Nystagmus assessments documented by emergency physicians in acute dizziness presentations: a target for decision support?

Quantifying Induced Nystagmus Using a Smartphone Eye Tracking Application (EyePhone)

BACKGROUND

There are ≈5 million annual dizziness visits to US emergency departments, of which vestibular strokes account for over 250 000. The head impulse, nystagmus, and test of skew eye examination can accurately distinguish vestibular strokes from peripheral dizziness. However, the eye-movement signs are subtle, and lack of familiarity and difficulty with recognition of abnormal eye movements are significant barriers to widespread emergency department use. To break this barrier, we sought to assess the accuracy of EyePhone, our smartphone eye-tracking application, for quantifying nystagmus.

METHODS AND RESULTS

We prospectively enrolled healthy volunteers and recorded the velocity of induced nystagmus using a smartphone eye-tracking application (EyePhone) and then compared the results with video oculography (VOG). Following a calibration protocol, the participants viewed optokinetic stimuli with incremental velocities (2-12 degrees/s) in 4 directions. We extracted slow phase velocities from EyePhone data in each direction and compared them with the corresponding slow phase velocities obtained by the VOG. Furthermore, we calculated the area under the receiver operating characteristic curve for nystagmus detection by EyePhone. We enrolled 10 volunteers (90% men) with an average age of 30.2±6 years. EyePhone-recorded slow phase velocities highly correlated with the VOG recordings (r=0.98 for horizontal and r=0.94 for vertical). The calibration significantly increased the slope of linear regression for horizontal and vertical slow phase velocities. Evaluating the EyePhone's performance using VOG data with a 2 degrees/s threshold showed an area under the receiver operating characteristic curve of 0.87 for horizontal and vertical nystagmus detection.

CONCLUSIONS

We demonstrated that EyePhone could accurately detect and quantify optokinetic nystagmus, similar to the VOG goggles.

Guideline Adherence to Benign Paroxysmal Positional Vertigo Treatment and Management in Primary Care

OBJECTIVE

To determine adherence to the 2017 American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) guidelines for the management and treatment of benign paroxysmal positional vertigo (BPPV) in primary care (PC) and compare whether key recommendations differed by sex, race, or insurance status.

STUDY DESIGN

Retrospective chart review.

SETTING

Twenty-six clinic locations within a single healthcare system.

METHODS

Charts of 458 patients diagnosed with BPPV in PC between 2018 and 2022 were reviewed. Encounters where the diagnosis of BPPV was made were identified. From the clinical encounter note, demographics, symptomatology, management, and treatment were extracted. Nonparametric analyses were used to identify whether AAO-HNS guidelines differed regarding sex, race, or insurance status.

RESULTS

Of 458 patients, 249 (54.4%) did not receive a diagnostic exam, and only 4 (0.9%) patients received imaging. Regarding treatment, only 51 (11.1%) received the Epley maneuver, with 263 (57.4%) receiving vestibular suppressant medication and 12.4% receiving a referral to a specialist. In regard to sex, race, or insurance status, there was no significant difference in receiving a Dix-Hallpike diagnostic maneuver, Epley maneuver, vestibular suppressant medication, imaging, or referral to a specialist.

CONCLUSION

Our data suggest that there continue to be gaps in the adherence to AAO-HNS guidelines; however, these gaps did not differ by sex, race, or insurance status. Care should be taken to increase the use of diagnostic and treatment maneuvers but decrease the use of vestibular-suppressant medications for the treatment of BPPV in PC.

Misdiagnosis-related harm quantification through mixture models and harm measures

Investigating and monitoring misdiagnosis-related harm is crucial for improving health care. However, this effort has traditionally focused on the chart review process, which is labor intensive, potentially unstable, and does not scale well. To monitor medical institutes' diagnostic performance and identify areas for improvement in a timely fashion, researchers proposed to leverage the relationship between symptoms and diseases based on electronic health records or claim data. Specifically, the elevated disease risk following a false-negative diagnosis can be used to signal potential harm. However, off-the-shelf statistical methods do not fully accommodate the data structure of a well-hypothesized risk pattern and thus fail to address the unique challenges adequately. To fill these gaps, we proposed a mixture regression model and its associated goodness-of-fit testing. We further proposed harm measures and profiling analysis procedures to quantify, evaluate, and compare misdiagnosis-related harm across institutes with potentially different patient population compositions. We studied the performance of the proposed methods through simulation studies. We then illustrated the methods through data analyses on stroke occurrence data from the Taiwan Longitudinal Health Insurance Database. From the analyses, we quantitatively evaluated risk factors for being harmed due to misdiagnosis, which unveiled some insights for health care quality research. We also compared general and special care hospitals in Taiwan and observed better diagnostic performance in special care hospitals using various new evaluation measures.

A new portable Fresnel magnifying loupe for nystagmus observation: a clinical education and clinical practice setting study

BACKGROUND

Dizziness is a common complaint of patients treated by primary care physicians. It is predominantly caused by peripheral vestibular disorders; however, central nervous system disorders should be excluded. Examination of the eye movements and nystagmus can help differentiate the disorders of the central nervous system from the peripheral vestibular disorders; however, it is often not performed appropriately. In medical education practice, nystagmus observation may facilitate an understanding of vestibular function and nystagmus characteristics. Thus, we proposed a medical education practice to master nystagmus observation using a recently developed portable Fresnel magnifying loupe that could be shielded by one eye.

METHODS

Thirty-three students from the Department of Physical Therapy and the Department of Speech, Language, and Hearing Therapy of the Mejiro University participated in this study. Postrotatory nystagmus was measured and compared using the new loupe and control methods, namely the naked eye and Frenzel goggles; we rated the ease of visibility using a five-point scale.

RESULTS

The number of detected cases of nystagmus was significantly higher with the new loupe than with the naked eye (p = 0.001). In addition, there were no significant differences in the nystagmus counts between the observations using the new loupe and Frenzel goggles (p = 0.087). No significant difference was observed in the visibility of eye movements between the loupe and naked eye (p = 1.00). The Frenzel goggles provided better visibility compared to that by the loupe (p = 0.034); however, none of the participants reported poor visibility using any of these methods.

CONCLUSIONS

Our newly developed Fresnel loupe allows for the observation of nystagmus counts a level of reduction in fixation suppression similar to that of Frenzel goggles in an educational practice setting. Furthermore, it enables the detection of significantly more nystagmus counts compared to that by the naked eye. It offers several advantages over Frenzel goggles, including its lightweight, thin, durable, and portable design. Additionally, the loupe does not rely on a power source and can be used under normal room lighting conditions.

TRIAL REGISTRATION

This study was approved by the Medical Research Ethics Committee of Mejiro University (approval number: 21medicine-021).

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").

Dizziness Among Population in a Tertiary care Centre in Maduranthagam

Dizziness is a common chief complaint and there is a broad variety of possible underlying diseases for dizziness. Physicians must distinguish the majority of patients with self-limiting conditions from those with serious illnesses that require acute treatment. Diagnosis can be a challenge sometimes due to lack of dedicated vestibular lab and injudicious use of vestibular suppressant medications. In total of 100 cases were taken into study in which the most common was found to be benign paroxysmal positional vertigo and the most serious was cerebellar infarct and space occupying lesion. Complete evaluation of the patient should be done to arrive at a diagnosis. Therefore, a modification in the assessment methods of the dizzy patients with emphasis on history and clinical presentation seems essential.

