David E. Newman-Toker

HINTS to Diagnose Stroke in the Acute Vestibular Syndrome Three-Step Bedside Oculomotor Examination More Sensitive Than Early MRI Diffusion-Weighted Imaging

Background and Purpose— Acute vestibular syndrome (AVS) is often due to vestibular neuritis but can result from vertebrobasilar strokes. Misdiagnosis of posterior fossa infarcts in emergency care settings is frequent. Bedside oculomotor findings may reliably identify stroke in AVS, but prospective studies have been lacking. Methods— The authors conducted a prospective, cross-sectional study at an academic hospital. Consecutive patients with AVS (vertigo, nystagmus, nausea/vomiting, head-motion intolerance, unsteady gait) with ≥1 stroke risk factor underwent structured examination, including horizontal head impulse test of vestibulo-ocular reflex function, observation of nystagmus in different gaze positions, and prism cross-cover test of ocular alignment. All underwent neuroimaging and admission (generally <72 hours after symptom onset). Strokes were diagnosed by MRI or CT. Peripheral lesions were diagnosed by normal MRI and clinical follow-up. Results— One hundred one high-risk patients with AVS included 25 peripheral and 76 central lesions (69 ischemic strokes, 4 hemorrhages, 3 other). The presence of normal horizontal head impulse test, direction-changing nystagmus in eccentric gaze, or skew deviation (vertical ocular misalignment) was 100% sensitive and 96% specific for stroke. Skew was present in 17% and associated with brainstem lesions (4% peripheral, 4% pure cerebellar, 30% brainstem involvement; &khgr;2, P=0.003). Skew correctly predicted lateral pontine stroke in 2 of 3 cases in which an abnormal horizontal head impulse test erroneously suggested peripheral localization. Initial MRI diffusion-weighted imaging was falsely negative in 12% (all <48 hours after symptom onset). Conclusions— Skew predicts brainstem involvement in AVS and can identify stroke when an abnormal horizontal head impulse test falsely suggests a peripheral lesion. A 3-step bedside oculomotor examination (HINTS: Head-Impulse—Nystagmus—Test-of-Skew) appears more sensitive for stroke than early MRI in AVS.

Diagnostic Errors—The Next Frontier for Patient Safety

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Normal head impulse test differentiates acute cerebellar strokes from vestibular neuritis

Objective: To test the diagnostic accuracy of the horizontal head impulse test (h-HIT) of vestibulo-ocular reflex (VOR) function in distinguishing acute peripheral vestibulopathy (APV) from stroke. Most patients with acute vertigo, nausea/vomiting, and unsteady gait have benign APV (vestibular neuritis or labyrinthitis) as a cause. However, some harbor life-threatening brainstem or cerebellar strokes that mimic APV. A positive h-HIT (abnormal VOR) is said to predict APV. Methods: Cross-sectional study at an urban, academic hospital over 6 years. Consecutive acute vestibular syndrome patients at high risk for stroke underwent structured examination (including h-HIT), neuroimaging, and admission. Stroke was confirmed by neuroimaging (MRI or CT). APV was diagnosed by normal MRI and appropriate clinical evolution in follow-up. Results: Forty-three subjects enrolled. One had an equivocal h-HIT. Patients with APV had a positive h-HIT (n = 8/8, 100%). Most patients with stroke had a negative h-HIT (n = 31/34, 91%). However, contrary to conventional wisdom, three patients with stroke (9%) demonstrated a positive h-HIT (1 vestibulocerebellar, 1 pontocerebellar, 1 pontocerebello-labyrinthine stroke). Conclusions: Patients with lateral pontine and cerebellar strokes can have a positive horizontal head impulse test (h-HIT), so the sign’s presence cannot be solely relied upon to identify a benign pathology. Additional clinical features (e.g., directionality of nystagmus, severity of truncal instability, nature of hearing loss) must be considered in patients with acute vestibular syndrome with a positive h-HIT before a central localization can be confidently excluded. Nonetheless, the h-HIT remains a useful bedside test—in acute vestibular syndrome patients, a negative h-HIT (i.e., normal VOR) strongly suggests a central lesion with a pseudo-labyrinthine presentation.

Bedside differentiation of vestibular neuritis from central “vestibular pseudoneuritis”

Acute unilateral peripheral and central vestibular lesions can cause similar signs and symptoms, but they require different diagnostics and management. We therefore correlated clinical signs to differentiate vestibular neuritis (40 patients) from central “vestibular pseudoneuritis” (43 patients) in the acute situation with the final diagnosis assessed by neuroimaging. Skew deviation was the only specific but non-sensitive (40%) sign for pseudoneuritis. None of the other isolated signs (head thrust test, saccadic pursuit, gaze evoked nystagmus, subjective visual vertical) were reliable; however, multivariate logistic regression increased their sensitivity and specificity to 92%.

