Infectious causes of stroke

New Directions in Infection-Associated Ischemic Stroke

The relationship between infections and stroke has not been fully characterized, probably delaying the development of specific treatments. This narrative review addresses mechanisms of stroke linked to infections, including hypercoagulability, endothelial dysfunction, vasculitis, and impaired thrombolysis. SARS-CoV-2, the virus that causes COVID-19, may promote the development of stroke, which may represent its most severe neurological complication. The development of specific therapies for infection-associated stroke remains a profound challenge. Perhaps the most important remaining issue is the distinction between infections that trigger a stroke versus infections that are truly incidental. This distinction likely requires the establishment of appropriate biomarkers, candidates of which are elevated levels of fibrin D-dimer and anticardiolipin/antiphospholipid antibodies. These candidate biomarkers might have potential use in identifying pathogenic infections preceding stroke, which is a precursor to establishing specific therapies for this syndrome.

Neuroimaging of Infectious Vasculopathy

Vasculitis is a complication of several infectious diseases affecting the central nervous system, which may result in ischemic and/or hemorrhagic stroke, transient ischemic attack, and aneurysm formation. Infectious agents may directly infect the endothelium causing vasculitis or indirectly affect the vessel wall through an immunological cascade. Clinical manifestations usually overlap with those of noninfectious vascular diseases, making diagnosis challenging. Neuroimaging enables the identification of inflammatory changes in intracranial vasculitis. In this article, we review the imaging features of infectious vasculitis of bacterial, viral, fungal and parasitic causes.

Infectious Causes of Stroke

Stroke is one of the primary causes of mortality and morbidity worldwide. It can be ischemic or hemorrhagic, and the former can be due to an in-situ thrombus or a distant embolus. Despite being a rare cause, stroke can also be caused in the setting of infection. Bacterial agents are the most common cause of stroke, among other infectious agents. Until the antibiotic era, rheumatic heart disease was a predisposing risk factor of infective endocarditis. VZV is the most common cause of strokes in pediatric and adult populations. Cryptococcus and Candida spp are the most common yeasts involved in CNS infections, especially in immunocompromised patients. In COVID-19 patients, ischemic strokes are more common than hemorrhagic strokes. In this review, we will discuss the most common infectious agents, with particular emphasis on COVID-19.

Manifesto on the Value of Adult Immunization: "We Know, We Intend, We Advocate"

Immunization through vaccination is a milestone achievement that has made a tremendous contribution to public health. Historically, immunization programs aimed firstly to protect children, who were disproportionally affected by infectious diseases. However, vaccine-preventable diseases can have significant impacts on adult mortality, health, and quality of life. Despite this, adult vaccinations have historically been overlooked in favor of other health priorities, because their benefits to society were not well recognized. As the general population is aging, the issue of vaccination in older adults is gaining importance. In high-income countries, recommendations for the routine vaccination of older adults have been gradually introduced. The Italian National Immunization Plan is considered to be among the most advanced adult vaccination plans in Europe. However, available data indicate there is low adherence to vaccination recommendations in Italy. The COVID-19 pandemic has exposed the damage that can be caused by an infectious disease, especially among adults and individuals with comorbidities. The aim of this “Manifesto”, therefore, is to provide an overview of the existing evidence on the value of adult vaccination, in the Italian context, with a call to action to healthcare providers and health authorities.

[Infections and inflammation in the development of stroke]

The review systematizes data on the role of infectious diseases and systemic inflammation in the pathogenesis of stroke. Various risk factors for stroke associated with pro-inflammatory reactions and their contribution to the pathogenesis of cerebrovascular pathology are analyzed. The interaction of systemic inflammation with hemostasis disturbances and clots formation, activation of autoreactive clones of cytotoxic lymphocytes, the progression of endothelial damage, and other processes is shown. Along with infection, these factors increase the risk of stroke. The key mechanisms of the pathogenesis from the development of acute or chronic inflammation to the preconditions of stroke are presented. The mechanisms of the acting of the infectious process as a trigger factor and/or medium-term or long-term risk factors of stroke are described. A separate section is devoted to the mechanisms of developing cerebrovascular diseases after COVID-19. Identifying an increased risk of stroke due to infection can be of great preventive value. Understanding of this risk by specialists followed by correction of drug therapy and rehabilitation measures can reduce the incidence of cerebrovascular complications in infectious patients.

