Neurologic Complications of Infective Endocarditis

Multimodality Imaging of Infective Endocarditis

Infective endocarditis (IE) is a complex multisystemic disease resulting from infection of the endocardium, the prosthetic valves, or an implantable cardiac electronic device. The clinical presentation of patients with IE varies, ranging from acute and rapidly progressive symptoms to a more chronic disease onset. Because of its severe morbidity and mortality rates, it is necessary for radiologists to maintain a high degree of suspicion in evaluation of patients for IE. Modified Duke criteria are used to classify cases as "definite IE," "possible IE," or "rejected IE." However, these criteria are limited in characterizing definite IE in clinical practice. The use of advanced imaging techniques such as cardiac CT and nuclear imaging has increased the accuracy of these criteria and has allowed possible IE to be reclassified as definite IE in up to 90% of cases. Cardiac CT may be the best choice when there is high clinical suspicion for IE that has not been confirmed with other imaging techniques, in cases of IE and perivalvular involvement, and for preoperative treatment planning or excluding concomitant coronary artery disease. Nuclear imaging may have a complementary role in prosthetic IE. The main imaging findings in IE are classified according to the site of involvement as valvular (eg, abnormal growths [ie, "vegetations"], leaflet perforations, or pseudoaneurysms), perivalvular (eg, pseudoaneurysms, abscesses, fistulas, or prosthetic dehiscence), or extracardiac embolic phenomena. The differential diagnosis of IE includes evaluation for thrombus, pannus, nonbacterial thrombotic endocarditis, Lambl excrescences, papillary fibroelastoma, and caseous necrosis of the mitral valve. The location of the lesion relative to the surface of the valve, the presence of a stalk, and calcification or enhancement at contrast-enhanced imaging may offer useful clues for their differentiation. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material.

A Rare Presentation of Perivalvular Abscess and Infective Valve Endocarditis as Multiple Cerebral Septic Emboli Mimicking Ischemic Stroke

The perivalvular cardiac abscess is a severe condition associated with infective endocarditis, leading to significant morbidity and mortality if not diagnosed and managed promptly. Neurological complications, particularly stroke, can occur due to embolic events resulting from cardiac abscesses. A 63-year-old female with end-stage renal disease and multiple comorbidities presented with altered mental status. Imaging revealed acute ischemic infarcts in the frontotemporal lobes, suggesting the embolic phenomenon. Blood cultures grew Enterococcus faecalis, and an echocardiogram showed severe aortic valve destruction with perivalvular abscess. Cardiac abscesses can cause severe complications, including tissue destruction, valve damage, and embolic events. Echocardiography is crucial for diagnosis, detecting vegetation, and assessing associated complications. Transthoracic echocardiography is reliable but has limitations, whereas transesophageal echocardiography is highly sensitive. Prompt antibiotic therapy and surgical intervention are crucial for treatment. Early initiation of appropriate antibiotic therapy and surgical intervention is crucial for positive outcomes. The choice of treatment should be individualized based on the patient's specific condition and the medical team's expertise.

Cerebrovascular Complication and Valve Surgery in Infective Endocarditis

Infective endocarditis (IE) with neurologic complications is common in patients with active IE. The most common and feared neurological complication of left-sided IE is cerebrovascular, from septic emboli causing ischemic stroke, intracranial hemorrhage (ICH), or an infectious intracranial aneurysm with or without rupture. In patients with cerebrovascular complications, valve replacement surgery is often delayed for concern of further neurological worsening. However, in circumstances when an indication for valve surgery to treat IE is present, the benefits of early surgical treatment may outweigh the potential neurologic deterioration. Furthermore, valve surgery has been associated with lower in-hospital mortality than medical therapy with intravenous antibiotics alone. Early valve surgery can be performed within 7 days of transient ischemic attack or asymptomatic stroke when medically indicated. Timing of valve surgery for IE after symptomatic medium or large symptomatic ischemic stroke or ICH remains challenging, and current data in the literature are conflicting about the risks and benefits. A delay of 2 to 4 weeks from the time of the cerebrovascular event is often recommended, balancing the risks and benefits of surgery. The range of timing of valve surgery varies depending on the clinical scenario, and is best determined by a multidisciplinary decision between cardiothoracic surgeons, cardiologists, infectious disease experts, and vascular neurologists in an experienced referral center.

