Neurological manifestations of infective endocarditis. Review of clinical and therapeutic challenges

Early Surgery for Infective Endocarditis Complicated With Neurologic Injury

OBJECTIVES

To estimate the association between early surgery and the risk of mortality in patients with left-sided infective endocarditis in the context of stroke.

DESIGN

Retrospective cohort study.

SETTING

This study was a multiinstitution study based on the Chang Gung Research Database, which contains electronic medical records from 7 hospitals in northern and southern Taiwan; these include 2 medical centers, 2 regional hospitals, and 3 district hospitals.

PARTICIPANTS

Patients with active left-sided infective endocarditis who underwent valve surgery between September 2002 and December 2018.

INTERVENTIONS

The authors divided patients into 2 groups, with versus without preoperative neurologic complications, had undergone early (within 7 d) or later surgery, and with brain ischemia or hemorrhage.

MEASUREMENTS AND MAIN RESULTS

Three hundred ninety-two patients with a median time from diagnosis to surgery of 6 days were included. No significant differences in postoperative stroke, in-hospital mortality, or follow-up outcomes were observed between the patients with and without neurologic complications. Among the patients with preoperative neurologic complications, patients who underwent early surgery had a lower 30-day postoperative mortality rate (13.1% v 25.8%; hazard ratio, 0.21; 95% CI 0.07-0.67). In the subgroup analysis of the comparison between brain ischemia and hemorrhage groups, there was no significant between-group difference in the in-hospital outcomes or outcomes after discharge.

CONCLUSIONS

Early cardiac surgery may be associated with more favorable clinical outcomes in patients with preoperative neurologic complications. Thus, preoperative neurologic complications should not delay surgical interventions.

Community-acquired Staphylococcus aureus meningitis in adults

BACKGROUND

Staphylococcus aureus is an uncommon cause of community-acquired bacterial meningitis. We aimed to describe patients with this disease.

METHODS

We evaluated clinical characteristics and outcome of adults with community-acquired S. aureus meningitis from prospective nationwide cohort studies from Denmark (2015-2020) and the Netherlands (2006-2021). Whole genome sequencing of S. aureus isolates was performed to evaluate the potential association between clonal complex and clinical characteristics.

RESULTS

We evaluated 111 episodes of community-acquired S. aureus meningitis: 65 from Denmark and 46 from the Netherlands. The median age was 66 years (interquartile range [IQR] 50-74) and 43 of 111 patients were female (39%). Concomitant infectious foci were found in 95 of 107 patients (89%), most commonly endocarditis (53 of 109 [49%]) and spondylodiscitis (43 of 109 [39%]). The triad of neck stiffness, altered mental status (Glasgow Coma Scale score <14), and fever was present in only 18 of 108 patients (17%). Surgery was performed in 14 of 33 patients (42%) with spondylodiscitis and 26 of 52 (50%) with endocarditis. A favorable outcome (Glasgow Outcome Scale score 5) occurred in 26 of 111 patients (23%), while 39 (35%) died. The most common bacterial clonal complexes (CC) were CC30 (16 [17%]), CC45 (16 [17%]), CC5 (12 [13%], and CC15 (10 [11%]); no associations between CCs and concomitant foci or outcome were found.

CONCLUSIONS

Community-acquired S. aureus meningitis is a severe disease with a high case fatality rate, occurring mainly in patients with concomitant endocarditis or spondylodiscitis.

A Rare and Interesting Presentation of Diabetic Ketoacidosis Caused by Native Aortic Valve Endocarditis Complicated by Aortic Root Abscess Resulting in Multiple Septic Emboli Causing Bowel Ischemia and Splenic Infarction

Diabetic ketoacidosis (DKA) is a serious life-threatening complication of diabetes, often precipitated by infection. Infective endocarditis (IE) is a serious precipitating factor for DKA, especially in patients with a previous cardiac surgery or valvular pathology. IE can be further complicated by life-threatening embolic events, which could be fatal if not detected and managed early and effectively. Our patient is a 54-year-old diabetic who presented with DKA precipitated by native aortic valve endocarditis complicated by an aortic root abscess, which was further complicated by septic emboli to the splenic artery and superior mesenteric artery leading to splenic infarction and bowel ischemia, respectively. To our knowledge and as per the literature reviewed, no case has been reported in a single patient who presented with DKA precipitated by IE complicated by aortic root abscess and multiple septic emboli resulting in bowel ischemia and splenic infarction.

Impact of Brain MRI on the Diagnosis of Infective Endocarditis and Treatment Decisions: Systematic Review and Meta-Analysis

BACKGROUND. Despite increasing use of brain MRI to evaluate patients with suspected infective endocarditis, the clinical impact of brain MRI in this setting has not yet been systematically reviewed. OBJECTIVE. The purpose of this study was to evaluate the frequency of brain MRI findings in patients with suspected or confirmed infective endocarditis and to determine the impact of such findings on clinical decisions. EVIDENCE ACQUISITION. A systematic search of the PubMed, Embase, and Cochrane databases was performed from January 1, 1990, to December 31, 2020, to identify original research investigations of brain MRI in patients with suspected or confirmed infective endocarditis. Study quality was assessed with QUADAS-2. Study endpoints included the frequency of brain MRI findings and the frequency of diagnostic modifications, modification of therapeutic plan, and modification of valve surgery plan resulting from MRI findings. Frequencies were pooled by means of the inverse variance method. Subgroup analysis was performed. EVIDENCE SYNTHESIS. A total of 21 studies with 2133 patients were included. Overall study quality was considered moderate. In terms of brain MRI findings, the pooled frequency of acute ischemic lesions was 61.9% (95% CI, 50.7-71.9%); of cerebral microbleeds, 52.9% (95% CI, 41.6-63.9%); hemorrhagic lesions, 24.7% (95% CI, 15.1-37.9%); abscess or meningitis, 9.5% (95% CI, 5.6-15.6%); and intracranial mycotic aneurysm, 6.2% (95% CI, 4.0-9.4%). Subgroup analysis after exclusion of three studies in which neurologic findings were the indication for all brain MRI examinations yielded similar frequencies of these findings. Six studies included results on the impact of brain MRI findings on clinical decisions. The frequencies of diagnostic modifications in two studies were 5.4% and 32.1%. The pooled frequency of therapeutic plan modification in six studies was 12.8% (95% CI, 6.5-23.7%) and of surgical plan modification in five studies was 14.2% (95% CI, 8.2-23.4%). CONCLUSION. In patients with suspected or confirmed infective endocarditis, brain MRI examinations commonly show relevant abnormalities that affect diagnostic and therapeutic clinical decisions. CLINICAL IMPACT. The findings support a potential role for screening brain MRI in the evaluation of patients with suspected or confirmed infective endocarditis, regardless of the presence or absence of neurologic symptoms.

