Immune-mediated encephalitis

A neurological deterioration in a child is both a significant worry to the family and a challenge to the doctor making a diagnosis. We are recognising that the immune system, which plays an important role in protecting and maintaining the brain and body, can contribute to brain disease in children when it becomes unregulated. Sometimes infection itself can trigger inflammation. It is important to work out the underlying cause of this inflammation.

Magnetic resonance imaging plays an important role. However, this can be normal in a proportion of children with brain inflammation, and other types of scans are now being researched but are not yet ready for clinical practice. Fluid around the brain and spine may show evidence of immune upregulation with cells or raised protein, but may also be normal. Careful measurement of chemicals released during inflammation may offer more clues, alongside measuring very specific components of the immune system like proteins that target the body called antibodies. It is important to interpret these tests carefully as they can be found even when there is no disease. Clinicians need to match these findings with how the patients present. Using these methods, researchers have started to recognize new conditions like myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) and another called virus-associated encephalopathy syndromes.

It is important to recognize these conditions to be able to begin to treat them. Treatments for neuroinflammation are aimed to promote recovery, and preventing the illness recurring. Furthermore, there is a move towards increasing treatment quickly if children fail to respond adequately. Clinicians and researchers are striving to create treatments targeted to the particular immune response in an individual child.