EVESTA: Emergency VESTibular Algorithm and its impact on the acute management of benign paroxysmal positional vertigo

OBJECTIVE

To synthesise evidence-based research concerning the assessment and management of acute dizziness via construction of a comprehensive clinical algorithm. Assess its clinical impact with an aim to improve the acute management of benign paroxysmal positional vertigo (BPPV) within Wyong Public Hospital ED in four key recommendations.

METHOD

Current best practice models of care were synthesised into a single clinical, district-based peer-reviewed algorithm by a specialist focus group. An observational pre- and post-implementation study was completed to assess the impact of the algorithm on the management of BPPV. A total of 162 notes (pre [control] n = 87 and post [intervention] n = 75) met the inclusion criteria. Adherence to the BPPV clinical practice guidelines statements 1a, 3a, 4a and 6 were analysed for statistical difference in practice between the two groups.

RESULTS

Following implementation of the Emergency VESTibular Algorithm (EVESTA), compliance showed a significant improvement in Hallpike-Dix performed by 27% (95% confidence interval [CI] 14-40%; defects pre-intervention 40%: post-intervention 13%) (P < 0.001), utilisation of neuroimaging reduced by 16% (95% CI 2-30%; 40%: 24%) (P < 0.05), repositioning techniques performed increased by 33% (95% CI 18-48%; 68%: 36%) (P < 0.001). Administration of vestibular suppressant medication reduced by 30% (95% CI 15-45%; 59%: 29%) (P < 0.001). An interrupted time series analysis confirmed significant change in BPPV admissions post-project -4.23% (95% CI -7.20, -1.27%) (P = 0.041).

CONCLUSION

Diagnosis and management of acute dizziness is challenging within the ED. Synthesis of best practice into a clinical algorithm has improved the diagnosis and evidence-based treatment of BPPV. There is continued opportunity to improve the efficiency and effectiveness in the management of both central and peripheral acute dizziness within the ED.

Vertical Nystagmus Recognition Based on Deep Learning

Vertical nystagmus is a common neuro-ophthalmic sign in vestibular medicine. Vertical nystagmus not only reflects the functional state of vertical semicircular canal but also reflects the effect of otoliths. Medical experts can take nystagmus symptoms as the key factor to determine the cause of dizziness. Traditional observation (visual observation conducted by medical experts) may be biased subjectively. Visual examination also requires medical experts to have enough experience to make an accurate diagnosis. With the development of science and technology, the detection system for nystagmus can be realized by using artificial intelligence technology. In this paper, a vertical nystagmus recognition method is proposed based on deep learning. This method is mainly composed of a dilated convolution layer module, a depthwise separable convolution module, a convolution attention module, a Bilstm-GRU module, etc. The average recognition accuracy of the proposed method is 91%. Using the same training dataset and test set, the recognition accuracy of this method for vertical nystagmus was 2% higher than other methods.

Dizziness Evaluation and Characterisation of Patients with Posterior Circulation Stroke in the Emergency Department; a Case Series Study

Introduction

Dizziness is a common scenario in the Emergency Departments (EDs). Among dizziness underlying causes, the posterior circulation stroke is especially relevant due to its mobimortality and concerning misdiagnosis rates. Therefore, we conducted this study to assess dizziness evaluation and baseline characteristics of patients with PS in the ED.

Methods

We conducted a 3-year retrospective observational study on PS cases confirmed by magnetic resonance imaging (MRI). Concretely, we analysed the demographic profile of these patients, the initial PS clinical presentation, and diagnostic workup (with emphasis on dizziness evaluation) performed at the ED.

Results

During the study period, 85 cases were registered. Risk factors for cardiovascular disease were present in 85.5% and previous visits to the ED due to dizziness were recorded in 16.5%. The main clinical presentation was dizziness, concretely as an acute vestibular syndrome (38.8%) with additional neurological signs or symptoms (80%). Evaluation by the otolaryngologist on call was requested in less than 10% of the cases and included the HINTS protocol use with a sensitivity of 100% for central nervous system underlying causality. A brain CT study was always performed with a sensitivity of 27%. However, 96.47% of patients were primarily admitted to the Neurology hospitalization ward and MRI was always performed in a mean time of 3.21 days confirming the diagnosis.

Conclusions

Dizziness is the most frequent symptom of PS. Patients usually present an AVS (associated with additional N-SS or not) and HINTS bedside examination is the most adequate protocol to differentiate a PS from other AVS causes until the diagnostic confirmation via MRI. Interestingly, mainly otolaryngologists seem to use HINTS. However, the use of CT is widespread despite its poor value.

Diagnosis of dizziness in the emergency department: A 1-year prospective single-center study

BACKGROUND

The management of dizziness and vertigo can be challenging in the emergency department (ED). It is important to rapidly diagnose vertebrobasilar stroke (VBS), as therapeutic options such as thrombolysis and anticoagulation require prompt decisions.

OBJECTIVE

This study aims to assess the rate of misdiagnosis in patients with dizziness caused by VBS in the ED.

METHODS AND RESULTS

The cohort was comprised of 66 patients with a mean age 56 years; 48% were women and 52% men. Among dizzy patients, 14% had VBS. We used Cohen's kappa test to quantify the agreement between two raters -namely, emergency physicians and neurologists -regarding the causes of dizziness in the ED. The Kappa value was 0.27 regarding the final diagnosis of central vertigo disorders and VBS, thus showing the low agreement. We used the χi2 test to show the association between the presence of two or more cardiovascular risk factors and admission to the stroke unit (p = 0.015).

CONCLUSION

There is a substantial rate of misdiagnosis in patients with dizziness caused by VBS in the ED. To reduce the number of missing diagnoses of VBS in the future, there is a need to train emergency physicians in neurovestibular examinations, including the HINTS examination for acute vestibular syndrome (AVS) and the Dix-Hallpike (DH) maneuver for episodic vestibular syndrome. Using video head impulse test could help reduce the rate of misdiagnosis of VBS in the ED.

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.

Assessment of Saudi Physicians and Physical Therapists' Adherence to the Updated Clinical Practice Guideline for Benign Paroxysmal Positional Vertigo: A Cross-Sectional Study

Introduction  Variations in clinical practice regarding the management of benign paroxysmal positional vertigo (BPPV) among clinicians have been noted in previous studies. Such variations might be related to the different adherence to clinical practice guidelines. Objective  To evaluate clinicians' adherence to BPPV guidelines and investigate the variations in the adherence between different specialties and qualifications. Methods  This is a cross-sectional study with a vignettes-based survey conducted between June and August, 2020. We included clinicians engaged in managing BPPV that had at least one year of clinical experience. We excluded students, and clinicians who were not involved in the management of individuals with BPPV. Participants were asked to make their management choices based on four hypothetical patient vignettes. The sample ranged from 77 participants for the first vignette to 45 participants for the last vignette. Results  We included 77 clinicians in the study, with the majority being Otolaryngologists (31.2%). The respondents' mean adherence to the guideline was of 63.3%. Result showed that Otolaryngologists' adherence was higher than that of clinicians from different specialties ( p  = 0.006, d  = 0.72). Furthermore, clinicians with a postgraduate degree were more likely to adhere than those with a bachelor's degree only ( p  = 0.014, d  = 0.58) and participants who were aware of the guideline were more likely to adhere to it ( p  < 0.001, d  = 1.05). Lastly, regression analysis exhibited that adherence was affected by postgraduate degree and guideline awareness. Conclusion  Otolaryngologists were more likely to adhere to the guideline than other specialties. Among all specialties, higher adherence was associated with guideline awareness and postgraduate degrees.

