100 Years Ago, Thousands Fell Into a Deep Sleep With No Explanation. Today, It’s Still a Mystery.

Here's what you'll learn when you read this story: Encephalitis lethargica (EL) is a mysterious neurological disease that impacted millions of people from 1917 to 1930, causing a wide range of symptoms including hypersomnia, immobility, and even deat... [5104 chars]