Characteristics and evolution of cerebral aneurysms among adults living with HIV: A retrospective, longitudinal case series.

OBJECTIVE: Previous research indicates an increased risk of cerebral aneurysm formation in adults living with human immunodeficiency virus (ALWH), however there are few longitudinal studies on the risk factors for and outcomes of cerebral aneurysms in this population. We aim to describe the characteristics and evolution of cerebral aneurysms in a large cohort of ALWH. MATERIALS AND METHODS: A chart review was completed for all adults evaluated at an urban, safety-net U.S. hospital between January 1, 2000, and October 22, 2021, with history of both HIV and at least one cerebral aneurysm. RESULTS: A total of 82 cerebral aneurysms were identified amongst 50 patients (52% female sex). Forty-six percent of patients with a nadir CD4 count less than 200 cells/mm3 (N=13) and 44% of patients with maximum viral load >10,000 copies/mL (N=18) developed new aneurysms or were found to have aneurysm growth over time compared with 29% of patients with a CD4 nadir above 200 cells/mm3 (N=21) and 22% of patients with maximum viral load

Validation of a Crisis Standards of Care Model for Prioritization of Limited Resources During the Coronavirus Disease 2019 Crisis in an Urban, Safety-Net, Academic Medical Center.

OBJECTIVES: The coronavirus disease 2019 pandemic has overwhelmed healthcare resources even in wealthy nations, necessitating rationing of limited resources without previously established crisis standards of care protocols. In Massachusetts, triage guidelines were designed based on acute illness and chronic life-limiting conditions. In this study, we sought to retrospectively validate this protocol to cohorts of critically ill patients from our hospital. DESIGN: We applied our hospital-adopted guidelines, which defined severe and major chronic conditions as those associated with a greater than 50% likelihood of 1- and 5-year mortality, respectively, to a critically ill patient population. We investigated mortality for the same intervals. SETTING: An urban safety-net hospital ICU. PATIENTS: All adults hospitalized during April of 2015 and April 2019 identified through a clinical database search. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Of 365 admitted patients, 15.89% had one or more defined chronic life-limiting conditions. These patients had higher 1-year (46.55% vs 13.68%; p < 0.01) and 5-year (50.00% vs 17.22%; p < 0.01) mortality rates than those without underlying conditions. Irrespective of classification of disease severity, patients with metastatic cancer, congestive heart failure, end-stage renal disease, and neurodegenerative disease had greater than 50% 1-year mortality, whereas patients with chronic lung disease and cirrhosis had less than 50% 1-year mortality. Observed 1- and 5-year mortality for cirrhosis, heart failure, and metastatic cancer were more variable when subdivided into severe and major categories. CONCLUSIONS: Patients with major and severe chronic medical conditions overall had 46.55% and 50.00% mortality at 1 and 5 years, respectively. However, mortality varied between conditions. Our findings appear to support a crisis standards protocol which focuses on acute illness severity and only considers underlying conditions carrying a greater than 50% predicted likelihood of 1-year mortality. Modifications to the chronic lung disease, congestive heart failure, and cirrhosis criteria should be refined if they are to be included in future models.

Admission Lymphocytopenia is Associated with Urinary Tract Infection and Nosocomial Infections in Hemorrhagic Stroke.

