THE CLINICAL CHALLENGE
Dizziness poses a conundrum for patients and health care providers. First, it is a common and nonspecific symptom accounting for over 4.3 million emergency department (ED) visits annually in the United States.1
Although the vast majority of patients with dizziness are experiencing a benign process, approximately 15% of patients have a dangerous and potentially life-threatening underlying cause. Differentiating the dangerous from benign causes can be challenging, especially because more than half of all patients in the ED report having experienced the subjective sensation of dizziness within the preceding week.2
The term “dizziness” means different things to different people. Classic teaching used the diagnostic paradigm that separates dizziness into “lightheadedness” or “vertigo” or “disequilibrium.” The value of this approach has been challenged and is currently being reassessed: In one study, patients were presented with a series of options to describe the “type” of dizziness experienced, and then reasked the same question with the same choices, but in a different sequence 6 minutes later. Concordance was less than 50%.3
In the real world, not all patients with vestibular dysfunction report vertigo, and not all patients with cardiovascular dysfunction report lightheadedness. Relying on symptom description to guide the differential considerations is a setup for diagnostic error.
As an alternative, patients are much more consistent in reporting the timing and triggers of their symptoms. As part of a history and review of systems, providers should elucidate the context of the symptoms to individualize the differential diagnosis.
Did the symptoms begin abruptly?
Has the dizziness been persistent or episodic?
Were there any precipitating triggers to provoke the dizziness?
Were there associated symptoms such as focal neurologic deficits, palpitations, shortness of breath, ear pain, or tinnitus?
These are all reasonable questions to ask to gain a better understanding of precisely what the patient experienced and hone in on the underlying cause.
We recommend using the ATTEST mnemonic as a helpful way to systematically approach the chief complaint of dizziness and avoid misdiagnosis.4,5
ATTEST stands for A
ssociated symptoms, T
igns, and T
esting (Figure 10.1
, Table 10.1)
. This approach focuses on key components of the history and examination to distinguish four different vestibular syndromes:
Acute spontaneous vestibular syndrome (ASVS)
Acute triggered vestibular syndrome (ATVS)
Episodic spontaneous vestibular syndrome (ESVS)
Episodic triggered vestibular syndrome (ETVS)
Figure 10.1: Diagnostic approach to the acutely dizzy patient. AVS, acute vestibular syndrome; BPPV, benign paroxysmal positional vertigo; CPPV, central paroxysmal positional vertigo; s-EVS spontaneous episodic vestibular syndrome; t-EVS, triggered episodic vestibular syndrome; TIA, transient ischemic attack.
TABLE 10.1 The ATTEST Mnemonic
Each of these distinct vestibular syndromes is discussed in greater detail later in this chapter in Approach/The Focused Examination section.
Reliably differentiating benign from dangerous causes of dizziness and vertigo can be difficult from the field. Individuals experiencing debilitating dizziness seeking medical care should not attempt to drive themselves. Prehospital providers should do their best to determine the likelihood of posterior circulation stroke by knowing the warning signs and symptoms, following local emergency medical service (EMS) protocols, using validated stroke recognition/severity grading tools, and adhering to destination determination protocols. A finger-stick glucose test is easy to perform and generally indicated, and if stroke is suspected, obtaining a confirmed time last known well (LKW) is very important in screening eligibility for stroke reperfusion therapies. If able, an electrocardiogram (ECG) is often useful to screen for cardiac dysrhythmias in addition to a full set of vital signs. If the patient is ambulatory, an assessment of gait stability is very helpful as well.