Alpha-Gal Syndrome: A Novel and Increasingly Common Cause of Anaphylaxis.

The alpha-gal syndrome is a recently described cause of anaphylaxis to red meat that has been increasing in frequency over time. It is related to Lone Star tick bites in the United States and occurs in many other parts of the world. It is especially common in the southeastern United States. In addition to the usual symptoms of anaphylaxis, gastrointestinal symptoms are prominent. Another unusual feature is the delay of several hours between eating meat and the development of symptoms. Diagnosis can be made by a blood test for the immunoglobulin E antibodies to a specific oligosaccharide. As many as 10% of patients diagnosed with idiopathic anaphylaxis have alpha-gal syndrome in some parts of the United States. The only current treatment is a meat-free diet. Clinician awareness of alpha-gal syndrome is low, and because severe recurrent life-threatening episodes can occur, it is an important condition for emergency clinicians to be aware of.

Bedside Testing in Acute Vestibular Syndrome-Evaluating HINTS Plus and Beyond-A Critical Review.

Acute vertigo and dizziness are frequent presenting symptoms in patients in the emergency department. These symptoms, which can be subtle and transient, present diagnostic challenges because they can be caused by a broad range of conditions that cut across many specialties and organ systems. Previous work has emphasized the value of combining structured history taking and a targeted examination focusing on subtle oculomotor signs. In this review, we discuss various diagnostic bedside algorithms proposed for the acutely dizzy patient. We analyzed these different approaches by calculating their area-under-the-curve (ROC) characteristics and sensitivity/specificity. We found that the algorithms that incorporated structured history taking and the use of subtle oculomotor signs had the highest diagnostic accuracy. In fact, both the HINTS+ bedside exam and the STANDING algorithm can more accurately diagnose acute strokes than early (<24 to 48 h after symptom onset) MRI with diffusion-weighted imaging (DWI). An important caveat is that HINTS and STANDING require moderate training to achieve this accuracy. Therefore, for physicians who have not undergone adequate training, other approaches are needed. These other approaches (e.g., ABCD2 score, PCI score, and TriAGe+ score) rely on vascular risk factors, clinical symptoms, and focal neurologic findings. While these other scores are easier for frontline providers to use, their diagnostic accuracy is far lower than HINTS+ or STANDING. Therefore, a focus on providing dedicated training in HINTS+ or STANDING techniques to frontline clinicians will be key to improving diagnostic accuracy and avoiding unnecessary brain imaging.

Acute headache in pregnant and post-partum patients: A clinical review.

BACKGROUND: Headaches during pregnancy and the post-partum period may be due to either an exacerbation of a pre-existing neurological presentation, a new pregnancy-related process, or a non-pregnancy related condition. Key physiologic changes during pregnancy and the post-partum period contribute to the vulnerability of this patient population and the increased risk of complications. OBJECTIVE OF THE REVIEW: Review causes of headaches in pregnant and post-partum patients as well as neuroimaging techniques performed. DISCUSSION: Headaches are a common complaint for pregnant and post-partum patients. For pregnant patients, a range of serious causes must be considered including cerebral venous thrombosis, posterior reversible encephalopathy syndrome and stroke. Primary headaches are responsible for most post-partum headaches, however other causes also include pre-clampsia, cerebral venous thrombosis and post-dural headache. Determining the optimal imaging technique in this vulnerable population remains a challenge given the scarce guidelines. CONCLUSION: The greatest difficulty while evaluating pregnant and post-partum patients presenting with an acute headache in an emergency setting is to determine whether the headache is due to a primary disorder such as migraines or is secondary to an underlying, sometimes serious pathology. The following review explores evidenced-based diagnosis of headache in this particular setting.

Guidelines for reasonable and appropriate care in the emergency department 3 (GRACE-3): Acute dizziness and vertigo in the emergency department.