Stroke associated with Mycoplasma hominis infection: a case report

BACKGROUND

Mycoplasmas are the smallest prokaryotic microorganisms in nature. Many cases of stroke post-Mycoplasma pneumoniae infection have been reported, particularly in the pediatric population. However, Mycoplasma hominis infection has not previously been associated with stroke.

CASE PRESENTATION

We report the case of a 36-year-old Greek woman who presented with an extensive stroke with an unspecified cause. She had a concurrent genital infection with Mycoplasma hominis for an unknown duration.

CONCLUSION

An association may exist between stroke and the immune response to Mycoplasma hominis infection.

Vaccination in Older Adults: An Underutilized Opportunity to Promote Healthy Aging in India

Over the last 50 years, the Indian population aged 50 years and above (older adults) has quadrupled and is expected to comprise 404 million people in 2036, representing 27% of the country's projected population. Consequently, the contribution of chronic disease to older adults' total burden of diseases in India is likely to escalate. Disease burden is notably amplified by immunosenescence, a deterioration of the immune system that develops with age, leading to increasing susceptibility to infectious diseases and other comorbidities. Older adults with infectious diseases have a higher incidence and likelihood of life-threatening comorbidities such as coronary artery disease, arrhythmia, stroke, myocardial infarction, hypertension, dyslipidemia, and diabetes mellitus. Therefore, immunization of older adults through vaccination might greatly reduce the burden imposed by vaccine preventable infectious diseases in this population. Here, we review evidence relevant to the disease burden among adults aged ≥ 50 years in India, and existing vaccination recommendations. Furthermore, we suggest a set of routine vaccinations for healthy older adults in India. There is a clear mandate to recognize the contributions of older adults to society and embrace strategies promoting healthy aging, which is described by the World Health Organization as the process of developing and maintaining functional ability and well-being in older age. Increasing vaccination awareness and coverage among older adults is an important step in that direction for India.

Optimal Timing of Surgery for Patients with Active Infective Endocarditis

Infective endocarditis (IE) is a rare but serious condition with a dismal prognosis. One of the keys to improving outcomes is the prompt identification of high-risk patients who have intracardiac and extracardiac (systemic and neurologic) complications. However, as cardiac and extracardiac complications indicating surgery add to the surgical risk for active IE, controversies surround the optimal indication and timing for surgery, especially in patients presenting neurologic complications. This article reviews the necessary evaluation for patients with suspected IE and proposes a state-of-the-art patient flow chart for evaluation of suspected IE.

The Correlation Between Stroke and Coronavirus Disease (COVID-19): Where is the Evidence?

Stroke is the second leading cause of death globally. Despite the decreasing trend in stroke mortality, its incidence and prevalence follow an upwards trajectory that is envisaged to continue for years to come. Previous literature has suggested a role for infectious disease in stroke aetiology; however, the pathophysiological basis for this has never fully been understood. Emerging infections, such as coronavirus disease (COVID-19), present new challenges that must be addressed, to prevent them from contributing to the predicted rise in stroke incidence. Almost one in 20 patients diagnosed with COVID-19 experience a stroke thereafter, hence achieving better understanding of the interactions between these disease entities is of major clinical significance.

Newly Diagnosed Leptospirosis and Subsequent Hemorrhagic Stroke: A Nationwide Population-Based Cohort Study

BACKGROUND AND PURPOSE

Preceding infection as an important risk factor for ischemic stroke has been reported but neglected for hemorrhagic stroke, especially in young and middle-aged patients. This study investigates whether newly diagnosed leptospirosis is associated with an increased risk of stroke.

