Wide variation and rising utilization of stroke magnetic resonance imaging: data from 11 states

"My attending really wants it!" Manual clinical decision support adjudicating the "better look" inpatient MRI at an academic medical center

OBJECTIVE

MRI utilization in the United States is relatively higher than in other parts of the world and inpatient MRI utilization is particularly difficult to manage given the lack of direct reimbursement. Body MRI studies present an opportunity to reduce inpatient MRI utilization since they are generally the least emergent. Our objective was to use a targeted questionnaire to probe the necessity of inpatient body MRI orders and present an opportunity to either cancel them or transition them to the outpatient realm METHODS: A 9-item questionnaire was devised asking questions about the urgency of the inpatient MRI order including the urgent management question, an inpatient procedure or whether it was recommended by a consultant. Peer-to-peer discussion walking through each of the questions was conducted by radiology housestaff with the ordering clinicians and responses recorded.

RESULTS

845 recorded responses reported a lack of specific clinical question in 23.9% of orders, 68.9% were recommended by a non-radiology consulting service and 16.1% were recommended by radiology studies. 17.0% orders were felt to be outpatient appropriate and 23.3% were considered possibly appropriate for the outpatient setting. 3.9% were canceled and 4.9% were transitioned to outpatient orders.

DISCUSSION

Engaging in a focused discussion about the urgency and appropriateness of an inpatient MRI body order following a list of scripted questions has the potential to reduce utilization. This approach also highlights the relatively high rate of indication uncertainty among ordering clinicians and the central role of consultants in prompting orders.

ACR Appropriateness Criteria® Cerebrovascular Diseases-Stroke and Stroke-Related Conditions

Cerebrovascular disease encompasses a vast array of conditions. The imaging recommendations for stroke-related conditions involving noninflammatory steno-occlusive arterial and venous cerebrovascular disease including carotid stenosis, carotid dissection, intracranial large vessel occlusion, and cerebral venous sinus thrombosis are encompassed by this document. Additional imaging recommendations regarding complications of these conditions including intraparenchymal hemorrhage and completed ischemic strokes are also discussed. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Baseline characteristics, reperfusion treatment secondary prevention and outcome after acute ischemic stroke in three different socioeconomic environments in Europe

INTRODUCTION

The differences in vascular risk factors' and stroke burden across Europe are notable, however there is limited understanding of the influence of socioeconomic environment on the quality of secondary prevention and outcome after acute ischemic stroke.

PATIENTS AND METHODS

In this observational multicenter cohort study, we analyzed baseline characteristics, reperfusion treatment, outcome and secondary prevention in patients with acute ischemic stroke from three tertiary-care teaching hospitals with similar service population size in different socioeconomic environments: Bern/CH/n = 293 (high-income), Gdansk/PL/n = 140 (high-income), and Lutsk/UA/n = 188 (lower-middle-income).

RESULTS

We analyzed 621 patients (43.2% women, median age = 71.4 years), admitted between 07 and 12/2019. Significant differences were observed in median BMI (CH = 26/PL = 27.7/UA = 27.8), stroke severity [(median NIHSS CH = 4(0-40)/PL = 11(0-33)/UA = 7(1-30)], initial neuroimaging (CT:CH = 21.6%/PL = 50.7%/UA = 71.3%), conservative treatment (CH = 34.1%/PL = 38.6%/UA = 95.2%) (each p < 0.001), in arterial hypertension (CH = 63.8%/PL = 72.6%/UA = 87.2%), atrial fibrillation (CH = 28.3%/PL = 41.4%/UA = 39.4%), hyperlipidemia (CH = 84.9%/PL = 76.4%/UA = 17%) (each p < 0.001) and active smoking (CH = 32.2%/PL = 27.3%/UA = 10.2%) (p < 0.007). Three-months favorable outcome (mRS = 0-2) was seen in CH = 63.1%/PL = 50%/UA = 59% (unadjusted-p = 0.01/adjusted-p CH-PL/CH-UA = 0.601/0.981), excellent outcome (mRS = 0-1) in CH = 48.5%/PL = 32.1%/UA = 27% (unadjusted-p < 0.001/adjusted-p CH-PL/CH-UA = 0.201/0.08 and adjusted-OR CH-UA = 2.09). Three-months mortality was similar between groups (CH = 17.2%/PL = 15.7%/UA = 4.8%) (unadjusted-p = 0.71/adjusted-p CH-PL/CH-UA = 0.087/0.24). Three-months recurrent stroke/TIA occurred in CH = 3.1%/PL = 10.7%/UA = 3.1%, adjusted-p/OR CH-PL = 0.04/0.32). Three-months follow-up medication intake rates were the same for antihypertensives. Statin/OAC intake was lowest in UA = 67.1%/25.5% (CH = 87.3%/39.2%/unadjusted-p < 0.001/adjusted-p CH-UA = 0.02/0.012/adjusted-OR CH-UA = 2.33/2.18). Oral intake of antidiabetics was lowest in CH = 10.8% (PL = 15.7%/UA = 16.1%/unadjusted-p = 0.245/adjusted-p CH-PL/CH-UA = 0.061/0.002/adjusted-OR CH-UA = 0.25). Smoking rates decreased in all groups during follow-up.

DISCUSSION AND CONCLUSION

Substantial differences in presentation, treatment and secondary prevention measures, are linked to a twofold difference in adjusted 3-months excellent outcome between Switzerland and Ukraine. This underscores the importance of socioeconomic factors that influence stroke outcomes, emphasizing the necessity for targeted interventions to address disparities in treatment and secondary prevention strategies.

Exploring the role of in-patient magnetic resonance imaging use among admitted ischemic stroke patients in improving patient outcomes and reducing healthcare resource utilization

Purpose

Despite the diagnostic and etiological significance of in-patient MRI in ischemic stroke (IS), its utilization is considered resource-intensive, expensive, and thus limiting feasibility and relevance. This study investigated the utilization of in-patient MRI for IS patients and its impact on patient and healthcare resource utilization outcomes.

Methods

This retrospective registry-based study analyzed 1,956 IS patients admitted to Halifax's QEII Health Centre between 2015 and 2019. Firstly, temporal trends of MRI and other neuroimaging utilization were evaluated. Secondly, we categorized the cohort into two groups (MRI vs. No MRI; in addition to a non-contrast CT) and investigated adjusted differences in patient outcomes at admission, discharge, and post-discharge using logistic regression. Additionally, we analyzed healthcare resource utilization using Poisson log-linear regression. Furthermore, patient outcomes significantly associated with MRI use underwent subgroup analysis for stroke severity (mild stroke including transient ischemic attack vs. moderate and severe stroke) and any acute stage treatment (thrombolytic or thrombectomy or both vs. no treatment) subgroups, while using an age and sex-adjusted logistic regression model.

Results

MRI was used in 40.5% patients; non-contrast CT in 99.3%, CT angiogram in 61.8%, and CT perfusion in 50.3%. Higher MRI utilization was associated with male sex, younger age, mild stroke, wake-up stroke, and no thrombolytic or thrombectomy treatment. MRI use was independently associated with lower in-hospital mortality (adjusted OR, 0.23; 95% CI, 0.15-0.36), lower symptomatic neurological status changes (0.64; 0.43-0.94), higher home discharge (1.32; 1.07-1.63), good functional outcomes at discharge (mRS score 0-2) (1.38; 1.11-1.72), lower 30-day stroke re-admission rates (0.48; 0.26-0.89), shorter hospital stays (regression coefficient, 0.92; 95% CI, 0.90-0.94), and reduced direct costs of hospitalization (0.90; 0.89-0.91). Subgroup analysis revealed significantly positive association of MRI use with most patient outcomes in moderate and severe strokes subgroup and non-acutely treated subgroup. Conversely, outcomes in mild strokes (including TIAs) subgroup and acute treatment subgroup were comparable regardless of MRI use.

Conclusion

A substantial proportion of admitted IS patients underwent MRI, and MRI use was associated with improved patient outcomes and reduced healthcare resource utilization. Considering the multifactorial nature of IS patient outcomes, further randomized controlled trials are suggested to investigate the role of increased MRI utilization in optimizing in-patient IS management.

