Navigating the Complexities of Acute Dizziness Diagnosis

Date: April 12, 2023 Reference: Edlow et al.Guidelines for Reasonable and appropriate care in the emergency department 3 (GRACE-3): Acute dizziness and vertigo in the emergency department. AEM May 2023 Guest Skeptic: Dr. Jonathon Edlow has practiced emergency medicine for nearly 40 years and is a Professor of Emergency Medicine at Harvard Medical School. His academic interest is avoiding the misdiagnosis of patients with neurological emergencies.  This is an SGEM Xtra and #SGEMHOP combined. We have reviewed the previous two GRACE guidelines published by the Society for Academic Emergency Medicine (SAEM). GRACE stands for Guidelines for Reasonable and Appropriate Care in the Emergency Department. This is the third GRACE project. GRACE-1 tackled the common issue of recurrent low risk chest pain (SGEM#337). This contrasts with other guidelines that only looked at a single emergency department presentation for chest pain. And GRACE-2 was about low-risk recurrent abdominal pain (SGEM#367). Now we come to GRACE-3. This time it was not a recurrent condition like chest pain or abdominal pain but rather acute vertigo or dizziness. The objective of the GRACE-3 guideline is to provide an evidence-based framework intended to support patients, clinicians, and other health-care professionals in their decisions about the evaluation and management of adult ED patients with acute dizziness who do not have an obvious central cause with frank neurological findings or an obvious general medical one. The population covered by these guidelines are adult patients presenting to the ED with acute dizziness or vertigo of less than two weeks. Let us clarify some terms because it is often not clear when what people mean by dizziness and vertigo. I tend to describe dizziness as light-headedness, unsteadiness, motion intolerance, imbalance, floating, or a tilting sensation. Dizziness in GRACE-3 was defined as the sensation of disturbed or impaired spatial orientation without a false or distorted sense of motion (Barany Society). Vertigo in GRACE-3 was defined as the sensation of self-motion (of head or body) when no self-motion is occurring, or the sensation of distorted self-motion during an otherwise normal head movement. The problem is that research shows that patients often use multiple descriptors simultaneously or change their main descriptor if asked again less than 10 minutes later. So, although your concept is exactly what has been taught for decades, data from the last decade and a half show that it’s simply not true. The author group came up with 15 evidence-based recommendations based on the timing and triggers of the dizziness. Let’s go through those recommendations with the first one being an overarching one. 15 Recommendations from GRACE-3 Recommendation 1: Emergency clinicians should receive training in bedside physical examination techniques for patients with the AVS (HINTS) and diagnostic and therapeutic maneuvers for BPPV (Dix-Hallpike test and Epley maneuver), since untrained ED physicians do not reliably apply or accurately interpret results of this bedside eye movement examination. [Ungraded Good Practice Statement] HINTS stands for Head Impulse, Nystagmus, and Test of Skew. It was initially touted as a highly sensitive, specific marker for cerebellar stroke in the ED. However, study results have been mixed and there is ongoing debate about how to train for and utilize this examination in the acute care setting. A 2021 study [1] reported that EM physicians could be trained on the HINTS and it gave a sensitivity of 97% for central vertigo (SGEM#376). However, a SRMA [2] that included EM physicians showed less impressive results with a sensitivity of 83. The authors of the review felt the use of HINTS by EM physicians had “not been shown to be sufficiently accurate to rule out a stroke.” (SGEM#310). There is a clear disconnect between what is possible for emergency physicians to do and what ...