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.

Invasive pneumococcal disease confirmed in five different sites including Austrian syndrome in a male patient with methamphetamine abuse

A 60-year-old man with no significant medical history was found unresponsive by his neighbour; he had neck stiffness on physical examination in the emergency department. He later developed acute hypoxic respiratory failure requiring endotracheal intubation. He is a binge drinker on weekends, and methamphetamine was detected in his urine. Contrast-enhanced CT of the chest, abdomen and pelvis revealed multifocal pneumonia, bilateral psoas abscesses and right infraspinatus muscle abscess. Blood, sputum and cerebrospinal fluid cultures grew Streptococcus pneumoniae Transthoracic echocardiography (TTE) revealed tricuspid endocarditis with mild valve insufficiency. He was initially treated with intravenous antibiotics and underwent incision and drainage of right psoas abscess. However, he still had recurrent fever and confusion. Repeat TTE showed larger vegetation, and he also developed septic emboli at the posterior basal right lower lobe pulmonary artery. The patient underwent tricuspid valve debridement and was finally discharged after completing 6 weeks of intravenous antibiotic treatment.

Screening of Natural Products and Approved Oncology Drug Libraries for Activity against Clostridioides difficile

Clostridioides difficile is the most common cause of healthcare-associated diarrhea. Infection of the gastrointestinal tract with this Gram-positive, obligate anaerobe can lead to potentially life-threatening conditions in the antibiotic-treated populace. New therapeutics are urgently needed to treat this infection and prevent its recurrence. Here, we screened two libraries from the National Cancer Institute, namely, the natural product set III library (117 compounds) and the approved oncology drugs set V library (114 compounds), against C. difficile. In the two libraries screened, 17 compounds from the natural product set III library and 7 compounds from the approved oncology drugs set V library were found to exhibit anticlostridial activity. The most potent FDA-approved drugs (mitomycin C and mithramycin A) and a promising natural product (aureomycin) were further screened against 20 clinical isolates of C. difficile. The anticancer drugs, mitomycin C (MIC₅₀ = 0.25 μg/ml) and mithramycin A (MIC₅₀ = 0.015 μg/ml), and the naturally derived tetracycline derivative, aureomycin (MIC₅₀ = 0.06 μg/ml), exhibited potent activity against C. difficile strains. Mithramycin A and aureomycin were further found to inhibit toxin production by this pathogen. Given their efficacy, these compounds can provide a quick supplement to current treatment to address the unmet needs in treating C. difficile infection and preventing its recurrence.

Methicillin-Resistant Staphylococcus aureus Prosthetic Valve Endocarditis: Pathophysiology, Epidemiology, Clinical Presentation, Diagnosis, and Management

Staphylococcus aureus prosthetic valve endocarditis (PVE) remains among the most morbid bacterial infections, with mortality estimates ranging from 40% to 80%. The proportion of PVE cases due to methicillin-resistant Staphylococcus aureus (MRSA) has grown in recent decades, to account for more than 15% of cases of S. aureus PVE and 6% of all cases of PVE. Because no large studies or clinical trials for PVE have been published, most guidelines on the diagnosis and management of MRSA PVE rely upon expert opinion and data from animal models or related conditions (e.g., coagulase-negative Staphylococcus infection). We performed a review of the literature on MRSA PVE to summarize data on pathogenic mechanisms and updates in epidemiology and therapeutic management and to inform diagnostic strategies and priority areas where additional clinical and laboratory data will be particularly useful to guide therapy. Major updates discussed in this review include novel diagnostics, indications for surgical management, the utility of aminoglycosides in medical therapy, and a review of newer antistaphylococcal agents used for the management of MRSA PVE.

Systematic Review of Endovascular, Surgical, and Conservative Options for Infectious Intracranial Aneurysms and Cardiac Considerations

INTRODUCTION

With rising rates of intravenous drug use, Infectious Intracranial aneurysms (IIAs) are a relevant topic for investigation. We performed a systematic review to better understand current practice patterns and limits of current published literature.

METHOD

131 publications with a total of 499 patients (665 aneurysms) were included. Of the 499 patients, 83 were single case reports, and 20.5% of the total had multiple aneurysms. 35.8% of all aneurysms were ruptured. Of those reporting treatment, options included conservative antibiotic therapy (30.0%), open surgical intervention (31.1%), and endovascular occlusion (31.8%). Chronologically, publication of IIAs has increased. Usage of endovascular therapies has grown, while conservative and surgical management have declined in the literature. Overall, 56.2% of aneurysms for which conservative therapy was initiated eventually either underwent intervention or death of patient occurred.

RESULTS

The issue of cardiac valve surgery in relationship to aneurysm therapy was discussed in 20.8% (80 patients) of all 384 infectious endocarditis patients; of which 15.0% (12) underwent valve surgery before aneurysm treatment and 85.0 patients (68)% underwent valve surgery after aneurysm treatment. For 51 of the patients where valve surgery followed aneurysm management, the corresponding aneurysm treatment modality could be determined; 58.8% (30) of whom were managed endovascularly. 32.7% (26) of all cases reporting cardiac surgery details underwent cardiac surgery during their admission with the IIA.

CONCLUSIONS

Overall, increasing trend of endovascular management of IIAs is evident, and a strong temporal preference exhibited by providers to perform cardiac surgery subsequently to IIA management.

