Acute diagnostic neurology: challenges and opportunities

Models of care in emergency neurology: from the Neuro Fast Track to the emergency neurologist-a position paper of the Italian Association for Emergency Neurology (ANEU)

I n the context of an adequate health care organization, the figure of the neurologist as an emergency operator (in the emergency room-ER-and/or in a dedicated outpatient clinic) is crucial for an effective functional connection with the territory (and therefore with general practitioners), a reduction in inappropriate ER accesses, specific diagnostic and therapeutic approaches to neurological emergencies in the ER and a reduction in nonspecific or even unnecessary instrumental investigations. In this position paper of the Italian Association of Emergency Neurology (ANEU: Associazione Neurologia dell'Emergenza Urgenza), these issues are addressed, and two important organizational solutions are proposed: 1) The Neuro Fast Track, as an outpatient organization approach strongly linked to general practitioners and non-neurological specialists and dedicated to cases with deferrable urgency (to be assessed within 72 h) 2) The identification of an emergency neurologist, who is engaged in ER assessments as a consultant and involved in the management of the semi-intensive care unit of the emergency neurology and the stroke unit according to an appropriate rotation, as well as in consultations for patients with neurological emergencies in inpatient wards The possibility of computerizing the screening of patients with deferrable urgency in the Neuro Fast Track is described. A dedicated app represents an important tool that can facilitate the identification of patients for whom deferred assessment is appropriate, the scheduling of neurological examinations and reductions in the booking time through a more rapid approach to specialist assessment and subsequent investigations.

Prevalence of neurological complaints among emergency department patients with severe hypertension

OBJECTIVE

Severe hypertension can accompany neurological symptoms without obvious signs of target organ damage. However, acute cerebrovascular events can also be a cause and consequence of severe hypertension. We therefore use US population-level data to determine prevalence and clinical characteristics of patients with severe hypertension and neurological complaints.

METHODS

We used nationally representative data from the National Hospital Ambulatory Medical Care Survey (NHAMCS) collected in 2016-2019 to identify adult ED patients with severely elevated blood pressure (BP) defined as systolic BP ≥ 180 mmHg and/or diastolic BP ≥120 mmHg. We used ED reason for visit data fields to define neurological complaints and used diagnosis data fields to define acute target organ damage. We applied survey visit weights to obtain national estimates.

RESULTS

Based on 5083 observations, an estimated 40.4 million patients (95% CI: 37.5-43.0 million) in EDs nationwide from 2016 to 2019 had severe hypertension, equating to 6.1% (95% CI: 5.7-6.5%) of all ED visits. Only 2.8% (95% CI: 2.0-3.9%) of ED patients with severe hypertension were diagnosed with acute cerebrovascular disease; hypertensive urgency was diagnosed in 92.0% (95% CI: 90.3-93.4%). Neurological complaints were frequent in both patients with (75.6%) and without (19.9%) cerebrovascular diagnoses. Hypertensive urgency patients with neurological complaints were more often older, female, had prior stroke/TIA, and had neuroimaging than patients without these complaints. Non-migraine headache and vertigo were the most common neurological complaints recorded.

CONCLUSION

In a nationally representative survey, one-in-sixteen ED patients had severely elevated BP and one-fifth of those patients had neurological complaints.

Fast Neuro: A Care Model to Expedite Access to Neurology Clinic

Objective:

We set out to improve outpatient neurology access while reducing patient volume in the emergency department (ED) for nonemergent neurologic complaints.

Methods:

We created a rapid-access model, UCLA Fast Neuro, for patients referred from affiliated emergency departments to outpatient neurology, enabling appointments within 1 week of referral. Rapid-access appointments were also available to established neurology patients with urgent concerns. Fast Neuro was built to reduce nonemergent neurologic care in the ED, improve outpatient neurology access, and avoid use of inpatient neurology services for nonemergent consults. The volume of referrals and neurology consults from the ED and wait time from referral to appointment were measured. Surveys were conducted at 3 and 6 months to assess satisfaction with the model by all stakeholders.