Trends in Disparities in Advanced Neuroimaging Utilization in Acute Stroke: A Population-Based Study

BACKGROUND

Our primary objective was to evaluate if disparities in race, sex, age, and socioeconomic status (SES) exist in utilization of advanced neuroimaging in year 2015 in a population-based study. Our secondary objective was to identify the disparity trends and overall imaging utilization as compared with years 2005 and 2010.

METHODS

This was a retrospective, population-based study that utilized the GCNKSS (Greater Cincinnati/Northern Kentucky Stroke Study) data. Patients with stroke and transient ischemic attack were identified in the years 2005, 2010, and 2015 in a metropolitan population of 1.3 million. The proportion of imaging use within 2 days of stroke/transient ischemic attack onset or hospital admission date was computed. SES determined by the percentage below the poverty level within a given respondent's US census tract of residence was dichotomized. Multivariable logistic regression was used to determine the odds of advanced neuroimaging use (computed tomography angiogram/magnetic resonance imaging/magnetic resonance angiogram) for age, race, gender, and SES.

RESULTS

There was a total of 10 526 stroke/transient ischemic attack events in the combined study year periods of 2005, 2010, and 2015. The utilization of advanced imaging progressively increased (48% in 2005, 63% in 2010, and 75% in 2015 [P<0.001]). In the combined study year multivariable model, advanced imaging was associated with age and SES. Younger patients (≤55 years) were more likely to have advanced imaging compared with older patients (adjusted odds ratio, 1.85 [95% CI, 1.62-2.12]; P<0.01), and low SES patients were less likely to have advanced imaging compared with high SES (adjusted odds ratio, 0.83 [95% CI, 0.75-0.93]; P<0.01). A significant interaction was found between age and race. Stratified by age, the adjusted odds of advanced imaging were higher for Black patients compared with White patients among older patients (>55 years; adjusted odds ratio, 1.34 [95% CI, 1.15-1.57]; P<0.01), but no racial differences among the young.

CONCLUSIONS

Racial, age, and SES-related disparities exist in the utilization of advanced neuroimaging for patients with acute stroke. There was no evidence of a change in trend of these disparities between the study periods.

Validation of the International Classification of Diseases, Tenth Revision Code for the National Institutes of Health Stroke Scale Score

BACKGROUND

Administrative data can be useful for stroke research but have historically lacked data on stroke severity. Hospitals increasingly report the National Institutes of Health Stroke Scale (NIHSS) score using an International Classification of Diseases, Tenth Revision (ICD-10) diagnosis code, but this code's validity remains unclear.

METHODS

We examined the concordance of ICD-10 NIHSS scores versus NIHSS scores recorded in CAESAR (Cornell Acute Stroke Academic Registry). We included all patients with acute ischemic stroke from October 1, 2015, when US hospitals transitioned to ICD-10, through 2018, the latest year in our registry. The NIHSS score (range, 0-42) recorded in our registry served as the reference gold standard. ICD-10 NIHSS scores were derived from hospital discharge diagnosis code R29.7xx, with the latter 2 digits representing the NIHSS score. Multiple logistic regression was used to explore factors associated with availability of ICD-10 NIHSS scores. We used ANOVA to examine the proportion of variation (R2) in the true (registry) NIHSS score that was explained by the ICD-10 NIHSS score.

RESULTS

Among 1357 patients, 395 (29.1%) had an ICD-10 NIHSS score recorded. This proportion increased from 0% in 2015 to 46.5% in 2018. In a logistic regression model, only higher registry NIHSS score (odds ratio per point, 1.05 [95% CI, 1.03-1.07]) and cardioembolic stroke (odds ratio, 1.4 [95% CI, 1.0-2.0]) were associated with availability of the ICD-10 NIHSS score. In an ANOVA model, the ICD-10 NIHSS score explained almost all the variation in the registry NIHSS score (R2=0.88). Fewer than 10% of patients had a large discordance (≥4 points) between their ICD-10 and registry NIHSS scores.

CONCLUSIONS

When present, ICD-10 codes representing NIHSS scores had excellent agreement with NIHSS scores recorded in our stroke registry. However, ICD-10 NIHSS scores were often missing, especially in less severe strokes, limiting the reliability of these codes for risk adjustment.

Imaging of Central Nervous System Ischemia

OBJECTIVE

This article describes imaging modalities used in the evaluation of patients presenting with symptoms of acute ischemic stroke.

LATEST DEVELOPMENTS

The year 2015 marked the beginning of a new era in acute stroke care with the widespread adoption of mechanical thrombectomy. Subsequent randomized controlled trials in 2017 and 2018 brought the stroke community even further into this new territory with the expansion of the eligibility window for thrombectomy using imaging-based patient selection, which led to an increase in the use of perfusion imaging. Now, after several years of routine use, the debate is ongoing as to when this additional imaging is truly required and when it results in unnecessary delays in time-sensitive stroke care. At this time, more than ever, a robust understanding of neuroimaging techniques, applications, and interpretation is essential for the practicing neurologist.

ESSENTIAL POINTS

CT-based imaging is the first step in most centers for the evaluation of patients presenting with symptoms of acute stroke because of its wide availability, speed, and safety. Noncontrast head CT alone is sufficient for IV thrombolysis decision making. CT angiography is very sensitive for the detection of large-vessel occlusion and can be used reliably to make this determination. Advanced imaging including multiphase CT angiography, CT perfusion, MRI, and MR perfusion can provide additional information useful for therapeutic decision making in specific clinical scenarios. In all cases, it is essential that neuroimaging be performed and interpreted rapidly to allow for timely reperfusion therapy.

Neuroimaging of Acute Ischemic Stroke: Multimodal Imaging Approach for Acute Endovascular Therapy

Advances in acute ischemic stroke (AIS) treatment have been contingent on innovations in neuroimaging. Neuroimaging plays a pivotal role in the diagnosis and prognosis of ischemic stroke and large vessel occlusion, enabling triage decisions in the emergent care of the stroke patient. Current imaging protocols for acute stroke are dependent on the available resources and clinicians' preferences and experiences. In addition, differential application of neuroimaging in medical decision-making, and the rapidly growing evidence to support varying paradigms have outpaced guideline-based recommendations for selecting patients to receive intravenous or endovascular treatment. In this review, we aimed to discuss the various imaging modalities and approaches used in the diagnosis and treatment of AIS.

Drivers of Ischemic Stroke Hospital Cost Trends Among Older Adults in the United States

PURPOSE

The increased use of neuroimaging and innovations in ischemic stroke (IS) treatment have improved outcomes, but the impact on median hospital costs is not well understood.

METHODS

A retrospective study was conducted using Medicare 5% claims data for 75,525 consecutive index IS hospitalizations for patients aged ≥65 years from 2012 to 2019 (values in 2019 dollars). IS episode cost was calculated in each year for trend analysis and stratified by cost components, including neuroimaging (CT angiography [CTA], CT perfusion [CTP], MRI, and MR angiography [MRA]), treatment (endovascular thrombectomy [EVT] and/or intravenous thrombolysis), and patient sociodemographic factors. Logistic regression was performed to analyze the drivers of high-cost episodes and median regression to assess drivers of median costs.

RESULTS

The median IS episode cost increased by 4.9% from $9,509 in 2012 to $9,973 in 2019 (P = .0021). Treatment with EVT resulted in the greatest odds of having a high-cost (>$20,000) hospitalization (odds ratio [OR], 71.86; 95% confidence interval [CI], 54.62-94.55), as did intravenous thrombolysis treatment (OR, 3.19; 95% CI, 2.90-3.52). Controlling for other factors, neuroimaging with CTA (OR, 1.72; 95% CI, 1.58-1.87), CTP (OR, 1.32; 95% CI, 1.14-1.52), and/or MRA (OR, 1.26; 95% CI, 1.15-1.38) had greater odds of having high-cost episodes than those without CTA, CTP, and MRA. Length of stay > 4 days (OR, 4.34; 95% CI, 3.99-4.72) and in-hospital mortality (OR, 1.85; 95% CI, 1.63-2.10) were also associated with high-cost episodes.

CONCLUSIONS

From 2012 to 2019, the median IS episode cost increased by 4.9%, with EVT as the main cost driver. However, the increasing treatment cost trends have been partially offset by decreases in median length of stay and in-hospital mortality.