OBJECTIVE: Growing evidence suggests that lymphocytopenia on admission (LOA) is associated with infectious complications and poor outcomes in intracerebral hemorrhage (ICH). Whether LOA preferentially increases the risk for community acquired infections or nosocomial infections is unknown. This study investigates the relationship between LOA and nosocomial infections in a cohort of patients with ICH in a safety-net hospital. MATERIAL AND METHODS: This is a single center, observational, retrospective study of 213 patients with non-traumatic ICH admitted to the neurocritical care unit between 2008 and 2014. Patients' clinical, demographic, lab and radiologic data were retrieved from institutional electronic medical records. Nosocomial infection was defined as clinical onset 48 h after admission. RESULTS: Prevalence of LOA was 24.8%. Patients with LOA showed significant associations with mechanical ventilation (67.9% versus 49.4%; p= 0.019), higher median ICH score (2 versus 1; p=0.006), nosocomial infection (43.4% versus 28.0%; p=0.038), nosocomial UTI (24.5% versus 8.9%; p=0.003). Adjusting for baseline covariates in a multivariate logistic regression, we observed an association of LOA with nosocomial UTI (OR, 3.66 [95% CI, 1.36-9.88], p=0.010). From the Cox proportional model, patients with LOA had 1.76 times the hazard of developing of nosocomial infection, compared to those without LOA ([95% CI: 1.01, 3.07], p=0.046) and had 3.27 times the hazard of developing nosocomial UTI, compared to those without LOA ([95% CI: 1.39, 7.67], p=0.007). CONCLUSIONS: This study is the first to show that LOA is associated with nosocomial urinary tract infections and significantly shorter times to develop nosocomial infections.

Cerebral Venous Sinus Thrombosis in COVID-19 Patients: A Multicenter Study and Review of Literature.

BACKGROUND: COVID-19 infection has been known to predispose patients to both arterial and venous thromboembolic events such as deep venous thrombosis, pulmonary embolism, myocardial infarction, and stroke. A few reports from the literature suggest that Cerebral Venous Sinus Thrombosis (CVSTs) may be a direct complication of COVID-19. OBJECTIVE: To review the clinical and radiological presentation of COVID-19 positive patients diagnosed with CVST. METHODS: This was a multicenter, cross-sectional, retrospective study of patients diagnosed with CVST and COVID-19 reviewed from March 1, 2020 to November 8, 2020. We evaluated their clinical presentations, risk factors, clinical management, and outcome. We reviewed all published cases of CVST in patients with COVID-19 infection from January 1, 2020 to November 13, 2020. RESULTS: There were 8 patients diagnosed with CVST and COVID-19 during the study period at 7 out of 31 participating centers. Patients in our case series were mostly female (7/8, 87.5%). Most patients presented with non-specific symptoms such as headache (50%), fever (50%), and gastrointestinal symptoms (75%). Several patients presented with focal neurologic deficits (2/8, 25%) or decreased consciousness (2/8, 25%). D-dimer and inflammatory biomarkers were significantly elevated relative to reference ranges in patients with available laboratory data. The superior sagittal and transverse sinuses were the most common sites for acute CVST formation (6/8, 75%). Median time to onset of focal neurologic deficit from initial COVID-19 diagnosis was 3 days (interquartile range 0.75-3 days). Median time from onset of COVID-19 symptoms to CVST radiologic diagnosis was 11 days (interquartile range 6-16.75 days). Mortality was low in this cohort (1/8 or 12.5%). CONCLUSIONS: Clinicians should consider the risk of acute CVST in patients positive for COVID-19, especially if neurological symptoms develop.

Endovascular Treatment of Infective Endocarditis-Related Acute Large Vessel Occlusion Stroke.

OBJECTIVES: Embolic stroke is a frequent complication of infective endocarditis yet lacks acute treatment as intravenous thrombolysis should be avoided due to high risk of intracerebral hemorrhage. Mechanical thrombectomy for large vessel occlusion may be a promising treatment but there is limited data on safety outcomes in infective endocarditis. MATERIALS AND METHODS: In this multi-center retrospective case series, we reviewed data from patients with infective endocarditis-related large vessel occlusion who underwent mechanical thrombectomy in 9 US hospitals. RESULTS: We identified 15 patients at 9 hospitals. A minority presented with signs suggesting infection (2 patients (14%) had fever, 7 (47%) were tachycardic, 2 (13%) were hypotensive, and 8 (53%) had leukocytosis). The median National Institute of Health Stroke Score decreased from 19 (range 9-25) at presentation to 7 post-thrombectomy (range 0-22, median best score post-thrombectomy), and the median modified Rankin Scale on or after discharge for survivors was 3 (range 0-6). Approximately 57% of patients had a modified Rankin Scale between 0 and 3 on or after discharge. Hemorrhagic transformation was observed in 7/15 (47%). The mechanical thrombectomy group had 2/9 petechial hemorrhagic transformation (22%), compared to 4/6 parenchymal hematomas (67%) in the tissue plasminogen activator + mechanical thrombectomy group. CONCLUSIONS: Our findings suggest that patients with large vessel occlusion due to infective endocarditis may not present with overt signs of infection. Mechanical thrombectomy may be an effective treatment in this patient population for whom intravenous thrombolysis should be avoided.

