Neurological Complications and Clinical Outcomes of Infective Endocarditis.

OBJECTIVES: The aim of this study is to explore the clinical features associated with neurological complications of infective endocarditis (IE) and to assess the impact of neurological complications on clinical outcomes. MATERIALS AND METHODS: The frequency of relevant clinical features was compared in a case series of IE patients with and without neurological complications admitted to a single health care system from 2015 to 2019. Variables with significant differences (p ≤ 0.05) in baseline characteristics in univariate logistic regression models were entered into multivariable models along with age to determine associations with neurological complications, unfavorable discharge outcomes (modified Rankin score ≥ 3), and in-hospital mortality. RESULTS: 260 patients with a mean age of 51 (±18) years and 103 (40%) females were included. Neurological complications occurred in 165 (63%) patients, with the most common being septic emboli (66 patients, 25%). In the regression analyses, antiplatelet usage (aOR 1.87, 95% CI [1.05-3.32]) and mitral valve vegetations (aOR 2.66, 95% CI [1.22-5.79]) were independently associated with neurological complications. Territorial infarction (aOR 4.13, 95% CI [1.89-9.06]) and encephalopathy (aOR 3.95, 95% CI [1.19-13.05]) were associated with an increased risk of unfavorable outcome, while cardiac surgery was associated with a lower risk of both unfavorable outcome (aOR 0.40, 95% CI [0.22-0.71]) and in-hospital mortality (aOR 0.18, 95% CI [0.09-0.35]). CONCLUSIONS: Neurological complications are common in IE patients and are associated with mitral valve endocarditis and antiplatelet usage. Of the neurological complications, territorial infarcts and encephalopathy are associated with unfavorable discharge outcomes.

Microemboli After Successful Thrombectomy Do Not Affect Outcome but Predict New Embolic Events.

Background and Purpose- We aimed to determine if microemboli after endovascular thrombectomy correlate with unfavorable outcomes despite successful recanalization. Methods- This is a prospective multicenter study of consecutive patients with ischemic stroke and occlusion of anterior circulation vessels (terminal internal carotid or main trunk of the middle cerebral artery/first-order branch of the main trunk of the middle cerebral artery segments of middle cerebral artery) after successful thrombectomy (modified Treatment In Cerebral Ischemia grades 2b-3). Microembolic signals (MES) were assessed by 30 minutes of transcranial Doppler monitoring within 72 hours of the last-seen-well time. Major outcomes included modified Rankin Scale at 90 days and infarct volume on head computed tomography at 24 hours. We also assessed early outcomes based on National Institutes of Health Stroke Scale variation and recurrence of stroke, transient ischemic attack, or systemic embolism within 90 days. Results- Among 111 patients, MES were detected in 43 (39%), with a median rate of 4 counts/h (interquartile range 2-12). The occurrence of MES was not associated with a significant difference in modified Rankin Scale (ordinal shift analysis, adjusted odds ratio, 1.06 [95% CI, 0.48-2.34] P=0.85) nor in functional independence (modified Rankin Scale, 0-2: adjusted odds ratio, 0.52 [95% CI, 0.19-1.39] P=0.19). Patients with and without MES had similar infarct volumes (adjusted beta, 11.2 [95% CI, -46.6 to +22.9] P=0.51) on 24-hour computed tomography. MES did predict new embolic events (adjusted Cox hazard ratio, 6.78 [95% CI, 1.63-27.8] P=0.01). Conclusions- MES detected by transcranial Doppler following endovascular treatment of anterior circulation occlusions do not predict clinical or radiological outcome. However, such emboli are an independent marker of recurrent embolic events within 90 days.

Treatment Approaches to Lacunar Stroke.