Trends in Utilization of Magnetic Resonance Imaging for Stroke Patients With Cardiac Rhythm Devices

Background and Purpose

Magnetic resonance imaging (MRI) is safe for most patients with cardiovascular implantable electronic devices (CIEDs). However, patients presenting with acute ischemic stroke or transient ischemic attack (AIS/TIA) who have CIEDs may undergo MRI less frequently than patients without devices. We assessed contemporary use of MRI for patients with AIS/TIA and the effect of a recent coverage revision by the Center for Medicare and Medicaid Services (CMS) on MRI utilization.

Methods

Using Optum® claims data from January 2012 to June 2019, we performed an interrupted time series analysis of MRI utilization during AIS/TIA hospitalizations with the April 2018 CMS coverage revision serving as the intervention. For patients treated after the coverage revision, we used multivariable logistic regression to determine the association between lack of CIED and MRI utilization for AIS/TIA.

Results

We identified 417,899 patient hospitalizations for AIS/TIA, of which 30,425 (7%) had a CIED present (CIED vs non-CIED patients: age 77.6 ± 9.8 vs 72.7 ± 12.3 years; 45.5% vs 54.3% female). From 2012 to 2019, annual MRI utilization increased from 3% to 20% for CIED patients and 58% to 66% for non-CIED patients. The CMS coverage revision was associated with a 4.2% absolute additional increase in MRI utilization for CIED patients. Non-CIED patients treated after the CMS coverage revision were substantially more likely than CIED patients to undergo MRI (adjusted OR 6.7, 95% CI: 6.3-7.1, P<.001).

Conclusions

MRI utilization has increased for stroke patients with CIEDs but remains far lower than in similar patients without devices.

Neuroimaging in acute ischemic stroke: Trends, disparities, and clinical impact

INTRODUCTION

Clinical studies over the past decade expanded the eligibility criteria for endovascular therapy, with advanced imaging selection and new devices leading to higher rates of good outcomes. Herein, we explore the current trends in neuroimaging, associated factors, and impact on treatment and clinical outcomes.

MATERIALS AND METHODS

This is a retrospective study of consecutive acute ischemic stroke patients, admitted to a comprehensive stroke center from 2016 to 2020. Patient characteristics, including age, sex, race, arrival method, admission National Institutes of Health Stroke Scale score and last known well to arrival time; imaging and treatment utilization; and discharge outcome by modified Rankin Scale and disposition were extracted from medical records. Trend and multivariable logistic regression analyses were performed, and trends were stratified by patient characteristics.

RESULTS

Of 4,125 acute ischemic stroke episodes, 15.1% received intravenous thrombolysis only, and 7.5% received endovascular thrombectomy from 2016 to 2020. Neuroimaging utilization trends significantly increased for computed tomography angiography (CTA) (48.7% to 75.2%, p < 0.001) and computed tomography perfusion (CTP) (0.26% to 32.9%, p < 0.001), and decreased for magnetic resonance angiography (MRA) (43.2% to 24.7%, p < 0.001). These trends held after adjusting for patient characteristics. Endovascular thrombectomy and intravenous thrombolysis were significantly more common in patients with CTA and CTP (p < 0.0001), and these treatments were associated with good clinical outcomes after controlling for patient characteristics.

CONCLUSION

We found significantly increased trends in CTA and CTP imaging, which were associated with endovascular thrombectomy and intravenous thrombolysis utilization, in acute ischemic stroke patients from 2016 to 2020.

Predicting the Severity of Neurological Impairment Caused by Ischemic Stroke Using Deep Learning Based on Diffusion-Weighted Images

Purpose: To develop a preliminary deep learning model that uses diffusion-weighted imaging (DWI) images to classify the severity of neurological impairment caused by ischemic stroke. Materials and Methods: This retrospective study included 851 ischemic stroke patients (711 patients in the training set and 140 patients in the test set). The patients’ NIHSS scores, which reflect the severity of neurological impairment, were reviewed upon admission and on Day 7 of hospitalization and were classified into two stages (stage 1 for NIHSS < 5 and stage 2 for NIHSS ≥ 5). A 3D-CNN was trained to predict the stage of NIHSS based on different preprocessed DWI images. The performance in predicting the severity of anterior and posterior circulation stroke was also investigated. The AUC, specificity, and sensitivity were calculated to evaluate the performance of the model. Results: Our proposed model obtained better performance in predicting the NIHSS stage on Day 7 of hospitalization than that at admission (best AUC 0.895 vs. 0.846). Model D trained with DWI images (normalized with z-score and resized to 256 × 256 × 64 voxels) achieved the best AUC of 0.846 in predicting the NIHSS stage at admission. Model E rained with DWI images (normalized with maximum−minimum and resized to 128 × 128 × 32 voxels) achieved the best AUC of 0.895 in predicting the NIHSS stage on Day 7 of hospitalization. Our model also showed promising performance in predicting the NIHSS stage on Day 7 of hospitalization for anterior and posterior circulation stroke, with the best AUCs of 0.905 and 0.903, respectively. Conclusions: Our proposed 3D-CNN model can effectively predict the neurological severity of IS using DWI images and performs better in predicting the NIHSS stage on Day 7 of hospitalization. The model also obtained promising performance in subgroup analysis, which can potentially help clinical decision making.

Updated Trends, Disparities, and Clinical Impact of Neuroimaging Utilization in Ischemic Stroke in the Medicare Population: 2012 to 2019

OBJECTIVE

The purpose of this study was to update trends, investigate sociodemographic disparities, and evaluate the impact on mortality of stroke neuroimaging across the United States from 2012 to 2019.

METHODS

Retrospective cohort study using CMS Medicare 5% Research Identifiable Files, representing consecutive ischemic stroke emergency department or hospitalized patients aged ≥65 years. A total of 85,547 stroke episodes with demographic and clinical information were analyzed using Cochran-Mantel-Haenszel tests and logistic regression. Outcome measures were neuroimaging (CT angiography [CTA], CT perfusion [CTP], MRI, MR angiography [MRA]) utilization, acute treatment (endovascular thrombectomy [EVT] and intravenous thrombolysis [IVT]), and mortality while in the hospital and at 30 days and 1 year post discharge.

RESULTS

Significantly increasing utilization trends for CTA (250%), CTP (428%) and MRI (18%), and a decreasing trend for MRA (-33%) were observed from 2012 to 2019 (P < .0001). Controlling for covariates in the logistic regression models, CTA and CTP were significantly associated with higher EVT and IVT utilization. Although CTA, MRI, and MRA were associated with lower mortality, CTP was associated with higher mortality post discharge. Less neuroimaging was performed in rural patients; older patients (≥80 years) had lower utilization of CTA, MRI, and MRA; female patients had lower rates of CTA; and Black patients had lower utilization of CTA and CTP.

CONCLUSIONS

CTA and CTP utilization increased in the Medicare ischemic stroke population from 2012 to 2019 and both were associated with greater EVT and IVT use. However, disparities exist in neuroimaging utilization across all demographic groups, and further understanding of the root causes of these disparities will be crucial to achieving equity in stroke care.

The Evaluation Value of Diffusion-Weighted Imaging for Brain Injury in Patients after Deep Hypothermic Circulatory Arrest

Objective

Cerebral complications may occur after surgery with deep hypothermic circulatory arrest (DHCA). Diffusion-weighted imaging (DWI) has shown promising results in detecting early changes of cerebral ischemia. However, studies in human models are limited. Here, we examined the significance of DWI for detecting brain injury in postoperative patients after DHCA.

Methods

Twelve patients who had undergone selective cerebral perfusion with DHCA were enrolled. All patients underwent magnetic resonance imaging (MRI) examinations before and after the operation with T1-weighted phase (T1W) and T2-weighted phase (T2W). Magnetic resonance angiography (3D TOF) was applied to observe intracranial arterial communication situations. DWI was employed to calculate the apparent diffusion coefficient (ADC) values. The neurocognitive function of patients was assessed preoperatively and postoperatively using the Montreal Cognitive Assessment Scale (MoCA), Hamilton Depression Scale (HAMD), and Hamilton Anxiety Scale (HAMA).