Results:

From January 2019 through January 2021, 201 patients were referred to outpatient neurology through UCLA Fast Neuro. Wait time for an outpatient neurology appointment was reduced from the prior period by 82.5% (7.0±5.5 days vs 40±4.1 days). The number of nonemergent consults from the ED was reduced by 60% (4.1±1.9/month vs 10.3±1.7/month). Surveys showed wide acceptance of the new model with 92% of attending physicians and advanced practice providers and 89% of residents endorsing that UCLA Fast Neuro patients did not detract from their clinic experience.

Conclusions:

UCLA Fast Neuro improved emergency room throughput, reduced inpatient neurology consults from the ED, and decreased wait times for outpatient neurology appointments without using the inpatient neurology service for nonurgent consults. UCLA Fast Neuro was successful. Exploration of how to scale and implement the model of access more broadly is warranted.

Emergency medicine physicians' perspectives on diagnostic accuracy in neurology: a qualitative study

OBJECTIVES

We sought to understand the knowledge, attitudes, and beliefs of emergency medicine (EM) physicians towards non-specific neurological conditions and the use of clinical decision support (CDS) to improve diagnostic accuracy.

METHODS

We conducted semi-structured interviews of EM physicians at four emergency departments (EDs) affiliated with a single US healthcare system. Interviews were conducted until thematic saturation was achieved. Conventional content analysis was used to identify themes related to EM physicians' perspectives on acute diagnostic neurology; directed content analysis was used to explore views regarding CDS. Each interview transcript was independently coded by two researchers using an iteratively refined codebook with consensus-based resolution of coding differences.

RESULTS

We identified two domains regarding diagnostic safety: (1) challenges unique to neurological complaints and (2) challenges in EM more broadly. Themes relevant to neurology included: (1) knowledge gaps and uncertainty, (2) skepticism about neurology, (3) comfort with basic as opposed to detailed neurological examination, and (4) comfort with non-neurological diseases. Themes relevant to diagnostic decision making in the ED included: (1) cognitive biases, (2) ED system/environmental issues, (3) patient barriers, (4) comfort with diagnostic uncertainty, and (5) concerns regarding diagnostic error identification and measurement. Most participating EM physicians were enthusiastic about the potential for well-designed CDS to improve diagnostic accuracy for non-specific neurological complaints.

CONCLUSIONS

Physicians identified diagnostic challenges unique to neurological diseases as well as issues related more generally to diagnostic accuracy in EM. These physician-reported issues should be accounted for when designing interventions to improve ED diagnostic accuracy.

Cost-Effectiveness of Advanced Neuroimaging for Transient and Minor Neurological Events in the Emergency Department

Background Accurate diagnosis of patients with transient or minor neurological events can be challenging. Recent studies suggest that advanced neuroimaging can improve diagnostic accuracy in low-risk patients with transient or minor neurological symptoms, but a cost-effective emergency department diagnostic evaluation strategy remains uncertain. Methods and Results We constructed a decision-analytic model to evaluate 2 diagnostic evaluation strategies for patients with low-risk transient or minor neurological symptoms: (1) obtain advanced neuroimaging (magnetic resonance imaging brain and magnetic resonance angiography head and neck) on every patient or (2) current emergency department standard-of-care clinical evaluation with basic neuroimaging. Main probability variables were: proportion of patients with true ischemic events, strategy specificity and sensitivity, and recurrent stroke rate. Direct healthcare costs were included. We calculated incremental cost-effectiveness ratios, conducted sensitivity analyses, and evaluated various diagnostic test parameters primarily using a 1-year time horizon. Cost-effectiveness standards would be met if the incremental cost-effectiveness ratio was less than willingness to pay. We defined willingness to pay as $100 000 US dollars per quality-adjusted life year. Our primary and sensitivity analyses found that the advanced neuroimaging strategy was more cost-effective than emergency department standard of care. The incremental effectiveness of the advanced neuroimaging strategy was slightly less than the standard-of-care strategy, but the standard-of-care strategy was more costly. Potentially superior diagnostic approaches to the modeled advanced neuroimaging strategy would have to be >92% specific, >70% sensitive, and cost less than or equal to standard-of-care strategy's cost. Conclusions Obtaining advanced neuroimaging on emergency department patient with low-risk transient or minor neurological symptoms was the more cost-effective strategy in our model.

