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.

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.

Recognizing Posterior Circulation Transient Ischemic Attacks Presenting as Episodic Isolated Dizziness.

Diagnosing patients presenting to the emergency department with self-limited episodes of isolated dizziness (the episodic vestibular syndrome) requires a broad differential diagnosis that includes posterior circulation transient ischemic attack. Because these patients are, by definition, asymptomatic without new neurologic findings on examination, the diagnosis, largely based on history and epidemiologic context, can be challenging. We review literature that addresses the frequency of posterior circulation transient ischemic attack in this group of patients compared with other potential causes of episodic vestibular syndrome. We present ways of distinguishing posterior circulation transient ischemic attack from vestibular migraine, the most common cause of episodic vestibular syndrome. We also present a diagnostic algorithm that may help clinicians to work their way through the differential diagnosis.

The Man Who Mistook a Hat for His Wife: Case Report of Aortic Dissection Presenting With Acute Hyperfamiliarity for Faces.

Acute aortic dissection is a challenging diagnosis for emergency physicians because of its high mortality and wide range of clinical presentations. We report a case of a previously healthy man who presented with hyperfamiliarity for faces syndrome as the predominant symptom of a large type A aortic dissection diagnosed by computed tomography angiography in the emergency department. Different elements of his presentation suggested possible other diagnoses, including transient global amnesia and transient ischemic attack. We discuss how evaluating these other diagnostic possibilities led to the correct diagnosis. Given increasing reports of painless aortic dissection, this case demonstrates the need to consider aortic dissection in patients with acute neurological symptoms.

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.

Diagnostic yield of CT angiography performed for suspected cervical artery dissection in the emergency department.

BACKGROUND AND PURPOSE: Computed tomography angiographies are frequently performed in the emergency department (ED) for the assessment of cervical artery dissection (CeAD) due to the high risk of associated morbidity, but their diagnostic utility is not fully evaluated. We assessed the radiological outcomes and clinical correlates of CTAs performed for suspected CeAD. MATERIALS AND METHODS: CTAs for all indications (IndicationALL) over a 10-year period were evaluated to identify those with CeAD. A subgroup of CTAs performed for suspected CeAD (IndicationDISSECTION) was identified and further assessed for clinical findings predictive of CeAD. Magnetic resonance angiography/fat-saturated images (MRA/FSI) performed after CTA were also assessed. RESULTS: Nine-thousand-two-hundred-four CTAs were performed by our ED for IndicationALL of which 850 (9.2%) were for IndicationDISSECTION. CeAD was noted in 1.5% (142/9204) among IndicationALL and in 6.1% (53/850) of IndicationDISSECTION CTAs. The most common radiological findings were mural thrombus and eccentric lumen. In the IndicationDISSECTION group, new headache (OR: 2.5, 95%CI: 1.2-5.7) and partial Horner syndrome (OR: 14.4, 95%CI: 4.2-49.9) predicted carotid dissection and cervical fracture (OR: 5.5, 95%CI: 2.1-14.6) predicted vertebral artery dissections. MRA/FSI confirmed CeAD in all positive cases, but in 2 CTAs read as negative, MRA/FSI was positive for vertebral artery dissection. CONCLUSION: Although the yield of CTAs for clinically suspected CeAD is low, the paucity of reliable clinical predictors, high risk of morbidity, availability in ED, and comparable performance to MRA/FSI justifies its widespread utilization for initial diagnosis of CeAD.

Retrospective Review of Pregnant Patients Presenting for Evaluation of Acute Neurologic Complaints.

STUDY OBJECTIVE: Data suggest an increase in neurologic-related hospitalizations during pregnancy. It is crucial for health care providers to develop effective strategies to evaluate this young, generally healthy cohort of patients for whom missed neurologic diagnoses can have devastating results. We aim to describe the epidemiology of this high risk patient population by investigating exam findings, imaging studies, and clinical outcomes of pregnant women presenting to the emergency department (ED) with acute neurologic complaints. METHODS: We conducted a 7-year retrospective chart review of pregnant patients presenting with neurologic chief complaints to the emergency department of an urban tertiary academic medical center in the northeastern United States. We investigated examination findings, imaging studies, and clinical outcomes. RESULTS: Between January 1, 2010, and May 31, 2017, 205 pregnant patients presented to the ED with a neurologic chief complaint. The majority of patients had a normal neurologic examination result. Patients with an abnormal examination result were not more likely to have clinically significant imaging findings. Within our population, 28% underwent imaging, and noncontrast magnetic resonance imaging was the most common modality. Five patients had clinically significant imaging findings. Specifically, 3.3% of patients with abnormal examination result had significant findings and 2.3% of those with a normal examination result had significant findings. A minority of the patients with a visit resulting in discharge (9.8%) returned to the ED within a 7-day period. None required additional neuroimaging. CONCLUSION: To our knowledge, our study is unique in that it incorporated all neurologic complaints. Headache was the most common complaint, followed by dizziness and seizures. Most of the headaches were related to first-trimester migraines. There was a high incidence of imaging used in clinical practice even when there was a normal neurologic examination result. A normal examination result does not adequately exclude serious intracranial pathology, and diagnostic vigilance is justified.