Results

The ADC values of the whole brain of patients after surgery were significantly higher than before surgery (P = 0.003). However, no significant difference in the ADC values of other regions before and after the operation was observed. There was no significant effect on the postoperative cognitive function of patients after surgery, but visual-spatial and executive abilities were significantly reduced, while psychological anxiety (P = 0.005) and depression levels (P < 0.05) significantly increased. Correlation analysis revealed a significant association between ADC change values and depression change values (P < 0.05).

Conclusion

DHCA demonstrated no significant effect on the cognitive function of patients but could affect the mood of patients. On the other hand, DWI demonstrated promising efficiency and accuracy in evaluating brain injury after DHCA.

Distribution and prognosis of acute ischaemic stroke with negative diffusion-weighted imaging

BACKGROUND AND PURPOSE

To examine the distribution and prognosis among patients with diffusion-weighted imaging (DWI)-negative acute ischaemic stroke (AIS) and explore the differences between mild (National Institute of Health Stroke Scale (NIHSS) score ≤5) and major (NIHSS score >5) ischaemic stroke in DWI-negative patients.

METHODS

Patients with AIS with baseline DWI from the Third China National Stroke Registry (CNSR-III), based on a prospective, observational, multicentre cohort study, between August 2015 and March 2018, were included. Patients were classified into negative and positive DWI groups depending on the existence of acute lesions on DWI.

RESULTS

Among 12 026 patients who had an ischaemic stroke, 932 (7.7%) had negative DWI. As the NIHSS score increased, the proportion of patients with DWI-negative AIS gradually decreased. Negative DWI was associated with a decreased risk of stroke recurrence (HR 0.63, 95% CI 0.49 to 0.82), combined vascular events (HR 0.72, 95% CI 0.56 to 0.92), mortality (HR 0.60, 95% CI 0.36 to 0.995) and poor functional outcomes (OR 0.57, 95% CI 0.43 to 0.76) within 1 year in all patients. Similar associations were observed in patients with mild AIS (p<0.05 for all) but not in patients with major AIS, excluding poor functional outcomes (OR 0.47, 95% CI 0.28 to 0.81).

CONCLUSIONS

The proportion of patients with DWI-negative AIS gradually decreased as the NIHSS score increased, and negative DWI was mainly observed in patients with mild AIS. Negative DWI was associated with a better prognosis for all patients with AIS. However, these associations were significant for mild AIS but not for those with major AIS.

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

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

Increasing false positive diagnoses may lead to overestimation of stroke incidence, particularly in the young: a cross-sectional study

Background

Stroke incidence is reportedly increasing in younger populations, although the reasons for this are not clear. We explored possible reasons by quantifying trends in neurologically focused emergency department (ED) visits, classification of stroke vs. TIA, and imaging use.

Methods

We performed a retrospective, serial, cross-sectional study using the National Hospital Ambulatory Medical Care Survey to examine time trends in age-stratified primary reasons for visit, stroke/TIA diagnoses, and MRI utilization from 1995 to 2000 and 2005–2015.

Results

Five million eight hundred thousand ED visits with a primary diagnosis of stroke (CI 5.3 M–6.4 M) were represented in the data. The incidence of neurologically focused reason for visits (Neuro RFVs) increased over time in both the young and in older adults (young: + 111 Neuro RFVs/100,000 population/year, CI + 94 − + 130; older adults: + 70 Neuro RFVs/100,000 population/year, CI + 34 − + 108). The proportion of combined stroke and TIA diagnoses decreased over time amongst older adults with a Neuro RFV (OR 0.95 per year, p < 0.01, CI 0.94–0.96) but did not change in the young (OR 1.00 per year, p = 0.88, CI 0.95–1.04). Within the stroke/TIA population, no changes in the proportion of stroke or TIA were identified. MRI utilization rates amongst patients with a Neuro RFV increased for both age groups.

Conclusions

We found, but did not anticipate, increased incidence of neurologically focused ED visits in both age groups. Given the lower pre-test probability of a stroke in younger adults, this suggests that false positive stroke diagnoses may be increasing and may be increasing more rapidly in the young than in older adults.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12883-021-02172-1.

Microbleeds, Cerebral Hemorrhage, and Functional Outcome After Endovascular Thrombectomy

OBJECTIVE

To determine whether pretreatment cerebral microbleeds (CMBs) presence and burden are correlated with an increased risk of intracranial hemorrhage (ICH) or poor functional outcome following endovascular thrombectomy (EVT) for acute ischemic stroke (AIS).

METHODS

Consecutive patients treated by EVT for anterior circulation AIS were retrospectively analyzed. Experienced neuroradiologists blinded to functional outcomes rated CMBs on T2*-MRI using a validated scale. We investigated associations of CMB presence and burden with ICH and poor clinical outcome at 3 months (modified Rankin Scale score >2).

RESULTS

Among 513 patients, 281 (54.8%) had a poor outcome and 89 (17.3%) had ≥1 CMBs. A total of 190 (37%) patients experienced ICH; 66 (12.9%) were symptomatic. CMB burden was associated with poor outcome in a univariable analysis (odds ratio [OR], 1.18; 95% confidence interval [CI], 1.03-1.36 per 1-CMB increase; p = 0.02), but significance was lost after adjustment for sex, age, stroke severity, hypertension, diabetes mellitus, atrial fibrillation, prior antithrombotic medication, IV thrombolysis, and reperfusion status (OR, 1.05; 95% CI, 0.92-1.20 per 1-CMB increase; p = 0.50). Results remained nonsignificant when taking into account CMB location or presumed underlying pathogenesis. CMB presence, burden, location, or presumed pathogenesis were not independently correlated with ICH.

CONCLUSIONS

Poor functional outcome or ICH were not correlated with CMB presence or burden on pre-EVT MRI after adjustment for confounding factors. Excluding such patients from reperfusion therapies is unwarranted.

CLASSIFICATION OF EVIDENCE

This study provides Class II evidence that in patients with AIS undergoing EVT, after adjustment for confounding factors, the presence of CMBs is not significantly associated with clinical outcome or the risk of ICH.

Frequency, Trends, and Outcomes of Cerebrovascular Events Associated With Atrial Fibrillation Hospitalizations

The main objective is to estimate the frequency, temporal trends, and outcomes of cerebrovascular events associated with atrial fibrillation (AF) hospitalization in the United States. The national inpatient sample data was utilized to identify hospitalizations with a primary or secondary diagnosis of AF from January 1, 2005 through September 31, 2015 for the present analysis. Jonckheere-Terpstra Trend was utilized to analyze trends from 2005 to 2015. Global Wald score was used to assess relative contributions of various covariates towards stroke among AF hospitalizations. Between the years 2005 and 2015, there were 36,457,323 (95.2%) AF hospitalizations without cerebrovascular events and 1,824,608 (4.8%) with cerebrovascular events included in the final analysis. There was a statistically significant increase in the proportion of overall stroke, AIS, and AHS (p_trend value <0.001) per 1,000 AF hospitalizations. The frequency of stroke per 1,000 AF hospitalizations was highest among patients with CHA2DS2VASc score ≥3 and Charlson's comorbidity index ≥3. The trend of in-hospital mortality decreased during the study period, however, it remained higher in those with cerebrovascular events compared to those without. Lastly, hypertension, advancing age, and chronic lung disease were major stroke predicting factors among AF hospitalizations. These cerebrovascular events were associated with longer length of stay and higher costs. In conclusion, the incidence of cerebrovascular events associated with AF hospitalizations remained significantly high and the trend continues to ascend despite technological advancements. Strategies should improve to reduce the risk of AF-related stroke in the United States.

The Cinderellas of the scanner: Magnetic resonance imaging 'pre-scan' and 'post-scan' times: Their determinants and impact on patient throughput

Background

Increasing demand for magnetic resonance imaging (MRI) has contributed to extended patient waiting times worldwide. This is particularly true in resource-limited environments, prompting this institutional workflow analysis.

Objective

To determine the ‘pre-’ and ‘post-scan’ times for normal-hour MRI studies conducted at a tertiary-level, public-sector South African hospital and to assess any association with demographic details, patient characteristics, anatomical site and scan parameters. A secondary objective was determination of the average daily MR ‘down’ time.