Bedside Clinicians' Perceptions on the Contributing Role of Diagnostic Errors in Acutely Ill Patient Presentation: A Survey of Academic and Community Practice

OBJECTIVES

This study aimed to explore clinicians' perceptions of the occurrence of and factors associated with diagnostic errors in patients evaluated during a rapid response team (RRT) activation or unplanned admission to the intensive care unit (ICU).

METHODS

A multicenter prospective survey study was conducted among multiprofessional clinicians involved in the care of patients with RRT activations and/or unplanned ICU admissions (UIAs) at 2 academic hospitals and 1 community-based hospital between April 2019 and March 2020. A study investigator screened eligible patients every day. Within 24 hours of the event, a research coordinator administered the survey to clinicians, who were asked the following: whether diagnostic errors contributed to the reason for RRT/UIA, whether any new diagnosis was made after RRT/UIA, if there were any failures to communicate the diagnosis, and if involvement of specialists earlier would have benefited that patient. Patient clinical data were extracted from the electronic health record.

RESULTS

A total of 1815 patients experienced RRT activations, and 1024 patients experienced UIA. Clinicians reported that 18.2% (95/522) of patients experienced diagnostic errors, 8.0% (42/522) experienced a failure of communication, and 16.7% (87/522) may have benefitted from earlier involvement of specialists. Compared with academic settings, clinicians in the community hospital were less likely to report diagnostic errors (7.0% versus 22.8%, P = 0.002).

CONCLUSIONS

Clinicians report a high rate of diagnostic errors in patients they evaluate during RRT or UIAs.

Predictive values of serum estradiol, calcium, and 25-hydroxyvitamin D levels for recurrence of benign paroxysmal positional vertigo in postmenopausal women

Objectives

This study aims to explore the predictive values of serum estradiol, calcium and 25-hydroxyvitamin D [25(OH)D] levels for benign paroxysmal positional vertigo (BPPV) recurrence in postmenopausal women.

Patients and methods

A total of 156 postmenopausal women (mean age: 59.5±7.4 years; range, 46 to 75 years) diagnosed with primary BPPV between January 2015 and August 2018 were included. After follow-up for one year, they were divided into non-recurrence (n=126) and recurrence groups (n=30). Fifty healthy females (mean age: 60.3±7.4 years; range, 48 to 75 years) with natural menopause for over one year were enrolled as the control group. Serum estradiol, calcium and 25(OH)D levels were compared, and their correlations in the recurrence group were analyzed by Pearson method. The predictive values of these levels for recurrence were evaluated using the receiver operating characteristic curve. Predisposing factors were determined by univariate and multivariate logistic regression analyses.

Results

Serum estradiol, calcium, and 25(OH)D levels of the control group were significantly higher than the non-recurrence and recurrence groups (p<0.05). The levels of recurrence group exceeded those of non-recurrence group (p<0.05). In recurrence group, estradiol level was positively correlated with those of calcium and 25(OH)D (r=0.7501, 0.7871, p<0.001), and calcium level was positively correlated with that of 25(OH)D (r=0.7904, p<0.001). The three levels had diagnostic values for recurrence. The maximum Youden’s index of their combination was 0.476, and the corresponding prognostic index was 13.04, suggesting a higher recurrence probability. Number of repositioning, Self-Rating Depression Scale score, levels of estradiol, calcium and 25(OH)D were predisposing factors for recurrence.

Conclusion

Serum estradiol, calcium, and 25(OH)D levels are significantly positively correlated in postmenopausal women with BPPV recurrence and their combination can be used to predict recurrence.

Cerebrovascular disease hospitalizations following emergency department headache visits: A nested case-control study

BACKGROUND

Delayed diagnosis of cerebrovascular disease (CVD) among patients can result in substantial harm. If diagnostic process failures can be identified at emergency department (ED) visits that precede CVD hospitalization, interventions to improve diagnostic accuracy can be developed.

METHODS

We conducted a nested case-control study using a cohort of adult ED patients discharged from a single medical center with a benign headache diagnosis from October 1, 2015 to March 31, 2018. Hospitalizations for CVD within 1 year of index ED visit were identified using a regional health information exchange. Patients with subsequent CVD hospitalization (cases) were individually matched to patients without subsequent hospitalization (controls) using patient age and visit date. Demographic, clinical, and ED process characteristics were assessed via detailed chart review. McNemar's test for categorical and paired t-test for continuous variables were used with statistical significance set at ≤0.05.

RESULTS

Of the 9157 patients with ED headache visits, 57 (0.6%, 95% confidence interval [CI] = 0.5-0.8) had a subsequent CVD hospitalization. Median time from ED visit to hospitalization was 107 days. In 25 patients (43.9%, 25/57) the CVD hospitalization and the index ED visit were at different hospitals. Fifty-three cases and 53 matched controls were included in the final study analysis. Cases and controls had similar baseline demographic and headache characteristics. Cases more often had a history of stroke (32.1% vs. 13.2%, p = 0.02) and neurosurgery (13.2% vs. 1.9%, p = 0.03) prior to the index ED visit. Cases more often had less than two components of the neurologic examination documented (30.2% vs. 11.3%, p = 0.03).

CONCLUSION

We found that 0.6% of patients with an ED headache visit had subsequent CVD hospitalization, often at another medical center. ED visits for headache complaints among patients with prior stroke or neurosurgical procedures may be important opportunities for CVD prevention. Documented neurologic examinations were poorer among cases, which may represent an opportunity for ED process improvement.

Nystagmus Parameters of Supine Roll Test Correlates With Prognosis After Repositioning Maneuver in Horizontal Semicircular Canal Benign Paroxysmal Positional Vertigo

Background: Positional nystagmus induced by supine roll test is characteristic for diagnosing horizontal semicircular canal benign paroxysmal positional vertigo (HC-BPPV). In this study, we aimed to explore the value of nystagmus parameters in by supine roll test (SRT) as prognostic factors in HC-BPPV.

Methods: We retrospectively analyzed the nystagmus parameters of 813 patients diagnosed with HC-BPPV by the SRT model in the SRM-IV system through video nystagmography. Then we used the computer-controlled canalith repositioning procedure (CCRP) mode for treatment. Based on the outcomes, patients were divided into either the cured group or the resistant group. The 1:1 propensity score matching (PSM) was applied to minimize potential selection bias. Then univariable and multivariable analyses were performed to identify the association of nystagmus parameters and the efficacy of CCRP.

Results: Among the 813 patients, 99 (12.2%) were classified in the resistant group. The right side of HC-BPPV patients was twice the number of the left side patients (537 vs. 276). PSM is used to pair resistant patients to the cured patients, in which 99 pairs were successfully matched. Results of univariate and multivariate analyses showed that patients in the resistant group have longer latency in the affected side [odds ratio (OR) = 1.231 (1.110–1.366); P < 0.001] and slower slow phase velocity (SPV) in the healthy side [OR = 0.957 (0.917–0.999); P = 0.045].

Conclusion: Nystagmus parameters may represent the characteristics of canalith. HC-BPPV patients with a longer latency in the affected side and slower SPV on the healthy side during SRT have a higher risk of HC-BPPV persisting after a single CCRP.

Curriculum for vestibular medicine (vestmed) proposed by the barany society

This document presents the initiative of the Bárány Society to improve diagnosis and care of patients presenting with vestibular symptoms worldwide.

The Vestibular Medicine (VestMed) concept embraces a wide approach to the potential causes of vestibular symptoms, acknowledging that vertigo, dizziness, and unsteadiness are non-specific symptoms that may arise from a broad spectrum of disorders, spanning from the inner ear to the brainstem, cerebellum and supratentorial cerebral networks, to many disorders beyond these structures.

