Encephalitis - Encephalitis Lethargica

Encephalitis Lethargica

Encephalitis lethargica is an atypical form of encephalitis which caused an epidemic from 1918 to 1930. Those who survived sank into a semi-conscious state that lasted for decades. Neurologist Oliver Sacks used the Parkinson's drug L-DOPA to revive those still alive in the late 1960s.

There have been only a small number of isolated cases in the years since, though in recent years a few patients have shown very similar symptoms. The cause is now thought to be either a bacterial agent or an autoimmune response following infection.