Reversible Cerebral Vasoconstriction Syndrome in Patients with Coronavirus Disease: A Multicenter Case Series.

BACKGROUND AND OBJECTIVES: RCVS (Reversible Cerebral Vasoconstrictive Syndrome) is a condition associated with vasoactive agents that alter endothelial function. There is growing evidence that endothelial inflammation contributes to cerebrovascular disease in patients with coronavirus disease 2019 (COVID-19). In our study, we describe the clinical features, risk factors, and outcomes of RCVS in a multicenter case series of patients with COVID-19. MATERIALS AND METHODS: Multicenter retrospective case series. We collected clinical characteristics, imaging, and outcomes of patients with RCVS and COVID-19 identified at each participating site. RESULTS: Ten patients were identified, 7 women, ages 21 - 62 years. Risk factors included use of vasoconstrictive agents in 7 and history of migraine in 2. Presenting symptoms included thunderclap headache in 5 patients with recurrent headaches in 4. Eight were hypertensive on arrival to the hospital. Symptoms of COVID-19 included fever in 2, respiratory symptoms in 8, and gastrointestinal symptoms in 1. One patient did not have systemic COVID-19 symptoms. MRI showed subarachnoid hemorrhage in 3 cases, intraparenchymal hemorrhage in 2, acute ischemic stroke in 4, FLAIR hyperintensities in 2, and no abnormalities in 1 case. Neurovascular imaging showed focal segment irregularity and narrowing concerning for vasospasm of the left MCA in 4 cases and diffuse, multifocal narrowing of the intracranial vasculature in 6 cases. Outcomes varied, with 2 deaths, 2 remaining in the ICU, and 6 surviving to discharge with modified Rankin scale (mRS) scores of 0 (n=3), 2 (n=2), and 3 (n=1). CONCLUSIONS: Our series suggests that patients with COVID-19 may be at risk for RCVS, particularly in the setting of additional risk factors such as exposure to vasoactive agents. There was variability in the symptoms and severity of COVID-19, clinical characteristics, abnormalities on imaging, and mRS scores. However, a larger study is needed to validate a causal relationship between RCVS and COVID-19.

Safety and Outcomes of Intravenous Thrombolytic Therapy in Ischemic Stroke Patients with COVID-19: CASCADE Initiative.

BACKGROUND: There is little information regarding the safety of intravenous tissue plasminogen activator (IV-tPA) in patients with stroke and COVID-19. METHODS: This multicenter study included consecutive stroke patients with and without COVID-19 treated with IV-tPA between February 18, 2019, to December 31, 2020, at 9 centers participating in the CASCADE initiative. Clinical outcomes included modified Rankin Scale (mRS) at hospital discharge, in-hospital mortality, the rate of hemorrhagic transformation. Using Bayesian multiple regression and after adjusting for variables with significant value in univariable analysis, we reported the posterior adjusted odds ratio (OR, with 95% Credible Intervals [CrI]) of the main outcomes. RESULTS: A total of 545 stroke patients, including 101 patients with COVID-19 were evaluated. Patients with COVID-19 had a more severe stroke at admission. In the study cohort, 85 (15.9%) patients had a hemorrhagic transformation, and 72 (13.1%) died in the hospital. After adjustment for confounding variables, discharge mRS score ≥2 (OR: 0.73, 95% CrI: 0.16, 3.05), in-hospital mortality (OR: 2.06, 95% CrI: 0.76, 5.53), and hemorrhagic transformation (OR: 1.514, 95% CrI: 0.66, 3.31) were similar in COVID-19 and non COVID-19 patients. High-sensitivity C reactive protein level was a predictor of hemorrhagic transformation in all cases (OR:1.01, 95%CI: 1.0026, 1.018), including those with COVID-19 (OR:1.024, 95%CI:1.002, 1.054). CONCLUSION: IV-tPA treatment in patients with acute ischemic stroke and COVID-19 was not associated with an increased risk of disability, mortality, and hemorrhagic transformation compared to those without COVID-19. IV-tPA should continue to be considered as the standard of care in patients with hyper acute stroke and COVID-19.

