Management of Acute Encephalitis

Initial Assessment and Care

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, as recommended by the Infectious Diseases Society 1
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, according to the Journal of Infection guidelines 1, 2
The American Academy of Neurology recommends that patients should be managed in appropriate settings including neurological wards, high dependency units, or intensive care units depending on severity 1

Access to neuroimaging (MRI preferred over CT) is essential for proper diagnosis, with a strong evidence recommendation (Level A) from the Infectious Diseases Society 1
Cerebrospinal fluid (CSF) analysis is critical for confirming diagnosis, with results of CSF PCR assays ideally available within 24-48 hours of lumbar puncture, as recommended by the Infectious Diseases Society 1
The Centers for Disease Control and Prevention recommends that 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 3

The Infectious Diseases Society of America recommends that Toxoplasma gondii should be treated with pyrimethamine plus either sulfadiazine or clindamycin (Level A-I) 4
The World Health Organization recommends that Plasmodium falciparum (cerebral malaria) should be treated with quinine, quinidine, or artemether (Level A-III) 4, 3
The National Institute of Neurological Disorders and Stroke recommends that Acute Disseminated Encephalomyelitis (ADEM) should be treated with high-dose corticosteroids (Level B-III) 5, 6

The Centers for Disease Control and Prevention recommends that 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 3
The American Academy of Neurology recommends that patients should not be discharged without either a definite or suspected diagnosis, and arrangements for outpatient follow-up and plans for ongoing therapy and rehabilitation should be formulated at a discharge meeting 3

The Infectious Diseases Society of America recommends that all patients should have access to assessment for rehabilitation, as sequelae of encephalitis may not be immediately apparent at discharge 3
The National Institute of Neurological Disorders and Stroke recommends that discharging patients without adequate follow-up planning should be avoided, as many patients experience ongoing complications including anxiety, depression, and cognitive deficits 3

MRI is the imaging modality of choice and should be obtained within 48 hours, as it detects early cerebral changes in approximately 90% of cases versus only 25% sensitivity for CT, according to the Journal of Infection 7
EEG is abnormal in >80% of encephalitis cases but need not be performed routinely in all patients, as stated in the Journal of Infection 7
Obtain EEG when distinguishing psychiatric versus organic causes in patients with mildly altered behavior, or when subtle motor or non-convulsive seizures are suspected, as recommended in the Journal of Infection 7

For cerebral malaria (Plasmodium falciparum), quinine, quinidine, or artemether should be administered, and exchange transfusion is recommended for ≥10% parasitemia, with corticosteroids not recommended, as per Clinical Infectious Diseases 8
Toxoplasma gondii should be treated with pyrimethamine plus either sulfadiazine or clindamycin, according to Clinical Infectious Diseases 8
Acute Disseminated Encephalomyelitis (ADEM) should be treated with high-dose corticosteroids as first-line, with alternatives including plasma exchange or intravenous immunoglobulin, as stated in Clinical Infectious Diseases 8

Corticosteroids are indicated for ADEM, VZV with vasculitis, and Baylisascaris procyonis, as per Clinical Infectious Diseases 8