The Bárány Society Vestibular Medicine Curriculum (BS-VestMed-Cur) is based on the concept that VestMed is practiced by different physician specialties and non-physician allied health professionals. Each profession has its characteristic disciplinary role and profile, but all work in overlapping areas. Each discipline requires good awareness of the variety of disorders that can present with vestibular symptoms, their underlying mechanisms and etiologies, diagnostic criteria and treatment options. Similarly, all disciplines require an understanding of their own limitations, the contribution to patient care from other professionals and when to involve other members of the VestMed community. Therefore, the BS-VestMed-Cur is the same for all health professionals involved, the overlaps and differences of the various relevant professions being defined by different levels of detail and depth of knowledge and skills.

The BS-VestMed-Cur defines a Basic and an Expert Level Curriculum. The Basic Level Curriculum covers the VestMed topics in less detail and depth, yet still conveys the concept of the wide net approach. It is designed for health professionals as an introduction to, and first step toward, VestMed expertise. The Expert Level Curriculum defines a Focused and Broad Expert. It covers the VestMed spectrum in high detail and requires a high level of understanding. In the Basic and Expert Level Curricula, the range of topics is the same and runs from anatomy, physiology and physics of the vestibular system, to vestibular symptoms, history taking, bedside examination, ancillary testing, the various vestibular disorders, their treatment and professional attitudes. Additionally, research topics relevant to clinical practice are included in the Expert Level Curriculum. For Focused Expert proficiency, the Basic Level Curriculum is required to ensure a broad overview and additionally requires an expansion of knowledge and skills in one or a few specific topics related to the focused expertise, e.g. inner ear surgery. Broad Expert proficiency targets professionals who deal with all sorts of patients presenting with vestibular symptoms (e.g. otorhinolaryngologists, neurologists, audiovestibular physicians, physical therapists), requiring a high level of VestMed expertise across the whole spectrum. For the Broad Expert, the Expert Level Curriculum is required in which the minimum attainment targets for all the topics go beyond the Basic Level Curriculum. The minimum requirements regarding knowledge and skills vary between Broad Experts, since they are tuned to the activity profile and underlying specialty of the expert.

  The BS-VestMed-Cur aims to provide a basis for current and future teaching and training programs for physicians and non-physicians. The Basic Level Curriculum could also serve as a resource for inspiration for teaching VestMed to students, postgraduate generalists such as primary care physicians and undergraduate health professionals, or anybody wishing to enter VestMed.

  VestMed is considered a set of competences related to an area of practice of established physician specialties and non-physician health professions rather than a separate clinical specialty. This curriculum does not aim to define a new single clinical specialty.

  The BS-VestMed-Cur should also integrate with, facilitate and encourage translational research in the vestibular field.

Differentiating central from peripheral causes of acute vertigo in an emergency setting with the HINTS, STANDING, and ABCD2 tests: A diagnostic cohort study

BACKGROUND

Diagnosing stroke in dizzy patients remains a challenge in emergency medicine. The accuracy of the neuroophthalmologic examination HINTS performed by emergency physicians (EPs) is unknown. Our objective was to determine the accuracy of the HINTS examination performed by trained EPs for diagnosing central cause of acute vertigo and unsteadiness and to compare it with another bedside clinical tool, STANDING, and with the history-based score ABCD2.

METHODS

This was a prospective diagnostic cohort study among patients with isolated vertigo and unsteadiness seen in a single emergency department (ED). Trained EPs performed HINTS and STANDING tests blinded to attending physicians. ABCD2 ≥ 4 was used as the threshold and was calculated retrospectively. The criterion standard was diffusion-weighted brain magnetic resonance imaging (MRI). Peripheral diagnoses were established by a normal MRI, and etiologies were further refined by an otologic examination.

RESULTS

We included 300 patients of whom 62 had a central lesion on neuroimaging including 49 strokes (79%). Of the 238 peripheral diagnoses, 159 were vestibulopathies, mainly benign paroxysmal positional vertigo (40%). HINTS and STANDING tests reached high sensitivities at 97% and 94% and NPVs at 99% and 98%, respectively. The ABCD2 score failed to predict half of central vertigo cases and had a sensitivity of 55% and a NPV of 87%. The STANDING test was more specific and had a better positive predictive value (PPV; 75% and 49%, respectively; positive likelihood ratio [LR+] = 3.71, negative likelihood ratio [LR-] = 0.09) than the HINTS test (67% and 44%, respectively; LR+ = 2.96, LR- = 0.04). The ABCD2 score was specific (82%, LR+ = 3.04, LR- = 0.56) but had a very low PPV (44%).

CONCLUSIONS

In the hands of EPs, HINTS and STANDING tests outperformed ABCD2 in identifying central causes of vertigo. For diagnosing peripheral disorders, the STANDING algorithm is more specific than the HINTS test. HINTS and STANDING could be useful tools saving both time and costs related to unnecessary neuroimaging use.

Statistical insights for crude-rate-based operational measures of misdiagnosis-related harms

In longitudinal event data, a crude rate is a simple quantification of the event rate, defined as the number of events during an evaluation window, divided by the at-risk population size at the beginning or mid-time point of that window. The crude rate recently received revitalizing interest from medical researchers who aimed to improve measurement of misdiagnosis-related harms using administrative or billing data by tracking unexpected adverse events following a "benign" diagnosis. The simplicity of these measures makes them attractive for implementation and routine operational monitoring at hospital or health system level. However, relevant statistical inference procedures have not been systematically summarized. Moreover, it is unclear to what extent the temporal changes of the at-risk population size would bias analyses and affect important conclusions concerning misdiagnosis-related harms. In this article, we present statistical inference tools for using crude-rate based harm measures, as well as formulas and simulation results that quantify the deviation of such measures from those based on the more sophisticated Nelson-Aalen estimator. Moreover, we present results for a generalized multibin version of the crude rate, for which the usual crude rate is a single-bin special case. The generalized multibin crude rate is more straightforward to compute than the Nelson-Aalen estimator and can reduce potential biases of the single-bin crude rate. For studies that seek to use multibin measures, we provide simulations to guide the choice regarding number of bins. We further bolster these results using a worked example of stroke after "benign" dizziness from a large data set.

Nystagmus Estimation for Dizziness Diagnosis by Pupil Detection and Tracking Using Mexican-Hat-Type Ellipse Pattern Matching

The detection of nystagmus using video oculography experiences accuracy problems when patients who complain of dizziness have difficulty in fully opening their eyes. Pupil detection and tracking in this condition affect the accuracy of the nystagmus waveform. In this research, we design a pupil detection method using a pattern matching approach that approximates the pupil using a Mexican hat-type ellipse pattern, in order to deal with the aforementioned problem. We evaluate the performance of the proposed method, in comparison with that of a conventional Hough transform method, for eye movement videos retrieved from Gifu University Hospital. The performance results show that the proposed method can detect and track the pupil position, even when only 20% of the pupil is visible. In comparison, the conventional Hough transform only indicates good performance when 90% of the pupil is visible. We also evaluate the proposed method using the Labelled Pupil in the Wild (LPW) data set. The results show that the proposed method has an accuracy of 1.47, as evaluated using the Mean Square Error (MSE), which is much lower than that of the conventional Hough transform method, with an MSE of 9.53. We conduct expert validation by consulting three medical specialists regarding the nystagmus waveform. The medical specialists agreed that the waveform can be evaluated clinically, without contradicting their diagnoses.