Chronic Kidney Disease as Risk Factor for Enlarged Perivascular Spaces in Patients With Stroke and Relation to Racial Group.

BACKGROUND AND PURPOSE: Enlarged perivascular spaces (EPVS) are considered subclinical markers of small vessel disease, associated with increased risk of stroke and dementia. Increasing evidence links chronic kidney disease (CKD) to small vessel disease. We explored the relationship between CKD and EPVS burden and the influence of racial group in this relation. METHODS: Consecutive patients with stroke who underwent brain magnetic resonance imaging were included (n=894). Racial group was categorized as White, Black, or other (other racial groups). CKD was defined by glomerular filtration rate <60 mL/minute per 1.73 m2 for >3 months. EPVS were rated following a standardized method, dichotomized for analyses (mild [<20] versus severe [≥20]), and stratified by brain region (basal ganglia and centrum semiovale). RESULTS: In multivariable-adjusted analysis, the association of CKD with severe EPVS varied across racial groups. Comparing patients with and without CKD within racial groups, we found that Whites with CKD had higher odds of severe centrum semiovale EPVS (odds ratio [OR], 2.41 [95% CI, 0.98-5.88]). Among patients with CKD, Black patients had higher odds of severe EPVS in the basal ganglia and centrum semiovale compared with Whites (OR, 1.93 [95% CI, 1.18-3.16] and OR, 1.90 [95% CI, 1.16-3.11], respectively) and other racial groups (OR, 2.03 [95% CI, 1.23-3.36] and OR, 2.02 [95% CI, 1.22-3.34], respectively). CONCLUSIONS: CKD was more prevalent in our sample of patients with stroke with severe EPVS in the centrum semiovale. The relation differed when stratified by racial group and brain topography. Further studies are needed to confirm that CKD may relate differently to subclinical measures of small vessel disease according to race.

Myoclonus in Patients With Coronavirus Disease 2019: A Multicenter Case Series.

OBJECTIVES: To describe the risk factors for and outcomes after myoclonus in a cohort of patients with coronavirus disease 2019. DESIGN: Multicenter case series. SETTING: Three tertiary care hospitals in Massachusetts, Georgia, and Virginia. PATIENTS: Eight patients with clinical myoclonus in the setting of coronavirus disease 2019. INTERVENTIONS & MEASUREMENTS AND MAIN RESULTS: Outcomes in patients with myoclonus were variable, with one patient who died during the study period and five who were successfully extubated cognitively intact and without focal neurologic deficits. In five cases, the myoclonus completely resolved within 2 days of onset, while in three cases, it persisted for 10 days or longer. Seven patients experienced significant metabolic derangements, hypoxemia, or exposure to sedating medications that may have contributed to the development of myoclonus. One patient presented with encephalopathy and developed prolonged myoclonus in the absence of clear systemic provoking factors. CONCLUSIONS: Our findings suggest that myoclonus may be observed in severe acute respiratory syndrome coronavirus 2 infected patients, even in the absence of hypoxia. This association warrants further evaluation in larger cohorts to determine whether the presence of myoclonus may aid in the assessment of disease severity, neurologic involvement, or prognostication.

COVID-19 in patients with myasthenia gravis.

