTrATE Approach to Dizziness, David E. Newman-Toker, MD, PhD)

One of the simplest ways to approach the dizzy patient is to categorize them based on the timing (episodic vs acute/continuous) and trigger (positional vs spontaneous; post-exposure vs spontaneous). Dizziness is difficult for patients to describe, so thinking of it in this way will minimize problems posed by vague and alternating histories to help narrow your differential and inform a targeted exam (Table 1).

A minority but significant percent of patients with acute vestibular syndrome have a stroke (population estimates range from 10-40%).1 Peripheral and benign causes includes cerumen impaction and benign positional vertigo. Symptoms are localized to the inner ear or CN8, are acute, benign, self-limited and often viral or post-viral. Vertigo with stroke is often abrupt, with maximum intensity at time of onset. Severe ataxia is common, but not always seen. Larger cerebellar strokes will produce symptoms localizing to the brainstem, like diplopia, dysarthria, limb ataxia, dysphagia, weakness or numbness, but 10% will have isolated vertigo without other symptoms.2

So, how can you tell the difference between central and peripheral causes?

Great reviews of vertigo can be found here, here, and here. While there are a number of articles in the Emergency Medicine literature, the most notable exam tool that is currently most broadly discussed is the HINTS exam.

The HINTS exam is an acronym for the three exam tools that help differentiate a non-hemorrhagic posterior cerebrovascular accident from other peripheral causes of acute vestibular syndrome. It stands for Head Impulse, Nystagmus, and Test of Skew. A number of derivation and validation studies, many of which were led by Dr. David Newman-Toker, have been published in recent years.

Kattah, et al6 found the HINTS. exam to be 100% sensitive and 96% specific for stroke in their 2009 publication in Stroke. In 2013, Newman-Toker, et al4 compared HINTS to the ABCD2 score in predicting ischemia in a prospective study among ED patients with one hour of dizziness at least one risk factor for stroke. They found HINTS to be superior to ABCD2 (ABCD2, SE61%, SP 62% vs HINTS SE 96.5% SP 84.4%), but both of these studies are limited by the fact that exams involved evaluations by specialists, primarily neuroophthalmologists, however Newman-Toker’s study included a vascular stroke trained emergency physician.

Finally, fresh off the presses is a new study just published in Neurology5 which used a combination of the ABCD2 score and HINTS exam to risk stratify patients into low, moderate, and high risk groups. The study was limited in that they used the HINTS exam in all patients, some who did not have nystagmus.   In the end, few patients with nystagmus who had a negative HINTS exam had a stroke.

Can EM physicians do it?

Obviously more studies remain to be done, but initial research is promising. Studies in EDs in Italy and Australia, for example, have shown high inter-evaluator reliability between emergency physicians and specialists7, 8 when assessing for stroke using exam findings of nystagmus, head impulse testing, and ability to ambulate.

What is the HINTS exam?

HINTS is a three part exam:

  1. Head Impulse
  2. Nystagmus
  3. Test of Skew
  • Head Impulse. This test relies on the vestibular-ocular reflex, which is a peripheral reflex that allows your eyes to focus while moving your head. When this is interrupted, your eyes lag. A POSITIVE test is consistent with peripheral vertigo. To

    Vestibulo-ocular Reflex

    say it another way, a positive head impulse test is reassuring.

    1. How to do it:
      1. Have patient fix eyes on your nose. And rapidly turn their head 20 degrees to one direction and back to center, then to other side.
        1. Eyes will stay fixed on your nose (if central)
        2. Eyes will first move to direction you moved their head, and then re-fixate on your nose. It is called “catch up” saccades. Eyes have to re-orient to your nose. = peripheral lesion

F4.large

  • Nystagmus
    1. Peripheral vertigo should have fast beating nystagmus in only one direction.
    2. If it is direction changing = central
    3. Vertical nystagmus = central

  • Test of Skew
    1. You are looking for vertically disconjungate gaze (aka one eye is higher than other).
    2. This can be overcome by fixation, but can be ‘uncovered’ by the alternating cover test. Have them look at nose, cover one eye, will prevent covered eye from fixating. Then rapidly remove hand and see if eye misaligned will come back into alignment. Seeing realignment as eye is fixating on your nose. You are looking for that re-alignment.

