NMDA receptor encephalitis: symptoms, tests and treatment

Encephalitis means inflammation of the brain. The NHS describes it as an uncommon but serious condition that can be life threatening and requires urgent treatment in hospital. It can be caused by infections, but it can also arise when the immune system mistakenly attacks the brain. Encephalitis International explains that this is autoimmune encephalitis, which can occur with or without a known trigger such as a previous infection or a tumour.

Anti-NMDA receptor encephalitis is one of the best-known forms of autoimmune encephalitis and often affects young people, according to Encephalitis International. The NHS pages read for this guide do not give the name of this specific condition or figures for how common it is, so this page does not give them either; it relies on the charity's description and on the NHS's general information about encephalitis.

Encephalitis International says symptoms of anti-NMDA receptor encephalitis can vary widely but commonly include memory problems, psychiatric symptoms, seizures and changes in behaviour. It adds that the condition can develop gradually, sometimes making it hard to diagnose in the early stages.

The NHS describes the general picture of encephalitis. It usually starts with flu-like symptoms such as a high temperature and headache, with muscle and joint aches and sometimes a rash. More serious symptoms follow over hours, days or weeks, and occasionally over several weeks or months.

• Confusion or disorientation, or drowsiness.

• Seizures or fits.

• Changes in personality and behaviour, such as feeling very agitated.

• Difficulty speaking, and seeing or hearing things that are not there.

• Weakness or loss of movement in parts of the body, or loss of feeling.

• Uncontrollable eye movements, eyesight problems or loss of consciousness.

The NHS says to dial 999 for an ambulance immediately if you or someone else has serious symptoms of encephalitis, because it is a medical emergency that needs to be seen in hospital as soon as possible. Symptoms of meningitis, such as a severe headache, sensitivity to bright lights, a stiff neck and a spotty rash that does not fade when a glass is pressed against it, may also be present.

The NHS says the symptoms of encephalitis can have a number of possible causes, so several tests may be needed. A CT or MRI scan of the brain can show whether it is encephalitis or another problem such as a stroke, brain tumour or aneurysm. A lumbar puncture removes fluid from around the spinal cord so it can be checked for signs of infection or a problem with the immune system, which are the main causes of encephalitis. An electroencephalogram (EEG) picks up the electrical signals from the brain, and blood, urine or other fluids can be tested for infection.

The NHS pages do not describe the specific antibody tests used to confirm autoimmune types, so those are best discussed with the neurology team. The NHS lists surgery to remove abnormal growths among the treatments if encephalitis was triggered by a tumour somewhere in the body.

The NHS says encephalitis needs to be treated urgently, usually in hospital and often in an intensive care unit, with treatment aimed at the underlying cause, relieving symptoms and supporting body functions. For problems with the immune system the options listed are steroid injections, usually for a few days, immunoglobulin therapy, which helps control the immune system, and plasmapheresis, a procedure that removes the substances attacking the brain from the blood. Surgery is used to remove a tumour if one triggered the illness.

Supportive care can include fluids, painkillers, medicines to control seizures and to help someone who is very agitated, oxygen or a ventilator, and medicine to reduce pressure inside the skull. How long someone needs to stay in hospital ranges from a few days to several weeks or even months, according to the NHS.

The NHS says some people eventually make a full recovery, although this can be a long and frustrating process, and many people never make a full recovery and are left with long-term problems caused by damage to the brain. Common complications include memory loss, frequent seizures, personality and behavioural changes, problems with attention, concentration, planning and problem solving, and persistent tiredness.

The NHS adds that these problems can have a significant impact on the person as well as family and friends, and that help and support is available. Encephalitis International offers a support team for patients and families, though this page does not give contact details.

The NHS says encephalitis is treated urgently in hospital, often in an intensive care unit, so the first stage of care is usually through emergency NHS services. Private care may play a part later, for example in rehabilitation. Keeping a written timeline of symptoms, which a relative may be best placed to write because the person affected may not recall events, helps the clinical team considerably.