Methods

A prospective descriptive study stratifying MRI workflow into ‘pre-scan’, ‘scan’, ‘post-scan’ and ‘down’ times. During ‘pre-‘ and ‘post-scan’ times patients occupied the scanner whilst staff performed tasks indirectly contributing to image acquisition. During ‘down’ time no patient occupied the MRI room. ‘Pre-’ and ‘post-scan’ times were compared with demographic details, patient characteristics, anatomical site and study parameters, utilising correlation analysis or analysis of variance (ANOVA).

Results

A total of 223 patients (n = 223) underwent 286 investigations in the 23-day review period. Seventy per cent of routine working time was utilised in image acquisition. The ‘pre-’ and ‘post-scan’ times together accounted for 19% and ‘down’ time for 11% of working time. Prolonged ‘pre-’ and ‘post-scan’ times were independently associated with age less than 12 years, anaesthesia, sedation and immobility (p < 0.01 in all cases). The longest median combined ‘pre-’ and ‘post-scan’ time by anatomical site (cholangiopancreatography, 21:46 min) was more than six times the shortest (pituitary fossa, 3:11 min).

Conclusion

A critical analysis of magnetic resonance ‘pre-’ and ‘post-scan’ times can provide valuable insights into opportunities for enhanced service efficiency.

Patients With Acute Ischemic Stroke Who Receive Brain Magnetic Resonance Imaging Demonstrate Favorable In-Hospital Outcomes

Background

Use of inpatient brain magnetic resonance imaging (MRI) in patients with acute ischemic stroke is highly institution dependent and has been associated with increased length and cost of hospital stay. We examined whether inpatient brain MRI in patients with acute ischemic stroke is associated with improved clinical outcomes to justify its resource requirements.

Methods and Results

The National Inpatient Sample database was queried retrospectively to find 94 003 patients who were admitted for acute ischemic stroke and then received inpatient brain MRI between 2012 and 2014. Multivariable regression analysis was performed with respect to a control group to assess for differences in the rates of inpatient mortality and complications, as well as the length and cost of hospital stay based on brain MRI use. Inpatient brain MRI was independently associated with lower rates of inpatient mortality (1.67% versus 3.09%; adjusted odds ratio [OR], 0.60; 95% CI, 0.53–0.68; P<0.001), gastrostomy (2.28% versus 2.89%; adjusted OR, 0.82; 95% CI, 0.73–0.93; P<0.001), and mechanical ventilation (1.97% versus 2.82%; adjusted OR, 0.68; 95% CI, 0.60–0.77; P<0.001). Brain MRI was independently associated with ≈0.32 days (8%) and $1131 (11%) increase in the total length (P<0.001) and cost (P<0.001) of hospital stay, respectively.

Conclusions

Inpatient brain MRI in patients with acute ischemic stroke is associated with substantial decrease in the rates of inpatient mortality and complications, at the expense of marginally increased length and cost of hospitalization.

Diagnostic accuracy of acute infarcts in multiple cerebral circulations for cardioembolic stroke: Literature review and meta-analysis

OBJECTIVE

To determine the diagnostic value of acute infarcts in multiple cerebral circulations (AIMCC) on MRI diffusion-weighted imaging (DWI) for cardioembolism (CE) stroke subtype in adult patients hospitalized with acute ischemic stroke, we conducted a systematic literature review and meta-analysis.

METHODS

MEDLINE was searched via PubMed for articles reporting patients hospitalized with acute ischemic stroke with MRI DWI categorized as AIMCC vs other and use of Trial of Org 10172 in Acute Stroke Treatment (TOAST) Criteria for cardioembolism subtype. Measures of diagnostic accuracy were calculated from the retrieved studies.

RESULTS

Seven eligible articles comprised 5813 patients. Bivariate random effects models estimated sensitivity 0.19 (95% CI, 0.13 to 0.27), specificity 0.89 (0.86 to 0.91), positive predictive value 0.37 (0.30 to 0.45), negative predictive value 0.76 (0.7 to 0.82), positive likelihood ratio 1.70 (1.13 to 2.57) and negative likelihood ratio 0.91 (0.83 to 1).

INTERPRETATION

The pattern of AIMCC on DWI is of limited diagnostic value. It is not sufficiently accurate to exclude cardiac pathology by a negative test nor does a positive test indicate a major increase in the probability of identifying a potential cardioembolic source.

Functional stroke symptoms: A prospective observational case series

OBJECTIVE

Functional symptoms are a common mimic of stroke in acute stroke settings, but there are no guidelines on how to manage such patients and scant research on their clinical profile. We explore the presentation of patients with functional stroke symptoms at admission and 2-month follow-up.

METHODS

We conducted a prospective observational study across four SE London acute stroke units, with two-month follow-up. Demographic information, clinical data and GP attendances were recorded. Patients completed self-report measures: Cognitive Behavioural Responses Questionnaire short version, Brief Illness Perception Questionnaire, Hospital Anxiety and Depression Scale, Work and Social Adjustment Scale and Short Form Health Survey.

RESULTS

Fifty-six patients (mean age: 50.9 years) were recruited at baseline; 40 with isolated functional symptoms, the remaining functional symptoms in addition to stroke. Thirty-one completed self-report follow-up measures. Of 56 participants, 63% were female. Patients presented symptoms across modalities, with unilateral and limb weakness the most frequent. There was inconsistent and ambiguous recording of symptoms on medical records. Approximately 40% of patients reported levels of anxiety and depression above the threshold indicating a probable diagnosis. Higher anxiety was associated with greater resting or all-or-nothing behaviours, embarrassment avoidance and symptom focussing on the CBRQ. Only SF-36 physical functioning improved at follow-up. Less than 50% who responded at follow-up were accessing a treatment, though 82% had ongoing symptoms.

CONCLUSION

Patients with functional symptoms in stroke settings report substantial distress, associated with cognitive-behavioural responses to symptoms. Follow-up data suggest recovery can be slow, indicating access to supportive interventions should be improved.

Motor impairments in transient ischemic attack increase the odds of a positive diffusion-weighted imaging: A meta-analysis

BACKGROUND

Unilateral motor impairment is a key symptom used in the diagnosis of transient ischemic attack (TIA). Diffusion-weighted imaging (DWI) is a promising diagnostic tool for detecting ischemic lesions. While both motor impairments and DWI abnormalities are linked to the diagnosis of TIA, the association between these prognostic factors is not well understood.

OBJECTIVE

To examine the association between unilateral motor impairments and the odds of a positive DWI in TIA. Further, to determine whether the time between symptom onset and neuroimaging (delay to scan) influences the odds of a positive DWI.

METHODS

We used PRISMA guidelines to conduct a systematic search from 1989 to 2018. We included studies that reported number of individuals with/without unilateral motor symptoms and a positive/negative DWI.

RESULTS

Twenty-four studies from North America, Australia, Asia, and Europe were submitted to a meta-analysis. A pooled odds ratio of 1.80 (95% CI, 1.45-2.24, p = 0.00; I2 = 57.38) suggested that the odds of a positive DWI are greater in TIA individuals who experience motor symptoms as compared with those who experience no motor symptoms. Further, increasing the time delay to scan from the symptom onset (>2 days) did not influence the odds of a positive DWI as compared with an earlier scan (≤2 days).

CONCLUSIONS

The current meta-analysis provides cumulative evidence from 6710 individuals with TIA that the presence of motor symptoms increases the odds of a positive DWI by two-folds. These findings transform the clinical perception into evidence-based knowledge that motor impairments elevate the risk for brain tissue damage. Unilateral motor impairments in a cerebrovascular event should increase a physician's suspicion of detecting brain infarctions. These findings may influence the clinical management of TIA by generating faster response to motor impairments in TIA and accelerating referral to specialized stroke clinic.

Diffusion-weighted imaging (DWI) ischemic volume is related to FLAIR hyperintensity-DWI mismatch and functional outcome after endovascular therapy

BACKGROUND

We assessed whether diffusion-weighted imaging (DWI) volume was associated with fluid-attenuated inversion recovery vascular hyperintensities (FVH)-DWI mismatch and functional outcome in patients with acute stroke who received endovascular therapy (EVT).

METHODS

Fifty-three acute stroke patients who received EVT were enrolled. FVH-DWI mismatch, DWI volume on admission, DWI volume on follow-up, DWI volume growth, the functional outcome at 3 months (mRS) and other clinical data were collected. Receiver operating characteristic (ROC) analysis was performed to evaluate the value of DWI volume in predicting functional outcome after stroke.

