Encephalitis Lethargica

Encephalitis lethargica (EL) is a disease characterized by high fever, headache, double vision, delayed physical and mental response, extreme tiredness (lethargy), and sometimes coma. Patients may also experience abnormal eye movements, upper body weakness, muscle pain, tremors, neck rigidity, and behavioral changes including psychosis. A worldwide epidemic of EL occurred from 1917 to 1928 with more than one million reported cases. Although occasional cases are reported with similar symptoms, EL epidemics have not recurred. The cause of this condition is unknown, but a viral origin is suspected. Treatment depends on a person's symptoms. Levodopa and other antiparkinson drugs may be effective in alleviating some symptoms.