Encephalitis Management Guidelines

Admission and Care Environment

Patients with suspected encephalitis are often severely ill, with disturbed behavior and at risk of seizures, increased intracranial pressure, aspiration, systemic complications, electrolyte disturbances, and death, and should be hospitalized immediately with access to specialized neurological care 1
Appropriate environments for care include neurology services, intensive care units, or intermediate care units 1
Patients with a decreased level of consciousness require urgent evaluation by the intensive care team for airway protection, ventilatory support, management of increased intracranial pressure, and correction of electrolyte imbalances 1
Transfer to a neurology service is recommended when a diagnosis is not rapidly established or a patient does not improve with treatment, and this transfer should occur as soon as possible and certainly within 24 hours of the request 2

All patients with suspected encephalitis should undergo a lumbar puncture (LP) as soon as possible after hospital admission, unless there is a clinical contraindication 3
If a contraindication to LP exists suggesting increased intracranial pressure, a brain scan should be performed as soon as possible 3
Access to neuroimaging (MRI and CT scan), under general anesthesia if necessary, and to neurophysiology (EEG) should be available, which may require transfer to a specialized neuroscience center 1
Results of CSF PCR tests should be available within 24-48 hours following lumbar puncture 1

Intravenous aciclovir (10 mg/kg three times a day) should be started if initial CSF and/or imaging results suggest viral encephalitis, or within 6 hours of admission if these results will not be available, or if the patient is very ill or deteriorating 4, 5
If the initial microscopic analysis of CSF or imaging is normal but clinical suspicion of HSV or VZV encephalitis persists, aciclovir should still be started within 6 hours of admission while awaiting other diagnostic investigations 4, 5
The dose of aciclovir should be reduced in patients with pre-existing renal failure 4

For patients returning from malaria-endemic areas, rapid antigen tests for malaria in the blood and ideally three thick and thin blood smears should be examined for malaria parasites 2
If cerebral malaria seems likely and there will be a delay in obtaining the blood smear result, antimalarial treatment should be considered and specialist advice obtained 2
No specific treatment is recommended for enteroviral encephalitis; in patients with severe disease, pleconaril (if available) or intravenous immunoglobulin may be considered 2, 1

The acute management of a patient with suspected encephalitis is multidisciplinary, potentially requiring the involvement not only of neurologists but also of infectious disease specialists, virologists, microbiologists, neurophysiologists, neuroradiologists, neurosurgeons, nursing staff trained in neurology and/or psychiatry, and intensive care staff 1
Brain biopsy has no place in the initial evaluation of suspected acute viral encephalitis, but stereotactic biopsy should be considered in patients for whom no diagnosis has been made after the first week, especially if there are focal abnormalities on imaging 5

Patients should not be discharged from the hospital without a definitive or suspected diagnosis 2
Arrangements for outpatient follow-up and plans for ongoing therapy and rehabilitation should be made at a discharge meeting, and should include at least one follow-up appointment 2
All patients, regardless of age, should have access to a rehabilitation assessment 2

Recognition of encephalitis in older people can be particularly difficult because they are more likely than younger people to have other causes of neurological disturbance, such as stroke 3
The sequelae and consequences of encephalitis may not be immediately apparent when a patient is discharged from the hospital after the acute illness, but anxiety, depression, and obsessive behaviors often become apparent later 2