International controlled study of revascularization and outcomes following COVID-positive mechanical thrombectomy.

BACKGROUND AND PURPOSE: Previous studies suggest that mechanisms and outcomes in patients with COVID-19-associated stroke differ from those in patients with non-COVID-19-associated strokes, but there is limited comparative evidence focusing on these populations. The aim of this study, therefore, was to determine if a significant association exists between COVID-19 status with revascularization and functional outcomes following thrombectomy for large vessel occlusion (LVO), after adjustment for potential confounding factors. METHODS: A cross-sectional, international multicenter retrospective study was conducted in consecutively admitted COVID-19 patients with concomitant acute LVO, compared to a control group without COVID-19. Data collected included age, gender, comorbidities, clinical characteristics, details of the involved vessels, procedural technique, and various outcomes. A multivariable-adjusted analysis was conducted. RESULTS: In this cohort of 697 patients with acute LVO, 302 had COVID-19 while 395 patients did not. There was a significant difference (p < 0.001) in the mean age (in years) and gender of patients, with younger patients and more males in the COVID-19 group. In terms of favorable revascularization (modified Thrombolysis in Cerebral Infarction [mTICI] grade 3), COVID-19 was associated with lower odds of complete revascularization (odds ratio 0.33, 95% confidence interval [CI] 0.23-0.48; p < 0.001), which persisted on multivariable modeling with adjustment for other predictors (adjusted odds ratio 0.30, 95% CI 0.12-0.77; p = 0.012). Moreover, endovascular complications, in-hospital mortality, and length of hospital stay were significantly higher among COVID-19 patients (p < 0.001). CONCLUSION: COVID-19 was an independent predictor of incomplete revascularization and poor functional outcome in patients with stroke due to LVO. Furthermore, COVID-19 patients with LVO were more often younger and had higher morbidity/mortality rates.

Characteristics of a COVID-19 Cohort With Large Vessel Occlusion: A Multicenter International Study.

BACKGROUND: The mechanisms and outcomes in coronavirus disease (COVID-19)-associated stroke are unique from those of non-COVID-19 stroke. OBJECTIVE: To describe the efficacy and outcomes of acute revascularization of large vessel occlusion (LVO) in the setting of COVID-19 in an international cohort. METHODS: We conducted an international multicenter retrospective study of consecutively admitted patients with COVID-19 with concomitant acute LVO across 50 comprehensive stroke centers. Our control group constituted historical controls of patients presenting with LVO and receiving a mechanical thrombectomy between January 2018 and December 2020. RESULTS: The total cohort was 575 patients with acute LVO; 194 patients had COVID-19 while 381 patients did not. Patients in the COVID-19 group were younger (62.5 vs 71.2; P < .001) and lacked vascular risk factors (49, 25.3% vs 54, 14.2%; P = .001). Modified thrombolysis in cerebral infarction 3 revascularization was less common in the COVID-19 group (74, 39.2% vs 252, 67.2%; P < .001). Poor functional outcome at discharge (defined as modified Ranklin Scale 3-6) was more common in the COVID-19 group (150, 79.8% vs 132, 66.7%; P = .004). COVID-19 was independently associated with a lower likelihood of achieving modified thrombolysis in cerebral infarction 3 (odds ratio [OR]: 0.4, 95% CI: 0.2-0.7; P < .001) and unfavorable outcomes (OR: 2.5, 95% CI: 1.4-4.5; P = .002). CONCLUSION: COVID-19 was an independent predictor of incomplete revascularization and poor outcomes in patients with stroke due to LVO. Patients with COVID-19 with LVO were younger, had fewer cerebrovascular risk factors, and suffered from higher morbidity/mortality rates.

Acute ischaemic stroke associated with SARS-CoV-2 infection in North America.

