Study of Acute Autoimmune Encephalitis With Positive Antibodies in Eastern France

The number of acute encephalitides diagnosed each year is gradually increasing, reaching approximately 5 to 10/100,000 per year; more than 50% of etiologies currently remain unknown. The majority of them are acute encephalitis of infectious origin, but it is estimated that 20% of encephalitis in northern Europe is related to an autoimmune mechanism with the majority of encephalitis with anti-NMDA Ac discovered recently in 2007. The study of a large American encephalitis cohort showed a death rate of 3% to 7% in cases of autoimmune encephalitis. Furthermore, delay in the initiation of effective treatment (tumor removal or immunotherapy) beyond 4 weeks is associated with a poor prognosis at 1 year. It is therefore necessary to better understand the signs of autoimmune encephalitis in order to recognize the disease quickly and to start a treatment quickly; in order to improve the management and the prognosis of these children.