Lacunar strokes are appropriately named for their ability to cavitate and form ponds or "little lakes" (Latin: lacune -ae meaning pond or pit is a diminutive form of lacus meaning lake). They account for a substantial proportion of both symptomatic and asymptomatic ischemic strokes. In recent years, there have been several advances in the management of large vessel occlusions. New therapies such as non-vitamin K antagonist oral anticoagulants and left atrial appendage closure have recently been developed to improve stroke prevention in atrial fibrillation; however, the treatment of small vessel disease-related strokes lags frustratingly behind. Since Fisher characterized the lacunar syndromes and associated infarcts in the late 1960s, there have been no therapies specifically targeting lacunar stroke. Unfortunately, many therapeutic agents used for the treatment of ischemic stroke in general offer only a modest benefit in reducing recurrent stroke while adding to the risk of intracerebral hemorrhage and systemic bleeding. Escalation of antithrombotic treatments beyond standard single antiplatelet agents has not been effective in long-term lacunar stroke prevention efforts, unequivocally increasing intracerebral hemorrhage risk without providing a significant benefit. In this review, we critically review the available treatments for lacunar stroke based on evidence from clinical trials. For several of the major drugs, we summarize the adverse effects in the context of this unique patient population. We also discuss the role of neuroprotective therapies and neural repair strategies as they may relate to recovery from lacunar stroke.

Cerebrovascular Accidents During Mechanical Circulatory Support: New Predictors of Ischemic and Hemorrhagic Strokes and Outcome.

BACKGROUND AND PURPOSE: Left ventricular assist devices (LVADs) have emerged as an effective treatment for patients with advanced heart failure refractory to medical therapy. Post-LVAD strokes are an important cause of morbidity and reduced quality of life. Data on risks that distinguish between ischemic and hemorrhagic post-LVAD strokes are limited. The aim of this study was to determine the incidence of post-LVAD ischemic and hemorrhagic strokes, their association with stroke risk factors, and their effect on mortality. METHODS: Data are collected prospectively on all patients with LVADs implanted at Brigham and Women's Hospital. We added retrospectively collected clinical data for these analyses. RESULTS: From 2007 to 2016, 183 patients (median age, 57; 80% male) underwent implantation of HeartMate II LVAD as a bridge to transplant (52%), destination therapy (39%), or bridge to transplant candidacy (8%). A total of 48 strokes occurred in 39 patients (21%): 28 acute ischemic strokes in 24 patients (13%) and 20 intracerebral hemorrhages in 19 patients (10.3%). First events occurred at a median of 238 days from implantation (interquartile range, 93-515) among those who developed post-LVAD stroke. All but 9 patients (4.9%) were on warfarin (goal international normalized ratio, 2-3.5) and all received aspirin (81-325 mg). Patients with chronic obstructive pulmonary disease were more likely to have an ischemic stroke (odds ratio, 2.96; 95% confidence interval, 1.14-7.70). Dialysis-dependent patients showed a trend toward a higher risk of hemorrhagic stroke (odds ratio, 6.31; 95% confidence interval, 0.99-40.47). Hemorrhagic stroke was associated with higher mortality (odds ratio, 3.92; 95% confidence interval, 1.34-11.45) than ischemic stroke (odds ratio, 3.17; 95% confidence interval, 1.13-8.85). CONCLUSIONS: Stroke is a major cause of morbidity and mortality in patients on LVAD support. Chronic obstructive pulmonary disease increases the risk of ischemic stroke, whereas dialysis may increase the risk of hemorrhagic stroke. Although any stroke increases mortality, post-LVAD hemorrhagic stroke was associated with higher mortality compared with ischemic stroke.

Oxidative Stress Biomarkers of Brain Damage: Hyperacute Plasma F2-Isoprostane Predicts Infarct Growth in Stroke.

