Neurocritical Care for Patients With Ischemic Stroke.

OBJECTIVE: Management of stroke due to large vessel occlusion (LVO) has undergone unprecedented change in the past decade. Effective treatment with thrombectomy has galvanized the field and led to advancements in all aspects of care. This article provides a comprehensive examination of neurologic intensive care unit (ICU) management of patients with stroke due to LVO. The role of the neurocritical care team in stroke systems of care and the importance of prompt diagnosis, initiation of treatment, and continued monitoring of patients with stroke due to LVO is highlighted. LATEST DEVELOPMENTS: The management of complications commonly associated with stroke due to LVO, including malignant cerebral edema and respiratory failure, are addressed, stressing the importance of early identification and aggressive treatment in mitigating negative effects on patients' prognoses. In the realm of medical management, this article discusses various medical therapies, including antithrombotic therapy, blood pressure management, and glucose control, outlining evidence-based strategies for optimizing patient outcomes. It further emphasizes the importance of a multidisciplinary approach to provide a comprehensive care model. Lastly, the critical aspect of family communication and prognostication in the neurologic ICU is addressed. ESSENTIAL POINTS: This article emphasizes the multidimensional aspects of neurocritical care in treating patients with stroke due to LVO.

Severity of Chest Imaging is Correlated with Risk of Acute Neuroimaging Findings among Patients with COVID-19.

BACKGROUND AND PURPOSE: Severe respiratory distress in patients with COVID-19 has been associated with higher rate of neurologic manifestations. Our aim was to investigate whether the severity of chest imaging findings among patients with coronavirus disease 2019 (COVID-19) correlates with the risk of acute neuroimaging findings. MATERIALS AND METHODS: This retrospective study included all patients with COVID-19 who received care at our hospital between March 3, 2020, and May 6, 2020, and underwent chest imaging within 10 days of neuroimaging. Chest radiographs were assessed using a previously validated automated neural network algorithm for COVID-19 (Pulmonary X-ray Severity score). Chest CTs were graded using a Chest CT Severity scoring system based on involvement of each lobe. Associations between chest imaging severity scores and acute neuroimaging findings were assessed using multivariable logistic regression. RESULTS: Twenty-four of 93 patients (26%) included in the study had positive acute neuroimaging findings, including intracranial hemorrhage (n = 7), infarction (n = 7), leukoencephalopathy (n = 6), or a combination of findings (n = 4). The average length of hospitalization, prevalence of intensive care unit admission, and proportion of patients requiring intubation were significantly greater in patients with acute neuroimaging findings than in patients without them (P < .05 for all). Compared with patients without acute neuroimaging findings, patients with acute neuroimaging findings had significantly higher mean Pulmonary X-ray Severity scores (5.0 [SD, 2.9] versus 9.2 [SD, 3.4], P < .001) and mean Chest CT Severity scores (9.0 [SD, 5.1] versus 12.1 [SD, 5.0], P = .041). The pulmonary x-ray severity score was a significant predictor of acute neuroimaging findings in patients with COVID-19. CONCLUSIONS: Patients with COVID-19 and acute neuroimaging findings had more severe findings on chest imaging on both radiographs and CT compared with patients with COVID-19 without acute neuroimaging findings. The severity of findings on chest radiography was a strong predictor of acute neuroimaging findings in patients with COVID-19.

CTA Protocols in a Telestroke Network Improve Efficiency for Both Spoke and Hub Hospitals.

BACKGROUND AND PURPOSE: Telestroke networks support screening for patients with emergent large-vessel occlusions who are eligible for endovascular thrombectomy. Ideal triage processes within telestroke networks remain uncertain. We characterize the impact of implementing a routine spoke hospital CTA protocol in our integrated telestroke network on transfer and thrombectomy patterns. MATERIALS AND METHODS: A protocol-driven CTA process was introduced at 22 spoke hospitals in November 2017. We retrospectively identified prospectively collected patients who presented to a spoke hospital with National Institutes of Health Stroke Scale scores ≥6 between March 1, 2016 and March 1, 2017 (pre-CTA), and March 1, 2018 and March 1, 2019 (post-CTA). We describe the demographics, CTA utilization, spoke hospital retention rates, emergent large-vessel occlusion identification, and rates of endovascular thrombectomy. RESULTS: There were 167 patients pre-CTA and 207 post-CTA. The rate of CTA at spoke hospitals increased from 15% to 70% (P < .001). Despite increased endovascular thrombectomy screening in the extended window, the overall rates of transfer out of spoke hospitals remained similar (56% versus 54%; P = .83). There was a nonsignificant increase in transfers to our hub hospital for endovascular thrombectomy (26% versus 35%; P = .12), but patients transferred >4.5 hours from last known well increased nearly 5-fold (7% versus 34%; P < .001). The rate of endovascular thrombectomy performed on patients transferred for possible endovascular thrombectomy more than doubled (22% versus 47%; P = .011). CONCLUSIONS: Implementation of CTA at spoke hospitals in our telestroke network was feasible and improved the efficiency of stroke triage. Rates of patients retained at spoke hospitals remained stable despite higher numbers of patients screened. Emergent large-vessel occlusion confirmation at the spoke hospital lead to a more than 2-fold increase in thrombectomy rates among transferred patients at the hub.