BACKGROUND: To analyse the clinical characteristics of COVID-19 with acute ischaemic stroke (AIS) and identify factors predicting functional outcome. METHODS: Multicentre retrospective cohort study of COVID-19 patients with AIS who presented to 30 stroke centres in the USA and Canada between 14 March and 30 August 2020. The primary endpoint was poor functional outcome, defined as a modified Rankin Scale (mRS) of 5 or 6 at discharge. Secondary endpoints include favourable outcome (mRS ≤2) and mortality at discharge, ordinal mRS (shift analysis), symptomatic intracranial haemorrhage (sICH) and occurrence of in-hospital complications. RESULTS: A total of 216 COVID-19 patients with AIS were included. 68.1% (147/216) were older than 60 years, while 31.9% (69/216) were younger. Median [IQR] National Institutes of Health Stroke Scale (NIHSS) at presentation was 12.5 (15.8), and 44.2% (87/197) presented with large vessel occlusion (LVO). Approximately 51.3% (98/191) of the patients had poor outcomes with an observed mortality rate of 39.1% (81/207). Age >60 years (aOR: 5.11, 95% CI 2.08 to 12.56, p<0.001), diabetes mellitus (aOR: 2.66, 95% CI 1.16 to 6.09, p=0.021), higher NIHSS at admission (aOR: 1.08, 95% CI 1.02 to 1.14, p=0.006), LVO (aOR: 2.45, 95% CI 1.04 to 5.78, p=0.042), and higher NLR level (aOR: 1.06, 95% CI 1.01 to 1.11, p=0.028) were significantly associated with poor functional outcome. CONCLUSION: There is relationship between COVID-19-associated AIS and severe disability or death. We identified several factors which predict worse outcomes, and these outcomes were more frequent compared to global averages. We found that elevated neutrophil-to-lymphocyte ratio, rather than D-Dimer, predicted both morbidity and mortality.

Age and Acute Ischemic Stroke Outcome in North American Patients With COVID-19.

Background Acute ischemic stroke (AIS) in the context of COVID-19 has received considerable attention for its propensity to affect patients of all ages. We aimed to evaluate the effect of age on functional outcome and mortality following an acute ischemic event. Methods and Results A prospectively maintained database from comprehensive stroke centers in Canada and the United States was analyzed for patients with AIS from March 14 to September 30, 2020 who tested positive for SARS-CoV-2. The primary outcome was Modified Rankin Scale score at discharge, and the secondary outcome was mortality. Baseline characteristics, laboratory values, imaging, and thrombectomy workflow process times were assessed. Among all 126 patients with COVID-19 who were diagnosed with AIS, the median age was 63 years (range, 27-94). There were 35 (27.8%) patients with AIS in the aged ≤55 years group, 47 (37.3%) in the aged 56 to 70 group, and 44 (34.9%) in the aged >70 group. Intravenous tissue plasminogen activator and thrombectomy rates were comparable across these groups, (P=0.331 and 0.212, respectively). There was a significantly lower rate of mortality between each group favoring younger age (21.9% versus 45.0% versus 48.8%, P=0.047). After multivariable adjustment for possible confounders, a 1-year increase in age was significantly associated with fewer instances of a favorable outcome of Modified Rankin Scale 0 to 2 (odds ratio [OR], 0.95; 95 CI%, 0.90-0.99; P=0.048) and higher mortality (OR, 1.06; 95 CI%, 1.02-1.10; P=0.007). Conclusions AIS in the context of COVID-19 affects young patients at much greater rates than pre-pandemic controls. Nevertheless, instances of poor functional outcome and mortality are closely tied to increasing age.

Pre-Hospital Diagnosis in Mobile Stroke Unit.

OBJECTIVES: Mobile stroke unit (MSU) has been shown to rapidly provide pre-hospital thrombolysis in acute ischemic stroke (AIS). MSU encounters neurological disorders other than AIS that require emergent treatment. METHODS/MATERIALS: We obtained pre-hospital diagnosis and treatment data from the prospectively collected dataset on 221 consecutive MSU encounters. Based on initial clinical evaluation and neuroimaging obtained on MSU, the diagnosis of AIS (definite, probable, and possible AIS, transient ischemic attack), intracranial hemorrhage, and likely stroke mimics was made. RESULTS: From July 2014 to April 2015, 221 patients were treated on MSU. 78 (35%) patients had initial clinical diagnosis of definite/probable AIS or TIA, 69 (31%) were diagnosed as possible AIS or TIA, 15 (7%) had intracranial hemorrhage while 59 patients (27%) were diagnosed as likely stroke mimics. Stroke mimics encountered included 13 (6%) metabolic encephalopathy, 11 (5%) seizures, 9 (4%) migraines, 3 (1%) substance abuse, 2 (1%) CNS tumor, 3 (1%) infectious etiology and 3 (1%) hypoglycemia. Fifty-four (24%) patients received non-thrombolytic treatments on MSU CONCLUSION: About one third of MSU encounters were not AIS initially, including intracranial hemorrhage and stroke mimics. MSU can be utilized to provide pre-hospital treatments in emergent neurological conditions other than AIS.