Diagnostic Challenges in Outpatient Stroke: Stroke Chameleons and Atypical Stroke Syndromes

Failure to diagnose transient ischemic attack (TIA) or stroke in a timely fashion is associated with significant patient morbidity and mortality. In the outpatient or clinic setting, we suspect that patients with minor, transient, and atypical manifestations of cerebrovascular disease are most prone to missed or delayed diagnosis. We therefore detail common stroke chameleon symptoms as well as atypical stroke presentations, broadly review new developments in the study of diagnostic error in the outpatient setting, suggest practical clinical strategies for diagnostic error reduction, and emphasize the need for rapid consultation of stroke specialists when appropriate. We also address the role of psychiatric disease and vascular risk factors in the diagnostic evaluation and treatment of suspected stroke/TIA patients. We advocate incorporating diagnostic time-outs into clinical practice to assure that the diagnosis of TIA or stroke is considered in all relevant patient encounters after a detailed history and examination are conducted in the outpatient setting.

Breakdowns in the initial patient-provider encounter are a frequent source of diagnostic error among ischemic stroke cases included in a large medical malpractice claims database

Background Misdiagnosis of dangerous cerebrovascular disease is a substantial public health problem. We sought to identify and describe breakdowns in the diagnostic process among patients with ischemic stroke to facilitate future improvements in diagnostic accuracy. Methods We performed a retrospective, descriptive study of medical malpractice claims housed in the Controlled Risk Insurance Company (CRICO) Strategies Comparative Benchmarking System (CBS) database from 1/1/2006 to 1/1/2016 involving ischemic stroke patients. Baseline claimant demographics, clinical setting, primary allegation category, and outcomes were abstracted. Among cases with a primary diagnosis-related allegation, we detail presenting symptoms and diagnostic breakdowns using CRICO's proprietary taxonomy. Results A total of 478 claims met inclusion criteria; 235 (49.2%) with diagnostic error. Diagnostic errors originated in the emergency department (ED) in 46.4% (n = 109) of cases, outpatient clinic in 27.7% (n = 65), and inpatient setting in 25.1% (n = 59). Across care-settings, the most frequent process breakdown was in the initial patient-provider encounter [76.2% (n = 179 cases)]. Failure to assess, communicate, and respond to ongoing symptoms was the component of the patient-provider encounter most frequently identified as a source of misdiagnosis in the ED. Exclusively non-traditional presenting symptoms occurred in 35.7% (n = 84), mixed traditional and non-traditional symptoms in 30.6% (n = 72), and exclusively traditional in 23.8% (n = 56) of diagnostic error cases. Conclusions Among ischemic stroke patients, breakdowns in the initial patient-provider encounter were the most frequent source of diagnostic error. Targeted interventions should focus on the initial diagnostic encounter, particularly for ischemic stroke patients with atypical symptoms.

Factors associated with hospitalization for ischemic stroke and TIA following an emergency department headache visit

BACKGROUND

Misdiagnosis of cerebrovascular disease among Emergency Department (ED) patients with headache has been reported. We hypothesized that markers of substandard diagnostic processes would be associated with subsequent ischemic cerebrovascular events among patients discharged from the ED with a headache diagnosis even after adjusting for demographic variables and medical history.

