Missed Strokes Using Computed Tomography Imaging in Patients With Vertigo

Abstract

Background and Purpose-The purpose of this study was to determine the proportion of emergency department (ED) patients with a diagnosis of peripheral vertigo who received computed tomography (CT) head imaging in the ED and to examine whether strokes were missed using CT imaging. Methods-This population-based retrospective cohort study assessed patients who were discharged from an ED in Ontario, Canada, with a diagnosis of peripheral vertigo, April 2006 to March 2011. Patients who received CT imaging (exposed) were matched by propensity score methods to patients who did not (unexposed). If performed, CT imaging was presumed to be negative for stroke because brain stem/cerebellar stroke would result in hospitalization. We compared the incidence of stroke within 30, 90, and 365 days subsequent to ED discharge between groups, to determine whether the exposed group had a higher frequency of early strokes than the matched unexposed group. Results-Among 41 794 qualifying patients, 8596 (20.6%) received ED head CT imaging, and 99.8% of these patients were able to be matched to a control. Among exposed patients, 25 (0.29%) were hospitalized for stroke within 30 days when compared with 11 (0.13%) among matched nonexposed patients. The relative risk of a 30-and 90-day stroke among exposed versus unexposed patients was 2.27 (95% confidence interval, 1.12-4.62) and 1.94 (95% confidence interval, 1.10-3.43), respectively. There was no difference between groups at 1 year. Strokes occurred at a median of 32.0 days (interquartile range, 4.0-33.0 days) in exposed patients, compared with 105 days (interquartile range, 11.5-204.5) in unexposed patients. Conclusions-One fifth of patients diagnosed with peripheral vertigo in Ontario received imaging that is not recommended in guidelines, and that imaging was associated with missed strokes.

Missed stroke in acute vertigo and dizziness: It is time for action, not debate

“…Certainly, head computed tomography (CT) scans are of little use in this scenario, given their low sensitivity for acute stroke, particularly in the posterior cranial fossa (missing >80%) . In fact, the authors of the present study recently published an article demonstrating that, among those discharged with a peripheral vestibular disorder, those who underwent CT during the ED visit (with a presumptively negative result) were 2.3 times more likely to suffer a stroke in the next 30 days than those who received no CT at all . This suggests that ED physicians are correctly risk stratifying patients, but being falsely reassured by a normal head CT.…”

Outcomes among patients discharged from the emergency department with a diagnosis of peripheral vertigo

“…There are many potential reasons why strokes may be misdiagnosed in the ED, including incomplete or lack of training in performing or interpreting focused neurovestibular exams, excessive focus on the type of dizziness, and misplaced faith in CT scans to “rule out” stroke . Prospective studies are needed to determine the best ways to enhance diagnostic accuracy in the ED, either by improving examination skills or providing technological assistance in diagnosis .…”

Symptom-Disease Pair Analysis of Diagnostic Error (SPADE): a conceptual framework and methodological approach for unearthing misdiagnosis-related harms using big data

“…4849 Frequent use of neuroimaging in patients discharged with BPPV suggests knowledge or skill gaps in bedside diagnosis of vertigo. 2650 Such process failures may correlate to misdiagnosis-related harms (eg, use of neuroimaging in ‘benign’ dizziness/vertigo is linked to increased odds of stroke readmission after discharge 51 ). For cancers, process failures can be identified by measuring diagnostic intervals (eg, time from index visit to advanced testing or specialty consultation to treatment) 4352 ; diagnostic delays can be correlated to outcomes and targeted for disease-specific process improvement.…”

“…The method is strongly supported by the fact that the dizziness-stroke dyad has an extensive body of remarkably coherent and consistent scientific literature 2628 that includes chart reviews, 151667 surveys, 6869 cross-sectional health services research studies, 50515670 prospective cohort studies 7172 and SPADE-type studies using look-back 25 and look-forward 21–23 methods. Problems inherent in human chart reviews, particularly hindsight and observer biases, 12–14 and flawed underlying documentation 15 suggest that this is probably not an ideal reference standard for SPADE.…”