Classification of vestibular symptoms: Towards an international classification of vestibular disorders

Alexandre Bisdorffa,∗, Michael Von Brevernb, Thomas Lempertc and David E. Newman-Tokerd Department of Neurology, Centre Hospitalier Emile Mayrisch, L-4005 Esch-sur-Alzette, Luxembourg Vestibular Research Group Berlin, Department of Neurology, Park-Klinik Weissensee, Berlin, Germany Vestibular Research Group Berlin, Department of Neurology, Schlosspark-Klinik, Berlin, Germany Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA

Spectrum of Dizziness Visits to US Emergency Departments: Cross-Sectional Analysis From a Nationally Representative Sample

OBJECTIVE To describe the spectrum of visits to US emergency departments (EDs) for acute dizziness and determine whether ED patients with dizziness are diagnosed as having a range of benign and dangerous medical disorders, rather than predominantly vestibular ones. PATIENTS AND METHODS A cross-sectional study of ED visits from the National Hospital Ambulatory Medical Care Survey (NHAMCS) used a weighted sample of US ED visits (1993-2005) to measure patient and hospital demographics, ED diagnoses, and resource use in cases vs controls without dizziness. Dizziness in patients 16 years or older was defined as an NHAMCS reason-for-visit code of dizziness/vertigo (1225.0) or a final International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis of dizziness/vertigo (780.4) or of a vestibular disorder (386.x). RESULTS A total of 9472 dizziness cases (3.3% of visits) were sampled over 13 years (weighted 33.6 million). Top diagnostic groups were otologic/vestibular (32.9%), cardiovascular (21.1%), respiratory (11.5%), neurologic (11.2%, including 4% cerebrovascular), metabolic (11.0%), injury/poisoning (10.6%), psychiatric (7.2%), digestive (7.0%), genitourinary (5.1%), and infectious (2.9%). Nearly half of the cases (49.2%) were given a medical diagnosis, and 22.1% were given only a symptom diagnosis. Predefined dangerous disorders were diagnosed in 15%, especially among those older than 50 years (20.9% vs 9.3%; P<.001). Dizziness cases were evaluated longer (mean 4.0 vs 3.4 hours), imaged disproportionately (18.0% vs 6.9% undergoing computed tomography or magnetic resonance imaging), and admitted more often (18.8% vs 14.8%) (all P<.001). CONCLUSION Dizziness is not attributed to a vestibular disorder in most ED cases and often is associated with cardiovascular or other medical causes, including dangerous ones. Resource use is substantial, yet many patients remain undiagnosed.

Does my dizzy patient have a stroke? A systematic review of bedside diagnosis in acute vestibular syndrome

Dizziness is the third most common major medical symptom reported in general medical clinics[1][1] and accounts for about 3%–5% of visits across care settings.[2][2] In the United States, this translates to 10 million ambulatory visits per year because of dizziness,[3][3] with roughly 25% of these

25-Year summary of US malpractice claims for diagnostic errors 1986–2010: an analysis from the National Practitioner Data Bank

Background We sought to characterise the frequency, health outcomes and economic consequences of diagnostic errors in the USA through analysis of closed, paid malpractice claims. Methods We analysed diagnosis-related claims from the National Practitioner Data Bank (1986–2010). We describe error type, outcome severity and payments (in 2011 US dollars), comparing diagnostic errors to other malpractice allegation groups and inpatient to outpatient within diagnostic errors. Results We analysed 350 706 paid claims. Diagnostic errors (n=100 249) were the leading type (28.6%) and accounted for the highest proportion of total payments (35.2%). The most frequent outcomes were death, significant permanent injury, major permanent injury and minor permanent injury. Diagnostic errors more often resulted in death than other allegation groups (40.9% vs 23.9%, p<0.001) and were the leading cause of claims-associated death and disability. More diagnostic error claims were outpatient than inpatient (68.8% vs 31.2%, p<0.001), but inpatient diagnostic errors were more likely to be lethal (48.4% vs 36.9%, p<0.001). The inflation-adjusted, 25-year sum of diagnosis-related payments was US

Diagnostic criteria for Menière's disease

38.8 billion (mean per-claim payout US

Diagnostic errors in the intensive care unit: a systematic review of autopsy studies

386 849; median US