INTRODUCTION: Coronavirus disease 2019 (COVID-19) has rapidly become a global pandemic, but little is known about its potential impact on patients with myasthenia gravis (MG). METHODS: We studied the clinical course of COVID-19 in five hospitalized patients with autoimmune MG (four with acetylcholine receptor antibodies, one with muscle-specific tyrosine kinase antibodies) between April 1, 2020-April 30-2020. RESULTS: Two patients required intubation for hypoxemic respiratory failure, whereas one required significant supplemental oxygen. One patient with previously stable MG had myasthenic exacerbation. One patient treated with tocilizumab for COVID-19 was successfully extubated. Two patients were treated for MG with intravenous immunoglobulin without thromboembolic complications. DISCUSSION: Our findings suggest that the clinical course and outcomes in patients with MG and COVID-19 are highly variable. Further large studies are needed to define best practices and determinants of outcomes in this unique population.

Seizure as the presenting symptom of COVID-19: A retrospective case series.

BACKGROUND: Coronavirus Disease 2019 (COVID-19) has rapidly become a global pandemic, with over 1.8 million confirmed cases worldwide to date. Preliminary reports suggest that the disease may present in diverse ways, including with neurological symptoms, but few published reports in the literature describe seizures in patients with COVID-19. OBJECTIVE: The objective of the study was to characterize the risk factors, clinical features, and outcomes of seizures in patients with COVID-19. METHODS: This is a retrospective case series. Cases were identified through a review of admissions and consultations to the neurology and neurocritical care services between April 1, 2020 and May 15, 2020. SETTING: The study setting was in a tertiary care, safety-net hospital in Boston, MA. PARTICIPANTS: Patients presenting with seizures and COVID-19 during the study period were included in the study. RESULTS: Seven patients met inclusion criteria (5 females, 71%). Patients ranged in age from 37 to 88 years (median: 75 years). Three patients had a prior history of well-controlled epilepsy (43%), while 4 patients had new-onset seizures, including 2 patients with prior history of remote stroke. Three patients had no preceding symptoms of COVID-19 prior to presentation (57%), and in all cases, seizures were the symptom that prompted presentation to the emergency department, regardless of prior symptoms of COVID-19. CONCLUSIONS: Provoking factors for seizures in patients with COVID-19 may include metabolic factors, systemic illness, and possibly direct effects of the virus. In endemic areas with community spread of COVID-19, clinicians should be vigilant for the infection in patients who present with seizures, which may precede respiratory symptoms or prompt presentation to medical care. Early testing, isolation, and contact tracking of these patients can prevent further transmission of the virus.

Posterior Reversible Encephalopathy Syndrome in Patients with Coronavirus Disease 2019: Two Cases and A Review of The Literature.

INTRODUCTION: Encephalopathy is a common complication of coronavirus disease 2019. Although the encephalopathy is idiopathic in many cases, there are several published reports of patients with posterior reversible encephalopathy syndrome in the setting of coronavirus disease 2019. OBJECTIVE: To describe the diverse presentations, risk factors, and outcomes of posterior reversible encephalopathy syndrome in patients with coronavirus disease 2019. METHODS: We assessed patients with coronavirus disease 2019 and a diagnosis of posterior reversible encephalopathy syndrome at our institution from April 1 to June 24, 2020. We performed a literature search to capture all known published cases of posterior reversible encephalopathy syndrome in patients with coronavirus disease 2019. RESULTS: There were 2 cases of posterior reversible encephalopathy syndrome in the setting of coronavirus 2019 at our institution during a 3-month period. One patient was treated with anakinra, an interleukin-1 inhibitor that may disrupt endothelial function. The second patient had an underlying human immunodeficiency virus infection. We found 13 total cases in our literature search, which reported modest blood pressure fluctuations and a range of risk factors for posterior reversible encephalopathy syndrome. One patient was treated with tocilizumab, an interleukin-6 inhibitor that may have effects on endothelial function. All patients had an improvement in their neurological symptoms. Interval imaging, when available, showed radiographic improvement of brain lesions. CONCLUSIONS: Risk factors for posterior reversible encephalopathy syndrome in patients with coronavirus disease 2019 may include underlying infection or immunomodulatory agents with endothelial effects in conjunction with modest blood pressure fluctuations. We found that the neurological prognosis for posterior reversible encephalopathy syndrome in the setting of coronavirus disease 2019 infection is favorable. Recognition of posterior reversible encephalopathy syndrome in this patient population is critical for prognostication and initiation of treatment, which may include cessation of potential offending agents and tight blood pressure control.

