Thursday, August 27, 2015

Consultant Teachings No. 4: "I'm Dizzy"

Clinical Scenario: It’s 3 AM in the ED when a 70 year old male with a history of hypertension comes in complaining of dizziness. You spend 10 minutes trying to get him to describe his dizziness, getting various descriptions of “lightheaded”, “spinning”, “imbalanced”, with him eventually saying “I’m just dizzy doc!!!”. The dizziness was described as sudden onset and had been constant for an hour, but had spontaneously resolved on arrival to the ED. During the episode, he had difficulty standing and stated that it felt like he would fall if he "didn’t hold onto something". He also noted some mild nausea and diaphoresis. Finally, he complained of a headache, though he has a long history of similar headaches. His initial head CT showed no acute process. 

Clinical Question: How do you evaluate a patient with acute dizziness?

Discussion & Literature Review

Dizziness and vertigo make up about 4% of chief complaints in the emergency department (ED) [1]. This chief complaint can be caused by pathology in many different body systems, and that pathology can range from benign to acutely life-threatening. For patients presenting to an ED with dizziness, affected systems include otologic/vestibular (32.9%), cardiovascular (21.1%), respiratory (11.5%), and neurologic (11.2%) as the top four diagnostic groups [2].

Dizziness Conundrum: Despite dizziness being a relatively common complaint, it can be very challenging to work up and manage. Traditional teaching on the evaluation of dizziness is to rely heavily on the quality of the dizziness, whether it is “spinning”, “lightheaded” or other similar descriptors [3]. However, this has been shown to be an ineffective means of establishing a differential diagnosis and may lead to dangerous misdiagnosis. Emergency department physicians (including residents) have been specifically studied and found to demonstrate over-reliance on symptom quality leading to subsequent high-risk reasoning [4,5]. There is also evidence that patients with the two most common vestibular disorders (benign paroxysmal positional vertigo (BPPV) and acute peripheral vestibulopathy) are often managed sub-optimally both in terms of diagnostic testing and prescribed treatment in the ED [6]. These studies suggest an opportunity to improve the emergency management of dizzy patients. 

History is Everything In the Dizzy Patient: As in all of medicine, obtaining an accurate and useful history is the single most important step in establishing the diagnosis of a patient with dizziness. The quality of dizziness lacks specificity in ED patients; one study found that patients describe their dizziness in multiple ways if given multiple options, may change their description of the dizziness if asked again only 5-10 minutes after initial questioning, and answer open-ended questions with vague or circular answers [7]. 

As opposed to the quality of symptoms, patients have been found to more reliably answer questions about the timing and triggers of their dizziness. This had led to the formulation of the “timing and triggers” model of history taking in the evaluation of a dizzy patient [8]. The goal of history-taking in this model is to identify the patient as having one of four syndromic patterns of dizziness:

· acute, spontaneous, prolonged (also known as the acute vestibular syndrome) 
· episodic, positional 
· episodic, spontaneous 
· chronic unsteadiness [8]. 

When asking about timing, attempt to clarify whether the dizziness is sudden or gradual onset, episodic or continuous, the duration of symptoms, and the frequency of symptoms. If the symptoms are episodic, clarify how long each episode lasts (seconds, minutes, hours, days) and make sure to ask if they completely return to normal between episodes or if they have constant symptoms with exacerbations. When asking about triggers, it is important to define true triggers as opposed to exacerbating factors. A common exacerbating factor is any form head movement, which generally worsens all forms of acute vestibular dizziness, so does not often help establish a diagnosis. However, if specific movements (i.e. rolling over in bed or changing posture) trigger the dizziness, this can lead to a diagnosis.  