Analysis of Stroke Detection during the COVID-19 Pandemic Using Natural Language Processing of Radiology Reports.

BACKGROUND AND PURPOSE: The coronavirus disease 2019 (COVID-19) pandemic has led to decreases in neuroimaging volume. Our aim was to quantify the change in acute or subacute ischemic strokes detected on CT or MR imaging during the pandemic using natural language processing of radiology reports. MATERIALS AND METHODS: We retrospectively analyzed 32,555 radiology reports from brain CTs and MRIs from a comprehensive stroke center, performed from March 1 to April 30 each year from 2017 to 2020, involving 20,414 unique patients. To detect acute or subacute ischemic stroke in free-text reports, we trained a random forest natural language processing classifier using 1987 randomly sampled radiology reports with manual annotation. Natural language processing classifier generalizability was evaluated using 1974 imaging reports from an external dataset. RESULTS: The natural language processing classifier achieved a 5-fold cross-validation classification accuracy of 0.97 and an F1 score of 0.74, with a slight underestimation (-5%) of actual numbers of acute or subacute ischemic strokes in cross-validation. Importantly, cross-validation performance stratified by year was similar. Applying the classifier to the complete study cohort, we found an estimated 24% decrease in patients with acute or subacute ischemic strokes reported on CT or MR imaging from March to April 2020 compared with the average from those months in 2017-2019. Among patients with stroke-related order indications, the estimated proportion who underwent neuroimaging with acute or subacute ischemic stroke detection significantly increased from 16% during 2017-2019 to 21% in 2020 (P = .01). The natural language processing classifier performed worse on external data. CONCLUSIONS: Acute or subacute ischemic stroke cases detected by neuroimaging decreased during the COVID-19 pandemic, though a higher proportion of studies ordered for stroke were positive for acute or subacute ischemic strokes. Natural language processing approaches can help automatically track acute or subacute ischemic stroke numbers for epidemiologic studies, though local classifier training is important due to radiologist reporting style differences.

Clinical and Neuroimaging Correlation in Patients with COVID-19.

BACKGROUND AND PURPOSE: Coronavirus disease 2019 (COVID-19) is increasingly being recognized for its multiorgan involvement, including various neurological manifestations. We examined the frequency of acute intracranial abnormalities seen on CT and/or MR imaging in patients with COVID-19 and investigated possible associations between these findings and clinical parameters, including length of hospital stay, requirement for intubation, and development of acute kidney injury. MATERIALS AND METHODS: This was a retrospective study performed at a large academic hospital in the United States. A total of 641 patients presented to our institution between March 3, 2020, and May 6, 2020, for treatment of coronavirus disease 2019, of whom, 150 underwent CT and/or MR imaging of the brain. CT and/or MR imaging examinations were evaluated for the presence of hemorrhage, infarction, and leukoencephalopathy. The frequency of these findings was correlated with clinical variables, including body mass index, length of hospital stay, requirement for intubation, and development of acute kidney injury as documented in the electronic medical record. RESULTS: Of the 150 patients, 26 (17%) had abnormal CT and/or MR imaging findings, with hemorrhage in 11 of the patients (42%), infarction in 13 of the patients (50%), and leukoencephalopathy in 7 of the patients (27%). Significant associations were seen between abnormal CT/MR imaging findings and intensive care unit admission (P = .039), intubation (P = .004), and acute kidney injury (P = .030). CONCLUSIONS: A spectrum of acute neuroimaging abnormalities was seen in our cohort of patients with coronavirus disease 2019, including hemorrhage, infarction, and leukoencephalopathy. Significant associations between abnormal neuroimaging studies and markers of disease severity (intensive care unit admission, intubation, and acute kidney injury) suggest that patients with severe forms of coronavirus disease 2019 may have higher rates of neuroimaging abnormalities.

Leukoencephalopathy Associated with Severe COVID-19 Infection: Sequela of Hypoxemia?