Outcomes of a novel ED observation pathway for mild traumatic brain injury and associated intracranial hemorrhage.

BACKGROUND: Recent studies have shown that the majority of non-anticoagulated patients with small subdural or subarachnoid intracranial hemorrhage (ICH) in the setting of mild traumatic brain injury do not experience clinical deterioration or require neurosurgical intervention. We implemented a novel ED observation pathway to reduce unnecessary admissions among patients with ICH in the setting of mild TBI (complicated mild TBI, cmTBI). METHODS: Prospective, single-center study of ED patients presenting to a Level-1 Trauma Center, 4/2016-12/2018. INCLUSION CRITERIA: head injury with GCS ≥ 14, minor positive CT findings (i.e. subdural hematoma <1 cm). EXCLUSION CRITERIA: GCS < 14, multi-system trauma procedural intervention or admission, epidural hematoma, skull fracture, seizure, anticoagulant/antiplatelet use beyond aspirin, physician discretion. OUTCOMES: pathway completion rate, ED length-of-stay (LOS), neurosurgical intervention, hospital LOS, 7-day return visits. RESULTS: 138 patients met all pathway criteria and were included in analysis. 113/138 (81.9%) patients were discharged home after observation with mean ED LOS of 17.3 h (median 15.4 h, SD +/- 10.5) including 91/111 (81.9%) patients transferred from outside hospitals (median 18.1 h, SD +/- 11.0). Increased age and aspirin use were correlated with pathway non-completion requiring admission, but not due to hematoma expansion. Among admitted patients, none required neurosurgical intervention. Seven (5.1%) 7-day return visits occurred, 3 (2%) related to initial cmTBI; 1 (0.9%) was admitted for neurologic monitoring. CONCLUSIONS: ED observation for patients with cmTBI resulted in an 82% pathway completion rate, including outside hospital transfers. These results suggest that patients with cmTBI may be safely discharged from the ED after a brief period of observation. Our pathway protocol and implementation involved neurosurgical consultation and the ability to perform repeat neurologic exams in the ED. Future studies should examine the feasibility of non-transfer protocols for appropriately selected patients and access to neurosurgical expertise in the community setting.

Role of C-reactive protein in effective utilization of emergent MRI for spinal infections.

PURPOSE: Emergent spinal MRI is recommended for patients with back pain and red flags for infection. However, many of these studies are negative due to low prevalence of spinal infections. Our purpose was to assess if C-reactive protein (CRP) can be used to guide effective utilization of emergent MRI for spinal infections. METHODS: 316/960 (33%) MRIs performed for infection by the emergency department over 75-month period had CRP levels obtained at presentation, after excluding patients receiving antibiotic or had spinal surgery in < 1 month. An MRI was considered positive when there was imaging evidence of spinal infection confirmed on follow-up by surgery/biopsy/drainage or definitive therapy. A CRP of ≤ 10 mg/L was considered normal and > 100 mg/L as highly elevated. RESULTS: CRP was normal in 95/316 (30%) and abnormal in 221/316 (70%) patients. MRI was positive in 43/316 (13.6%) patients, all of whom had abnormal CRP. CRP (p < 0.001) and intravenous drug use (IVDU; p = 0.002) were independently associated with a positive MRI. Receiver operator characteristic (ROC) analysis showed AUC of 0.76 for CRP, slightly improving with IVDU. Sensitivity, specificity, and negative predictive values for CRP level cut-off: 10 mg/L, 100%, 35%, and 100%, and 100 mg/L, 58%, 70% and 91%, respectively. CONCLUSION: Abnormal CRP, although extremely sensitive, lacks specificity in predicting a positive MRI for spinal infection unless highly elevated. However, a normal CRP (absent recent antibiotic or surgery) makes spinal infection unlikely, and its routine use as a screening test can help reducing utilization of emergent MRI for this purpose.