Stroke risk, phenotypes, and death in COVID-19: Systematic review and newly reported cases.

OBJECTIVES: To investigate the hypothesis that strokes occurring in patients with coronavirus disease 2019 (COVID-19) have distinctive features, we investigated stroke risk, clinical phenotypes, and outcomes in this population. METHODS: We performed a systematic search resulting in 10 studies reporting stroke frequency among patients with COVID-19, which were pooled with 1 unpublished series from Canada. We applied random-effects meta-analyses to estimate the proportion of stroke among COVID-19. We performed an additional systematic search for cases series of stroke in patients with COVID-19 (n = 125), and we pooled these data with 35 unpublished cases from Canada, the United States, and Iran. We analyzed clinical characteristics and in-hospital mortality stratified into age groups (<50, 50-70, >70 years). We applied cluster analyses to identify specific clinical phenotypes and their relationship with death. RESULTS: The proportions of patients with COVID-19 with stroke (1.8%, 95% confidence interval [CI] 0.9%-3.7%) and in-hospital mortality (34.4%, 95% CI 27.2%-42.4%) were exceedingly high. Mortality was 67% lower in patients <50 years of age relative to those >70 years of age (odds ratio [OR] 0.33, 95% CI 0.12-0.94, p = 0.039). Large vessel occlusion was twice as frequent (46.9%) as previously reported and was high across all age groups, even in the absence of risk factors or comorbid conditions. A clinical phenotype characterized by older age, a higher burden of comorbid conditions, and severe COVID-19 respiratory symptoms was associated with the highest in-hospital mortality (58.6%) and a 3 times higher risk of death than the rest of the cohort (OR 3.52, 95% CI 1.53-8.09, p = 0.003). CONCLUSIONS: Stroke is relatively frequent among patients with COVID-19 and has devastating consequences across all ages. The interplay of older age, comorbid conditions, and severity of COVID-19 respiratory symptoms is associated with an extremely elevated mortality.

Integration of Real-Time Electronic Health Records and Wireless Technology in a Mobile Stroke Unit.

BACKGROUND: UCHealth's Mobile Stroke Unit (MSU) at University of Colorado Hospital is an ambulance equipped with a computed tomography (CT) scanner and tele-stroke capabilities that began clinical operation in Aurora, Colorado January 2016. As one of the first MSU's in the United States, it was necessary to design unique and dynamic information technology infrastructure. This includes high-speed cellular connectivity, Health Insurance Portability and Accountability Act compliance, cloud-based and remote access to electronic medical records (EMR), and reliable and rapid image transfer. Here we describe novel technologies incorporated into the MSU. Technological data-handling aspects of the MSU were reviewed. Functions evaluated include wireless connectivity while in transit, EMR access and manipulation in the field, CT with image transfer from the MSU to the hospital's Picture Archiving Communication System (PACS), and video and audio communication for neurological assessment. METHODS/RESULTS: The MSU wireless system was designed with redundancy to avoid dropped signals during data transfer. Two separate Internet Protocol destinations with split-tunnel architecture are assigned, for videoconferencing and for EMR data transfer. Brain images acquired in the ambulance CT scanner are transferred initially to an onboard laptop, then via Citrix Receiver to the hospital-based PACS server where they can be viewed in PACS or EMR by the stroke neurologist, neuroradiologist, and other providers. PACS and Radiology Information System are 2 of the XenApps utilized by CT technologists on board the MSU. DISCUSSION/CONCLUSIONS: These technologies will serve as a blueprint for development of similar units elsewhere, and as a framework for improvement in this technology.

Neuroterrorism Preparedness for the Neurohospitalist.

In this review article, we highlight several potential biologic and chemical agents of "neuroterrorism" of which neurohospitalists should be aware: anthrax, botulism toxin, brucella, plague, smallpox, organophosphates and nerve agents, cyanide, and carfentanil. Such agents may have direct neurologic effects, resulting in encephalopathy, paralysis, and/or respiratory failure. Neurohospitalists should be on the lookout for abnormal neurologic syndrome clustering, especially among patients presenting to the emergency department. If use of such a "neuroterrorism" agent is suspected, the neurohospitalist should immediately consult with emergency department personnel, infection control, infectious disease physicians, and/or Poison Control to make sure the scene is safe and to stabilize and isolate patients if necessary. The neurohospitalist should also immediately contact their local and/or state health department (or alternatively the US Centers for Disease Control and Prevention Emergency Operations Center) to report their suspicions and to obtain guidance and assistance.