There is increasing evidence to suggest that complications of coronavirus disease 2019 (COVID-19) infection are not only limited to the pulmonary system but can also involve the central nervous system. Here, we report 6 critically ill patients with COVID-19 infection and neuroimaging findings of leukoencephalopathy. While these findings are nonspecific, we postulate that they may be a delayed response to the profound hypoxemia the patients experienced due to the infection. No abnormal enhancement, hemorrhage, or perfusion abnormalities were noted on MR imaging. In addition, Severe Acute Respiratory Syndrome coronavirus 2 was not detected in the CSF collected from the 2 patients who underwent lumbar puncture. Recognition of COVID-19-related leukoencephalopathy is important for appropriate clinical management, disposition, and prognosis.

Preserving Access: A Review of Stroke Thrombectomy during the COVID-19 Pandemic.

Thrombectomy for large-vessel-occlusion stroke is a highly impactful treatment. The spread of coronavirus 19 (COVID-19) across the United States and the globe impacts access to this crucial intervention through widespread societal and institutional changes. In this document, we review the implications of COVID-19 on the emergency care of large-vessel occlusion stroke, reviewing specific infection-control recommendations, available literature, existing resources, and expert consensus. As a population, patients with large-vessel occlusion stroke face unique challenges during pandemics. These are broad in scope. Responses to these challenges through adaptation of stroke systems of care and with imaging, thrombectomy, and postprocedural care are detailed. Preservation of access to thrombectomy must be prioritized for its public health impact. While the extent of required changes will vary by region, tiered planning for both escalation and de-escalation of measures must be a part of each practice. In addition, preparations described serve as templates in the event of future pandemics.

Telestroke-the promise and the challenge. Part one: growth and current practice.

Acute ischemic stroke remains a major public health concern, with low national treatment rates for the condition, demonstrating a disconnection between the evidence of treatment benefit and delivery of this treatment. Intravenous thrombolysis and endovascular thrombectomy are both strongly evidence supported and exquisitely time sensitive therapies. The mismatch between the distribution and incidence of stroke presentations and the availability of specialist care significantly affects access to care. Telestroke, the use of telemedicine for stroke, aims to surmount this hurdle by distributing stroke expertise more effectively, through video consultation with and examination of patients in locations removed from specialist care. This is the first of a detailed two part review, and explores the growth and current practice of telestroke, including the specific role it plays in the assessment and management of patients after emergent large vessel occlusion.

Telestroke-the promise and the challenge. Part two-expansion and horizons.

Acute ischemic stroke remains a major public health concern, with low national treatment rates for the condition, demonstrating a disconnection between the evidence of treatment benefit and delivery of this treatment. Intravenous thrombolysis and endovascular thrombectomy are both strongly evidence supported and exquisitely time sensitive therapies. The mismatch between the distribution and incidence of stroke presentations and the availability of specialist care significantly affects access to care. Telestroke, the use of telemedicine for stroke, aims to surmount this hurdle by distributing stroke expertise more effectively, through video consultation with and examination of patients in locations removed from specialist care. This is the second of a two part review, and is focused on the challenges telestroke faces for wider adoption. It further details the anticipated evolution of this novel therapeutic platform, and the potential roles it holds in stroke prevention, ambulance based care, rehabilitation, and research.

Current Procedural Terminology: History, Structure, and Relationship to Valuation for the Neuroradiologist.

The year 1965 was critical for US health care policy. In that year, Medicare was created as part of the Social Security Act under President Lyndon B. Johnson after several earlier attempts by Presidents Franklin Roosevelt and Harry Truman. In 1966, the American Medical Association first published a set of standard terms and descriptors to document medical procedures, known as Current Procedural Terminology, or CPT. Fifty years later, though providers have certainly heard the term "CPT code," most would benefit from an enhanced understanding of the historical basis, current structure, and relationship to valuation of Current Procedural Terminology. This article will highlight this evolution, particularly as it relates to neuroradiology.

Cerebral Angiography for Evaluation of Patients with CT Angiogram-Negative Subarachnoid Hemorrhage: An 11-Year Experience.