METHODS

We identified 3699 in-patients who were aged ≥18 years and newly diagnosed with leptospirosis. We also randomly selected a comparison cohort 14 796 in-patients from the general population by using a propensity score matching method (at a 1:4 ratio). We analyzed the risks of stroke by using Cox proportional hazard regression models.

RESULTS

The adjusted hazard ratio (HR; 95% CI) of stroke for the leptospirosis group was 1.14 (0.93-1.38; P=0.200) as opposed to the comparison group after adjusting sex, age, and comorbidities. However, adjusted HR (95% CI) of ischemic stroke and hemorrhagic stroke was 1.01 (0.80-1.29) and 1.58 (1.12-2.23), respectively. The strength of association between leptospirosis and hemorrhagic stroke remained statistically significant after variation of leptospirosis and stroke definitions. The post hoc subgroup analysis indicated that a patient with leptospirosis had a significantly greater risk of hemorrhagic stroke in male (adjusted HR, 1.62 [95% CI, 1.08-2.44]) and individuals between age 18 and 39 (adjusted HR, 3.67 [95% CI, 1.33-10.14]). The risk of hemorrhagic stroke among people with leptospirosis was highest in the first 2 years after diagnosis (adjusted HR, 1.97 [95% CI, 1.15-3.38]).

CONCLUSIONS

A 2.49-fold risk of stroke was found among the leptospirosis cohort of aged younger than 39 years. Age acted as an effect modifier between the leptospirosis and risk of new-onset stroke.

Intracranial Mycotic Aneurysm in a Left Ventricular Assist Device Patient: A Complication to Avoid

In the current era of the increasing use of left ventricular assist devices (LVADs) as a bridge to transplant or destination therapy, early diagnosis and therapy of complications are imperative to provide a better quality of life and improve outcomes. This case illustrates how superficial infections can lead to drastic complications in the setting of LVADs. The lack of signs and symptoms of systemic inflammatory response could be explained by cellular immunity impairment in patients on LVAD support. The formation of aneurysms is enhanced in the LVAD population due to altered hemodynamic physiology. It is possible that the combination of impaired cellular immunity and altered hemodynamics of the present-day continuous flow LVADS increases the risk of mycotic aneurysm formation and rupture in patients infected with less virulent organisms.

Ischemic stroke in COVID-19: An urgent need for early identification and management

OBJECTIVE

In the setting of the Coronavirus Disease 2019 (COVID-19) global pandemic caused by SARS-CoV-2, a potential association of this disease with stroke has been suggested. We aimed to describe the characteristics of patients who were admitted with COVID-19 and had an acute ischemic stroke (AIS).

METHODS

This is a case series of PCR-confirmed COVID-19 patients with ischemic stroke admitted to an academic health system in metropolitan Atlanta, Georgia (USA) between March 24th, 2020 and July 17th, 2020. Demographic, clinical, and radiographic characteristics were described.

RESULTS

Of 396 ischemic stroke patients admitted during this study period, 13 (2.5%) were also diagnosed with COVID-19. The mean age of patients was 61.6 ± 10.8 years, 10 (76.9%) male, 8 (61.5%) were Black Americans, mean time from last normal was 4.97 ± 5.1 days, and only one received acute reperfusion therapy. All 13 patients had at least one stroke-associated co-morbidity. The predominant pattern of ischemic stroke was embolic with 4 explained by atrial fibrillation. COVID-19 patients had a significantly higher rate of cryptogenic stroke than non-COVID-19 patients during the study period (69% vs 17%, p = 0.0001).