Lacunar Stroke in Cryptococcal Meningitis: Clinical and Radiographic Features.

OBJECTIVE: Cryptococcal meningitis carries a high mortality, and survivors are left with considerable neurologic sequelae and marked disability. We lack a clear understanding of the pathogenesis of neurologic sequelae and description of stroke features in this population. We aim to describe clinical and radiographic features and predictors of stroke in a cohort of patients with cryptococcal meningitis. METHODS: We collected key information on patients diagnosed with cryptococcal meningitis at the University of Colorado Hospital between 2000 and 2018 (n = 42). Of those, 32 had neuroimaging studies available. Bivariate and risk ratio estimates regression models were performed to identify predictors of stroke. RESULTS: We found a 26% ischemic stroke complication rate in individuals with cryptococcal meningitis. Most strokes were acute (75%), lacunar (100%), multiple (88%), bilateral (63%), and involving the basal ganglia (75%). Presence of malignancy (38% versus 8%, P = .085) was higher in stroke in individuals with cryptococcal meningitis, although not statistically significant. Every unit decrease in hemoglobin and serum sodium were predictors for 1.35 and 1.14 times increase in the risk of ischemic stroke, respectively. The presence of hyponatremia carried a RR of 5.7 (95% confidence interval, 1.7-34, P = .005). Cryptococcal meningitis lead to death in 19% of patients and a considerable rate of neurologic sequela among survivors. CONCLUSIONS: Cryptococcal meningitis carries a high risk of lacunar stroke, particularly in the basal ganglia. Cryptococcal meningitis-associated stroke is common and frequently associated with neurologic disability among survivors. We need to understand the possible role of malignancy, anemia, and hyponatremia in the onset of ischemic stroke.

Internal carotid artery dissection after a roller coaster ride in a 4-year-old: case report and review of the literature.

BACKGROUND: Strokes associated with roller-coaster rides are unusual. PATIENT: A previously healthy 4-year-old boy developed acute onset of left-sided weakness when flying home from a trip to an amusement park. He had frequented two roller coaster rides the day prior. Upon evaluation, he was found to have an acute right middle cerebral artery territory infarction. RESULTS: Cerebral angiography showed dissection of the right cervical internal carotid artery and right middle cerebral artery occlusion involving the M1 segment. He was treated with aspirin. Evaluation for underlying connective tissue diseases was unremarkable. CONCLUSION: We speculate that repetitive forces of acceleration and deceleration may have led to a cervical internal carotid artery intimal tear, followed by thromboembolism. It remains uncertain what the threshold of susceptibility to repetitive rotational changes and tolerability to G forces in an otherwise healthy child truly is.

The absence of the calcium-buffering protein calbindin is associated with faster age-related decline in hippocampal metabolism.

Although reductions in the expression of the calcium-buffering proteins calbindin D-28K (CB) and parvalbumin (PV) have been observed in the aging brain, it is unknown whether these changes contribute to age-related hippocampal dysfunction. To address this issue, we measured basal hippocampal metabolism and hippocampal structure across the lifespan of C57BL/6J, calbindin D-28k knockout (CBKO) and parvalbumin knockout (PVKO) mice. Basal metabolism was estimated using steady state relative cerebral blood volume (rCBV), which is a variant of fMRI that provides the highest spatial resolution, optimal for the analysis of individual subregions of the hippocampal formation. We found that like primates, normal aging in C57BL/6J mice is characterized by an age-dependent decline in rCBV-estimated dentate gyrus (DG) metabolism. Although abnormal hippocampal fMRI signals were observed in CBKO and PVKO mice, only CBKO mice showed accelerated age-dependent decline of rCBV-estimated metabolism in the DG. We also found age-independent structural changes in CBKO mice, which included an enlarged hippocampus and neocortex as well as global brain hypertrophy. These metabolic and structural changes in CBKO mice correlated with a deficit in hippocampus-dependent learning in the active place avoidance task. Our results suggest that the decrease in CB that occurs during normal aging is involved in age-related hippocampal metabolic decline. Our findings also illustrate the value of using multiple MRI techniques in transgenic mice to investigate mechanisms involved in the functional and structural changes that occur during aging.