A Primer on Computed Tomography Perfusion Imaging for the Emergency Physician.

BACKGROUND: Brain noncontrast computed tomography (CT), CT angiography, and magnetic resonance imaging have been used clinically for decades, and emergency physicians have a good understanding of their indications, the meaning of their results, and some facility with the interpretation of CT. However, brain CT perfusion (CTP) is relatively new and emergency physicians are less familiar with its basic concepts, indications, and role in managing patients with neurological emergencies. OBJECTIVE: We will review the parameters of clinical interest on a CTP report, and how to incorporate them into clinical decision-making. DISCUSSION: Endovascular therapies paired with CTP have opened up a new frontier in stroke management for severely debilitated stroke patients. It is important for emergency physicians to have an understanding of CTP and how to use it clinically. CONCLUSION: Taking care of patients with large-vessel occlusions is multidisciplinary, and emergency physicians need to understand CTP imaging and its clinical utility.

Acute Dizziness.

Dizziness is a common chief complaint with an extensive differential diagnosis that includes both benign and serious conditions. Physicians must distinguish the majority of patients who suffer from self-limiting conditions from those with serious illnesses that require acute treatment. The preferred approach to the diagnosis of an acutely dizzy patient emphasizes different aspects of the history to guide a focused physical examination, with the goal of differentiating benign peripheral vestibular conditions from dangerous posterior circulation strokes. Currently, misdiagnoses are frequent and diagnostic testing costs are high. This partly relates to use of an outdated diagnostic paradigm. This commonly used traditional approach relies on dizziness "symptom quality" or "type" (vertigo, presyncope, disequilibrium) to guide inquiry. It does not distinguish benign from dangerous causes and is inconsistent with current best evidence. A better approach categorizes patients into three groups based on timing and triggers. Each category has its own differential diagnosis and targeted bedside approach: (1) acute vestibular syndrome, where bedside physical examination differentiates vestibular neuritis from stroke; (2) spontaneous episodic vestibular syndrome, where associated symptoms help differentiate vestibular migraine from transient ischemic attack; and (3) triggered episodic vestibular syndrome, where the Dix-Hallpike and supine roll test help differentiate benign paroxysmal positional vertigo from posterior fossa structural lesions. The "timing and triggers" diagnostic approach for the acutely dizzy derives from current best evidence and offers the potential to reduce misdiagnosis while simultaneously decreasing diagnostic test overuse, unnecessary hospitalization, and incorrect treatments.

Missed Serious Neurologic Conditions in Emergency Department Patients Discharged With Nonspecific Diagnoses of Headache or Back Pain.

STUDY OBJECTIVE: Serious neurologic conditions can be missed on initial emergency department (ED) visit and discharge diagnosis oftentimes remains a nonspecific symptom. We aim to examine the incidence of potential harm from serious neurologic conditions in ED patients discharged with a nonspecific diagnosis of headache or back pain, identify specific missed conditions, and determine risk factors for potential misdiagnosis-related harm. METHODS: This was a retrospective analysis using the population-based data of 6 US states from the State Emergency Department Databases and State Inpatient Databases from 2006 through 2012. We identified adults (≥18 years) discharged from the ED with a diagnosis of atraumatic headache or back pain. The primary outcome was a composite of return ED visit and hospitalization for primary diagnosis of a serious neurologic condition or inhospital death within 30 days of ED discharge. RESULTS: There were 2,101,081 ED discharges with a nonspecific diagnosis of headache and 1,381,614 discharges with a nonspecific diagnosis of back pain. Overall, 0.5% of the headache patients and 0.2% of back pain patients had a primary outcome. The most common missed condition for headache was ischemic stroke (18.1%). The most common missed condition for back pain was intraspinal abscess (41%). In both populations, advanced age, male sex, non-Hispanic white, and comorbidities (eg, neurologic disorders, HIV/AIDS, malignancy) were associated with higher odds of outcome. CONCLUSION: A small proportion of ED patients discharged with nonspecific diagnoses of headache or back pain returned with a serious neurologic condition or inhospital death within 30 days.