What are the new management guidelines for acute encephalitis?

New Management Guidelines for Acute Encephalitis

Patients with suspected acute encephalitis require immediate neurological specialist assessment and should be managed in a setting where clinical neurological review can be obtained within 24 hours of referral to optimize outcomes related to morbidity and mortality. 1

Initial Management and Care Setting

• Patients with falling level of consciousness require urgent assessment by Intensive Care Unit staff for airway protection, ventilatory support, management of raised intracranial pressure, optimization of cerebral perfusion pressure, and correction of electrolyte imbalances 1
• Patients should be managed in appropriate settings including neurological wards, high dependency units, or intensive care units depending on severity 1
• Transfer to a specialist neuroscience unit should be arranged when diagnosis is not rapidly established or when a patient fails to improve with therapy, occurring within 24 hours of being requested 1

Diagnostic Approach

• Access to neuroimaging (MRI preferred over CT), potentially under general anesthesia if needed, is essential for proper diagnosis 1, 2
• Cerebrospinal fluid (CSF) analysis is critical for confirming diagnosis, with results of CSF PCR assays ideally available within 24-48 hours of lumbar puncture 1
• Brain biopsy should be reserved only for unusual and diagnostically difficult cases that remain undiagnosed despite extensive evaluation 2, 3

Treatment Guidelines by Etiology

Viral Encephalitis

• Herpes Simplex Virus (HSV): Acyclovir is the recommended treatment with strong evidence (Level A recommendation) 2, 3
• Varicella Zoster Virus (VZV): Acyclovir may also be effective 2
• Cytomegalovirus (CMV): Ganciclovir and foscarnet are recommended, particularly in immunocompromised patients 2
• Enterovirus: No specific treatment is routinely recommended; in severe cases, pleconaril (if available) or intravenous immunoglobulin may be considered (Level C recommendation) 1

Protozoan Causes

• Toxoplasma gondii: Pyrimethamine plus either sulfadiazine or clindamycin is recommended (Level A-I); alternatives include trimethoprim-sulfamethoxazole alone (Level B-I) or pyrimethamine combined with atovaquone, clarithromycin, azithromycin, or dapsone (Level B-III) 1
• Plasmodium falciparum (cerebral malaria): Quinine, quinidine, or artemether is recommended (Level A-III); exchange transfusion for patients with >10% parasitemia (Level B-III) 1
• Acanthamoeba: Consider trimethoprim-sulfamethoxazole plus rifampin plus ketoconazole (Level C-III) 1

Post-infectious/Post-vaccination Encephalitis

• Acute Disseminated Encephalomyelitis (ADEM): High-dose corticosteroids are recommended (Level B-III); alternatives include plasma exchange (Level B-III) and intravenous immunoglobulin (Level C-III) 1

Special Considerations for Travelers

• Patients returning from malaria-endemic areas should have rapid blood malaria antigen tests and ideally three thick and thin blood films examined for malaria parasites 1
• If cerebral malaria seems likely and there will be delay in obtaining malaria film results, anti-malarial treatment should be initiated and specialist advice obtained 1

Discharge Planning and Follow-up

• Patients should not be discharged without either a definite or suspected diagnosis 1
• Arrangements for outpatient follow-up and plans for ongoing therapy and rehabilitation should be formulated at a discharge meeting, including at least one follow-up appointment 1
• All patients should have access to assessment for rehabilitation, as sequelae of encephalitis may not be immediately apparent at discharge 1

Common Pitfalls to Avoid

• Delaying neuroimaging and lumbar puncture; these should be performed promptly unless specific contraindications exist 1, 2
• Failing to distinguish between infectious encephalitis and post-infectious/post-immunization encephalitis (like ADEM), as management approaches differ significantly 1
• Overlooking the multidisciplinary nature of care needed, which may require input from neurologists, infectious disease physicians, intensivists, and rehabilitation specialists 1
• Discharging patients without adequate follow-up planning, as many patients experience ongoing complications including anxiety, depression, and cognitive deficits 1