CONCLUSIONS

In our case series, ischemic stroke affected COVID-19 patients with traditional stroke risk factors at an age typically seen in non-COVID populations, and mainly affecting males and Black Americans. We observed a predominantly embolic pattern of stroke with a higher than expected rate of cryptogenic strokes, a prolonged median time to presentation and symptom recognition limiting the use of acute reperfusion treatments. These results highlight the need for increased community awareness, early identification, and management of AIS in COVID-19 patients.

Large Vessel Occlusion Secondary to COVID-19 Hypercoagulability in a Young Patient: A Case Report and Literature Review

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) initially most appreciated for its pulmonary symptoms, is now increasingly recognized for causing multi-organ disease and stroke in the setting of a hypercoagulable state. We report a case of 33-year-old African American woman with COVID-19 who developed acute malignant middle cerebral artery infarction due to thromboembolic occlusion of the left terminal internal carotid artery and middle cerebral artery stem. Mechanical thrombectomy was challenging and ultimately unsuccessful resulting in limited reperfusion of <67% of the affected vascular territory, and thrombectomized clot was over 50 mm in length, at least three times the average clot length. The final stroke size was estimated at 224 cubic centimeters. On admission her D-dimer level was 94,589 ng/mL (normal 0-500 ng/ml). Throughout the hospitalization D-dimer decreased but never reached normal values while fibrinogen trended upward. Hypercoagulability panel was remarkable for mildly elevated anticardiolipin IgM of 16.3 MPL/mL (normal: 0-11.0 MPL/mL). With respect to remaining stroke workup, there was no evidence of clinically significant stenosis or dissection in the proximal internal carotid artery or significant cardioembolic source including cardiomyopathy, atrial fibrillation, cardiac thrombus, cardiac tumor, valvular abnormality, aortic arch atheroma, or patent foramen ovale. She developed malignant cytotoxic cerebral edema and succumbed to complications. This case underscores the importance of recognizing hypercoagulability as a cause of severe stroke and poor outcome in young patients with COVID-19 and highlights the need for further studies to define correlation between markers of coagulopathy in patients with COVID-19 infection and outcome post stroke.

Stroke in young adults: Current trends, opportunities for prevention and pathways forward

Cardiovascular disease remains a major contributor to morbidity and mortality in the US and elsewhere, and stroke is a leading cause of disability worldwide. Despite recent success in diminishing stroke incidence in the general US population, in parallel there is now a concerning propensity for strokes to happen at younger ages. Specifically, the incidence of stroke for US adults 20-44 years of age increased from 17 per 100,000 US adults in 1993 to 28 per 100,000 in 2015. Occurrence of strokes in young adults is particularly problematic as these patients are often affected by physical disability, depression, cognitive impairment and loss of productivity, all of which have vast personal, social and economic implications. These concerning trends among young adults are likely due to increasing trends in the prevalence of modifiable risk factors amongst this population including hypertension, hyperlipidemia, obesity and diabetes, highlighting the importance of early detection and aggressive prevention strategies in the general population at early ages. In parallel and compounding to the issue, troublesome trends are evident regarding increasing rates of substance abuse among young adults. Higher rates of strokes have been noted particularly among young African Americans, indicating the need for tailored prevention and social efforts targeting this and other vulnerable groups, including the primordial prevention of risk factors in the first place, reducing stroke rates in the presence of prevalent risk factors such as hypertension, and improving outcomes through enhanced healthcare access. In this narrative review we aim to emphasize the importance of stroke in young adults as a growing public health issue and increase awareness among clinicians and the public health sector. For this purpose, we summarize the available data on stroke in young adults and discuss the underlying epidemiology, etiology, risk factors, prognosis and opportunities for timely prevention of stroke specifically at young ages. Furthermore, this review highlights the gaps in knowledge and proposes future directions moving forward.

Risk of subsequent ischemic stroke in patients with nontyphoidal salmonellosis: A nationwide population-based cohort study

OBJECTIVES

To explore the association between nontyphoidal salmonellosis (NTS) and the risk of acute ischemic stroke (IS) by using a nationwide, population-based study.

