The Economic Times

People across Europe, North America slept for days or stared blankly for hours during this 100-year-old strange epidemic and scientists are still searching why

During the 1918 flu pandemic, a mysterious illness, encephalitis lethargica, emerged in Europe and North America, causing extreme sleepiness and immobility. Many survivors later developed Parkinson's-like symptoms. Despite overlapping with the flu, its exact cause remains unknown, baffling scientists for over a century. This enigmatic sleeping sickness epidemic continues to intrigue researchers.