Surgical Management of Infective Endocarditis Complicated by Embolic Stroke: Practical Recommendations for Clinicians

There has been an overall improvement in surgical mortality for patients with infective endocarditis (IE), presumably because of improved diagnosis and management, centered around a more aggressive early surgical approach. Surgery is currently performed in approximately half of all cases of IE. Improved survival in surgery-treated patients is correlated with a reduction in heart failure and the prevention of embolic sequelae. It is reported that between 20% and 40% of patients with IE present with stroke or other neurological conditions. It is for these IE patients that the timing of surgical intervention remains a point of considerable discussion and debate. Despite evidence of improved survival in IE patients with earlier surgical treatment, a significant proportion of patients with IE and preexisting neurological complications either undergo delayed surgery or do not have surgery at all, even when surgery is indicated and guideline endorsed. Physicians and surgeons are caught in a common conundrum where the urgency of the heart operation must be balanced against the real or perceived risks of neurological exacerbation. Recent data suggest that the risk of neurological exacerbation may be lower than previously believed. Current guidelines reflect a shift toward early surgery for such patients, but there continue to be important areas of clinical equipoise. Individualized clinical assessment is of major importance for decision making, and, as such, we emphasize the need for the functioning of an endocarditis team, including cardiac surgeons, cardiologists, infectious diseases specialists, neurologists, neurosurgeons, and interventional neuroradiologists. Here, we present 2 illustrative cases, critically review contemporary data, and offer conceptual and practical suggestions for clinicians to address this important, common, and often fatal cardiac condition.

Preoperative Cerebrovascular Evaluation in Patients With Infective Endocarditis

Approximately 12% to 40% of infective endocarditis patients experience cerebrovascular complications. One of the major clinical challenges in cerebrovascular medicine is management of infective endocarditis patients with cerebrovascular complications who require valve operations. Cerebrovascular specialists are often summoned to address appropriate preoperative brain imaging, timing of surgery, and estimation of the risk of perioperative cerebral embolization and hemorrhage. This article addresses these issues based on the available evidence.

Neurologic complications in infective endocarditis: identification, management, and impact on cardiac surgery

Neurologic complications of infective endocarditis (IE) are common and frequently life threatening. Neurologic events are not always obvious. The prediction and management of neurologic complications of IE are not easily approached algorithmically, and the impact they have on timing and ability to surgically repair or replace the affected valve often requires a painstaking evaluation and joint effort across multiple medical disciplines in order to achieve the best possible outcome. Although specific recommendations are always tailored to the individual patient, there are some guiding principles that can be used to help direct the decision-making process. Herein, we review the pathophysiology, epidemiology, manifestations, and diagnosis of neurological complications of IE and further consider the impact they have on clinical decision making.

Unreported neurological complications of Gemella bergeriae infective endocarditis

We report the first case of native aortic and mitral valve endocarditis due to Gemella bergeriae from the Middle East in a young patient with rheumatic heart disease. Our case illustrates a fulminant course of infection with G. bergeriae endocarditis that was complicated by embolic stroke, as well as intracerebral and subarachnoid haemorrhage secondary to rupture of a mycotic aneurysm in the right middle cerebral artery. This case highlights the dire, unreported neurological complications of infective endocarditis due to a rare causative organism-G. bergeriae.

Neurologic complications of valvular heart disease

Valvular heart disease (VHD) is frequently associated with neurologic complications; cerebral embolism is the most common of these since thrombus formation results from the abnormalities in the valvular surfaces or from the anatomic and physiologic changes associated with valve dysfunction, such as atrial or ventricular enlargement, intracardiac thrombi, and cardiac dysrhythmias. Prosthetic heart valves, particularly mechanical valves, are very thrombogenic, which explains the high risk of thromboembolism and the need for anticoagulation for the prevention of embolism. Infective endocarditis is a disease process with protean manifestations that include not only cerebral embolism but also intracranial hemorrhage, mycotic aneurysms, and systemic manifestations such as fever and encephalopathy. Other neurologic complications include nonbacterial thrombotic endocarditis, a process associated with systemic diseases such as cancer and systemic lupus erythematosus. For many of these conditions, anticoagulation is the mainstay of treatment to prevent cerebral embolism, therefore it is the potential complications of anticoagulation that can explain other neurologic complications in patients with VHD. The prevention and management of these complications requires an understanding of their natural history in order to balance the risks posed by valvular disease itself against the risks and benefits associated with treatment.

Ultrasound-based imaging in neurocritical care patients: a review of clinical applications

OBJECTIVE

To analyze the diagnostic, monitoring, and procedural applications of ultrasound (US) imaging in neurocritical care (NCC) patients.

METHOD

US imaging has been extensively validated in various subset of critically ill patients, but not specifically in the NCC population. We reviewed the clinical applications of US imaging for heart, vascular, brain, and lung evaluation and for possible procedural uses in NCC patients. Major neurosurgical books, journals, testimonials, authors' personal experience, and scientific databases were analyzed.

RESULTS

Cardiac US imaging provides accurate information at NCC arrival to stratify risk factors, including presence of atrial septal defect/patent formen ovale, abnormal ventricular function, or pericardial effusion, and to monitor cardiac anatomy and function during the NCC stay for guiding goal-directed therapy. Vascular US in NCC patients has three especially relevant indications: to screen anatomy and flow in extracranial supra-aortic arteries, to diagnose deep vein thrombosis, and to optimize the safety of central venous catheterization. Brain US has important clinical applications in the NCC, including transcranial Doppler and emerging techniques for cerebral blood flow evaluation with contrast-enhanced US imaging. Lung US, as demonstrated in other intensive care unit patients, provides accurate diagnosis of anatomical and functional abnormalities and enables diagnosis of pleural effusion, pneumothorax, lung consolidation, pulmonary abscess and interstitial-alveolar syndrome, and lung recruitment/derecruitment. US imaging can effectively guide percutaneous tracheostomy.

CONCLUSION

In conclusion, US imaging is an important diagnostic tool that provides real-time information at the bedside to stratify risk, monitor for complications, and guide invasive procedures in NCC patients.