European Stroke Organisation (ESO) guidelines on intravenous thrombolysis for acute ischaemic stroke

Intravenous thrombolysis is the only approved systemic reperfusion treatment for patients with acute ischaemic stroke. These European Stroke Organisation (ESO) guidelines provide evidence-based recommendations to assist physicians in their clinical decisions with regard to intravenous thrombolysis for acute ischaemic stroke. These guidelines were developed based on the ESO standard operating procedure and followed the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) methodology. The working group identified relevant clinical questions, performed systematic reviews and meta-analyses of the literature, assessed the quality of the available evidence, and wrote recommendations. Expert consensus statements were provided if not enough evidence was available to provide recommendations based on the GRADE approach. We found high quality evidence to recommend intravenous thrombolysis with alteplase to improve functional outcome in patients with acute ischemic stroke within 4.5 h after symptom onset. We also found high quality evidence to recommend intravenous thrombolysis with alteplase in patients with acute ischaemic stroke on awakening from sleep, who were last seen well more than 4.5 h earlier, who have MRI DWI-FLAIR mismatch, and for whom mechanical thrombectomy is not planned. These guidelines provide further recommendations regarding patient subgroups, late time windows, imaging selection strategies, relative and absolute contraindications to alteplase, and tenecteplase. Intravenous thrombolysis remains a cornerstone of acute stroke management. Appropriate patient selection and timely treatment are crucial. Further randomized controlled clinical trials are needed to inform clinical decision-making with regard to tenecteplase and the use of intravenous thrombolysis before mechanical thrombectomy in patients with large vessel occlusion.

Risk of postoperative neurological exacerbation in patients with infective endocarditis and intracranial haemorrhage

OBJECTIVES

Cardiac surgery in patients with infective endocarditis (IE) and preoperative intracranial haemorrhage (pre-ICH) is a highly debatable issue, and guidelines are still not well defined. The goal of this study was to investigate the effect of cardiac surgery and its timing on the clinical outcomes of patients with IE and pre-ICH.

METHODS

We did a single-centre retrospective analysis of data from patients with preoperative brain imaging who had surgery for left-sided IE between January 2007 and May 2018.

RESULTS

Among the 363 patients included in the study, 34 had pre-ICH. Hospital mortality was similar between the patients with and without pre-ICH (29% vs 27%, respectively; P = 0.84). Unadjusted, postoperative neurological deterioration appeared higher in patients with pre-ICH (24% vs 17%; P = 0.35). In multivariable analysis, pre-ICH did not qualify as an independent predictor for either postoperative neurological deterioration [odds ratio 1.10, 95% confidence interval (CI) 0.44-2.73; P = 0.84] or hospital mortality (odds ratio 1.02, 95% CI 0.43-2.40; P = 0.96). Postoperative partial thromboplastin time was significantly elevated in 4 patients with relevant post-ICH compared with those patients without relevant post-ICH (65.5 vs 37.6, respectively; P = 0.004).

CONCLUSIONS

Pre-ICH was not an independent predictor for postoperative neurological deterioration or hospital mortality in patients with IE. Postoperative coagulation management seems to be crucial in patients with IE with ICH. Although this is to date the largest monocentric study addressing surgical decision and timing, the number of patients with pre-ICH was low. Therefore, these conclusions should be regarded with caution; randomized clinical trials are needed.

Contribution of Severe Dental Caries Induced by Streptococcus mutans to the Pathogenicity of Infective Endocarditis

Streptococcus mutans, a major pathogen of dental caries, is regarded as a causative agent of infective endocarditis (IE), which mainly occurs in patients with underlying heart disease. However, it remains unknown whether severe dental caries that extend to pulp space represent a possible route of infection. In the present study, we evaluated the virulence of S. mutans for IE development using rats with concurrent severe dental caries and heart valve injury. Dental caries was induced in rats through the combination of a caries-inducing diet and the administration of S. mutans into the oral cavity. Then, the heart valves of a subset of rats were injured using a sterile catheter and wire under general anesthesia. The rats were euthanized at various times with various stages of dental caries. The number of teeth affected by dental caries with pulp exposure was increased in the rats in a time-dependent manner. S. mutans was recovered from injured heart tissue, which was mainly observed in rats with higher number of S. mutans bacteria in mandibular bone and a larger number of teeth in which caries extended to pulp. Dental caries was more severe in rats with heart injury than in rats without heart injury. Sequencing analysis targeting 16S rRNA revealed that specific oral bacteria appeared only in rats with heart injury, which may be related to the development of dental caries. Our findings suggest that dental caries caused by the combination of S. mutans infection and sucrose intake may contribute to S. mutans colonization in injured heart tissue.

Staphylococcus Toxin-Mediated Motor Polyneuropathy

Staphylococcus aureus infection is known to cause a variety of neurologic complications, most involving the CNS, however, rarely have cases of S. aureus affecting the peripheral nervous system been reported in literature. We report a case of S. aureus toxin-mediated motor polyneuropathy in a patient presenting with acute flaccid quadriplegia.