Safer Stroke-Dx Instrument: Identifying Stroke Misdiagnosis in the Emergency Department

BACKGROUND

Missed or delayed diagnosis of acute stroke, or false-negative stroke (FNS), at initial emergency department (ED) presentation occurs in ≈9% of confirmed stroke patients. Failure to rapidly diagnose stroke can preclude time-sensitive treatments, resulting in higher risks of severe sequelae and disability. In this study, we developed and tested a modified version of a structured medical record review tool, the Safer Dx Instrument, to identify FNS in a subgroup of hospitalized patients with stroke to gain insight into sources of ED stroke misdiagnosis.

METHODS

We conducted a retrospective cohort study at 2 unaffiliated comprehensive stroke centers. In the development and confirmatory cohorts, we applied the Safer Stroke-Dx Instrument to report the prevalence and documented sources of ED diagnostic error in FNS cases among confirmed stroke patients upon whom an acute stroke was suspected by the inpatient team, as evidenced by stroke code activation or urgent neurological consultation, but not by the ED team. Inter-rater reliability and agreement were assessed using interclass coefficient and kappa values (κ).

RESULTS

Among 183 cases in the development cohort, the prevalence of FNS was 20.2% (95% CI, 15.0-26.7). Too narrow a differential diagnosis and limited neurological examination were common potential sources of error. The interclass coefficient for the Safer Stroke-Dx Instrument items ranged from 0.42 to 0.91, and items were highly correlated with each other. The κ for diagnostic error identification was 0.90 (95% CI, 0.821-0.978) using the Safer Stroke-Dx Instrument. In the confirmatory cohort of 99 cases, the prevalence of FNS was 21.2% (95% CI, 14.2-30.3) with similar sources of diagnostic error identified.

CONCLUSIONS

Hospitalized patients identified by stroke codes and requests for urgent neurological consultation represent an enriched population for the study of diagnostic error in the ED. The Safer Stroke-Dx Instrument is a reliable tool for identifying FNS and sources of diagnostic error.

Stroke hospitalization after misdiagnosis of "benign dizziness" is lower in specialty care than general practice: a population-based cohort analysis of missed stroke using SPADE methods

OBJECTIVES

Isolated dizziness is a challenging stroke presentation in the emergency department, but little is known about this problem in other clinical settings. We sought to compare stroke hospitalizations after treat-and-release clinic visits for purportedly "benign dizziness" between general and specialty care settings.

METHODS

This was a population-based retrospective cohort study from a national database. We included clinic patients with a first incident treat-and-release visit diagnosis of non-specific dizziness/vertigo or a peripheral vestibular disorder (ICD-9-CM 780.4 or 386.x [not 386.2]). We compared general care (internal medicine, family medicine) vs. specialty care (neurology, otolaryngology) providers. We used propensity scores to control for baseline stroke risk differences unrelated to dizziness diagnosis. We measured excess (observed>expected) stroke hospitalizations in the first 30 d (i.e., missed strokes associated with an adverse event).

RESULTS

We analyzed 144,355 patients discharged with "benign dizziness" (n=117,117 diagnosed in general care; n=27,238 in specialty care). After propensity score matching, patients in both groups were at higher risk of stroke in the first 30 d (rate difference per 10,000 treat-and-release visits for "benign dizziness" 24.9 [95% CI 18.6-31.2] in general care and 10.6 [95% CI 6.3-14.9] in specialty care). Short-term stroke risk was higher in general care than specialty care (relative risk, RR 2.2, 95% CI 1.5-3.2) while the long-term risk was not significantly different (RR 1.3, 95% CI 0.9-1.9), indicating higher misdiagnosis-related harms among dizzy patients who initially presented to generalists after adequate propensity matching.

CONCLUSIONS

Missed stroke-related harms in general care were roughly twice that in specialty care. Solutions are needed to address this care gap.

Diagnosing Stroke in Acute Vertigo: Sensitivity and Specificity of HINTS Battery in Indian Population

Introduction

Most patients presenting with acute vertigo are believed to suffer from acute, self-limited, presumed viral or post-viral vestibular neuritis (VN). But 25% of such cases can be "Pseudo VN", and are due to central causes, most often stroke. The aim of the present research was to study the sensitivity and specificity of Head Impulse, Nystagmus, Skew deviation (HINTS) battery for diagnosis of stroke in patients with acute-onset first episode of spontaneous vertigo.

Materials and Methods

Seventy-five patients who visited outpatient department or admitted between August 2014 and April 2016 with acute-onset first episode of spontaneous vertigo were included. Each patient was subjected to bedside oculomotor tests and HINTS. All patients underwent magnetic resonance imaging (MRI) of the brain. Stroke was diagnosed by MRI brain. If initial MRI brain was normal and still clinical signs favor stroke, repeat MRI brain-diffusion-weighted imaging study was done at 72 h after symptom onset to confirm the diagnosis. The sensitivity, specificity, positive predictive value, negative predictive value, accuracy and Youden's Index were used to quantify the diagnostic efficiency of HINTS at presentation against final MRI.

Results

Patients presented with acute-onset first episode of spontaneous vertigo, HINTS battery was found to be more sensitive than the initial MRI of the brain done in first 24 h in diagnosing stroke (97.1 % Vs 82.9%). The specificity of the initial MRI of the brain and HINTS battery was 100.0 % and 80.0% respectively.

Conclusions

The HINTS battery was more sensitive than the initial MRI of the brain in diagnosing stroke in first 24 h in patients presented with acute-onset first episode of spontaneous vertigo.

Agreement Between Physical Therapists in Diagnosing Benign Paroxysmal Positional Vertigo

BACKGROUND AND PURPOSE

Individuals with benign paroxysmal positional vertigo (BPPV) are frequently referred to physical therapy for management, but little is known on how reliable therapists are at diagnosing BPPV. The purpose of the study was to examine the agreement between physical therapists in identifying nystagmus and diagnosing BPPV.

METHODS

Thirty-eight individuals with complaints of positional vertigo, 19 from each of 2 clinics (clinics 1 and 2) that specialize in vestibular rehabilitation, had eye movements recorded using video goggles during positioning tests including supine-to-sit, supine roll, and Dix-Hallpike tests. Three therapists from each of the clinics independently observed videos, documented nystagmus characteristics of each testing position, and made a diagnosis for each case. Kappa (κ) statistics were calculated between therapists within each clinic for nystagmus identification and diagnosis.

RESULTS

Clinic 1 therapists demonstrated substantial to almost perfect agreement in identifying nystagmus during positional tests (κ = 0.68-1, P < 0.005). Clinic 2 therapists showed moderate to almost perfect agreement for presence of nystagmus (κ = 0.57-1, P < 0.005). Therapists at both sites had almost perfect agreement of diagnosis side, canal, and mechanism (κ = 0.81-1, P < 0.005).

DISCUSSION AND CONCLUSION

Therapists utilized observations from multiple positional tests to determine diagnoses. This was evident by occasional disagreement in nystagmus presence and characteristics, but agreement in diagnosis, including ruling out BPPV. The results may not be generalizable to all physical therapists or therapists' ability to diagnose central and atypical nystagmus presentations. Experienced physical therapists demonstrated strong agreement in diagnosing common forms of BPPV.Video Abstract available for more insight from the authors (see the Video Supplemental Digital Content 1, available at: http://links.lww.com/JNPT/A340).

Real-world virtual patient simulation to improve diagnostic performance through deliberate practice: a prospective quasi-experimental study

OBJECTIVES

Diagnostic errors are pervasive in medicine and most often caused by clinical reasoning failures. Clinical presentations characterized by nonspecific symptoms with broad differential diagnoses (e.g., dizziness) are especially prone to such errors.