Complete graft dehiscence 8 months after repair of acute type A aortic dissection

Acute type A aortic dissection is a dreaded differential diagnosis of acute chest pain. Long-term outcome mainly depends on pre-existing comorbidities and post-operative complications. We present a patient with aortic graft dehiscence and subsequent severe aortic regurgitation due to fungal graft infection 8 months after repair of acute type A aortic dissection. Redo aortic surgery had to be delayed for 28 days due to intracerebral haemorrhage caused by septic embolism and clipping of a mycotic left middle cerebral artery aneurysm. Surgery revealed a circumferentially detached graft at the site of the proximal anastomosis thereby forming a massive pseudoaneurysm. The patient underwent successful aortic root replacement using a Freestyle porcine root bioprosthesis (25 mm), followed by re-anastomosis of the coronary arteries and partial replacement of the ascending aorta with a 28 mm Dacron graft. The patient was discharged on day 67 in stable cardiac condition with persistent neurological deficits. This case highlights the challenging management of patients with aortic graft infection and neurological dysfunction after redissection of the ascending aorta who require redo cardiac surgery.

Current treatment of active infective endocarditis with brain complications

We describe the optimal timing of surgery in active infective endocarditis patients with brain complications. (1) Non-hemorrhagic infarction: elective surgery has been recommended in patients with non-hemorrhagic infarction. However, the timing is changing to an earlier phase. Recent studies have shown that silent brain embolism and small-size infarction (15-20 mm) without coma can be operated safely without delay. On the other hand, in patients with large non-hemorrhagic infarction with impaired consciousness, early surgery is not recommended. (2) Non-ruptured infectious intracranial aneurysm: treatment strategies for patients with infectious aneurysms without rupture remain controversial. However, the treatments are generally as follows. If the intracranial aneurysm without rupture decreases in size by administration of effective antibiotics, neurosurgery will not be required and cardiac surgery can be prioritized without delay. When the aneurysm without rupture enlarges and changes its morphology, neurosurgery or endovascular surgery should be prioritized to prevent its rupture. (3) Hemorrhagic stroke: this type is classified into primary intra-cerebral hemorrhage due to simple necrotic arteritis, hemorrhagic transformation of ischemic infarcts, and rupture of intracranial infectious aneurysms. Among these, primary intracerebral hemorrhage is the most frequently observed. In patients with the primary intracerebral hemorrhage, surgery must be postponed for at least 4 weeks to prevent exacerbation of bleeding. In patients with ruptured infectious aneurysm, neurosurgery or endovascular surgery is performed initially and cardiac surgery should be postponed at least 2-3 weeks.

Infective Endocarditis Complicated by Acute Ischemic Stroke from Septic Embolus: Successful Solitaire FR Thrombectomy

Infective endocarditis (IE) is often complicated by systemic embolization. Acute stroke due to septic emboli is a particularly dreaded complication. Optimal treatment for acute stroke in IE has not been well outlined. Fibrinolytic therapy may be associated with increased risk for hemorrhagic transformation in patients with acute stroke in the setting of IE. We present a case of IE complicated by acute stroke which was successfully treated with mechanical thrombectomy. This case illustrates a role of mechanical thrombectomy devices in this patient population.

Warfarin therapy and incidence of cerebrovascular complications in left-sided native valve endocarditis

Anticoagulant therapy has been anticipated to increase the risk of cerebrovascular complications (CVC) in native valve endocarditis (NVE). This study investigates the relationship between ongoing oral anticoagulant therapy and the incidence of symptomatic CVC in left-sided NVE. In a prospective cohort study, the CVC incidence was compared between NVE patients with and without ongoing warfarin. Among 587 NVE episodes, 48 (8%) occurred in patients on warfarin. A symptomatic CVC was seen in 144 (25%) patients, with only three on warfarin. CVC were significantly less frequent in patients on warfarin (6% vs. 26%, odds ratio [OR] 0.20, 95% confidence interval [CI] 0.06-0.6, p = 0.006). No increase in haemorrhagic lesions was detected in patients on warfarin. Staphylococcus aureus aetiology (adjusted OR [aOR] 6.3, 95% CI 3.8-10.4) and vegetation length (aOR 1.04, 96% CI 1.01-1.07) were risk factors for CVC, while warfarin on admission (aOR 0.26, 95% CI 0.07-0.94), history of congestive heart failure (adjusted OR 0.22, 95% CI 0.1-0.52) and previous endocarditis (aOR 0.1, 95% CI 0.01-0.79) correlated with lower CVC frequency.

[Infectious endocarditis due to Gemella morbillorum found by splenic infarction--a case report]

A 64-year-old man with prostate cancer and bone metastasis admitted for nausea, left abdominal pain showed no abnormal, and fever, abdominal ultrasound or chest X-ray findings. Despite antibiotics, left abdominal pain persisted for several days. Abdominal computed tomography (CT), showed splenic infarction. Transesophageal echocardiography suggested infectious endocarditis (IE) as a possible infarction cause, and roth spots were found on the retina. Gemella morbillorum was detected from blood culture. IE commonly causes Fever of Unknown Origin found by infarction. G. morbillorum, an anaerobic gram-positive, viridans group streptococci, is indigenous to the oropharynx, upper respiratory, urogenital, and gastrointestinal tracts, and is thought to have weak toxicity and pathogenicity in the body.

Chronic fungal sinusitis leading to disastrous cerebral aspergillosis: a case report

Cerebral angioinvasion is a fatal complication of disseminated aspergillosis and has been rarely described in diabetic population in the absence of ketoacidosis. We present a case of invasive fungal sinusitis in a 79 year old diabetic man who presented with chronic frontal headaches. Despite appropriate medical and surgical treatment, the disease progressed and the patient eventually succumbed to a fatal ruptured mycotic aneurysm. We emphasize that clinicians should consider this in the differential diagnoses of all diabetics who present with chronic sinusitis, as early diagnosis could be the key in the successful treatment.

Brain magnetic resonance findings in infective endocarditis with neurological complications

PURPOSE

Diagnosing infective endocarditis and its complications can be difficult because of the nonspecific symptoms. We reviewed findings of intracranial abnormalities on magnetic resonance imaging (MRI) in 14 patients with neurological complications and herein discuss the overall intracranial MRI findings.