To help guide your evaluation of the patient with acute vestibular syndrome, check out this new, handy guideline put together by Dr. Napoli and Dr. Siket:

Posterior stroke visio. AN 12#2

Guideline for the Acute Dizzy Patient in the Emergency Department, 2015

Try out the exam on your next dizzy patient and see how it goes. The best way to get comfortable with this exam is to practice!

 

Looking for more info?

Another EM overview of acute vestibular syndrome can be found on EMCrit.

Thank you to my Faculty Editors: Anthony Napoli, MD and Matt Siket, MD, MS

References/Further Reading:

  1. Tarnutzer AA, Berkowitz AL, Robinson KA, Hsieh Y, Newman-Toker DE. Does my dizzy patient have a stroke? A systematic review of bedside diagnosis in acute vestibular syndrome. CMAJ, June 14, 2011, 183(9).
  2. Nelson JA, Viirre K. Review: The Clinical Differentiation of Cerebellar Infarction from Common Vertigo Syndromes. West J Emerg Med. 2009;10(4):273-277.
  3. Newman-Toker DE, Kerber KA, Hsieh YH, et al. HINTS outperforms ABCD2 to screen for stroke in acute continuous vertigo and dizziness. Acad Emerg Med 2013;20:986–996.
  4. Seemungal BM, Bronstein AM. Review: A practical approach to acute vertigo. Pract Neurol 2008; 8: 211–221.
  5. Kerber KA, Meurer WJ, Brown DL, Burke JF, Hofer TP, Tsodikov A, Hoeffner EG, Fendrick AM, Adelman EE, Morgenstern LB. Stroke risk stratification in acute dizziness presentations: A prospective imaging-based study. Neurology 2015;85:1869–1878.
  6. Kattah, JC, Talkad AV, Wang DZ, Hsieh Y, 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;3504-3510.
  7. Vanni S, Pecci R, Casati C, Moroni F, Risso M, Ottaviani M, Nazerian P, Grifoni S, Vannucchi P. STANDING, a four-step bedside algorithm for differential diagnosis of acute vertigo in the Emergency Department. Acta Otorhinolaryngol Ital 2014;34:419-426.
  8. Vanni S, Nazerian P, Casati C, Moroni F, Risso M, Ottaviani M, Pecci R, Pepe G, Vannucchi P, Grifoni S. Can emergency physicians accurately and reliably assess acute vertigo in the emergency department? Emerg Med Australas. 2015 Apr;27(2):126-31.

Perusing the Literature (PTL): Haloperidol for Migraines

Introducing the newest blog section – Perusing the Literature (PTL). This section includes summaries of recent articles that residents and attendings have stumbled across that have raised an eyebrow. These monthly posts are meant to spark a discussion and do not represent a change in the standard of care (unless otherwise noted).

Let’s get the ball rolling!

______________________________________________________________________________

November 2015: Haloperidol for Migraines

The Article: Gaffigan ME, et al. A Randomized Control Trial of Intravenous Haloperidol vs. Intravenous Metoclopramide for Acute Migraine Therapy in the Emergency Department. J Emerg Med. 2015 Sep;49(3):326-34.

The One-Liner: Intravenous haloperidol appears to be as safe and effective as metoclopramide for the ED treatment of migraine headaches.

Background: Headache accounts for 2–5% of ED visits and is the 5th most common ED complaint. Current first-line ED therapies include dopamine receptor antagonists such as prochlorperazine and metoclopramide, often with diphenhydramine. Studies have shown these medications to be safe and more effective than opiates, NSAIDs, and sumatriptan. Haloperidol is another dopamine antagonist and has been reported to be effective in the treatment of migraine headaches.