RESULTS

The FVH-DWI mismatch group had a smaller DWI volume on admission (13.86±19.58 vs. 65.07±52.21; t=-4.301, P=0.000), a smaller DWI volume on follow-up (29.88±33.52 vs. 112.43±87.19; t=-4.143, P=0.000), and a lower DWI volume growth (16.02±19.90 vs. 47.36±40.06; t=-3.326, P=0.003) than those of the no FVH-DWI mismatch group. The good functional outcome group had a smaller DWI volume on admission (13.30±13.26 vs. 68.56±54.28; t=-5.611, P=0.000), a smaller DWI volume on follow-up (27.65±18.80 vs. 120.25±90.37; t=-5.720, P=0.000), lower DWI volume growth (14.35±15.06 vs. 51.69±41.17; t=-4.737, P=0.001) and a higher FVH-DWI mismatch ratio (75.76% vs. 35%; t=8.647; P=0.004) than those of the poor functional outcome group. ROC analysis showed that the sensitivity and specificity of DWI volume on admission for predicting functional outcome were 65% and 96.97%, respectively (the optimal cut-off value: 33.50 mL); DWI volume on follow-up was 48.6 mL, with a sensitivity and specificity of 80% and 87.88%, respectively; DWI volume growth was 22.25 mL, with a sensitivity and specificity of 70% and 87.88%, respectively.

CONCLUSIONS

DWI volume and DWI volume growth can provide the prognostic information of acute stroke patients after thrombectomy.

Association Between Blood Pressure Variability and Cerebral Small-Vessel Disease: A Systematic Review and Meta-Analysis

Background

Research links blood pressure variability (BPV) with stroke; however, the association with cerebral small‐vessel disease (CSVD) remains unclear. As BPV and mean blood pressure are interrelated, it remains uncertain whether BPV adds additional information to understanding cerebrovascular morphological characteristics.

Methods and Results

A systematic review was performed from inception until March 3, 2019. Eligibility criteria included population, adults without stroke (<4 weeks); exposure, BPV quantified by any metric over any duration; comparison, (1) low versus high or mean BPV and (2) people with versus without CSVD; and outcomes, (1) CSVD as subcortical infarct, lacunae, white matter hyperintensities, cerebral microbleeds, or enlarged perivascular spaces; and (2) standardized mean difference in BPV. A total of 27 articles were meta‐analyzed, comprising 12 309 unique brain scans. A total of 31 odds ratios (ORs) were pooled, indicating that higher systolic BPV was associated with higher odds for CSVD (OR, 1.27; 95% CI, 1.14–1.42; I²=85%) independent of mean systolic pressure. Likewise, higher diastolic BPV was associated with higher odds for CSVD (OR, 1.30; 95% CI, 1.14–1.48; I²=53%) independent of mean diastolic pressure. There was no evidence of a pairwise interaction between systolic/diastolic and BPV/mean ORs (P=0.47), nor a difference between BPV versus mean pressure ORs (P=0.58). Fifty‐four standardized mean differences were pooled and provided similar results for pairwise interaction (P=0.38) and difference between standardized mean differences (P=0.70).

Conclusions

On the basis of the available studies, BPV was associated with CSVD independent of mean blood pressure. However, more high‐quality longitudinal data are required to elucidate whether BPV contributes unique variance to CSVD morphological characteristics.

Diffusion-weighted imaging volume and diffusion-weighted imaging volume growth in acute stroke: associations with fluid-attenuated inversion recovery hyperintensities-diffusion-weighted imaging mismatch and functional outcome

PURPOSE

This study assessed the association between diffusion-weighted imaging (DWI) volume and fluid-attenuated inversion recovery vascular hyperintensity (FVH)-DWI mismatch, functional outcome in patients with acute stroke patients receiving endovascular therapy, as well as the value of DWI volume in predicting functional outcome with stroke patients.

METHODS

In 38 stroke patients who received endovascular therapy, FVH-DWI mismatch, DWI volume on admission, DWI volume on follow-up, DWI volume growth, the functional outcome at 3 months [modified Rankin scale (mRS)], and other clinical data were collected. Statistical analysis was performed to compare the associations with the above variables and predict functional outcome after stroke.

RESULTS

Compared with no FVH-DWI mismatch group (n = 15), FVH-DWI mismatch group (n = 23) had a smaller DWI volume on admission (t = -2.980; P = 0.008), smaller DWI volume on follow-up (t = -2.911; P = 0.009), lower DWI volume growth (t = -2.328; P = 0.031). The 3-month outcome (1.87 ± 0.92) in patients with FVH-DWI mismatch was better than that (2.93 ± 1.62) of patients with no FVH-DWI mismatch (t = -2.307; P = 0.032). Spearman's rank correlation analysis revealed that FVH-DWI mismatch (r = 0.327; P = 0.045), DWI volume on admission (r = 0.414; P = 0.010), DWI volume on follow-up (r = 0.486; P = 0.002), and DWI volume growth (r = 0.467; P = 0.003) were positively correlated with mRS at 3 months. ROC analysis showed when the optimal cutoff value of DWI volume on admission was 33.50, the sensitivity and specificity for predicting functional outcome was 60 and 95.65%, respectively.

CONCLUSIONS

Evaluating DWI volume on admission, DWI volume on follow-up as well as DWI volume growth comprehensively may be useful in predicting the functional outcome of acute stroke patients after thrombectomy.

Trends in stroke hospitalisation rates in Extremadura between 2002 and 2014: Changing the notion of stroke as a disease of the elderly

BACKGROUND

The incidence of stroke in Spain has been evaluated in several studies, whose results are highly variable and not comparable. No studies of stroke have analysed epidemiological changes in younger patients.

METHOD

We conducted a retrospective observational study using the Spanish health system's Minimum Data Set and included all patients older than 19 hospitalised due to stroke (ICD-9-CM codes 434.01, 434.11, 434.91, 430, 431, 432.9, 436, and 435) between 2002 and 2013. The analysis was performed using joinpoint regression.

RESULTS

A total of 39,321 patients were identified (47.25% were women); 3.73% were aged 20-44, 6.29% were 45-54, 11.49% were 55-64, 23.89% were 65-74, and 54.60% were > 74 years. The hospitalisation rate due to ischaemic stroke has increased significantly in men aged 45-54 (+6.7%; 95% CI, 3.3-10.2) and in women aged 20-44 and 45-54 (+6.1%; 95% CI, 0.8-11.7 and +5.7%; 95% CI, 3.0-8.4, respectively). We also observed a significant increase in the rate of hospitalisation due to ischaemic stroke in men aged over 74 (+4.2%; 95% CI, 1.3-7.2). The rate of hospitalisations due to transient ischaemic attack has also increased significantly whereas the rate of hospitalisations due to brain haemorrhage has stabilised over time.

CONCLUSIONS

Our results provide indirect evidence that the epidemiological profile of stroke is changing based on the increase in hospitalisation rates in young adults.

Cerebral microbleeds shouldn't dictate treatment of acute stroke: a retrospective cohort study evaluating risk of intracerebral hemorrhage

Background

Intravenous tissue plasminogen activator (IV tPA) after acute ischemic stroke carries the risk of symptomatic intracerebral hemorrhage (sICH). Cerebral microbleeds (CMBs) may indicate increased risk of hemorrhage and can be seen on magnetic resonance imaging (MRI). In this study, we examined the association between CMBs and sICH, focusing on the predictive value of their presence, burden, and location.

Methods

Records from all patients presenting to two academic stroke centers with acute ischemic stroke treated with IV tPA over a 5-year period were retrospectively reviewed. Demographic, medical, and imaging variables were evaluated. The presence, number, and location (lobar vs nonlobar) of CMBs were noted on gradient echo MRI sequences obtained during the admission. Univariable and multivariable statistical models were used to determine the relationship between CMBs and hemorrhagic (symptomatic and asymptomatic) transformation.