BACKGROUND AND PURPOSE: CT angiography is increasingly used to evaluate patients with nontraumatic subarachnoid hemorrhage given its high sensitivity for aneurysms. We investigated the yield of digital subtraction angiography among patients with SAH or intraventricular hemorrhage and a negative CTA. MATERIALS AND METHODS: An 11-year, single-center retrospective review of all consecutive patients with CTA-negative SAH was performed. Noncontrast head CT, CTA, DSA, and MR imaging studies were reviewed by 2 experienced interventional neuroradiologists and 1 neuroradiologist. RESULTS: Two hundred thirty patients (mean age, 54 years; 51% male) with CTA-negative SAH were identified. The pattern of SAH was diffuse (40%), perimesencephalic (31%), sulcal (31%), isolated IVH (6%), or identified by xanthochromia (7%). Initial DSA yield was 13%, including vasculitis/vasculopathy (7%), aneurysm (5%), arteriovenous malformation (0.5%), and dural arteriovenous fistula (0.5%). An additional 6 aneurysms/pseudoaneurysms (4%) were identified by follow-up DSA, and a single cavernous malformation (0.4%) was identified by MRI. No cause of hemorrhage was identified in any patient presenting with isolated intraventricular hemorrhage or xanthochromia. Diffuse SAH was due to aneurysm rupture (17%); perimesencephalic SAH was due to aneurysm rupture (3%) or vasculitis/vasculopathy (1.5%); and sulcal SAH was due to vasculitis/vasculopathy (32%), arteriovenous malformation (3%), or dural arteriovenous fistula (3%). CONCLUSIONS: DSA identifies vascular pathology in 13% of patients with CTA-negative SAH. Aneurysms or pseudoaneurysms are identified in an additional 4% of patients by repeat DSA following an initially negative DSA. All patients with CT-negative SAH should be considered for DSA. The pattern of SAH may suggest the cause of hemorrhage, and aneurysms should specifically be sought with diffuse or perimesencephalic SAH.

Application of a Novel Brain Arteriovenous Malformation Endovascular Grading Scale for Transarterial Embolization.

BACKGROUND AND PURPOSE: The advent of modern neuroendovascular techniques has highlighted the need for a simple, effective, and reliable brain arteriovenous malformation endovascular grading scale. A novel scale of this type has recently been described. It incorporates the number of feeding arteries, eloquence, and the presence of an arteriovenous fistula component. Our aim is to assess the validity of this grading scale. MATERIALS AND METHODS: We retrospectively reviewed all suspected brain arteriovenous malformations at Massachusetts General Hospital from 2005 to 2013, identifying 126 patients who met the inclusion criteria. Spearman correlations between endovascular and Spetzler-Martin grading scales and long-term outcomes were performed. Median endovascular grades were compared between treatment modalities and endovascular outcomes. Binary regression analysis was performed with major endovascular complications as a dichotomized dependent variable. Intraclass correlation coefficients were calculated for interobserver reliability of the endovascular grading scale. RESULTS: A significant Spearman correlation between the endovascular grade and the Spetzler-Martin grade was demonstrated (ρ = 0.5, P < .01). Differences in the median endovascular grades between the endovascular cure (median = 2) and endovascular complication groups (median = 4) (P < .05) and between the endovascular cure and successful multimodal treatment groups (median = 3) (P < .05) were demonstrated. The endovascular grade was the only independent predictor of complications (OR = 0.5, P < .01). The intraclass correlation coefficient of the endovascular grade was 0.71 (P < .01). CONCLUSIONS: Validation of a brain arteriovenous malformation endovascular grading scale demonstrated that endovascular grades of ≤II were associated with endovascular cure, while endovascular grades of ≤III were associated with multimodal cure or significant lesion reduction and favorable outcome. The endovascular grade provides useful information to refine risk stratification for endovascular and multimodal treatment.

Combining MRI with NIHSS thresholds to predict outcome in acute ischemic stroke: value for patient selection.

BACKGROUND AND PURPOSE: Selecting acute ischemic stroke patients for reperfusion therapy on the basis of a diffusion-perfusion mismatch has not been uniformly proved to predict a beneficial treatment response. In a prior study, we have shown that combining clinical with MR imaging thresholds can predict clinical outcome with high positive predictive value. In this study, we sought to validate this predictive model in a larger patient cohort and evaluate the effects of reperfusion therapy and stroke side. MATERIALS AND METHODS: One hundred twenty-three consecutive patients with anterior circulation acute ischemic stroke underwent MR imaging within 6 hours of stroke onset. DWI and PWI volumes were measured. Lesion volume and NIHSS score thresholds were used in models predicting good 3-month clinical outcome (mRS 0-2). Patients were stratified by treatment and stroke side. RESULTS: Receiver operating characteristic analysis demonstrated 95.6% and 100% specificity for DWI > 70 mL and NIHSS score > 20 to predict poor outcome, and 92.7% and 91.3% specificity for PWI (mean transit time) < 50 mL and NIHSS score < 8 to predict good outcome. Combining clinical and imaging thresholds led to an 88.8% (71/80) positive predictive value with a 65.0% (80/123) prognostic yield. One hundred percent specific thresholds for DWI (103 versus 31 mL) and NIHSS score (20 versus 17) to predict poor outcome were significantly higher in treated (intravenous and/or intra-arterial) versus untreated patients. Prognostic yield was lower in right- versus left-sided strokes for all thresholds (10.4%-20.7% versus 16.9%-40.0%). Patients with right-sided strokes had higher 100% specific DWI (103.1 versus 74.8 mL) thresholds for poor outcome, and the positive predictive value was lower. CONCLUSIONS: Our predictive model is validated in a much larger patient cohort. Outcome may be predicted in up to two-thirds of patients, and thresholds are affected by stroke side and reperfusion therapy.