MATERIALS AND METHODS

We retrospectively reviewed patients with infective endocarditis from August 2004 to August 2006. Brain MRI, the causative bacteria, and abnormal neurological symptoms were reviewed for 14 patients with neurological complications.

RESULTS

Of the 14 patients, 13 showed intracranial abnormalities on MRI. Embolization was seen in 10 patients, hemorrhage in 3, abscess formation in 3, and encephalitis in 2. Hyperintense lesions with a central hypointense area on T2-weighted and/or T2*-weighted imaging (Bull's-eye-like lesion) were seen in four patients. A combination of these intracranial abnormalities was observed in 6 patients.

CONCLUSION

The MRI findings associated with infective endocarditis are wide-ranging: embolization, hemorrhage, meningitis, cerebritis, abscess, the bull's-eye-like lesion. Clinicians should consider the possibility of infective endocarditis in patients with unknown fever and neurological abnormality. Brain MRI should be promptly performed for those patients, and T2*-weighted imaging is recommended for an early diagnosis of infective endocarditis.

Acute inflammatory demyelinating polyneuropathy and a unilateral babinski/plantar reflex

Acquired acute demyelinating peripheral polyneuropathy (AADP) is a general classification of pathologies that could affect secondary the peripheral nervous system. They are characterized by an autoimmune process directed towards myelin. Clinically they are characterized by progressive weakness and mild sensory changes. Acute inflammatory demyelinating polyneuropathy often is referred to as Guillain-Barré syndrome (GBS). GBS is the major cause of acute nontraumatic paralysis in healthy people and it is caused by autoimmune response to viral agents (influenza, coxsackie, Epstein-Barr virus, or cytomegalovirus) or bacterial infective organisms (Campylobacter jejuni, Mycoplasma pneumoniae). A detailed history, with symptoms of progressive usually bilateral weakness, hyporeflexia, with a typical demyelinating EMG pattern supports the diagnosis. Progressive affection of respiratory muscles and autonomic instability coupled with a protracted and unpredictable recovery normally results in the need for ICU management. We present a case report of a patient with a typical GBS presentation but with a unilateral upgoing plantar reflex (Babinski sign). A unifying diagnosis was made and based on a literature search in Pubmed appears to be the first described case of its kind.

Epidemiology and clinical outcomes of infective endocarditis in hemodialysis patients

BACKGROUND

Infective endocarditis is one of the most serious complications of bacteremia in patients undergoing chronic hemodialysis and is more frequent than previously recognized. The aim of our study was to describe the clinical characteristics, outcome, and factors predicting mortality of infective endocarditis in hemodialysis patients.

METHODS

In this retrospective review, all patients on chronic hemodialysis admitted to a 600-bed urban teaching hospital with infective endocarditis over a 15-year period (1990 to 2004), were identified using discharge codes. Modified Duke criteria were retrospectively applied, and patients fulfilling the criteria for definite endocarditis were included in the study.

RESULTS

Sixty-nine patients on hemodialysis with definite endocarditis were identified. The predominant type of vascular access was double-lumen catheter (66.7%). The mean duration of dialysis was 37 +/- 32 months. The predominant organism was Staphylococcus aureus (57.9%), of which 57.5% were methicillin susceptible. The most frequently infected valve was mitral (49.3%), followed by aortic (21.7%) and tricuspid (10.1%) valves. The cardiac and neurologic complication rates were 40.6% and 37.7%, respectively. Fifteen patients underwent valvular heart surgery. The overall in-hospital mortality was 49.3% (34 of 69). More patients who had surgery survived than patients who did not (12 of 15 versus 23 of 54; p = 0.018, odds ratio = 5.39, 95% confidence interval: 1.3 to 17.6). On logistic regression, valve surgery was the only independent factor predicting survival (p = 0.023).

CONCLUSIONS

The prognosis of infective endocarditis in hemodialysis patients is poor, with surgery serving as an independent predictor of survival.

Trends in neurological complications of endocarditis

Neurological complications (NCs) are a major cause of morbidity and mortality in patients with infectious endocarditis (IE). The frequency of these complications has been found to remain constant since the preantibiotic era despite profound epidemiological changes and therapeutic advances. We have reviewed retrospectively all the cases of IE attended at a single institution between 1985 and 2003, aiming to study the clinical characteristics of the NCs, and to analyse possible temporal trends in their frequency. Among 550 patients with IE, 71 (13%) suffered NCs. NCs presented more frequently in native (NVE) and prosthetic (PVE) valve endocarditis (17% and 20%, respectively) than in endocarditis associated with drug addiction (IDU-NVE) or pacemeker (6% and 9%, respectively). Cerebrovascular disorders were the most frequent NCs (60% of the patients had ischemic events and 21% had haemorrhages). Meningitis and cerebral abscess occurred in 16% and 3% of patients with NCs, respectively, and diffuse encephalopathy in 13%. Staphylococus aureus infection was the only factor associated with NCs, but only in NVE. During the study period there was a trend for increasing frequency of NCs in IE patients, probably associated to several factors: a decrease in IDUNVE, an increase in more aggressive nosocomial acquired NVE, and an increase in NVE caused by S. aureus. Mortality among patients with NCs (34%) was significantly higher than in IE patients without them (11%). During the study period mortality increased in patients with NVE and NCs.

Pseudomonas aeruginosa infective endocarditis presenting as bacterial meningitis

Pseudomonas aeruginosa is a rare cause of infective endocarditis. The case of community-acquired P. aeruginosa infective endocarditis reported here is the first described in the literature to present as bacterial meningitis. Furthermore, new risk factors for P. aeruginosa infective endocarditis, including mitral annular calcification and re-use of insulin syringes, are proposed. Treatment of P. aeruginosa infective endocarditis complicated by bacterial meningitis is discussed.

