From the Guidelines
Encephalitis is a serious and potentially life-threatening complication in patients with left-sided endocarditis, and prompt recognition and treatment are crucial to improve outcomes. The risks of encephalitis in patients with left-sided endocarditis include the potential for septic emboli to travel to the brain, causing direct infection or inflammatory responses in brain tissue 1. Signs and symptoms of encephalitis in this context include:
- Fever
- Headache
- Altered mental status
- Confusion
- Seizures
- Focal neurological deficits
- Neck stiffness
- Photophobia
- Decreased consciousness
- Personality changes
- Speech difficulties
- Motor weakness
These symptoms can develop rapidly or gradually depending on the cause and severity. For patients with endocarditis, prompt antibiotic therapy is essential, typically involving intravenous antibiotics such as vancomycin (15-20 mg/kg every 8-12 hours), ceftriaxone (2g daily), or gentamicin (3 mg/kg daily) for 4-6 weeks, depending on the causative organism 1. Blood cultures should be obtained before starting antibiotics. Neuroimaging (MRI preferred over CT) is crucial to assess for brain involvement 1. Supportive care including seizure management with benzodiazepines (lorazepam 0.1 mg/kg IV) followed by antiepileptic drugs if needed, and management of increased intracranial pressure may be necessary. The connection between endocarditis and encephalitis occurs when infected vegetations on heart valves fragment and embolize to cerebral vessels, causing either direct infection or inflammatory responses in brain tissue 1. Early recognition and treatment significantly improve outcomes in these patients. In addition to antibiotic therapy, surgical intervention may be necessary in certain cases, such as when there is a high risk of embolism or when the patient has developed heart failure or other complications 1. It is essential to individualize each case and consider all factors associated with increased risk to determine the best therapeutic approach 1.
From the Research
Risks of Encephalitis in Left-Sided Endocarditis
- The risk of neurological complications, including encephalitis, is high in patients with left-sided infective endocarditis, with a total incidence of cerebrovascular complications (CVCs) of 65% 2.
- Independent risk factors associated with all neurological complications include vegetation size ≥3 cm, Staphylococcus aureus as a cause, mitral valve involvement, and anticoagulant therapy 3.
- A larger heart valvular vegetation size is a risk factor for both symptomatic and silent CVCs, while Staphylococcus aureus etiology confers a higher risk for symptomatic cerebral complication only 2.
Signs of Encephalitis in Left-Sided Endocarditis
- Neurological complications of infective endocarditis include ischemic and hemorrhagic strokes, cerebral microbleeding, infectious intracranial aneurysms, meningitis, brain abscesses, and encephalopathy 4.
- The majority of left-sided endocarditis patients have brain lesions that may alter management decisions, warranting the systematic use of magnetic resonance imaging 4.
- CNS complications, including encephalitis, are associated with mortality in both native valve endocarditis and prosthetic valve endocarditis 5.
Neurological Deficits in Left-Sided Endocarditis
- Moderate to severe ischemic stroke and brain hemorrhage have a significant negative impact on the outcome of infective endocarditis 3.
- Early appropriate antimicrobial treatment is critical, and transitory discontinuation of anticoagulant therapy should be considered 3.
- The timing of surgery is crucial, with earlier surgery appearing to be safe in most ischemic strokes, while ideally surgery should be delayed for 3 to 4 weeks in patients with hemorrhagic strokes 4.