Safety and effectiveness of sacroplasty: a large single-center experience.

BACKGROUND AND PURPOSE: Sacral insufficiency fractures are a common cause of severe low back pain and immobilization in patients with osteoporosis or cancer. Current practice guideline recommendations range from analgesia and physical therapy to resection with surgical fixation. We sought to assess the safety and effectiveness of sacroplasty, an emerging minimally invasive treatment. MATERIALS AND METHODS: We performed a retrospective review of institutional databases for percutaneous sacroplasty performed between January 2004 and September 2013. Demographic and procedural data and pre- and posttreatment Visual Analog Scale, Functional Mobility Scale, and Analgesic Scale scores were reviewed. Overall response was rated by using a 4-point scale (1, complete resolution of pain; 2, improvement of pain; 3, no change; 4, worsened pain) assessed at short-term follow-up. RESULTS: Fifty-three patients were included; most (83%) were female. Fracture etiology was cancer-related (55%), osteoporotic insufficiency (30%), and minor trauma (15%). No major complication or procedure-related morbidity occurred. There were statistically significant decreases in the Visual Analog Scale (P < .001), Functional Mobility Scale (P < .001), and Analgesic Scale scores (P < .01) in 27 patients with recorded data: pretreatment Visual Analog Scale (median [interquartile range], 9.0 [8.0-10.0]); Functional Mobility Scale, 3.0 (2.0-3.0); and Analgesic Scale scores, 3.0 (3.0-4.0) were reduced to 3.0 (0.0-5.8), 1.0 (0.25-2.8), and 3.0 (2.0-3.8) posttreatment. When we used the overall 4-point score at a mean of 27 days, 93% (n = 45) reported complete resolution or improvement in overall pain. CONCLUSIONS: In this single-center cohort, sacroplasty was a safe and effective procedure. There were significant short-term gains in pain relief, increased mobility, and decreased dependence on pain medication.

Transarterial onyx embolization of cranial dural arteriovenous fistulas: long-term follow-up.

BACKGROUND AND PURPOSE: Endovascular therapy with liquid embolic agents is a common treatment strategy for cranial dural arteriovenous fistulas. This study evaluated the long-term effectiveness of transarterial Onyx as the single embolic agent for curative embolization of noncavernous cranial dural arteriovenous fistulas. MATERIALS AND METHODS: We performed a retrospective review of 40 consecutive patients with 41 cranial dural arteriovenous fistulas treated between March 2006 and June 2012 by using transarterial Onyx embolization with intent to cure. The mean age was 57 years; one-third presented with intracranial hemorrhage. Most (85%) had cortical venous drainage. Once angiographic cure was achieved, long-term treatment effectiveness was assessed with DSA and clinical follow-up. RESULTS: Forty-nine embolization sessions were performed; 85% of cranial dural arteriovenous fistulas were treated in a single session. The immediate angiographic cure rate was 95%. The permanent neurologic complication rate was 2% (mild facial palsy). Thirty-five of the 38 patients with initial cure underwent short-term follow-up DSA (median, 4 months). The short-term recurrence rate was only 6% (2/35). All patients with occlusion at short-term DSA undergoing long-term DSA (median, 28 months) had durable occlusion. No patient with long-term clinical follow-up (total, 117 patient-years; median, 45 months) experienced hemorrhage. CONCLUSIONS: Transarterial embolization with Onyx as the single embolic agent results in durable long-term cure of noncavernous cranial dural arteriovenous fistulas. Recurrence rates are low on short-term follow-up, and all patients with angiographic occlusion on short-term DSA follow-up have experienced a durable long-term cure. Thus, angiographic cure should be defined at short-term follow-up angiography instead of at the end of the final embolization session. Finally, long-term DSA follow-up may not be necessary if occlusion is demonstrated on short-term angiographic follow-up.