Vascular Encephalopathy Associated With Bacterial Endocarditis in Four Dogs

Vascular encephalopathy is a commonly encountered clinical complication of infectious endocarditis in humans, but it has been infrequently reported in dogs. A series of four dogs with bacterial endocarditis that subsequently developed acute onset of neurological deficits is described. Clinical signs, diagnostic test results, and outcomes for each case are presented and compared with the human clinical syndrome.

Central nervous system infections in injection drug users

Central nervous system infections in injection drug users are often devastating in terms of excess morbidity and mortality. In injection drug users with infective endocarditis, embolization from infected valvular vegetations may cause cerebral infarction, intracranial hemorrhage, and the formation of brain abscess. Focal intracranial infections (i.e., brain abscess and spinal epidural abscess) may occur in the absence of infective endocarditis, resulting from bacteremia that seeds the brain or epidural space. Antimicrobial therapy, combined with surgical intervention, may be essential to improve outcome from these neurologic complications. Toxin-mediated diseases (especially tetanus and wound botulism) are also seen in injection drug users. Inoculation of Clostridium spp at injection sites may lead to toxin generation and disease. Clinicians must maintain a high level of suspicion for these diagnoses in injection drug users.

Successful surgical management of patients with infective endocarditis associated with acute neurologic deficits

Subjects were 2 patients with neurologic deficits due to infective endocarditis. The first, a 30-year-old woman with acute ischemic stroke, was found to have vegetation from infective endocarditis as the embolic source. Two weeks after she experienced an acute ischemic stroke, we conducted elective cardiac surgery. The second, a 16-year-old girl with infective endocarditis, suffered a ruptured mycotic aneurysm in the left carotid system complicated by intracranial hemorrhage. We conducted a successful staged mitral valve replacement following craniotomy.

Intracranial infective aneurysms presenting with haemorrhage: an analysis of angiographic findings, management and outcome

AIM

This study is an analysis of angiographic findings in 17 patients with infective aneurysms who presented with intracranial haemorrhage and reviews the management and outcome in the context of the existing literature.

MATERIALS AND METHODS

A retrospective study of infective aneurysms in 17 patients was carried out. Cranial angiography was performed in all patients. The location, size and outline of aneurysms were analysed. Ten patients were managed conservatively and six patients underwent surgery for the ruptured infective aneurysms and were followed up for a period of 35.8 months and 23 months, respectively.

RESULTS

Twenty-two aneurysms were identified (five unruptured) in 17 patients. Twenty aneurysms (90. 9%) were distal in location and two (9.1%) proximal. Sixty percent were in the posterior circulation with 55% in the posterior cerebral artery (PCA) territory, 27.3% in the middle cerebral artery (MCA) territory and 9.1% in the anterior cerebral artery (ACA) territory. Fourteen aneurysms were small (3-5 mm) and eight were medium sized (6-9 mm). 72.7% of aneurysms had irregular outline and 27.3% regular outline. Out of the 10 ruptured aneurysms managed conservatively, eight resolved. One patient died, presumably due to rebleed, and one had infarction due to parent vessel thrombosis. Six aneurysms were surgically managed with good results. Of the five unruptured aneurysms one was surgically managed and the remaining four conservatively managed patients did not bleed during follow-up.

CONCLUSION

Patients with ruptured infective aneurysms fared well with medical management and the outcome in this series is better than that reported in literature. Patients on conservative management, however, need closer monitoring with angiographic follow-up. Active management is required with enlarging or persisting aneurysms.

Magnetic resonance imaging features of brain stem abscessation in two cats

Premortem magnetic resonance imaging (MRI) was performed in two cats with brain stem abscessation confirmed post mortem by histology and recovery of multiple bacterial species. The MRI features of the abscesses were distinctive and included a thick and marked enhancement of the abscess capsule and extension of the lesion from a tympanic bulla in one cat. A focal area of increased signal intensity was present on T2-weighted images. A circumscribed area of decreased signal intensity was surrounded by a ring of increased signal intensity on precontrast T1-weighted images. A center of decreased signal intensity with a thick, markedly enhanced abscess capsule was observed on post contrast T1-weighted images. These findings are compared to the current experimental and clinical literature of brain abscess. The underlying pathogenesis of MRI features is reviewed.

Acetylsalicylic acid reduces vegetation bacterial density, hematogenous bacterial dissemination, and frequency of embolic events in experimental Staphylococcus aureus endocarditis through antiplatelet and antibacterial effects

BACKGROUND

Platelets are integral to cardiac vegetations that evolve in infectious endocarditis. It has been postulated that the antiplatelet aggregation effect of aspirin (ASA) might diminish vegetation evolution and embolic rates.

METHODS AND RESULTS

Rabbits with Staphylococcus aureus endocarditis were given either no ASA (controls) or ASA at 4, 8, or 12 mg. kg-1. d-1 IV for 3 days beginning 1 day after infection. Vegetation weights and serial echocardiographic vegetation size, vegetation and kidney bacterial densities, and extent of renal embolization were evaluated. In addition, the effect of ASA on early S aureus adherence to sterile vegetations was assessed. In vitro, bacterial adherence to platelets, fibrin matrices, or fibrin-platelet matrices was quantified with either platelets exposed to ASA or S aureus preexposed to salicylic acid (SAL). ASA at 8 mg. kg-1. d-1 (but not at 4 or 12 mg. kg-1. d-1) was associated with substantial decreases in vegetation weight (P<0.05), echocardiographic vegetation growth (P<0.001), vegetation (P<0.05) and renal bacterial densities and renal embolic lesions (P<0.05) versus controls. Diminished aggregation resulted when platelets were preexposed to ASA or when S aureus was preexposed to SAL (P<0.05). S aureus adherence to sterile vegetations (P<0.05) or to platelets in suspension (P<0.05), fibrin matrices (P<0.05), or fibrin-platelet matrices (P<0.05) was significantly reduced when bacteria were preexposed to SAL.

CONCLUSIONS

ASA reduces several principal indicators of severity and metastatic events in experimental S aureus endocarditis. These benefits involve ASA effects on both the platelet and the microbe.

The presence of infection-related antiphospholipid antibodies in infective endocarditis determines a major risk factor for embolic events

OBJECTIVES

The impact of infection-associated antiphospholipid antibodies (APA) on endothelial cell activation, blood coagulation and fibrinolysis was evaluated in patients with infective endocarditis with and without major embolic events.