METHODS

We conducted a case-control study of adult ED patients diagnosed with a primary headache disorder at Montefiore Medical Center from 9/1/2013-9/1/2018. Cases were defined as patients hospitalized for an ischemic stroke or TIA within 365 days of their index ED visit. Control patients were defined as those who lacked a subsequent hospitalization for cerebrovascular disease. Pre-specified demographic, clinical, and diagnostic process factors were compared between groups; conditional logistic regression was used to assess the separate and joint influence of baseline features on risk of cerebral ischemia.

RESULTS

A total of 93 consecutive headache patients with a subsequent ischemic stroke/TIA hospitalization were matched to 93 controls (n = 186). Cases were older than controls and more likely to have traditional cerebrovascular risk factors. Neurological consultation was obtained more often for cases (13% vs. 4%; P = 0.03), cases were in the ED for longer (6 vs. 5 h, P = 0.03), and more frequently received neuroimaging (80% vs. 48%; P < 0.0001). Rates of neurological examination, documented differential diagnoses, and clear discharge follow up plans were similar between cases and controls. In our conditional logistic regression model, only history of prior stroke/TIA was associated with increased odds of subsequent cerebral ischemia.

CONCLUSION

Factors associated with diagnostic process failures did not increase the odds of subsequent ischemic stroke/TIA hospitalization following ED headache visit in our study.

High-Risk Chief Complaints III: Neurologic Emergencies

A careful history and thorough physical examination are necessary in patients presenting with acute neurologic dysfunction. Patients presenting with headache should be screened for red-flag criteria that suggest a dangerous secondary cause warranting imaging and further diagnostic workup. Dizziness is a vague complaint; focusing on timing, triggers, and examination findings can help reduce diagnostic error. Most patients presenting with back pain do not require emergent imaging, but those with new neurologic deficits or signs/symptoms concerning for acute infection or cord compression warrant MRI. Delay to diagnosis and treatment of acute ischemic stroke is a frequent reason for medical malpractice claims.

Assessing diagnostic error in cerebral venous thrombosis via detailed chart review

Background Diagnostic error in cerebral venous thrombosis (CVT) has been understudied despite the harm associated with misdiagnosis of other cerebrovascular diseases as well as the known challenges of evaluating non-specific neurological symptoms in clinical practice. Methods We conducted a retrospective cohort study of CVT patients hospitalized at a single center. Two independent reviewers used a medical record review tool, the Safer Dx Instrument, to identify diagnostic errors. Demographic and clinical factors were abstracted. We compared subjects with and without a diagnostic error using the t-test for continuous variables and the chi-square (χ2) test or Fisher's exact test for categorical variables; an alpha of 0.05 was the cutoff for significance. Results A total of 72 CVT patients initially met study inclusion criteria; 19 were excluded due to incomplete medical records. Of the 53 patients included in the final analysis, the mean age was 48 years and 32 (60.4%) were women. Diagnostic error occurred in 11 cases [20.8%; 95% confidence interval (CI) 11.8-33.6%]. Subjects with diagnostic errors were younger (42 vs. 49 years, p = 0.13), more often women (81.8% vs. 54.8%, p = 0.17), and were significantly more likely to have a past medical history of a headache disorder prior to the index CVT visit (7.1% vs. 36.4%, p = 0.03). Conclusions Nearly one in five patients with complete medical records experienced a diagnostic error. Prior history of headache was the only evaluated clinical factor that was more common among those with an error in diagnosis. Future work on distinguishing primary from secondary headaches to improve diagnostic accuracy in acute neurological disease is warranted.

The use of a dedicated neurological triage system improves process times and resource utilization: a prospective observational study from an interdisciplinary emergency department

Background

Patients with neurological symptoms have been contributing to the increasing rates of emergency department (ED) utilization in recent years. Existing triage systems represent neurological symptoms rather crudely, neglecting subtler but relevant aspects like temporal evolution or associated symptoms. A designated neurological triage system could positively impact patient safety by identifying patients with urgent need for medical attention and prevent inadequate utilization of ED and hospital resources.