Ischaemic stroke

Stroke is the second highest cause of death globally and a leading cause of disability, with an increasing incidence in developing countries. Ischaemic stroke caused by arterial occlusion is responsible for the majority of strokes. Management focuses on rapid reperfusion with intravenous thrombolysis and endovascular thrombectomy, which both reduce disability but are time-critical. Accordingly, improving the system of care to reduce treatment delays is key to maximizing the benefits of reperfusion therapies. Intravenous thrombolysis reduces disability when administered within 4.5 h of the onset of stroke. Thrombolysis also benefits selected patients with evidence from perfusion imaging of salvageable brain tissue for up to 9 h and in patients who awake with stroke symptoms. Endovascular thrombectomy reduces disability in a broad group of patients with large vessel occlusion when performed within 6 h of stroke onset and in patients selected by perfusion imaging up to 24 h following stroke onset. Secondary prevention of ischaemic stroke shares many common elements with cardiovascular risk management in other fields, including blood pressure control, cholesterol management and antithrombotic medications. Other preventative interventions are tailored to the mechanism of stroke, such as anticoagulation for atrial fibrillation and carotid endarterectomy for severe symptomatic carotid artery stenosis.

Blood Culture-Negative but Clinically Diagnosed Infective Endocarditis Complicated by Intracranial Mycotic Aneurysm, Brain Abscess, and Posterior Tibial Artery Pseudoaneurysm

Blood culture-negative endocarditis is often severe and difficult to diagnose. It is necessary to emphasize the importance for the early diagnosis and accurate treatment of blood culture-negative endocarditis. Here, we described the relevant clinical information of a blood culture-negative but clinically diagnosed infective endocarditis complicated by intracranial mycotic aneurysm, brain abscess, and posterior tibial artery pseudoaneurysm. This patient was a 65-year-old man with a 9-month history of intermittent fever and died in the end for the progressive neurological deterioration. Although the blood culture is negative, this patient was clinically diagnosed as infective endocarditis according to Duke criteria. This patient course was complicated not only by cerebral embolism, intracranial mycotic aneurysm, and brain abscess but also by posterior tibial artery aneurysm of the lower extremity. The clinical findings of this patient suggest that the confirmatory microbiology is essential for the treatment of blood culture-negative infective endocarditis. Clinicians should be aware of the detriment of blood culture-negative infective endocarditis for its multiple complications may occur in one patient. The delayed etiological diagnosis and insufficient treatment may aggregate the clinical outcome of blood culture-negative infective endocarditis.

The imaging features of cerebral septic infarction in two patients with infective endocarditis

BACKGROUND

Neurologic complications are frequently seen in infective endocarditis (IE) and were identified in about 70% of patients with IE. However, the imaging features of the cerebral septic infarction were less investigated.

PURPOSE

To demonstrate the imaging features of the cerebral septic infarction of IE.

MATERIAL AND METHODS

Two patients were clinically diagnosed as IE according to the modified Duke criterion. We studied their imaging profiles and reviewed the literature of the imaging features of neurologic complications of IE.

RESULTS

The critical features are multiple ischemic and hemorrhagic lesions, most of which locate at the cortical-medullary junction. The septic infarctions are irregular patchy in shape and have characteristic imaging features indicating complications of IE.

CONCLUSION

Magnetic resonance imaging (MRI) with different sequences can detect the features and provide clinical evidence to physicians to make the correct diagnoses and then the treatment plans.

Neurologic Complications in the Intensive Care Unit

Complications involving the central and peripheral nervous system are frequently encountered in critically ill patients. All components of the neuraxis can be involved including the brain, spinal cord, peripheral nerves, neuromuscular junction, and muscles. Neurologic complications adversely impact outcome and length of stay. These complications can be related to underlying critical illness, pre-existing comorbid conditions, and commonly used and life-saving procedures and medications. Familiarity with the myriad neurologic complications that occur in the intensive care unit can facilitate their timely recognition and treatment. Additionally, awareness of treatment-related neurologic complications may inform decision-making, mitigate risk, and improve outcomes.

Symptomatic and Asymptomatic Neurological Complications of Infective Endocarditis: Impact on Surgical Management and Prognosis

Objectives

Symptomatic neurological complications (NC) are a major cause of mortality in infective endocarditis (IE) but the impact of asymptomatic complications is unknown. We aimed to assess the impact of asymptomatic NC (AsNC) on the management and prognosis of IE.

Methods

From the database of cases collected for a population-based study on IE, we selected 283 patients with definite left-sided IE who had undergone at least one neuroimaging procedure (cerebral CT scan and/or MRI) performed as part of initial evaluation.