Results

Of 292 patients (mean age 62.8 years (SD 15.3), 49% African-American, 52% women), 21% (n = 62) had at least one CMB, 1% (n = 3) had > 10 CMBs, and 1% (n = 3) were diagnosed with probable cerebral amyloid angiopathy. After treatment, 16% (n = 46) developed hemorrhagic transformation, of which 6 (2%) were sICH. There was no association between CMB presence (p = .135) or location (p = .325) with sICH; however, those with a high CMB burden (> 10 CMB) were more likely to develop sICH (OR 37.8; 95% CI: 2.7–539.3; p = .007).

Conclusions

Our findings support prior findings that a high CMB burden (> 10) in patients with acute stroke treated with IV tPA are associated with a higher risk of sICH. However, the overall rate of sICH in the presence of CMB is very low, indicating that the presence of CMBs by itself should not dictate the decision to treat with thrombolytics.

Development and validation of a priori risk model for extensive white matter lesions in people age 65 years or older: the Dijon MRI study

OBJECTIVES

The objective was to develop and validate a risk model for the likelihood of extensive white matter lesions (extWML) to inform clinicians on whether to proceed with or forgo diagnostic MRI.

DESIGN

Population-based cohort study and multivariable prediction model.

SETTING

Two representative samples from France.

PARTICIPANTS

Persons aged 60-80 years without dementia or stroke. Derivation sample n=1714; validation sample n=789.

PRIMARY AND SECONDARY OUTCOME MEASURES

Volume of extWML (log cm³) was obtained from T2-weighted images in a 1.5 T scanner. 20 candidate risk factors for extWML were evaluated with the C-statistic. Secondary outcomes in validation included incident stroke over 12 years follow-up.

RESULTS

The multivariable prediction model included six clinical risk factors (C-statistic=0.61). A cut-off of 7 points on the multivariable prediction model yielded the optimum balance in sensitivity 63.7% and specificity 54.0% and the negative predictive value was high (81.8%), but the positive predictive value was low (31.5%). In further validation, incident stroke risk was associated with continuous scores on the multivariable prediction model (HR 1.02; 95% CI 1.01 to 1.04, P=0.02) and dichotomised scores from the multivariable prediction model (HR 1.28; 95% CI 1.02 to 1.60, P=0.03).

CONCLUSIONS

A simple clinical risk equation for WML constituted by six variables can inform decisions whether to proceed with or forgo brain MRI. The high-negative predictive value demonstrates potential to reduce unnecessary MRI in the population aged 60-80 years.

Examining Healthcare Segregation Among Racial and Ethnic Minorities Receiving Spine Surgical Procedures in the State of Florida

STUDY DESIGN

This was a retrospective review of the Florida Inpatient Dataset (2011-2014).

OBJECTIVE

To examine healthcare segregation among African American and Hispanic patients treated with one of four common spine surgical procedures.

SUMMARY OF BACKGROUND DATA

Racial and ethnic minorities are known to be at increased risk of adverse events after spine surgery. Healthcare segregation has been proposed as a source for these disparities, but has not been systematically examined for patients undergoing spine surgery.

METHODS

African American, Hispanic, and White patients who underwent one of the four lumbar spine surgical procedures under study were included. Volume cut-offs were previously established for surgical providers and hospitals. Surgeons and hospitals were dichotomized based on these metrics as low- or high-volume providers. Multivariable logistic regression analysis was used to determine the likelihood of patients receiving surgery from a low volume provider, adjusting for sociodemographic and clinical characteristics.

RESULTS

African Americans were found to be at significantly increased odds of receiving surgery from a low-volume surgeon (P < 0.001) and were significantly more likely to receive surgery at a low-volume hospital (P < 0.007) for all procedures except decompression (P = 0.56). Like findings were encountered for Hispanic patients. Hispanic patients were 55% to three-times more likely to receive surgery from a low-volume surgeon depending on the procedure and 28% to 56% more likely to be treated at a low-volume hospital. African Americans were 34% to 82% more likely to receive surgery from a low-volume surgeon depending on the procedure and 10% to 17% more likely to be treated at a low-volume hospital.

CONCLUSION

The results of this work identify the phenomenon of racial and ethnic healthcare segregation among low-volume providers for lumbar spine procedures in the State of Florida. This may be a contributing factor to the increased risk of adverse events after spine surgery known to exist among minorities.

LEVEL OF EVIDENCE

3.

Impact on patient management of the implementation of a magnetic resonance imaging dedicated to neurological emergencies

RATIONALE, AIMS AND OBJECTIVES

Neurological emergencies consumed a high amount of resources in emergency department (ED). We aimed to study the effect of the implementation of a magnetic resonance imaging (MRI) dedicated to emergencies on the management of patients admitted in ED for neurological emergencies.

METHODS

We enrolled consecutive patients who underwent computed tomography and/or MRI for neurological disorders categorized as the suspicion of stroke and other reasons, over 2 periods that differed according to the priority access to computed tomography in the first period versus priority access to MRI in the second one. Criteria used to evaluate the effectiveness of the management were door-to-imaging time, ED length of stay, diagnostic performance, patient orientation, and length of hospitalization stay.

RESULTS

When priority access to MRI, the door-to-imaging time was 31 minutes longer (P = .005) for patients suspected of stroke or transient ischaemic attack (TIA) and 70 minutes for the others (P < .001). The ED length of stay was 42 minutes shorter (P = .013) for stroke/TIA patients and 26 minutes longer (P = .029) for other patients. The proportion of patients with stroke mimics (no stroke amongst suspected stroke/TIA) increased (16.7% vs 25.6%, P = .017) as well as discharged patients (21.6% vs 29.6%, P = .002). The proportion of patients with stroke/TIA amongst other reasons of admission remained unchanged (P = .114). The median length of hospitalization stay decreased from 9 to 7 days for the stroke/TIA patients (P = .042).

CONCLUSIONS

The implementation of a MRI optimized the quality of care and diagnostic accuracy for patients admitted in ED with a better identification of stroke mimics, avoiding unnecessarily hospitalizations. The management of stroke-TIA patients was not modified, but their length of hospital stay reduced.

Dual-Energy CT in Emergency Neuroimaging: Added Value and Novel Applications

Dual-energy computed tomography (CT) is a powerful diagnostic tool that is becoming more widely clinically available. Dual-energy CT has the potential to aid in the detection or add diagnostic confidence in the evaluation of a variety of emergent neurologic conditions with use of postprocessing techniques that allow one to take advantage of the different x-ray energy-dependent absorption behaviors of different materials. Differentiating iodine from hemorrhage may help in delineating CT angiographic spot signs, which are small foci of intracranial hemorrhage seen on CT angiograms in cases of acute hemorrhage. Bone subtraction can be used to effectively exclude osseous structures surrounding enhancing vessels at imaging for improved vessel visualization and to create images that are similar in appearance to three-dimensional magnetic resonance imaging vessel reconstructions. Bone subtraction may also be helpful for improving the conspicuity of small extra-axial fluid collections and extra-axial masses. Material characterization can be helpful for clarifying whether small foci of intermediate attenuation represent hemorrhage, calcification, or a foreign material, and it may also be useful for quantifying the amount of hemorrhage or iodine in preexisting or incidentally detected lesions. Virtual monochromatic imaging also can be used to problem solve in challenging cases. ^©RSNA, 2016.

Diagnosis of DWI-negative acute ischemic stroke: A meta-analysis

OBJECTIVE

To determine the prevalence of diffusion-weighted imaging (DWI)-negative acute ischemic stroke (AIS) and to identify clinical characteristics of patients with DWI-negative AIS.

METHODS

We systematically searched PubMed and Ovid/MEDLINE for relevant studies between 1992, the year that the DWI sequence entered clinical practice, and 2016. Studies were included based upon enrollment of consecutive patients presenting with a clinical diagnosis of AIS prior to imaging. Meta-analysis was performed to synthesize study-level data, estimate DWI-negative stroke prevalence, and estimate the odds ratios (ORs) for clinical characteristics associated with DWI-negative stroke.

RESULTS

Twelve articles including 3,236 AIS patients were included. The meta-analytic synthesis yielded a pooled prevalence of DWI-negative AIS of 6.8%, 95% confidence interval (CI) 4.9-9.3. In the 5 studies that reported proportion data for DWI-negative and DWI-positive AIS based on the ischemic vascular territory (n = 1,023 AIS patients), DWI-negative stroke was strongly associated with posterior circulation ischemia, as determined by clinical diagnosis at hospital discharge or repeat imaging (OR 5.1, 95% CI 2.3-11.6, p < 0.001).

