Encephalitis

Also called Inflammation of the brain, Autoimmune encephalitis

Inflammation of the brain itself. Fever with confusion or personality change is the pattern, and treatment within hours changes the outcome.

What it is

Inflammation of the brain, either from infection, most often herpes simplex virus, or from the immune system attacking the brain, called autoimmune encephalitis.

It is distinct from meningitis, which is inflammation of the membranes around the brain. Meningitis classically causes headache, fever, neck stiffness and a rash; encephalitis affects brain function itself, so the hallmark is altered behaviour, confusion, personality change or seizures.

The most important fact is about timing. Herpes simplex encephalitis is treatable with intravenous aciclovir, and the outcome depends heavily on how quickly it is started. Treatment is begun on suspicion, before tests confirm anything, and any delay costs brain tissue. Untreated it has a very high mortality; treated early, many people recover well.

Autoimmune encephalitis, including NMDA receptor encephalitis, often presents with psychiatric symptoms first, and people are frequently admitted to mental health services before anybody recognises it. New psychosis with seizures, movement disorder, or a fluctuating level of consciousness should prompt neurological investigation.

Survivors commonly have lasting difficulties with memory, fatigue, concentration and emotional regulation, out of proportion to how well they look, and rehabilitation is under-provided.

Signs you might notice

Flu-like symptoms and fever, followed by:

Confusion, disorientation, or behaving out of character.

Personality or behaviour change, sometimes dramatic.

Seizures.

Drowsiness or reduced consciousness.

Severe headache, sensitivity to light, neck stiffness.

Speech or memory problems, weakness, or loss of coordination.

New psychiatric symptoms, hallucinations or psychosis, particularly with seizures or abnormal movements.

999 immediately for fever with confusion, altered behaviour, seizure or drowsiness. Say the word encephalitis; it changes what is done and how fast.

In a baby: fever with floppiness, poor feeding, a bulging fontanelle, irritability or a high-pitched cry.

How it can affect day-to-day life

The recovery is the part nobody is prepared for. Memory problems, profound fatigue, difficulty concentrating, irritability and emotional changes persist long after discharge, and the person often looks entirely well.

Families describe a person who came home but is not quite the same, and getting recognition and rehabilitation for that is a fight.

Epilepsy develops in a proportion of survivors and needs proper management.

Returning to work or school usually has to be phased over months, and expectations set at discharge are often unrealistically optimistic.

Neuropsychology assessment is the intervention that explains what has changed and what will help, and it is frequently not offered unless asked for.

For autoimmune encephalitis, the psychiatric misdiagnosis at the start leaves families with real anger, and that deserves acknowledging.

Supporting someone well

Call 999 for fever with confusion, altered behaviour or seizure. Do not wait.

Say encephalitis at triage.

Expect treatment to start before the diagnosis is confirmed; that is correct.

Afterwards, ask for neurorehabilitation and specifically for neuropsychology assessment.

Ask for fatigue management and a phased return to work or school; see occupational therapy.

Keep a record of what has changed: memory, temper, concentration. Families see what clinics do not.

Ask about epilepsy risk and what to do in a seizure.

Get support for the family in their own right; this is a bereavement-like experience for a person who is still here.

Where to get help

999 or A and E immediately.

Neurology and neurorehabilitation services afterwards.

Encephalitis International run a support line and are the specialist charity, with excellent recovery material.

Headway on 0808 800 2244 for the brain injury aftermath.