What are the main symptoms?
Who is affected?
The majority of cases occur in young adults and children, although cases have been diagnosed in people in their 80’s! Females are approximately four times more likely to be affected than males.
What tests are required to diagnose Anti-NMDA?
A diagnosis of anti-NMDA receptor encephalitis requires antibodies to be detected in the body fluids of someone with symptoms consistent with anti-NMDA receptor encephalitis. Antibodies may be found in either blood or spinal fluid. Tests on the spinal fluid are more accurate than those on the blood. Therefore, if blood tests are negative, the spinal fluid should be tested before concluding that the patient does not have anti-NMDA receptor encephalitis.
Imaging is an important part of the evaluation of a patient with suspected anti-NMDA receptor encephalitis, and should include studies looking at the brain (MRI) and studies looking at the body for an associated tumour.
What is the treatment?
Patients diagnosed with anti-NMDA receptor encephalitis need to be admitted to hospital where they can be monitored and attended to by a team of doctors, nurses and other health professionals. Although every patient’s disease, symptoms and experience is different, most are treated with medications that reduce the levels of antibodies in the blood and spinal fluid. These include corticosteroids (“steroids”), intravenous immunoglobulin (antibodies collected from healthy blood donors that bind host antibodies) and plasmapheresis (PLEX; that involves use of a machine to filter antibodies out of the host’s blood).
Occasionally, the use of more powerful drugs are required to eliminate antibodies. The drugs most commonly used to treat Anti-NMDA Receptor Encephalitis are rituximab (Rituxin®) and cyclophosphamide 9 (Cytoxin®). Many other medications may also be required, including those used to control blood pressure, stop seizures, ease anxiety, improve sleep, and to treat hallucinations or abnormal behaviours.
Medications may need to be continued after the patient has begun to recover.
What is the prognosis?
Although anti-NMDA receptor encephalitis is a serious life-threatening disease, the majority of patients who receive prompt diagnosis and treatment go on to make a good recovery.
Recovery is generally slow and may occur over months or even years. The recovery process is often complicated by many ups and downs, and by fears of relapse or re-emergence of symptoms. It is important during this period that the patient continues to be closely monitored by their physician. Even after recovery is well-established, routine medical assessments remain very important, including repeat imaging to ensure that no tumour is found. Unfortunately, not all people affected by anti-NMDA receptor encephalitis recover.
The disease can be fatal, with most patients dying due to cardiac arrest (stopping of the heart), or from complications associated with long stays in hospitals and the use of powerful immune suppressing medications (which makes people more susceptible to serious infections). Some patients may not recover completely, and friends and family may notice changes in the patient’s personality or some other aspect that is different from before the onset of illness.
What are the chances of a relapse?
Relapses may occur in 14-25% of patients. Although no test is available to predict which patients will experience a relapse, research has shown that relapses are more likely to occur in patients in whom a tumour has not been identified, and in those whom were not treated with immune suppressing medications during their first attack.
Immune suppressing medications may be taken for prolonged periods of time (even after recovery) to prevent a relapse.
When relapses occur, they usually involve the same symptoms experienced during the first attack–although the symptoms may be less severe, and may not all occur at the same time, or in the same order as before.
Is it contagious?
Is it hereditary?
Currently there is no evidence to suggest that anti-NMDA receptor encephalitis is hereditary. Autoimmune diseases may, however, be more likely in some families. Research is ongoing considering a possible genetic link in anti-NMDA receptor encephalitis.