Optimization of resources and modifications in acute ischemic stroke care in response to the global COVID-19 pandemic.

BACKGROUND: The COVID-19 pandemic has presented unprecedented challenges to healthcare organizations worldwide. A steadily rising number of patients requiring intensive care, a large proportion from racial and ethnic minorities, demands creative solutions to provide high-quality care while ensuring healthcare worker safety in the face of limited resources. Boston Medical Center has been particularly affected due to the underserved patient population we care for and the increased risk of ischemic stroke in patients with COVID-19 infection. METHODS: We present protocol modifications developed to manage patients with acute ischemic stroke in a safe and effective manner while prioritizing judicious use of personal protective equipment and intensive care unit resources. CONCLUSION: We feel this information will benefit other organizations facing similar obstacles in caring for the most vulnerable patient populations during this ongoing public health crisis.

Intravenous tPA for Acute Ischemic Stroke in Patients with COVID-19.

BACKGROUND/PURPOSE: Coronavirus disease 2019 (COVID-19) is associated with increased risk of acute ischemic stroke (AIS), however, there is a paucity of data regarding outcomes after administration of intravenous tissue plasminogen activator (IV tPA) for stroke in patients with COVID-19. METHODS: We present a multicenter case series from 9 centers in the United States of patients with acute neurological deficits consistent with AIS and COVID-19 who were treated with IV tPA. RESULTS: We identified 13 patients (mean age 62 (±9.8) years, 9 (69.2%) male). All received IV tPA and 3 cases also underwent mechanical thrombectomy. All patients had systemic symptoms consistent with COVID-19 at the time of admission: fever (5 patients), cough (7 patients), and dyspnea (8 patients). The median admission NIH stroke scale (NIHSS) score was 14.5 (range 3-26) and most patients (61.5%) improved at follow up (median NIHSS score 7.5, range 0-25). No systemic or symptomatic intracranial hemorrhages were seen. Stroke mechanisms included cardioembolic (3 patients), large artery atherosclerosis (2 patients), small vessel disease (1 patient), embolic stroke of undetermined source (3 patients), and cryptogenic with incomplete investigation (1 patient). Three patients were determined to have transient ischemic attacks or aborted strokes. Two out of 12 (16.6%) patients had elevated fibrinogen levels on admission (mean 262.2 ± 87.5 mg/dl), and 7 out of 11 (63.6%) patients had an elevated D-dimer level (mean 4284.6 ±3368.9 ng/ml). CONCLUSIONS: IV tPA may be safe and efficacious in COVID-19, but larger studies are needed to validate these results.

Subarachnoid hemorrhage guidance in the era of the COVID-19 pandemic - An opinion to mitigate exposure and conserve personal protective equipment.

Aneurysmal subarachnoid hemorrhage (SAH) patients require frequent neurological examinations, neuroradiographic diagnostic testing and lengthy intensive care unit stay. Previously established SAH treatment protocols are impractical to impossible to adhere to in the current COVID-19 crisis due to the need for infection containment and shortage of critical care resources, including personal protective equipment (PPE). Centers need to adopt modified protocols to optimize SAH care and outcomes during this crisis. In this opinion piece, we assembled a multidisciplinary, multicenter team to develop and propose a modified guidance algorithm that optimizes SAH care and workflow in the era of the COVID-19 pandemic. This guidance is to be adapted to the available resources of a local institution and does not replace clinical judgment when faced with an individual patient.

Cerebral Venous Sinus Thromboses in Patients with SARS-CoV-2 Infection: Three Cases and a Review of the Literature.

