A century ago, people worldwide were affected by a mysterious illness known as “sleepy sickness” that caused uncontrollable sleep in its victims. This disease emerged in northern France in 1916 and spread rapidly to India, Central America, North America, and Europe. Rather than simply feeling tired, individuals with sleepy sickness would fall into deep, prolonged slumber and sometimes not wake up for weeks or even months. Tragically, 30 to 40% of those infected with the illness died, mostly from respiratory failure.
By 1930, the epidemic of sleepy sickness had mostly disappeared, but the cause of the disease, how it spread, and its potential for recurrence remain unknown. Encephalitis lethargica, as it is now known, is a rare disease without a known cause, although some researchers suspect it may be linked to a virus. While there was a pandemic of encephalitis lethargica from 1916 to 1930, there have been no reports of a similar outbreak since then.
In cases of encephalitis lethargica, some individuals developed Parkinson’s disease after recovering from the illness. Treatment may involve using medications like levodopa to manage symptoms depending on the individual’s condition. The progression of the disease can vary based on any complications or other disorders the person may have.
One woman, Eleanore Carey, who lived in New York during the outbreak of the disease, described the experience as feeling like she was “being buried in a pit as deep as the centre of the Earth.” She struggled to wake up from her deep slumber and found it physically impossible to do so, despite the efforts of those around her. This terrifying ordeal was shared by many during the time of the outbreak.