[Encephalitis lethargica in the Netherlands; renewed interest in a mysterious disease]

In the first half of the 20th century, during the Spanish flu pandemic, more than half a million people died from a mysterious disease sleeping sickness which was named 'encephalitis lethargica'. Despite extensive research, the cause of the disease has not yet been established. In the Netherlands many doctors published cases in the Nederlands Tijdschrift voor Geneeskunde (Dutch Journal of Medicine), also when chronic forms of the disease arose. An attempt to treat patients suffering from the chronic disease with levodopa initially had spectacular results but eventually lead to a new disappointment as a result of severe side effects. The experiment was stopped prematurely. Encephalitis lethargica is still being sporadically diagnosed in the 21st century. Recent research suggests that an autoimmune response targeted at the basal ganglia, possibly caused by a streptococcal infection, plays a role in the aetiology of the disease.