Examination Tools and Tips: On physical examination, general medical and neurologic screening exams are important. Focal abnormalities on these exams may suggest a diagnosis (i.e. unilateral weakness or ataxia may suggest stroke, new cardiac murmur may suggest myocardial infarction or aortic dissection). However, there are specific physical exam maneuvers that can also be performed. The most commonly employed is the Dix-Hallpike maneuver to evaluate for benign paroxysmal positional vertigo (BPPV). This should be employed only if the patient describes episodic dizziness. The Dix-Hallpike maneuver will worsen the already-present spontaneous nystagmus during the acute vestibular syndrome, but this should not be taken as a positive test. The other test an ED provider should be familiar with is the HINTS-Plus exam [9]. This is a three step test of skew deviation, nystagmus, and head impulse testing (video links to a positive head impulse test, which suggests a peripheral etiology) combined with an assessment for unilateral hearing loss. This test is concerning for a central etiology with the presence of skew deviation, direction changing or vertical nystagmus, a negative head impulse test, and/or new unilateral hearing loss. In the evaluation of the acute vestibular syndrome, this bedside test is more accurate in the acute setting than MRI for diagnosing a posterior circulation stroke. Another physical exam pearl is that some patients can suppress nystagmus with visual fixation, so removing fixation can bring out their nystagmus. An easy way to do this is to turn off the lights and use your ophthalmoscope, which will block fixation and give you a magnified view of the eye for easier visualization of the nystagmus.

Summary and differential diagnosis: Once a patient’s complaints have been characterized by history as one of the four syndromic patterns discussed above, the differential diagnosis is much more limited. The physical examination assesses for specific diagnoses, which then guides further workup and treatment.

Source: Newman-Toker, D. E., Symptoms and signs of neuro-otologic disorders, Continuum (Minneap Minn), 2012, 18(5 Neuro-otology):1016-1040.

Submitted by Alex Dietz, Neurology PGY-4
Faculty Reviewed by Peter Panagos
Everyday EBM Editor: Maia Dorsett, PGY-4

[1] Saber Tehrani, A. S., Coughlan, D., Hsieh, Y. H., Mantokoudis, G., Korley, F. K., Kerber, K. A., Frick, K. D., et al., Rising annual costs of dizziness presentations to U.S. emergency departments, Acad Emerg Med, 2013, 20(7):689-696.
[2] Newman-Toker, D. E., Hsieh, Y. H., Camargo, C. A., Pelletier, A. J., Butchy, G. T. and Edlow, J. A., Spectrum of dizziness visits to US emergency departments: cross-sectional analysis from a nationally representative sample, Mayo Clin Proc, 2008, 83(7):765-775.
[3] Kerber, K. A. and Newman-Toker, D. E., Misdiagnosing Dizzy Patients: Common Pitfalls in Clinical Practice, Neurol Clin, 2015, 33(3):565-575.
[4] Newman-Toker, D. E., Charted records of dizzy patients suggest emergency physicians emphasize symptom quality in diagnostic assessment, Ann Emerg Med, 2007, 50(2):204-205.
[5] Stanton, V. A., Hsieh, Y. H., Camargo, C. A., Edlow, J. A., Lovett, P. B., Lovett, P., Goldstein, J. N., et al., Overreliance on symptom quality in diagnosing dizziness: results of a multicenter survey of emergency physicians, Mayo Clin Proc, 2007, 82(11):1319-1328.

[6] Newman-Toker, D. E., Camargo, C. A., Hsieh, Y. H., Pelletier, A. J. and Edlow, J. A., Disconnect between charted vestibular diagnoses and emergency department management decisions: a cross-sectional analysis from a nationally representative sample, Acad Emerg Med, 2009, 16(10):970-977.
[7]Newman-Toker, D. E., Cannon, L. M., Stofferahn, M. E., Rothman, R. E., Hsieh, Y. H. and Zee, D. S., Imprecision in patient reports of dizziness symptom quality: a cross-sectional study conducted in an acute care setting, Mayo Clin Proc, 2007, 82(11):1329-1340.
[8] Newman-Toker, D. E., Symptoms and signs of neuro-otologic disorders, Continuum (Minneap Minn), 2012, 18(5 Neuro-otology):1016-1040.
[9] Saber Tehrani, A. S., Kattah, J. C., Mantokoudis, G., Pula, J. H., Nair, D., Blitz, A., Ying, S., et al., Small strokes causing severe vertigo: frequency of false-negative MRIs and nonlacunar mechanisms, Neurology, 2014, 83(2):169-173.

Title Image source: wikipedia.

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