CONCLUSIONS

A small but significant percentage of patients with AIS have a negative DWI scan. Patients with neurologic deficits consistent with posterior circulation ischemia have 5 times the odds of having a negative DWI scan compared to patients with anterior circulation ischemia. AIS remains a clinical diagnosis and urgent reperfusion therapy should be considered even when an initial DWI scan is negative.

The impact of installing an MR scanner in the emergency department for patients presenting with acute stroke-like symptoms

PURPOSE

We examined the impact of an MR scanner in the emergency department (ED) on ED length of stay (LOS), hospital (H) LOS, hospital admission rate, hospitalization costs, and ED re-presentation rate of patients presenting with stroke-like symptoms (SLS). We hypothesized that the ED MR would increase efficiency of patient care.

METHODS

The number of MRIs performed in the ED vs. inpatient setting, EDLOS, HLOS, hospitalization charges, admission rate, discharge diagnoses, and 30-60-day ED re-presentation rates were determined for ED patients with SLS six months before (2011) and after (2012) ED MR installation.

RESULTS

362 and 448 patients with SLS presented to the ED, and 196 and 176 patients were admitted in 2011 and 2012 respectively. In 2011, 36 (18.4%) admitted patients, and, in 2012, 68 (38.6%) had MRIs in the ED, p<0.001. In 2011, 74 (37.8%) admitted patients were diagnosed with ischemic stroke, compared to 92 (52.3%) in 2012, p=0.007. HLOS was longer and charges higher for patients with stroke. No patients returned with a confirmed diagnosis of CVA or TIA within 0-60days after being discharged from the ED with negative MR.

CONCLUSIONS

With the ED MR, more admitted patients 1) got scanned in the ED and 2) were diagnosed with stroke. Because this led to more patients on the stroke service actually suffering from strokes (and not other diagnoses), the overall HLOS and charges of patients presenting with SLS were not reduced by ED MR screening. Discharge after a negative ED MR did not incur risk of TIAs or strokes over the ensuing 60days. Therefore, not only does a dedicated MR scanner in the ED aid in the acute diagnosis of a CVA or other neurologic disorder, but it does so without the risk of under-diagnosing TIAs or evolving strokes in the presence of a negative MRI.

Have clinicians adopted the use of brain MRI for patients with TIA and minor stroke?

BACKGROUND

Use of MRI with diffusion-weighted imaging (DWI) can identify infarcts in 30%-50% of patients with TIA. Previous guidelines have indicated that MRI-DWI is the preferred imaging modality for patients with TIA. We assessed the frequency of MRI utilization and predictors of MRI performance.

METHODS

A review of TIA and minor stroke patients evaluated at Veterans Affairs hospitals was conducted with regard to medical history, use of diagnostic imaging within 2 days of presentation, and in-hospital care variables. Chart abstraction was performed in a subset of hospitals to assess clinical variables not available in the administrative data.

RESULTS

A total of 7,889 patients with TIA/minor stroke were included. Overall, 6,694 patients (84.9%) had CT or MRI, with 3,396/6,694 (50.7%) having MRI. Variables that were associated with increased odds of CT performance were age >80 years, prior stroke, history of atrial fibrillation, heart failure, coronary artery disease, anxiety, and low hospital complexity, while blood pressure >140/90 mm Hg and high hospital complexity were associated with increased likelihood of MRI. Diplopia (87% had MRI, p = 0.03), neurologic consultation on the day of presentation (73% had MRI, p < 0.0001), and symptom duration of >6 hours (74% had MRI, p = 0.0009) were associated with MRI performance.

CONCLUSIONS

Within a national health system, about 40% of patients with TIA/minor stroke had MRI performed within 2 days. Performance of MRI appeared to be influenced by several patient and facility-level variables, suggesting that there has been partial acceptance of the previous guideline that endorsed MRI for patients with TIA.

Trends in Transient Ischemic Attack Hospitalizations in the United States

Background

Transient ischemic attack (TIA) is a major predictor of subsequent stroke. No study has assessed nation‐wide trends in hospitalization for TIA in the United States.

Methods and Results

Temporal trends in hospitalization for TIA (International Classification of Diseases, Ninth Revision code 435.0–435.9) from 2000 to 2010 were assessed among adults aged ≥25 years using the Nationwide Inpatient Sample. Age‐, sex‐, and race/ethnic‐specific TIA hospitalization rates were calculated using the weighted number of hospitalizations as the numerator and the US population as the denominator. Age‐adjusted rates were standardized to the 2000 US Census population. From 2000 to 2010, age‐adjusted TIA hospitalization rates decreased from 118 to 83 per 100 000 (overall rate reduction, −29.7%). Age‐specific TIA hospitalization rates increased for individuals aged 24 to 44 years (10–11 per 100 000), but decreased for individuals aged 45 to 64 (74 to 65 per 100 000), 65 to 84 (398 to 245 per 100 000), and ≥85 years (900 to 619 per 100 000). Blacks had the highest age‐adjusted yearly hospitalization rates, followed by Hispanics and whites (124, 82, and 67 per 100 000 in 2010). Rates slightly increased for blacks, but decreased for Hispanics and whites. Compared to women, age‐adjusted TIA hospitalization rates were lower and declined more steeply in men (132 to 89 per 100 000 versus 134 to 97 per 100 000).

Conclusions

Although overall TIA hospitalizations have decreased in the United States, the reduction has been more pronounced among older individuals, men, whites, and Hispanics. These findings highlight the need to target risk‐factor control among women, blacks, and individuals aged <45 years.

Temporal Trends in the Use of Investigations After Stroke or Transient Ischemic Attack

BACKGROUND

Guidelines recommend that patients with stroke or transient ischemic attack (TIA) undergo neuroimaging and cardiac investigations to determine etiology and guide treatment. It is not known how the use of these investigations has changed over time and whether there have been associated changes in management.

OBJECTIVES

To evaluate temporal trends in the use of brain and vascular imaging, echocardiography, and antithrombotic and surgical therapy after stroke or TIA.

RESEARCH DESIGN

We analyzed 42,738 patients with stroke or TIA presenting to any of the 11 regional stroke centers in Ontario, Canada between 2003 and 2012 using the Ontario Stroke Registry database. The study period was divided into 1-year intervals and we used the Cochran-Armitage test to determine trends over time.

RESULTS

Between 2003/2004 and 2011/2012, the proportion of patients undergoing brain imaging increased from 96% to 99%, as did the proportion receiving ≥3 brain scans (21%-39%), magnetic resonance imaging (13%-50%), vascular imaging (62%-88%), or echocardiography (52%-70%) (P<0.0001 for all comparisons). There was an increase in the proportion receiving any antithrombotic therapy (83%-91%, P<0.0001) but no change in use of anticoagulation (25% overall and 68% in subgroup with atrial fibrillation) or carotid revascularization (1.4%-1.5%, P=0.49).

CONCLUSIONS

The use of investigations after stroke has increased over time without concomitant changes in medical or surgical management. Although initial neurovascular imaging is in accordance with practice guidelines, the use of multiple imaging procedures and routine echocardiography are of uncertain clinical effectiveness.

Adaptation of neurological practice and policy to a changing US health-care landscape

Health care in the USA is undergoing a drastic transformation under the Patient Protection and Affordable Care Act. The Patient Protection and Affordable Care Act is driving major health-care policy changes by connecting payment for traditional health-care services to value-based care initiatives and emphasising population health and innovative mechanisms to deliver care. Under the Patient Protection and Affordable Care Act, neurological practice will need to adapt and transform. Therefore, neurological policy should consider employing a new framework for neurological residency training, developing interdisciplinary team approaches to neurological subspecialty care, and strengthening the primary care-neurological specialty care interface to avoid redundancies and other medical waste. Additionally, neurological policy will need to support a more robust review of diagnostic and care pathway use to reduce avoidable expenditures, and test and implement bundled payments for key neurological diagnoses. In view of an anticipated 19% shortage of US neurologists in the next 10 years, development of new neurological policy under the Patient Protection and Affordable Care Act is paramount.