BACKGROUND

An embolic event is a common and severe complication of infective endocarditis. Despite the fact that APAs are known to be associated with infectious diseases, their pathogenic role in infective endocarditis has not been clearly defined.

METHODS

The relationship among the occurrence of major embolic events, echocardiographic vegetation size, endothelial cell activation, thrombin generation, fibrinolysis and APA was examined in 91 patients with definite infective endocarditis, including 26 patients with embolic events and 65 control subjects without embolic events.

RESULTS

Overall, 14.3% of patients exhibited elevated APA levels. Embolic events occurred more frequently in patients with elevated levels of APA than in patients without (61.5% vs. 23.1%; p = 0.008). Patients with elevated levels of APA showed higher levels of prothrombin-fragment F1 +2 (p = 0.005), plasminogen-activator inhibitor 1 (p = 0.0002), von Willebrand factor (p = 0.002) and lower levels of activated protein C (p = 0.001) than patients with normal levels of APA. Thrombin generation and endothelial cell activation were both positively correlated with levels of APA. The occurrence of elevated APA levels was frequently associated with structural valve abnormalities (p = 0.01) and vegetations >1.3 cm (p = 0.002).

CONCLUSIONS

Infection-associated elevated APA levels in patients with infective endocarditis are related to endothelial cell activation, thrombin generation and impairment of fibrinolysis. This may contribute to the increased risk for major embolic events in these patients.

Stroke in the medical intensive-care unit

OBJECTIVE

To analyze the occurrence and outcome of new-onset stroke in critically ill patients admitted to a medical intensive-care unit.

MATERIAL AND METHODS

We reviewed the medical records of patients admitted to the medical intensive-care units of two hospitals between 1985 and 1995. In addition, computed tomographic scans or scan reports were assessed.

RESULTS

We identified 19 patients with a critical medical illness and a new-onset stroke. Of this study group, ischemic stroke developed in 10 patients, 8 of whom were found to have bihemispheric infarction. A single territory infarct (the middle cerebral artery territory) was noted in two patients. The presumed mechanisms for ischemic stroke were disseminated intravascular coagulation (N = 6), cholesterol embolization (N = 1), discontinuation of warfarin therapy before an invasive procedure (N = 1), septic emboli (N = 1), and cardioversion (N = 1). In nine patients, an intracranial hemorrhage developed. Seven patients had a single lobar hematoma, whereas multiple intracerebral hematomas were found in two patients. Disseminated intravascular coagulation and rupture of a mycotic aneurysm in proven infective endocarditis were the most common mechanisms for hemorrhagic stroke. In all patients with an ischemic stroke, sudden hemiparesis rapidly progressed to coma. In patients with an intracranial hematoma and sudden onset of coma, unilateral fixed pupil was the most common initial manifestation. Of the 19 patients, 17 died and 2 remained severely disabled.

CONCLUSION

Coma is a common initial manifestation of stroke in patients with a critical medical illness, and disseminated intravascular coagulation has a major etiologic role. New-onset stroke in the setting of critical medical illness generally is a complication in a terminally ill patient.

Vasculitis owing to infection

Infections are a recognized cause of secondary vasculitis. A variety of pathogens have a propensity to involve blood vessels. Vasculitis, non-vasculitic vasculopathy, and mycotic aneurysms lead to infarction and hemorrhage of nervous system tissue. Treatment of infection-related vasculitis should include appropriate antimicrobial therapy directed against the offending pathogen, and appropriate management of cerebrovascular complications.

Focal neurologic deficits in infective endocarditis and other septic diseases

INTRODUCTION

Focal neurologic deficits in sepsis frequently result from parenchymal lesions due to cerebral embolism. The aim of this study was to characterize clinical, laboratory and radiologic patterns of those patients.

PATIENTS AND METHODS

Medical records of 30 patients with focal neurologic symptoms during sepsis were analyzed retrospectively.

RESULTS

24 patients (22 with infective endocarditis) had ischemic stroke. Cerebrospinal fluid (CSF) analyses revealed inflammation in 11 of 12 patients. Patients who died (11/24) suffered more frequently from secondary intracerebral hemorrhage (p = 0.0031), which was significantly associated with intravenous high-dose anticoagulation (p = 0.0059). Six patients had slowly progressive focal neurologic deficits without evidence for stroke. All showed CSF inflammation and three developed multiple cerebral abscesses.

CONCLUSIONS

There are two distinctive groups of patients with focal neurologic deficits during sepsis. One presents with stroke and CNS inflammation (septic embolic focal encephalitis). The other group develops slowly progressive focal neurologic deficits and sometimes multiple cerebral abscesses (septic metastatic focal encephalitis).

Neck pain and headache in an afebrile 15-year-old

Nuchal rigidity and headache are important signs of bacterial meningitis, although, in the absence of fever other etiologies would be considered. An evaluation of a 15-year-old boy with the above features, focal neurological deficits, and two cerebral contrast enhancing ring lesions is discussed.

Neurological complications of infective endocarditis

We reviewed the files of 80 successive patients with native and prosthetic valve endocarditis admitted to Riyadh Armed Forces Hospital. Neurological complications (NC) occurred in 28 (35%) patients. The valves involved were mitral in 12 (43%), aortic in eight (29%), combined mitral and aortic lesions in six (21%), and others in two (7%). The common causative organisms were Stretococci in 12 (43%), Staphylococcus aureus and Staphylococcus epidermides, both occuring in four (14%). Compared to the 52 infective endocarditis patients with no neurological complications (NNC), the NC occurred more frequently in male patients, those with aortic valve lesion, those with atrial fibrillation, those with delayed therapy and those with causative organisms being Streptococci or Staphylococci. Eleven patients died (39%), 12 (43%) recovered with motor sequelae, six (21%) had seizure disorder, and five (18%) had full recovery. The frequency of neurological complications and mortality is comparable to those reported in the literaturel; however, the frequency of strokes was higher in our patients.