Results

Among those 283 patients, 100 had symptomatic neurological complications (SNC) prior to the investigation, 35 had an asymptomatic neurological complications (AsNC), and 148 had a normal cerebral imaging (NoNC). The rate of valve surgery was 43% in the 100 patients with SNC, 77% in the 35 with AsNC, and 54% in the 148 with NoNC (p<0.001). In-hospital mortality was 42% in patients with SNC, 8.6% in patients with AsNC, and 16.9% in patients with NoNC (p<0.001). Among the 135 patients with NC, 95 had an indication for valve surgery (71%), which was performed in 70 of them (mortality 20%) and not performed in 25 (mortality 68%). In a multivariate adjusted analysis of the 135 patients with NC, age, renal failure, septic shock, and IE caused by S. aureus were independently associated with in-hospital and 1-year mortality. In addition SNC was an independent predictor of 1-year mortality.

Conclusions

The presence of NC was associated with a poorer prognosis when symptomatic. Patients with AsNC had the highest rate of valve surgery and the lowest mortality rate, which suggests a protective role of surgery guided by systematic neuroimaging results.

Scientific Rationale for the Inclusion and Exclusion Criteria for Intravenous Alteplase in Acute Ischemic Stroke

Purpose—

To critically review and evaluate the science behind individual eligibility criteria (indication/inclusion and contraindications/exclusion criteria) for intravenous recombinant tissue-type plasminogen activator (alteplase) treatment in acute ischemic stroke. This will allow us to better inform stroke providers of quantitative and qualitative risks associated with alteplase administration under selected commonly and uncommonly encountered clinical circumstances and to identify future research priorities concerning these eligibility criteria, which could potentially expand the safe and judicious use of alteplase and improve outcomes after stroke.

Methods—

Writing group members were nominated by the committee chair on the basis of their previous work in relevant topic areas and were approved by the American Heart Association Stroke Council’s Scientific Statement Oversight Committee and the American Heart Association’s Manuscript Oversight Committee. The writers used systematic literature reviews, references to published clinical and epidemiology studies, morbidity and mortality reports, clinical and public health guidelines, authoritative statements, personal files, and expert opinion to summarize existing evidence and to indicate gaps in current knowledge and, when appropriate, formulated recommendations using standard American Heart Association criteria. All members of the writing group had the opportunity to comment on and approved the final version of this document. The document underwent extensive American Heart Association internal peer review, Stroke Council Leadership review, and Scientific Statements Oversight Committee review before consideration and approval by the American Heart Association Science Advisory and Coordinating Committee.

Results—

After a review of the current literature, it was clearly evident that the levels of evidence supporting individual exclusion criteria for intravenous alteplase vary widely. Several exclusionary criteria have already undergone extensive scientific study such as the clear benefit of alteplase treatment in elderly stroke patients, those with severe stroke, those with diabetes mellitus and hyperglycemia, and those with minor early ischemic changes evident on computed tomography. Some exclusions such as recent intracranial surgery are likely based on common sense and sound judgment and are unlikely to ever be subjected to a randomized, clinical trial to evaluate safety. Most other contraindications or warnings range somewhere in between. However, the differential impact of each exclusion criterion varies not only with the evidence base behind it but also with the frequency of the exclusion within the stroke population, the probability of coexistence of multiple exclusion factors in a single patient, and the variation in practice among treating clinicians.

Co-occurrence of multiple cerebral infarctions due to hypercoagulability associated with malignancy and meningeal carcinomatosis as the initial manifestation of gastric cancer

Background

Meningeal carcinomatosis and hypercoagulability associated with malignancy are typical late stage complications in cancer patients. The co-occurrence of meningeal carcinomatosis and cerebral infarction related to hypercoagulability associated with malignancy in an individual as the initial manifestation of malignancy has not been previously reported.

Case presentation

Herein, we report the case of an 80-year-old patient who presented with meningeal carcinomatosis and hypercoagulability related to malignancy as the initial manifestation of occult gastric cancer. The patient displayed consciousness disturbance, mild left facial paralysis, and bilateral positive Babinski’s sign. Using brain magnetic resonance imaging, the patient was diagnosed as having acute multiple cerebral infarctions. Cerebrospinal fluid (CSF) cytology showed adenocarcinoma and upper gastrointestinal endoscopy disclosed scirrhous gastric cancer. The patient presented with headache, fever, and meningeal irritation with a subacute course. Tuberculous or fungal meningitis was initially suspected; however, cytological evidence of adenocarcinoma in the CSF led to the diagnosis of meningeal carcinomatosis.

Conclusion

The comorbidity of hypercoagulability associated with malignancy and meningeal carcinomatosis should be considered in a patient presenting with multiple cerebral infarctions, progressive disturbance of consciousness, fever, and meningeal irritation.