[PS2-1B-K] Autoimmune encephalitis- clinical features and therapeutic decision making
The discovery of autoantibodies that bind to cell surface proteins in cerebrospinal fluid and serum have changed the investigation and treatment of acquired encephalitis syndromes in children and adults. Many of the cell surface antigens are neuronal receptors or synaptic proteins. In adults, many of these syndromes are paraneoplastic whereas in children they are rarely associated with tumours, but instead are often para-infectious, post-infectious or unexplained.
Anti-NMDAR encephalitis and is the most common autoimmune encephalitis in children, and causes ~5-10% of all encephalitis in children. The clinical syndrome is highly recognizable with agitation, psychosis, aphasia and movement disorders being characteristic. Although CSF is often abnormal, brain MRI if often non-specific or normal. The encephalitis often takes weeks to evolve and many months to improve. A new consensus criteria for ‘suspected anti-NMDAR encephalitis’ that can be applied whilst awaiting antibody testing, and has good sensitivity and specificity.
Antibodies against myelin oligodendrocyte glycoprotein is another important biomarker that is associated with autoimmune demyelination syndromes including acute disseminated encephalomyelitis, optic neuritis and myelitis, but not multiples sclerosis. The disorder can be relapsing which is often steroid responsive but steroid dependent.
Other rarer autoantibodies found in children include antibodies against GABA-A receptor, glycine receptor, DPPX dopamine-2 receptor and GAD.
General tenets in the treatment of autoimmune encephalitis include: patients given immune therapy do better than those who do not receive immune therapy; early treatment is better than late; if a patient fails a first line therapy (steroids, intravenous immunoglobulin, plasma exchange), consider second line therapy (rituximab, cyclophosphamide).
Anti-NMDAR encephalitis and is the most common autoimmune encephalitis in children, and causes ~5-10% of all encephalitis in children. The clinical syndrome is highly recognizable with agitation, psychosis, aphasia and movement disorders being characteristic. Although CSF is often abnormal, brain MRI if often non-specific or normal. The encephalitis often takes weeks to evolve and many months to improve. A new consensus criteria for ‘suspected anti-NMDAR encephalitis’ that can be applied whilst awaiting antibody testing, and has good sensitivity and specificity.
Antibodies against myelin oligodendrocyte glycoprotein is another important biomarker that is associated with autoimmune demyelination syndromes including acute disseminated encephalomyelitis, optic neuritis and myelitis, but not multiples sclerosis. The disorder can be relapsing which is often steroid responsive but steroid dependent.
Other rarer autoantibodies found in children include antibodies against GABA-A receptor, glycine receptor, DPPX dopamine-2 receptor and GAD.
General tenets in the treatment of autoimmune encephalitis include: patients given immune therapy do better than those who do not receive immune therapy; early treatment is better than late; if a patient fails a first line therapy (steroids, intravenous immunoglobulin, plasma exchange), consider second line therapy (rituximab, cyclophosphamide).