Methods: This was a prospective, double-blinded, randomized, controlled trial at a single emergency department of patients presenting with migraine headache. Each subject was given a 1L normal saline bolus and a baseline ECG completed. Diphenhydramine 25mg IV was administered, followed by the study medication – metoclopramide 10mg IV or haloperidol 5mg IV. Pain, nausea, restlessness, and sedation were assessed at 0, 20, 40, 60, and 80 min. After 80 min, the subject was either discharged home or offered rescue therapies at the discretion of the treating physician. Prior to discharge, a second ECG was obtained. Subjects were to be contacted at 48-hours after discharge and were asked if they were happy with the medication received, and if they had any recurrent or persistent symptoms specifically, headache, sleepiness, restlessness, agitation, nausea, vomiting, or chest pain.

Results:

  • A total of 64 patients were enrolled – 31 randomized to haloperidol and 33 metoclopramide.
  • Mean reduction in pain from baseline was statistically and clinically significant for both haloperidol and metoclopramide groups.
  • Pain scores between the groups did not differ at baseline, at the last measurement, in the magnitude of the pre-post treatment change, or in the time to pain relief.
  • More patients in the metoclopramide group required a rescue medication for pain relief (p < 0.02).
  • Sleepiness was statistically more common in the group that was to receive haloperidol (p < 0.02). There were no other differences between the groups in any of the other side-effect questions asked (nausea, restlessness, chest pain).
  • Mean QTcs were equal and normal in the two groups and did not change after treatment for either group.
  • 43/64 patients were reached for 48-hour follow up. Restlessness reported more by the haloperidol group (43% vs 10%, p < 0.015).

Limitations:

  • The study was single centered and admittedly small.
  • The study used a convenience sample, subjects were relatively young and mostly female (81%).
  • Post-treatment ECGs were obtained in only 45% of subjects.
  • Telephone follow up was obtained in only 67% of subjects.

 

Posted by Adam Janicki, MD, PGY4

Reviewed by Gita Pensa, MD, Clinical Assistant Professor, Department of Emergency Medicine

CITW 6: A Clumsy Foot

Welcome back to another Clinical Image of the Week from the case files of the Brown EM Residency!

HPI: 74 y/o male with multiple medical problems who presents to the ED with four days of left leg pain, left foot numbness, and a new left foot drop. Additionally, his wife points out that she has noticed a new rash extending up his left foot and leg. He denies any fevers, chills, recent infections or trauma to the leg.

Vitals: BP 157/72, HR 77, T 98.8 °F, RR 16, SpO2 97 % on RA

Notable PE: Numbness and rash (see below) noted on the dorsal aspect of the left foot, extending up the lateral aspect of the left leg to the knee. 3/5 strength with dorsiflexion of the left foot.

Rash 1
Rash 2
What’s the diagnosis?

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Lumbar Puncture Part 2: Pearls, Pitfalls, and Troubleshooting

a monthly blog series on procedures


Take your LP skills to Eleven: this is spinal tap!

Last week we discussed the basics of the adult LP. This week we will guide you through some difficult scenarios and their solutions.

THE SPOOKED PATIENT

troubleshootingYour patient is nervous and squirmy

  • Consider having an assistant hold and position the patient.
  • Steady the shaft of the needle with your non-dominant hand.
  • Talk to the patient. Here are some examples of what you can say prior to the procedure:
    • “I will numb up your back, and that should be the only part that hurts.”
    • “Most of the procedure is just setting up my materials.”
  • During the procedure, the patient cannot see you, which can be anxiety provoking. Describe each step of the procedure in a calm manner. And try to avoid THIS.
  • If necessary, administer an anxiolytic such as a benzodiazepine.

troubleshootingYour patient is very sensitive to pain

  • First, lidocaine!
    • Did you inject enough volume into the deeper structures of the back? As Dr. Whit Fisher mentioned in the comments of the previous post, make sure you gather extra lidocaine (only 5ml in the LP tray). In a sterile fashion, draw up an extra 5-10 ml with the help of an assistant.
    • Note: if trying a new interspace, make sure this area is also anesthetized.
  • Patient still in pain? Consider administration of an analgesic such as an opioid.

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