BACKGROUND AND PURPOSE: Oxidative stress is an early response to cerebral ischemia and is likely to play an important role in the pathogenesis of cerebral ischemic injury. We sought to evaluate whether hyperacute plasma concentrations of biomarkers of oxidative stress, inflammation, and tissue damage predict infarct growth (IG). METHODS: We prospectively measured plasma F2-isoprostane (F2-isoP), urinary 8-oxo-7,8-dihydro-2'-deoxyguoanosine, plasma oxygen radical absorbance capacity assay, high sensitivity C reactive protein, and matrix metalloproteinase 2 and 9 in consecutive patients with acute ischemic stroke presenting within 9 hours of symptom onset. Patients with baseline diffusion-weighted magnetic resonance imaging and follow-up diffusion-weighted imaging or computed tomographic scan were included to evaluate the final infarct volume. Baseline diffusion-weighted imaging volume and final infarct volume were analyzed using semiautomated volumetric method. IG volume was defined as the difference between final infarct volume and baseline diffusion-weighted imaging volume. RESULTS: A total of 220 acute ischemic stroke subjects were included in the final analysis. One hundred seventy of these had IG. Baseline F2-isoP significantly correlated with IG volume (Spearman ρ=0.20; P=0.005) and final infarct volume (Spearman ρ=0.19; P=0.009). In a multivariate binary logistic regression model, baseline F2-isoP emerged as an independent predictor of the occurrence of IG (odds ratio, 2.57; 95% confidence interval, 1.37-4.83; P=0.007). In a multivariate linear regression model, baseline F2-isoP was independently associated with IG volume (B, 0.38; 95% confidence interval, 0.04-0.72; P=0.03). CONCLUSIONS: Elevated hyperacute plasma F2-isoP concentrations independently predict the occurrence of IG and IG volume in patients with acute ischemic stroke. If validated in future studies, measuring plasma F2-isoP might be helpful in the acute setting to stratify patients with acute ischemic stroke for relative severity of ischemic injury and expected progression.

Stroke in Pregnancy.

Pregnancy and the postpartum period confer an increased risk of stroke. The risk appears to be increased for all strokes during the puerperium and for hemorrhagic strokes during pregnancy. During pregnancy, physiologic systems are under increased stress to accommodate the growing fetus, which results in substantial hemodynamic, cardiovascular, hematologic, immunologic, and structural connective tissue changes that account for much of this increased risk. In addition, preeclampsia-eclampsia has major effects on the vascular system, and this disorder, unique to pregnancy, is another major contributor to this risk. The common independent vascular risk factors for stroke, such as hypertension, diabetes, hyperlipidemia, and smoking, may also be present to contribute to the risks conferred by pregnancy. Though uncommon, stroke during pregnancy and in the postpartum period causes substantial morbidity and mortality in affected women, and it poses a significant risk to the fetus. This review will discuss the epidemiology of pregnancy-associated stroke, specific risk factors and mechanisms, clinical presentation and management, and future directions.

Cerebrovascular Hemodynamics in Women.

Sex and gender, as biological and social factors, significantly influence health outcomes. Among the biological factors, sex differences in vascular physiology may be one specific mechanism contributing to the observed differences in clinical presentation, response to treatment, and clinical outcomes in several vascular disorders. This review focuses on the cerebrovascular bed and summarizes the existing literature on sex differences in cerebrovascular hemodynamics to highlight the knowledge deficit that exists in this domain. The available evidence is used to generate mechanistically plausible and testable hypotheses to underscore the unmet need in understanding sex-specific mechanisms as targets for more effective therapeutic and preventive strategies.

Emerging Cases of Powassan Virus Encephalitis in New England: Clinical Presentation, Imaging, and Review of the Literature.

BACKGROUND: Powassan virus (POWV) is a rarely diagnosed cause of encephalitis in the United States. In the Northeast, it is transmitted by Ixodes scapularis, the same vector that transmits Lyme disease. The prevalence of POWV among animal hosts and vectors has been increasing. We present 8 cases of POWV encephalitis from Massachusetts and New Hampshire in 2013-2015. METHODS: We abstracted clinical and epidemiological information for patients with POWV encephalitis diagnosed at 2 hospitals in Massachusetts from 2013 to 2015. We compared their brain imaging with those in published findings from Powassan and other viral encephalitides. RESULTS: The patients ranged in age from 21 to 82 years, were, for the most part, previously healthy, and presented with syndromes of fever, headache, and altered consciousness. Infections occurred from May to September and were often associated with known tick exposures. In all patients, cerebrospinal fluid analyses showed pleocytosis with elevated protein. In 7 of 8 patients, brain magnetic resonance imaging demonstrated deep foci of increased T2/fluid-attenuation inversion recovery signal intensity. CONCLUSIONS: We describe 8 cases of POWV encephalitis in Massachusetts and New Hampshire in 2013-2015. Prior to this, there had been only 2 cases of POWV encephalitis identified in Massachusetts. These cases may represent emergence of this virus in a region where its vector, I. scapularis, is known to be prevalent or may represent the emerging diagnosis of an underappreciated pathogen. We recommend testing for POWV in patients who present with encephalitis in the spring to fall in New England.