METHODS

We hypothesized that novice clinicians could achieve proficiency diagnosing dizziness by training with virtual patients (VPs). This was a prospective, quasi-experimental, pretest-posttest study (2019) at a single academic medical center. Internal medicine interns (intervention group) were compared to second/third year residents (control group). A case library of VPs with dizziness was developed from a clinical trial (AVERT-NCT02483429). The approach (VIPER - Virtual Interactive Practice to build Expertise using Real cases) consisted of brief lectures combined with 9 h of supervised deliberate practice. Residents were provided dizziness-related reading and teaching modules. Both groups completed pretests and posttests.

RESULTS

For interns (n=22) vs. residents (n=18), pretest median diagnostic accuracy did not differ (33% [IQR 18-46] vs. 31% [IQR 13-50], p=0.61) between groups, while posttest accuracy did (50% [IQR 42-67] vs. 20% [IQR 17-33], p=0.001). Pretest median appropriate imaging did not differ (33% [IQR 17-38] vs. 31% [IQR 13-38], p=0.89) between groups, while posttest appropriateness did (65% [IQR 52-74] vs. 25% [IQR 17-36], p<0.001).

CONCLUSIONS

Just 9 h of deliberate practice increased diagnostic skills (both accuracy and testing appropriateness) of medicine interns evaluating real-world dizziness 'in silico' more than ∼1.7 years of residency training. Applying condensed educational experiences such as VIPER across a broad range of common presentations could significantly enhance diagnostic education and translate to improved patient care.

Diagnostic Error of Neuro-ophthalmologic Conditions: State of the Science

BACKGROUND

Diagnostic error is prevalent and costly, occurring in up to 15% of US medical encounters and affecting up to 5% of the US population. One-third of malpractice payments are related to diagnostic error. A complex and specialized diagnostic process makes neuro-ophthalmologic conditions particularly vulnerable to diagnostic error.

EVIDENCE ACQUISITION

English-language literature on diagnostic errors in neuro-ophthalmology and neurology was identified through electronic search of PubMed and Google Scholar and hand search.

RESULTS

Studies investigating diagnostic error of neuro-ophthalmologic conditions have revealed misdiagnosis rates as high as 60%-70% before evaluation by a neuro-ophthalmology specialist, resulting in unnecessary tests and treatments. Correct performance and interpretation of the physical examination, appropriate ordering and interpretation of neuroimaging tests, and generation of a differential diagnosis were identified as pitfalls in the diagnostic process. Most studies did not directly assess patient harms or financial costs of diagnostic error.

CONCLUSIONS

As an emerging field, diagnostic error in neuro-ophthalmology offers rich opportunities for further research and improvement of quality of care.

Bedside video-ophthalmoscopy as an aid in the diagnosis of central vestibular syndromes

The evaluation of central vestibular syndromes, especially in the acute setting, can pose a challenge even for the most experienced clinician. Of particular importance is the evaluation of ocular torsion and nystagmus, which can be sensitive for central vestibular pathology, but easily missed by the untrained eye. We present two cases of acute vestibular syndrome of central origin in which the use of magnified fundoscopy at the bedside aided the precise anatomical diagnosis to inform appropriate further management. We also review aspects of the pathophysiology and anatomy of vestibular roll plane disorders. In case 1, the finding of position-dependent ocular torsion facilitated a rapid distinction between central skew deviation and a trochlear nerve palsy. In case 2, the fundoscopic magnification identified a pure rotatory nystagmus indicative of a central vestibular disorder. Ophthalmoscopy remains a useful bedside technique in acute vertigo, but the use of inexpensive magnification with a smartphone can provide objective and recordable evidence of central vestibular pathology, aiding therapeutic decisions.

Diagnostic Errors Are Common in Acute Pediatric Respiratory Disease: A Prospective, Single-Blinded Multicenter Diagnostic Accuracy Study in Australian Emergency Departments

Background: Diagnostic errors are a global health priority and a common cause of preventable harm. There is limited data available for the prevalence of misdiagnosis in pediatric acute-care settings. Respiratory illnesses, which are particularly challenging to diagnose, are the most frequent reason for presentation to pediatric emergency departments. Objective: To evaluate the diagnostic accuracy of emergency department clinicians in diagnosing acute childhood respiratory diseases, as compared with expert panel consensus (reference standard). Methods: Prospective, multicenter, single-blinded, diagnostic accuracy study in two well-resourced pediatric emergency departments in a large Australian city. Between September 2016 and August 2018, a convenience sample of children aged 29 days to 12 years who presented with respiratory symptoms was enrolled. The emergency department discharge diagnoses were reported by clinicians based upon standard clinical diagnostic definitions. These diagnoses were compared against consensus diagnoses given by an expert panel of pediatric specialists using standardized disease definitions after they reviewed all medical records. Results: For 620 participants, the sensitivity and specificity (%, [95% CI]) of the emergency department compared with the expert panel diagnoses were generally poor: isolated upper respiratory tract disease (64.9 [54.6, 74.4], 91.0 [88.2, 93.3]), croup (76.8 [66.2, 85.4], 97.9 [96.2, 98.9]), lower respiratory tract disease (86.6 [83.1, 89.6], 92.9 [87.6, 96.4]), bronchiolitis (66.9 [58.6, 74.5], 94.3 [80.8, 99.3]), asthma/reactive airway disease (91.0 [85.8, 94.8], 93.0 [90.1, 95.3]), clinical pneumonia (63·9 [50.6, 75·8], 95·0 [92·8, 96·7]), focal (consolidative) pneumonia (54·8 [38·7, 70·2], 86.2 [79.3, 91.5]). Only 59% of chest x-rays with consolidation were correctly identified. Between 6.9 and 14.5% of children were inappropriately prescribed based on their eventual diagnosis. Conclusion: In well-resourced emergency departments, we have identified a previously unrecognized high diagnostic error rate for acute childhood respiratory disorders, particularly in pneumonia and bronchiolitis. These errors lead to the potential of avoidable harm and the administration of inappropriate treatment.

The Bucket Test Improves Detection of Stroke in Patients With Acute Dizziness

BACKGROUND

It is challenging to detect posterior circulation strokes in patients presenting to the emergency department (ED) with acute dizziness. The current approach uses a combinatorial head-impulse, nystagmus, and test-of-skew method and is sensitive enough to differentiate central causes from peripheral ones. However, it is difficult to perform and underused. Further, magnetic resonance imaging (MRI) of the brain is not always available and can have low sensitivity for detecting posterior circulation strokes.

OBJECTIVES

We evaluated the feasibility and utility of the bucket test (BT), which measures the difference between patient's subjective perception of the visual vertical and the true vertical, as a screening tool for stroke in patients presenting to the ED with acute dizziness.

METHODS

In this work, we prospectively enrolled 81 patients that presented to our academic medical center ED with dizziness as their chief complaint. The BT was performed 3 times for every patient.

RESULTS

Seventy-one patients met the study criteria and were included in the analysis. Ten patients were excluded because of a history of drug-seeking behavior. There were no reported difficulties performing the BT. Six patients (8%) were diagnosed with ischemic stroke on MRI and 1 additional patient was diagnosed with transient ischemic attack and found to have a stroke on subsequent MRI. All 7 patients with dizziness attributed to cerebrovascular etiology had an abnormal BT, resulting in a sensitivity of 100% (95% confidence interval [CI] 59-100%). The specificity of the BT was 38% (95% CI 24-52%). The positive predictive value of the BT for detecting stroke was 18% (95% CI 15-21%).

