User:Mr. Ibrahem/Encephalitis lethargica

Encephalitis lethargica (EL) is a form of brain inflamation initially characterized by fever, headache, double vision, psychosis, and lethargy. In most cases, this gradually results in some degree of coma. Parkinson's or epilepsy may develop in the years following the initial illness.

The cause is unknown. Proposal include an infection such as influenza or an autoimmune process. In at least some cases, the disease appeared to spread between people. In pregnancy, the baby may also be affected. The underlying mechanism involved inflammation of specific parts of the brain, the mesencephalon and the diencephalon. Diagnosis was based on symptoms after ruling out other potential cases.

Treatment is based on the symptoms. Levodopa may result in significant, though temporary improvement. Outcomes depend on the associated complications. About a third of people died. Many of those who survived were left with permanent disabled.

Outbreaks of disease occurred around the world starting in 1916 until 1930 and affected about 5 million people. Outbreaks are believed to have occurred prior, and less than 20 cases have been documented since. The condition was first described by in 1917 by Constantin von Economo and Jean-René Cruchet. It has also been called "sleeping sickness" or "sleepy sickness"; though is not related to tsetse fly-transmitted sleeping sickness.