Soluble and catalytically active endothelin converting enzyme-1 is present in cerebrospinal fluid of subarachnoid hemorrhage patients.

Endothelin converting Enzyme-1 (ECE-1) is essential for the production of Endothelin-1 (ET-1), which is associated with vasospasm following subarachnoid hemorrhage (SAH). We have previously demonstrated the presence of a catalytically active soluble form of ECE-1 in the media of endothelial cells. We aimed to determine if this form of ECE-1 exists in vivo, in cerebrospinal fluid (CSF) of SAH patients. We examined CSF taken from SAH subjects for the presence of soluble ECE-1 using a bradykinin based quenched fluorescent substrate assay. We obtained further confirmation by characterizing the CSF mediated cleavage products of BigET-1 and BigET18₋34 (6 µg/ml) using mass spectrometry. The specificity of cleavage was confirmed using the ECE-1 inhibitor CGS35066 5 nmol/L. SAH CSF samples had mean ECE-1 activity of 0.127 ± 0.037 µmols of substrate cleaved/µl of CSF/24 h. The C-terminal peptides generated upon the cleavage of BigET-1 and BigET18₋34 were detected 48 h after incubation of these substrates with CSF. Cleavage of these substrates was inhibited by CGS35066. Results of Western blots also produced strong evidence for the presence of truncated soluble ECE-1 in CSF. These results strongly suggest the presence of a truncated but catalytically active form of ECE-1 in the CSF of SAH subjects. Further studies are necessary to determine the biological significance of soluble ECE-1 in CSF of SAH subjects, including an association with vasospasm after SAH.

Stroke in pregnancy: a case-oriented review.

Stroke is a rare but serious complication of pregnancy and the postpartum period. Yet, despite its rarity, it remains a major cause of serious morbidity and long-term disability in young women. In this review, we use cases to illustrate many of the most important issues that arise when managing pregnancy-associated stroke.

Cerebrovascular complications of pregnancy and the postpartum period.

Cerebrovascular complications of pregnancy, though uncommon, threaten women with severe morbidity or death, and they are the main causes of major long-term disability associated with pregnancy. In this review, we discuss the epidemiology, pathophysiology, presentation and diagnosis, and management and outcomes of ischemic and hemorrhagic stroke and cerebral venous thrombosis. We also discuss the posterior reversible encephalopathy syndrome, the reversible cerebral vasoconstriction syndrome including postpartum cerebral angiopathy, and their relationship as overlapping manifestations of pre-eclampsia-eclampsia.

White matter hyperintensity volume correlates with matrix metalloproteinase-2 in acute ischemic stroke.

BACKGROUND: White matter hyperintensity (WMH), a common radiographic finding associated with stroke risk and outcome, has been linked to matrix metalloproteinase (MMP) activity and increased levels of oxidative stress in nonstroke populations. We sought to determine whether WMH severity is associated with plasma levels of MMPs and oxidative stress (F2-isoprostane) in subjects with acute ischemic stroke (AIS). METHODS: We measured plasma biomarker levels at baseline and 48 hours in consecutive AIS subjects. White matter hyperintensity volume (WMHv) was quantified on admission magnetic resonance imaging using a validated semiautomated protocol, and Spearman correlation coefficients were derived for all measured biomarkers. RESULTS: We enrolled 405 AIS subjects (mean age 70±15 years; 58% male; median WMHv 3.4 cm3, interquartile range 1.4-9.5). WMHv and age were strongly correlated (ρ=.57, P<.0001). WMHv and MMP-2 levels were correlated at baseline (ρ=.23, P<.0001) and at 48 hours poststroke (ρ=.19, P=.002). In multivariate analysis, 48-hour MMP-2 levels were independently associated with WMHv (ß=.12, P=.04). MMP-9 and F2-isioprostane levels did not correlate with WMHv. CONCLUSIONS: In AIS patients, MMP-2 levels are associated with the pre-existing burden of WMH. If validated, these findings may further elucidate the role of MMP-2 in pathophysiology of chronic cerebrovascular injury, such as WMH, and in brain susceptibility to acute ischemia.