CONCLUSIONS

The BT is an easy, cheap, safe, and quick test that is feasible and sensitive to screen acutely dizzy patients for stroke in the ED.

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.

Diagnosis of Patients with Acute Dizziness

Using an algorithmic approach to acutely dizzy patients, physicians can often confidently make a specific diagnosis that leads to correct treatment and should reduce the misdiagnosis of cerebrovascular events. Emergency clinicians should try to become familiar with an approach that exploits timing and triggers as well as some basic "rules" of nystagmus. The gait should always be tested in all patients who might be discharged. Computed tomographic scans are unreliable to exclude posterior circulation stroke presenting as dizziness, and early MRI (within the first 72 hours) also misses 10% to 20% of these cases.

Risk of acute brain lesions in dizzy patients presenting to the emergency room: who needs imaging and who does not?

The usefulness of brain imaging studies in dizzy patients presenting to the emergency department (ED) is controversial. We aimed to assess the ‘real-world’ probability of ischemic stroke and other acute brain lesions (ABLs) in these patients to create an algorithm that helps decision-making on whether which and when brain imaging is needed. By reviewing medical records, we identified 610 patients presenting with dizziness, vertigo or imbalance to our university hospital’s ED and receiving neurological workup. We collected timing/triggers of symptoms, ABCD² score, focal neurological abnormalities, HINTS (head impulse, nystagmus, test-of-skew) and other central oculomotor signs. ABLs were extracted from CT/MRI reports. Uni-/multivariate logistic regression analyses investigated associations between clinical parameters and ABLs. Finally, the likelihood of ABLs was assessed for different clinically defined subgroups (‘dizziness syndromes’). Early CT (day 1) was performed in 539 (88%) and delayed MR imaging (median: day 4) in 299 (49%) patients. ABLs (89% ischemic stroke) were revealed in 75 (24%) of 318 patients with adequate imaging (MRI or lesion-positive CT). The risk for ABLs increased with the presence of central oculomotor signs (odds ratio 2.8, 95% confidence interval 1.5–5.2) or focal abnormalities (OR 3.3, 95% CI 1.8–6.2). The likelihood of ABLs differed between dizziness syndromes, e.g., HINTS-negative acute vestibular syndrome: 0%, acute imbalance syndrome with ABCD²-score ≥ 4: 50%. We propose a clinical pathway, according to which patients with HINTS-negative acute vestibular syndrome should not receive brain imaging, whereas imaging is suggested in dizzy patients with acute imbalance, central oculomotor signs or focal abnormalities.

An Educational Intervention for Acute Dizziness Care: A Randomized, Vignette-based Study

IMPORTANCE

Benign paroxysmal positional vertigo (BPPV) is a common cause of acute dizziness. Strong evidence exists for diagnosing BPPV using the Dix-Hallpike Test (DHT) and treating it with the canalith repositioning maneuver (CRM). Despite this, both are infrequently used in the emergency department (ED).

OBJECTIVE

As an early method to evaluate a BPPV-focused educational intervention, we evaluated whether an educational intervention improved ED provider performance on hypothetical stroke and BPPV cases delivered by vignette.

DESIGN

A randomized, controlled, educational intervention study in ED physicians. The intervention aimed to promote the appropriate use of the DHT and CRM. A BPPV vignette, a stroke-dizziness (safety) vignette, and vignette scoring schemes (higher scores indicating more optimal care) used previously established vignette methodology.

SETTING

We recruited participants at the exhibitor hall of an emergency medicine annual meeting.

PARTICIPANTS

We recruited 48 emergency physicians. All were board certified or residency trained and board eligible. All were engaged in the active practice of emergency medicine. None were trainees.

INTERVENTIONS

Intervention group: a narrated, educational presentation by computer followed by the clinical vignettes.

CONTROL GROUP

Received no educational intervention and completed the clinical vignettes-intended to mirror current clinician practice.

MAIN OUTCOME MEASURE

Primary endpoint: total score (out of 200 points) on a vignette-based scoring instrument assessing the performance of history, physical, and diagnostic testing on hypothetical stroke and BPPV cases.

RESULTS

The efficacy threshold was crossed at the interim analysis. The intervention group had higher performance scores compared with controls (113.2 versus 68.6, p < 0.00001). BPPV and safety subscores were both significantly higher in the intervention group. Sixty-two percent of the intervention group planned to use the DHT versus 29% of controls. After the vignette described characteristic BPPV nystagmus, 100% of the intervention group planned to use the CRM versus 17% of controls.

CONCLUSIONS AND RELEVANCE

The educational intervention increased provider performance in dizziness vignettes, including more frequent appropriate use of the DHT/CRM. These findings indicate the intervention positively influenced planned behavior. Future work is needed to implement and evaluate this intervention in clinical practice.

Rate of diagnostic errors and serious misdiagnosis-related harms for major vascular events, infections, and cancers: toward a national incidence estimate using the “Big Three”

Background

Missed vascular events, infections, and cancers account for ~75% of serious harms from diagnostic errors. Just 15 diseases from these “Big Three” categories account for nearly half of all serious misdiagnosis-related harms in malpractice claims. As part of a larger project estimating total US burden of serious misdiagnosis-related harms, we performed a focused literature review to measure diagnostic error and harm rates for these 15 conditions.

Methods

We searched PubMed, Google, and cited references. For errors, we selected high-quality, modern, US-based studies, if available, and best available evidence otherwise. For harms, we used literature-based estimates of the generic (disease-agnostic) rate of serious harms (morbidity/mortality) per diagnostic error and applied claims-based severity weights to construct disease-specific rates. Results were validated via expert review and comparison to prior literature that used different methods. We used Monte Carlo analysis to construct probabilistic plausible ranges (PPRs) around estimates.

Results

Rates for the 15 diseases were drawn from 28 published studies representing 91,755 patients. Diagnostic error (false negative) rates ranged from 2.2% (myocardial infarction) to 62.1% (spinal abscess), with a median of 13.6% [interquartile range (IQR) 9.2–24.7] and an aggregate mean of 9.7% (PPR 8.2–12.3). Serious misdiagnosis-related harm rates per incident disease case ranged from 1.2% (myocardial infarction) to 35.6% (spinal abscess), with a median of 5.5% (IQR 4.6–13.6) and an aggregate mean of 5.2% (PPR 4.5–6.7). Rates were considered face valid by domain experts and consistent with prior literature reports.

Conclusions

Diagnostic improvement initiatives should focus on dangerous conditions with higher diagnostic error and misdiagnosis-related harm rates.

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.

Comparing Expert and Non-Expert Assessment of Patients Presenting with Neurological Symptoms to the Emergency Department: A Retrospective Observational Study

OBJECTIVE

Referrals to neurology in emergency departments (ED) are continuously increasing, currently representing 15% of all admissions. Existing triage systems were developed for general medical populations and have not been validated for patients with neurological symptoms.

METHODS

To characterize neurological emergencies, we first retrospectively analyzed symptoms, service times and resources of the cohort of neurological referrals to a German interdisciplinary ED (IED) during 2017 according to urgency determined by final IED diagnosis. In a second step, we performed a retrospective assignment of consecutive patients presenting in April 2017 according to internal guidelines as either acute (requiring diagnostic/therapeutic procedures within 24 hrs) or non-acute neurological conditions as well as a retrospective classification according to the Emergency Severity Index (ESI). Both assessments were compared with the urgency according to the final ER diagnosis.