INTRODUCTION: Early studies suggest that acute cerebrovascular events may be common in patients with coronavirus disease 2019 (COVID-19) and may be associated with a high mortality rate. Most cerebrovascular events described have been ischemic strokes, but both intracerebral hemorrhage and rarely cerebral venous sinus thrombosis (CVST) have also been reported. The diagnosis of CVST can be elusive, with wide-ranging and nonspecific presenting symptoms that can include headache or altered sensorium alone. OBJECTIVE: To describe the presentation, barriers to diagnosis, treatment, and outcome of CVST in patients with COVID-19. METHODS: We abstracted data on all patients diagnosed with CVST and COVID-19 from March 1 to August 9, 2020 at Boston Medical Center. Subsequently, we reviewed the literature and extracted all published cases of CVST in patients with COVID-19 from January 1, 2020 through August 9, 2020 and included all studies with case descriptions. RESULTS: We describe the clinical features and management of CVST in 3 women with COVID-19 who developed CVST days to months after initial COVID-19 symptoms. Two patients presented with encephalopathy and without focal neurologic deficits, while one presented with visual symptoms. All patients were treated with intravenous hydration and anticoagulation. None suffered hemorrhagic complications, and all were discharged home. We identified 12 other patients with CVST in the setting of COVID-19 via literature search. There was a female predominance (54.5%), most patients presented with altered sensorium (54.5%), and there was a high mortality rate (36.4%). CONCLUSIONS: During this pandemic, clinicians should maintain a high index of suspicion for CVST in patients with a recent history of COVID-19 presenting with non-specific neurological symptoms such as headache to provide expedient management and prevent complications. The limited data suggests that CVST in COVID-19 is more prevalent in females and may be associated with high mortality.

Infectious Etiologies of Stroke.

Central nervous system (CNS) infections are a frequently underappreciated potential etiology of cerebrovascular disease. Highlighted in this review are a selection of infectious agents that lead to cerebrovascular complications through various mechanisms including multifocal vasculopathy, focal infiltrative vasculitis and vasospasm, and direct vessel wall invasion and thrombus formation. Diagnosis of stroke due to underlying CNS infection requires a high index of clinical suspicion and careful consideration of neuroimaging, serum, and cerebrospinal fluid studies in addition to a detailed history and neurologic examination. Prompt and targeted treatment is essential in these conditions, which frequently herald a poor prognosis. Specifically, cerebrovascular complications associated with varicella zoster virus, syphilis, tuberculosis, aspergillosis, and acute bacterial meningitis are addressed here in detail.

Infectious Myelitis.

Myelitis refers to inflammation of the spinal cord which can result in a spectrum of neurologic impairment. Infectious pathogens are an important etiologic category, and can result in myelitis through direct pathogenic effect or through immune-mediated parainfection; this review focuses on the former category. The spectrum of clinical manifestations is summarized and a diagnostic workup provided to aid clinicians in developing an approach to patients presenting with symptoms suggestive of infectious myelitis. This is followed by an overview of the important viral, bacterial, parasitic, and fungal causes of infectious myelitis. The typical presentations, diagnostic modalities, and treatment approaches are outlined for key pathogens culprit in infectious myelitis to allow clinicians to promptly recognize and diagnose specific infectious etiologies of myelitis.

Neurosurgical Infections.

Patients in the neurointensive care unit often undergo life-saving neurosurgical interventions that can be associated with serious complications. Infection is a common and sometimes fatal complication of such procedures. Infection may occur not only in the setting of major cranial and spinal surgery, but also with common minor procedures that utilize neurosurgical devices, such as placement of external ventricular drains, ventriculoperitoneal shunts, and deep brain stimulators. In this article, we review the epidemiology and microbiology of these infections, and discuss their general and procedure-specific risk factors and treatment options.

Imaging of Intracranial Infections.

Central nervous system (CNS) infections are a major source of morbidity and mortality despite the remarkable progress in prevention and treatment of infectious disease. Because of the difficulty of direct tissue sampling, imaging plays a crucial role in detecting, diagnosing, and monitoring the therapeutic response of CNS infections. An accurate diagnosis in CNS infections is especially rewarding, given the availability of potential effective antimicrobials.Bacterial, viral, fungal, and parasitic infections may affect the brain and/or its meningeal coverings, and can be characterized by a variety of radiological patterns that help narrow the differential diagnoses and eventually tailor the optimal management.This review addresses the typical imaging findings of intracranial infectious diseases in both immunocompetent and immunocompromised patients.