Follow-up ASPECTS improves prediction of potentially lethal malignant edema in patients with large middle cerebral artery stroke.

BACKGROUND: Recent studies have shown that follow-up head CT is a strong predictor of functional outcomes in patients with middle cerebral artery stroke and mechanical thrombectomy. We sought to determine whether total and/or regional follow-up Alberta Stroke Program Early CT Score (ASPECTSfu) are associated with important clinical outcomes during hospitalization and improve the performance of clinical prediction models of potentially lethal malignant edema (PLME). METHODS: We conducted a retrospective study of patients at three medical centers in a major North American metropolitan area with baseline and follow-up head CTs after large middle cerebral artery stroke between 2006 and 2022. We used multivariable logistic regression to test the association of total and regional ASPECTSfu with PLME (cerebral edema related death or surgery), adjusting for total baseline ASPECTS, age, sex, admission glucose, tissue plasminogen activator, and mechanical thrombectomy. We compared existing clinical risk models with and without total or regional ASPECTSfu using area under the curve. RESULTS: In our 560 patient cohort, lower total ASPECTSfu was significantly associated with higher odds of PLME when adjusting for confounders (OR 1.69, 95% CI 1.49 to 2.0), and improved model discrimination compared with existing models and models using baseline ASPECTS. Deep territory involvement (OR 2.46, 95% CI 1.53 to 4.01) and anterior territory involvement (OR 3.23, 95% CI 1.88 to 5.71) were significantly associated with PLME. CONCLUSIONS: Lower ASPECTSfu and certain locations on regional ASPECTSfu, including deep and anterior areas, were significantly associated with PLME. Including ASPECTSfu information improved discrimination of established edema prediction models and could be used immediately to help facilitate clinical management decisions and prognostication.

Strokes in Patients With Injection Drug Use and Tricuspid Valve Endocarditis - A Case Series.

Research Design: In this study, we describe patients from a tertiary care safety-net hospital endocarditis registry with tricuspid valve infective endocarditis (TVIE), and concomitant acute or subacute ischemic stroke predominantly associated with injection drug use (IDU). We retrospectively obtained data pertinent to neurologic examinations, history of injection drug use (IDU), blood cultures, transthoracic/transesophageal echocardiography (TTE/TEE), neuroimaging, and Modified Rankin Scale (mRS) scores at discharge. Only those patients with bacteremia, tricuspid valve vegetations, and neuroimaging consistent with acute to subacute ischemic infarction and microhemorrhages in two cases were included in this series. Results: Of 188 patients in the registry, 66 patients had TVIE and 10 of these were complicated by ischemic stroke. Neurologic symptoms were largely non-specific, eight patients had altered mental status and only 3 had focal deficits. Nine cases were associated with IDU. Two patients had evidence of a patent foramen ovale on echocardiography. Blood cultures grew S. aureus species in 9 of the patients, all associated with IDU. Three patients died during hospitalization. The mRS score at discharge for survivors ranged 0-4. Conclusions: Patients with strokes from TVIE had heterogeneous presentations and putative mechanisms. We noted that robust neuroimaging is lacking for patients with TVIE from IDU and that such patients may benefit from neuroimaging as a screen for strokes to assist peri-operative management. Further inquiry is needed to elucidate stroke mechanisms in these patients.