Encephalitis Lethargica

Encephalitis lethargica or von Economo disease is an atypical form of encephalitis. Also known as "sleepy sickness" (though different from the sleeping sickness transmitted by the tsetse fly), it was first described by the neurologist Constantin von Economo in 1917. The disease attacks the brain, leaving some victims in a statue-like condition, speechless and motionless. Between 1915 and 1926, an epidemic of encephalitis lethargica spread around the world; no recurrence of the epidemic has since been reported, though isolated cases continue to occur.