Death from encephalitis

Encephalitis is an inflammation of the brain, usually caused by infection or through the immune system attacking the brain. Encephalitis is a serious neurological condition and unfortunately, despite improvements in specific and more supportive treatments such as intensive care management, it still has a high mortality (death) rate.

The mortality rate varies but can be up to 40% depending on a number of factors including the cause of the encephalitis, an individual’s underlying health and the treatment given. Encephalitis has a high mortality because the brain is central in the body’s functioning and there are many challenges in treating encephalitis effectively.

A commonly identified infective cause of encephalitis is the herpes simplex virus (HSV), and this form can be associated with a mortality of up to 30% with specific anti-viral treatment, and up to 70-80% without the treatment. If an individual requires ventilation, has long or repetitive seizures (status epilepticus), or has a low level of consciousness, they are at higher risk of dying from encephalitis.   Autoimmune encephalitis can range between 12-40% depending on the cause.  Sometimes, despite extensive testing, it is not possible to discover the cause of the encephalitis which can lead to difficulty giving effective targeted treatment.

Death in encephalitis is usually caused by severe swelling of the brain. The skull limits the space into which the brain can swell, which results in pressure on the brainstem, at the bottom of the brain. The brainstem is the part of the brain that controls the vital functions of breathing and circulation. When the brainstem is under this type of a severe pressure it ceases to function.

The rapid course of encephalitis can be traumatic and overwhelming. There are a number of sources of help for families in grief. Please see the factsheet on Dealing with Bereavement for more detailed information on these resources. We have support service staff at the Encephalitis Society who can talk through any issues that family and friends may have, and, if appropriate put bereaved families in touch with each other. Such sharing of difficult experiences can help the grieving process.

By Dr Ava Easton, Encephalitis International and reviewed by Dr Greta Wood and Dr Benedict Michael, University of Liverpool

FS063V4 Death from encephalitis (acute stage)

Date created: January 1999; Last update: January 2022; Review date: January 2025

Disclaimer: We try to ensure that the information is easy to understand, accurate and up-to-date as possible. If you would like more information on the source material and references the author used to write this document please contact the Encephalitis International. None of the authors of the above document has declared any conflict of interest, which may arise from being named as an author of this document.