RESULTS

In a 12-month period, 36.4% of 5340 patients were rated as having an urgent neurological condition; this correlated with age, door-to-doctor time, imaging resource use and admission (p < 0.001, respectively). In a subset of 275 patients, 59% were retrospectively triaged as acute according to neurological expertise and 48% according to ESI categories 1 and 2. Neurological triage identified urgency with a significantly higher sensitivity (94.8, p < 0.01) but showed a significantly lower specificity (55.1, p < 0.05) when compared to ESI (80.5 and 65.2, respectively).

CONCLUSION

The ESI may not take specific aspects of neurological emergency (eg, time-sensitivity) sufficiently into account. Refinements of existing systems or supplementation with dedicated neurological triage tools based on neurological expertise and experience may improve the triage of patients with neurological symptoms.

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.

Comparison of acute vertigo diagnosis and treatment practices between otolaryngologists and non-otolaryngologists: A multicenter scenario-based survey

Acute vertigo is a common problem in emergency departments. However, clinical strategies of acute vertigo care vary among care providers. The aim of the study was to investigate differences in diagnosis [Dix-Hallpike test, the head impulse, nystagmus, and the test of skew (HINTS) procedure, and imaging modalities] and treatment (pharmacological treatments and the Epley maneuver) by otolaryngologists and non-otolaryngologists in emergency medicine settings. We used a multicenter case-based survey for the study. Four clinical vignettes of acute vertigo (posterior canal benign paroxysmal positional vertigo, vestibular neuritis, Meniere disease, and nonspecific vertigo) were used. Total 151 physicians from all study sites participated in the study. There were 84 non-otolaryngologists (48 emergency physicians and 36 internists) and 67 otolaryngologists. The multivariate analysis indicated that otolaryngologists ordered fewer CT scans (odds ratio (OR), 0.20; 95% confidence interval (CI), 0.07-0.53) and performed fewer HINTS procedures (OR, 0.17; 95% CI, 0.06-0.46), but used the Dix-Hallpike method more often (OR, 2.36; 95% CI, 1.01-5.52) for diagnosis compared to non-otolaryngologists. For treatment, otolaryngologists were less likely to use the Epley method (OR, 0.19; 95% CI, 0.07-0.53) and metoclopramide (OR, 0.09; 95% CI, 0.01-0.97) and more likely to use sodium bicarbonate (OR, 20.50; 95% CI, 6.85-61.40) compared to non-otolaryngologists. We found significant differences in the acute vertigo care provided by non-otolaryngologists and otolaryngologists from a vignette-based research. To improve acute vertigo care, educational systems focusing on acute vertigo are needed.

Implementation of evidence-based practice for benign paroxysmal positional vertigo: DIZZTINCT- A study protocol for an exploratory stepped-wedge randomized trial

Background

Benign paroxysmal positional vertigo (BPPV) is the most common peripheral vestibular disorder, and accounts for 8% of individuals with moderate or severe dizziness. BPPV patients experience substantial inconveniences and disabilities during symptomatic periods. BPPV therapeutic processes – the Dix-Hallpike Test (DHT) and the Canalith Repositioning Maneuver (CRM) – have an evidence base that is at the clinical practice guideline level. The most commonly used CRM is the modified Epley maneuver. The DHT is the gold standard test for BPPV and the CRM is supported by numerous randomized controlled trials and systematic reviews. Despite this, BPPV care processes are underutilized.

Methods/design

This is a stepped-wedge, randomized clinical trial of a multi-faceted educational and care-process-based intervention designed to improve the guideline-concordant care of patients with BPPV presenting to the emergency department (ED) with dizziness. The unit of randomization and target of intervention is the hospital. After an initial observation period, the six hospitals will undergo the intervention in five waves (two closely integrated hospitals will be paired). The order will be randomized. The primary endpoint is measured at the individual patient level, and is the presence of documentation of either the Dix-Hallpike Test or CRM. The secondary endpoints are referral to a health care provider qualified to treat dizziness for CRM and 90-day stroke rates following an ED dizziness visit. Formative evaluations are also performed to monitor and identify potential and actual influences on the progress and effectiveness of the implementation efforts.

Discussion

If this study safely increases documentation of the DHT/CRM, this will be an important step in implementing the use of these evidenced-based processes of care. Positive results will support conducting larger-scale follow-up studies that assess patient outcomes. The data collection also enables evaluation of potential and actual influences on the progress and effectiveness of the implementation efforts.

Trial registration

ClinicalTrials.gov, ID: NCT02809599. The record was first available to the public on 22 June 2016 prior to the enrollment of the first patients in October 2016.

Electronic supplementary material

The online version of this article (10.1186/s13063-018-3099-0) contains supplementary material, which is available to authorized users.

Unique Clinical Language Patterns Among Expert Vestibular Providers Can Predict Vestibular Diagnoses

OBJECTIVE

To identify novel language usage by expert providers predictive of specific vestibular conditions.

STUDY DESIGN

Retrospective chart review and natural language processing. Level IV.

SETTING

Tertiary referral center.

PATIENTS

Patients seen for vestibular complaint.

INTERVENTION(S)

Natural language processing and machine learning analyses of semantic and syntactic patterns in clinical documentation from vestibular patients.

MAIN OUTCOME MEASURE

Accuracy of Naïve Bayes predictive models correlating language usage with clinical diagnoses.

RESULTS

Natural language analyses on 866 physician-generated histories from vestibular patients found 3,286 unique examples of language usage of which 614 were used 10 or greater times. The top 15 semantic types represented only 11% of all Unified Medical Language System semantic types but covered 86% of language used in vestibular patient histories. Naïve Bayes machine learning algorithms on a subset of 255 notes representing benign paroxysmal positional vertigo, vestibular migraine, anxiety-related dizziness and central dizziness generated strong predictive models showing an average sensitivity rate of 93.4% and a specificity rate of 98.2%. A binary model for assessing whether a subject had a specific diagnosis or not had an average AUC for the receiver operating characteristic curves of .995 across all conditions.

CONCLUSIONS

These results indicate that expert providers utilize unique language patterns in vestibular notes that are highly conserved. These patterns have strong predictive power toward specific vestibular diagnoses. Such language elements can provide a simple vocabulary to aid nonexpert providers in formulating a differential diagnosis. They can also be incorporated into clinical decision support systems to facilitate accurate vestibular diagnosis in ambulatory settings.

A New Diagnostic Approach to the Adult Patient with Acute Dizziness

BACKGROUND

Dizziness, a common chief complaint, has an extensive differential diagnosis that includes both benign and serious conditions. Emergency physicians must distinguish the majority of patients with self-limiting conditions from those with serious illnesses that require acute treatment.

OBJECTIVE OF THE REVIEW

This article presents a new approach to diagnosis of the acutely dizzy patient that 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 in the emergency department.

DISCUSSION

Currently, misdiagnoses are frequent and diagnostic testing costs are high. This relates in part to use of an outdated, prevalent, diagnostic paradigm. The traditional approach, which relies on dizziness symptom quality or type (i.e., vertigo, presyncope, or disequilibrium) to guide inquiry, does not distinguish benign from dangerous causes, and is inconsistent with current best evidence. A new approach divides patients into three key categories using timing and triggers, guiding a differential diagnosis and targeted bedside examination protocol: 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.

CONCLUSIONS

The timing and triggers diagnostic approach for the acutely dizzy patient derives from current best evidence and offers the potential to reduce misdiagnosis while simultaneously decreases diagnostic test overuse, unnecessary hospitalization, and incorrect treatments.