Methods

We compared basic demographic information, chief complaint/presenting symptom, door-to-doctor time and length of stay (LOS) as well as utilization of ED resources of patients presenting with neurological symptoms or complaints during a one-month period before as well as after the introduction of the Heidelberg Neurological Triage System (HEINTS) in our interdisciplinary ED. In a second step, we compared diagnostic and treatment processes for both time periods according to assigned acuity.

Results

During the two assessment periods, 299 and 300 patients were evaluated by a neurologist, respectively. While demographic features were similar for both groups, overall LOS (p < 0.001) was significantly shorter, while CT (p = 0.023), laboratory examinations (p = 0.006), ECG (p = 0.011) and consultations (p = 0.004) were performed significantly less often when assessing with HEINTS. When considering acuity, an epileptic seizure was less frequently evaluated as acute with HEINTS than in the pre-HEINTS phase (p = 0.002), while vertigo patients were significantly more often rated as acute with HEINTS (p < 0.001). In all cases rated as acute, door-to-doctor-time (DDT) decreased from 41.0 min to 17.7 min (p < 0.001), and treatment duration decreased from 304.3 min to 149.4 min (p < 0.001) after introduction of HEINTS triage.

Conclusion

A dedicated triage system for patients with neurological complaints reduces DDT, LOS and ED resource utilization, thereby improving ED diagnostic and treatment processes.

Uncompleted emergency department care and discharge against medical advice in patients with neurological complaints: a chart review

Background

Uncompleted emergency department care and against-medical-advice discharge represent relevant medical problems with impact on patient safety and potential medicolegal and socioeconomic consequences. They may also indicate structural or procedural problems in the emergency department (ED) relating to patient management and flow. While patients with neurological complaints frequently leave the ED against medical advice or without being seen, no dedicated analysis of this group of patients aiming at the identification of characteristics associated with irregular ED discharge has been performed so far.

Methods

A chart review was performed of all patients with neurological complaints presenting to a German interdisciplinary emergency department between January and December 2017 for neurological evaluation. Demographics, mode of presentation, process times, presenting symptoms and diagnosis were recorded. Patients leaving against medical advice after an informed consent discussion and signing of documentation (DAMA) or leaving prematurely without notifying ED staff (PL) were compared to the total of patients who were admitted or discharged (non-DAMA/PL).

Results

Of all patients presenting with neurological symptoms or complaints, 3% left against medical advice and 2.2% left prematurely. DAMA/PL patients were younger (p < .001), and they were more frequently self-presenting (p < 0.001). Headaches, seizures and sensory deficits were the most frequent presenting symptoms in DAMA/PL patients, and 56.1% of those presenting with a seizure had a history of epilepsy. The most common documented reason for leaving was the duration of door-to-doctor time.

Conclusions

Younger age, self-presenting mode of presentation and presentation with headache, seizures or sensory deficits are associated with premature leave or against-medical-advice discharge of patients with neurological complaints from the ED, and long waiting times were given as the major reason for leaving the ED. Increasing ED staff’s awareness of these factors and the optimization of pre-hospital assessment and demand management, thereby positively impacting on patient flow and ED process times, may help to prevent irregular discharges from the ED.

Inter-rater Agreement for the Diagnosis of Stroke Versus Stroke Mimic

BACKGROUND AND PURPOSE

Patients who present emergently with acute neurological signs and symptoms represent unique diagnostic challenges for clinicians. We sought to characterize the reliability of physician diagnosis in differentiating aborted or imaging-negative acute ischemic stroke from stroke mimic.

METHODS

We constructed 10 case-vignettes of patients treated with thrombolysis with subsequent clinical improvement who lacked radiographic evidence of infarction. Using an online survey, we asked physicians to select a most likely final diagnosis after reading each case-vignette. Inter-rater agreement was evaluated using percent agreement and κ statistic for multiple raters with 95% confidence intervals reported.