This third Guideline for Reasonable and Appropriate Care in the Emergency Department (GRACE-3) from the Society for Academic Emergency Medicine is on the topic adult patients with acute dizziness and vertigo in the emergency department (ED). A multidisciplinary guideline panel applied the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach to assess the certainty of evidence and strength of recommendations regarding five questions for adult ED patients with acute dizziness of less than 2 weeks' duration. The intended population is adults presenting to the ED with acute dizziness or vertigo. The panel derived 15 evidence-based recommendations based on the timing and triggers of the dizziness but recognizes that alternative diagnostic approaches exist, such as the STANDING protocol and nystagmus examination in combination with gait unsteadiness or the presence of vascular risk factors. As an overarching recommendation, (1) emergency clinicians should receive training in bedside physical examination techniques for patients with the acute vestibular syndrome (AVS; HINTS) and the diagnostic and therapeutic maneuvers for benign paroxysmal positional vertigo (BPPV; Dix-Hallpike test and Epley maneuver). To help distinguish central from peripheral causes in patients with the AVS, we recommend: (2) use HINTS (for clinicians trained in its use) in patients with nystagmus, (3) use finger rub to further aid in excluding stroke in patients with nystagmus, (4) use severity of gait unsteadiness in patients without nystagmus, (5) do not use brain computed tomography (CT), (6) do not use routine magnetic resonance imaging (MRI) as a first-line test if a clinician trained in HINTS is available, and (7) use MRI as a confirmatory test in patients with central or equivocal HINTS examinations. In patients with the spontaneous episodic vestibular syndrome: (8) search for symptoms or signs of cerebral ischemia, (9) do not use CT, and (10) use CT angiography or MRI angiography if there is concern for transient ischemic attack. In patients with the triggered (positional) episodic vestibular syndrome, (11) use the Dix-Hallpike test to diagnose posterior canal BPPV (pc-BPPV), (12) do not use CT, and (13) do not use MRI routinely, unless atypical clinical features are present. In patients diagnosed with vestibular neuritis, (14) consider short-term steroids as a treatment option. In patients diagnosed with pc-BPPV, (15) treat with the Epley maneuver. It is clear that as of 2023, when applied in routine practice by emergency clinicians without special training, HINTS testing is inaccurate, partly due to use in the wrong patients and partly due to issues with its interpretation. Most emergency physicians have not received training in use of HINTS. As such, it is not standard of care, either in the legal sense of that term ("what the average physician would do in similar circumstances") or in the common parlance sense ("the standard action typically used by physicians in routine practice").

Epley maneuver for benign paroxysmal positional vertigo: Evidence synthesis for guidelines for reasonable and appropriate care in the emergency department.

BACKGROUND: Canalith repositioning maneuvers (such as the Epley maneuver) are recommended by specialty guidelines for management of benign paroxysmal positional vertigo (BPPV) yet are frequently underutilized in the emergency department (ED). METHODS: We conducted a systematic review of systematic reviews to summarize the evidence of Epley maneuver for the treatment of posterior canal (pc) BPPV in any setting. We included systematic reviews of randomized controlled trials (RCTs) that compared Epley to control in adult patients with pc-BPPV. Titles, abstracts, and full texts were screened in duplicate. The Grading of Recommendations, Assessment, Development and Evaluation (GRADE) assessment was used to rate certainty of evidence. Odds ratios (OR) and 95% confidence intervals (CI) are reported. Meta-analysis of individual studies was conducted with random and fixed effects. RESULTS: From 2,228 titles, 7 systematic reviews were selected for quality assessment. One review was of higher methodological quality, included only RCTs, and was the most current and comprehensive. Five of the 11 RCTs of the review, including 312 patients with pc-BPPV diagnosed by Dix-Hallpike, were relevant to our question. Meta-analysis of 4 RCTs (251 patients) showed the use of Epley (as compared to control) was associated with higher complete resolution of vertigo at 1 week (OR 7.19, CI 1.52 to 33.98, moderate certainty). Meta-analysis of 3 RCTs (195 patients) showed the use of Epley was associated with higher conversion to negative Dix-Hallpike at 1 week (OR 6.67, CI 1.52 to 33.98, moderate certainty). The number-needed-to-treat was 3. Meta-analysis of the outcomes at 1 month, and when observational studies were included, showed similar results. No serious adverse effects were reported. CONCLUSIONS: Symptoms of pc-BPPV improve with the Epley maneuver. Emergency clinicians should become familiar with performing the Epley for BPPV. Further studies on ED implementation and clinician education of Epley are needed.

Impact of Clinician Training Background and Stroke Location on Bedside Diagnostic Test Accuracy in the Acute Vestibular Syndrome - A Meta-Analysis.

OBJECTIVE: Acute dizziness/vertigo is usually due to benign inner-ear causes but is occasionally due to dangerous neurologic ones, particularly stroke. Because symptoms and signs overlap, misdiagnosis is frequent and overuse of neuroimaging is common. We assessed the accuracy of bedside findings to differentiate peripheral vestibular from central neurologic causes. METHODS: We performed a systematic search (MEDLINE and Embase) to identify studies reporting on diagnostic accuracy of physical examination in adults with acute, prolonged dizziness/vertigo ("acute vestibular syndrome" [AVS]). Diagnostic test properties were calculated for findings. Results were stratified by examiner type and stroke location. RESULTS: We identified 6,089 citations and included 14 articles representing 10 study cohorts (n = 800). The Head Impulse, Nystagmus, Test of Skew (HINTS) eye movement battery had high sensitivity 95.3% (95% confidence interval [CI] = 92.5-98.1) and specificity 92.6% (95% CI = 88.6-96.5). Sensitivity was similar by examiner type (subspecialists 94.3% [95% CI = 88.2-100.0] vs non-subspecialists 95.0% [95% CI = 91.2-98.9], p = 0.55), but specificity was higher among subspecialists (97.6% [95% CI = 94.9-100.0] vs 89.1% [95% CI = 83.0-95.2], p = 0.007). HINTS sensitivity was lower in anterior cerebellar artery (AICA) than posterior inferior cerebellar artery (PICA) strokes (84.0% [95% CI = 65.3-93.6] vs 97.7% [95% CI = 93.3-99.2], p = 0.014) but was "rescued" by the addition of bedside hearing tests (HINTS+). Severe (grade 3) gait/truncal instability had high specificity 99.2% (95% CI = 97.8-100.0) but low sensitivity 35.8% (95% CI = 5.2-66.5). Early magnetic resonance imaging (MRI)-diffusion-weighted imaging (DWI; within 24-48 hours) was falsely negative in 15% of strokes (sensitivity 85.1% [95% CI = 79.2-91.0]). INTERPRETATION: In AVS, HINTS examination by appropriately trained clinicians can differentiate peripheral from central causes and has higher diagnostic accuracy for stroke than MRI-DWI in the first 24-48 hours. These techniques should be disseminated to all clinicians evaluating dizziness/vertigo. ANN NEUROL 2023;94:295-308.