METHODS

A retrospective cohort study using claim data from Taiwan's National Health Insurance Research Database (NHIRD), patients aged 18 years and older with histories of NTS (N = 1618) were included from January 1, 2000-December 31, 2012, and the non-NTS group (N = 6472) without NTS were matched by propensity score. The follow-up period was defined as the time from the initial diagnosis of NTS to the date of development of IS, death or 31 December, 2013. Patients previously diagnosed with stroke were excluded. The Cox proportional hazard model with robust sandwich estimator was used to estimate the hazard ratio (HR) and 95% confidence interval (CI) of IS after adjusting for demographic and clinical covariates.

RESULTS

The adjusted hazard ratio (aHR) for the NTS group compared with the non-NTS group was 1.34 (95% confidence interval [CI], 1.10-1.65) for overall stroke. Furthermore, the NTS cohort had an increased risk of IS compared to the non-NTS groups (aHR, 1.42; 95% CI, 1.14-1.78). Stratified analysis showed that compared with propensity score matched non-NTS group, subjects aged ≥65 years, female, those with hypertension, hyperlipidemia, COPD, cancer and heart failure had higher risk of developing stroke. A 1.93-fold significant increase risk for stroke was observed during the first 3-12 months of follow-up (95% CI, 1.07-3.48).

CONCLUSIONS

Patients with NTS is associated with increased risk of developing ischemic stroke compared with non-NTS patients. Timely and mindful treatment plan about NTS may be a milestone to stroke prevention especially in some subpopulation.

COVID-19 and Stroke: Incidental, Triggered or Causative

Stroke is a serious neurological comorbidity observed during the ongoing COVID-19 (coronavirus associated disease 2019) pandemic caused by SARS-CoV-2 (severe acute respiratory syndrome, corona virus 2) and includes ischemic stroke, intracerebral haemorrhage and cerebral venous thrombosis. We reviewed factors that could potentially contribute to the occurrence of stroke among patients with COVID-19. There could be an interaction between the conventional risk factors of stroke, infection, systemic inflammatory response and plaque destabilisation. Inflammatory markers, D-dimer elevation and increased cytokine activity have been observed in patients with COVID-19. Other probable contributing factors include cardiac injury leading to embolism, a prothrombotic state and a possibility of direct neuroinvasive potential causing vasculopathy. Data from stroke patients gathered in large multicentric cohorts could help shed more light on the occurrence, behaviour, aetiology, pathophysiology, biomarkers and outcomes of stroke occurring during the ongoing pandemic.

Cryptogenic Stroke: Anatomy of the Stroke Work-Up

Despite advances in understanding the cause of ischemic stroke, cryptogenic stroke remains a diagnostic and therapeutic challenge for clinicians. Approximately 15% to 40% of all ischemic strokes have no identifiable cause. CS is a diagnosis of exclusion after completing the standard stroke work-up. Further investigation needs to be tailored individually according to results of the clinical evaluation so appropriate secondary prevention strategies can be applied.

Stroke in the Young: a Global Update

PURPOSE OF REVIEW

We aim to evaluate the epidemiology, racial and gender disparity, etiology, and treatment of stroke in the younger population.

RECENT FINDINGS

The younger age group without vascular risk factors exhibits an increased prevalence of cardio-embolism in context of patent foramen ovale/atrial septal aneurysm strokes, from other determined etiology of non-atherosclerotic vasculopathy including dissection, inherited or acquired thrombophilia, and other unusual causes of stroke. Ethnic disparities also exist in certain populations. The prevalence of stroke in the young is increasing due to several factors. Since stroke is often disabling, this trend poses an enormous threat to socioeconomic stability especially in developing countries. In young patients with an absence of conventional vascular risk factors and negative preliminary stroke work-up, clinicians must consider less common causes of stroke in this population. There is prime opportunity for future investigations as there is currently a lack of evidence-based management guidelines for these uncommon etiologies based on research completed to date.