Neurologic complications of infective endocarditis observed in a south Indian referral hospital

We retrospectively reviewed the records of 110 patients with infective endocarditis (IE) who were hospitalized between 1977 and 1994 at a tertiary referral center in Southern India to assess the occurrence of neurologic complications and the factors that contribute to their development, and to compare our experience from a developing country with the reported data from developed countries. There were 62 males and 48 females, aged 0.6-59 (mean 24.0) years. Rheumatic heart disease (RHD) was the most frequent underlying cardiac lesion accounting for 65 (59.1%) patients. Neurologic complications were observed in 58 (52.7%) patients: cerebral embolism was the most frequent (23 patients). Thirty-five (31.8%) patients died. Mortality in the group with neurologic complications (41.4%) was significantly higher than in the group without (21.2%) (p = 0.04). The duration of symptoms prior to the diagnosis was longer in the group with neurologic complications, mean 174.9 versus 95.6 days (p = 0.03). We conclude that (1) IE occurs at younger ages in the Third World and RHD still constitute the major underlying heart disease; (2) in spite of the differences in the general aspects of IE between developed and developing nations, the frequency and gravity of neurologic complications are similar, (3) mortality is significantly increased in patients with neurologic complications; and (4) delay in the diagnosis of IE contributes to the development of neurologic complications.

Valve replacement in patients with endocarditis and acute neurologic deficit

BACKGROUND

Acute neurologic deficits occur in up to 40% of patients with left heart endocarditis. Appropriate evaluation and management of patients with acute neurologic dysfunction who require valve operations for endocarditis remain controversial. This retrospective review was undertaken to develop recommendations for the evaluation and treatment of these challenging patients.

METHODS

From 1983 to 1995, 247 patients underwent operations for left heart native valve endocarditis at the Johns Hopkins Hospital. From a review of medical and pathology records, 34 patients (14%) with preoperative neurologic deficits were identified. Data on these 34 patients were recorded and analyzed.

RESULTS

Causes of neurologic dysfunction included embolic cerebrovascular accident (n = 23, 68%), embolic cerebrovascular accident with hemorrhage (n = 4, 12%), ruptured mycotic aneurysm (n = 3, 9%), transient ischemic attack (n = 2, 6%), and meningitis (n = 2, 6%). Preoperative diagnostic studies included computed tomography (32 patients), magnetic resonance imaging (11 patients), cerebral angiogram (14 patients), and lumbar puncture (2 patients). Computed tomography demonstrated structural lesions in 29 of 32 patients; in only 1 patient did magnetic resonance imaging reveal a lesion not already seen on computed tomography. Of 14 patients having cerebral angiograms, 7 had a mycotic aneurysm. Three mycotic aneurysms had ruptured, and these were clipped before cardiac operations. The mean interval from onset of neurologic deficit to cardiac operation was 22.2 +/- 2.8 days for all patients and 22.1 +/- 3.0 days for those with embolic cerebrovascular accident. The hospital mortality rate was 6%. New or worse neurologic deficits occurred in 2 patients (6%).

CONCLUSIONS

Neurologic deficits are common in patients with endocarditis referred for cardiac operations. Despite substantial preoperative morbidity, most of these patients do well if the operation can be delayed for 2 to 3 weeks. Computed tomography scan is the preoperative imaging technique of choice, as routine magnetic resonance imaging and cerebral angiogram are unrewarding. Cerebral angiogram is indicated only if computed tomography reveals hemorrhage.

Surgical management of infective endocarditis associated with cerebral complications. Multi-center retrospective study in Japan

To establish guidelines for the surgical treatment of patients with infective endocarditis who have cerebrovascular complications, we conducted a detailed retrospective study of 181 of 244 patients with cerebral complications among 2523 surgical cases of infective endocarditis of the Japanese Association of Thoracic Surgery. The results showed that 9.7% of all patients with infective endocarditis had associated cerebral complications: 108 (44.3%) had active native valve endocarditis, 96 (39.3%) had healed native valve endocarditis, and 40 (16.4%) had prosthetic valve endocarditis. The hospital mortality of the patients with cerebral complications was 11.0% in the group as a whole: 13.9% in active native valve endocarditis, 3.1% in healed native valve endocarditis, and 37.5% in prosthetic valve endocarditis. Diseased valves included the following aortic valve in 55.5%, mitral valve 49.8%, tricuspid valve in 1.3%, and pulmonary valve in 1.3%. In 181 patients with cerebral complications, organisms were detected as follows: gram-positive cocci in 133 (73.5% [Streptococcus in 85, Staphylococcus in 32]), gram-negative in 18 (9.9%), fungus in 11 (6.1%), and unknown in 64.6%, cerebral bleeding in 31.5%, cerebral abscess in 2.8%, and meningitis in 1.1%. Hospital mortality rate and an exacerbation rate of cerebral complications, including related death, according to the interval from onset of cerebral infarction to cardiac surgery, were as follows: 66.3% and 45.5% within 24 hours, 31.3% and 43.8% between 2 and 7 days, 16.7% and 16.7% between 8 and 14 days, 10.0% and 10.0% between 15 and 21 days, 26.3% and 10.5% between 22 and 28 days, and 7.0% and 2.3% over 4 weeks later, respectively. A significant correlation existed between the interval and the exacerbation of cerebral complications (tied p = 0.008). Preoperative risk factors affecting exacerbation of cerebral complications were as follows: (1) severity of cerebral complications (p = 0.006), (2) intervals (p = 0.012), and (3) uncontrolled congestive heart failure as indications for cardiac surgery (p = 0.014). One patient underwent a cardiac operation within 24 hours of the onset of cerebral hemorrhage and died of cerebral damage. No exacerbations occurred in 10 patients who underwent their operation between 2 and 28 days. Nevertheless, exacerbations occurred in 19.0% of patients whose operation was done more than 4 weeks later. These data suggest that cardiac operations can be done safely 4 weeks after cerebral infarction, and if the delay is more than 2 weeks, the exacerbation rate will be around 10%. The risk of progression of cerebral damage is still significant 15 days and even 4 weeks after cerebral hemorrhage.