Misdiagnosis in the Emergency Department: Time for a System Solution.

This Viewpoint offers 3 insights in response to the AHRQ report on diagnostic errors made in US emergency departments: focus on the delivery systems instead of individuals, establish ways to set definitions and assess error rates, and design safe delivery systems to prevent errors.

Vestibular suppressants for benign paroxysmal positional vertigo: A systematic review and meta-analysis of randomized controlled trials.

BACKGROUND: Benign paroxysmal positional vertigo (BPPV) is a common cause of acute dizziness. Medication use for its treatment remains common despite guideline recommendations against their use. OBJECTIVES: The objective was to evaluate the efficacy and safety of vestibular suppressants in patients with BPPV compared to placebo, no treatment, or canalith repositioning maneuvers (CRMs). METHODS: We searched MEDLINE, Cochrane, EMBASE, and ClinicalTrials.gov from inception until March 25, 2022. for randomized controlled trials (RCTs) comparing antihistamines, phenothiazines, anticholinergics, and/or benzodiazepines to placebo, no treatment, or a CRM. RESULTS: Five RCTs, enrolling 296 patients, were included in the quantitative analysis. We found that vestibular suppressants may have no effect on symptom resolution at the point of longest follow-up (14-31 days in four studies) when evaluated as a continuous outcome (standardized mean difference -0.03 points, 95% confidence interval [CI] -0.53 to 0.47). Conversely, CRMs may improve symptom resolution at the point of longest follow-up as a dichotomous outcome when compared to vestibular suppressants (relative risk [RR] 0.63, 95% CI 0.52 to 0.78). Vestibular suppressants had an uncertain effect on symptom resolution within 24 h (mean difference [MD] 5 points, 95% CI -16.92 to 26.94), repeat emergency department (ED)/clinic visits (RR 0.37, 95% CI 0.12 to 1.15), patient satisfaction (MD 0 points, 95% CI -1.02 to 1.02), and quality of life (MD -1.2 points, 95% CI -2.96 to 0.56). Vestibular suppressants had an uncertain effect on adverse events. CONCLUSIONS: In patients with BPPV, vestibular suppressants may have no effect on symptom resolution at the point of longest follow-up; however, there is evidence toward the superiority of CRM over these medications. Vestibular suppressants have an uncertain effect on symptom resolution within 24 h, repeat ED/clinic visits, patient satisfaction, quality of life, and adverse events. These data suggest that a CRM, and not vestibular suppressants, should be the primary treatment for BPPV.

Benign paroxysmal positional vertigo: A practical approach for emergency physicians.

Benign paroxysmal positional vertigo (BPPV) is a very common condition in the population and an important cause of acute vertigo or dizziness in patients presenting to an emergency department (ED). Despite this, abundant evidence shows that current ED management of patients with BPPV is suboptimal. Common ED management processes include brain imaging and treatment with vestibular suppressant medications such as meclizine, neither of which is recommended by current guidelines. The most efficient management of BPPV is to perform a bedside test (Dix-Hallpike test) and then to treat the patients with a bedside positional (the Epley) maneuver. In this practical review we emphasize the efficient management for the most common form of BPPV-posterior canal BPPV. Using this management will reduce resource utilization (laboratory testing, brain imaging, specialist consultation), reduce ED length of stay, and reduce use of ineffective mediations that have side effects but little therapeutic effect. Application of these practices would improve important patient-centered outcomes such as symptom reduction, radiation exposure, side effects from medications, and less need for urgent follow-up with another health care provider. The article also discusses the approach to patients in whom the Dix-Hallpike and/or Epley maneuvers do not seem to work. This includes a discussion the second most common variant of BPPV (horizontal canal BPPV) and criteria for safe discharge of patients. Another important advantage of learning BPPV best practices is that it is enormously satisfying for the clinician, not unlike treating a child with a nursemaid's elbow.