RESULTS

Sixty-five physicians participated in the survey. Most participants were in practice for ≥5 years and over half were vascular neurologists. Physicians agreed on the most likely final diagnosis 71% of the time, κ of 0.21 (95% confidence interval, 0.06-0.54). Percent agreement was similar across participant practice locations, years of experience, subspecialty training, and personal experience with thrombolysis.

CONCLUSIONS

We found modest agreement among surveyed physicians in distinguishing ischemic stroke syndromes from stroke mimics in patients without radiographic evidence of infarction and clinical improvement after thrombolysis. Methods to improve diagnostic consensus after thrombolysis are needed to assure acute ischemic stroke patients and stroke mimics are treated safely and accurately.

Stroke Chameleons and Stroke Mimics in the Emergency Department

PURPOSE OF REVIEW

We discuss the frequency of stroke misdiagnosis in the emergency department (ED), identify common diagnostic pitfalls, describe strategies to reduce diagnostic error, and detail ongoing research.

RECENT FINDINGS

The National Academy of Medicine has re-defined and highlighted the importance of diagnostic errors for patient safety. Recent rates of stroke under-diagnosis (false-negative cases, "stroke chameleons") range from 2-26% and 30-43% for stroke over-diagnosis (false-positive cases, "stroke mimics"). Failure to diagnosis stroke can preclude time-sensitive treatments and has been associated with poor outcomes. Strategies have been developed to improve detection of posterior circulation stroke syndromes, but ongoing work is needed to reduce under-diagnosis in other atypical stroke presentations. The published rates of harm associated with stroke over-diagnosis, particularly thrombolysis of stroke mimics, remain low. Additional strategies to improve the accuracy of stroke diagnosis should focus on rapid clinical reasoning in the time-sensitive setting of acute ischemic stroke and identifying imperfections in the healthcare system which may contribute to diagnostic error.

ED misdiagnosis of cerebrovascular events in the era of modern neuroimaging: A meta-analysis

OBJECTIVE

With the emergency department (ED) being a high-risk site for diagnostic errors, we sought to estimate ED diagnostic accuracy for identifying acute cerebrovascular events.

METHODS

MEDLINE and Embase were searched for studies (1995-2016) reporting ED diagnostic accuracy for ischemic stroke, TIA, or subarachnoid hemorrhage (SAH). Two independent reviewers determined inclusion. We identified 1,693 unique citations, examined 214 full articles, and analyzed 23 studies. Studies were rated on risk of bias (QUADAS-2). Diagnostic data were extracted. We prospectively defined clinical presentation subgroups to compare odds of misdiagnosis.

RESULTS

Included studies reported on 15,721 patients. Studies were at low risk of bias. Overall sensitivity (91.3% [95% confidence interval (CI) 90.7-92.0]) and specificity (92.7% [91.7-93.7]) for a cerebrovascular etiology was high, but there was significant variation based on clinical presentation. Misdiagnosis was more frequent among subgroups with milder (SAH with normal vs abnormal mental state; false-negative rate 23.8% vs 4.2%, odds ratio [OR] 7.03 [4.80-10.31]), nonspecific (dizziness vs motor findings; false-negative rate 39.4% vs 4.4%, OR 14.22 [9.76-20.74]), or transient (TIA vs ischemic stroke; false discovery rate 59.7% vs 11.7%, OR 11.21 [6.66-18.89]) symptoms.

CONCLUSIONS

Roughly 9% of cerebrovascular events are missed at initial ED presentation. Risk of misdiagnosis is much greater when presenting neurologic complaints are mild, nonspecific, or transient (range 24%-60%). This difference suggests that many misdiagnoses relate to symptom-specific factors. Future research should emphasize studying causes and designing error-reduction strategies in symptom-specific subgroups at greatest risk of misdiagnosis.