(Image: Günter Peters/ullstein bild via Getty)

Knut the polar bear may have met an early end but he wasn’t forgotten. The cute polar bear cub born at Berlin Zoo in 2006 and controversially reared by zookeepers, drowned as an adult after experiencing epileptic seizures. Now, the condition responsible for his death has been identified.

The cause of the seizures was unknown since no bacteria, virus or parasite could be found to explain the underlying brain inflammation. The mystery was finally solved by Harald Pruess from the German Centre for Neurodegenerative Diseases in Berlin and his team, who normally study dementia in people.


They analysed samples of Knut’s cerebrospinal fluid, which bathes the brain and spinal cord, and found high levels of an antibody known to attack a glutamate receptor in the brain. In humans, this is a sign of a disease called autoimmune encephalitis. Knut’s case is the first ever reported in a non-human.

(Image: Christian Schroth/ullstein bild via Getty)

The team thinks the disease, which is treatable with immune-suppressing drugs, may be widespread among mammals. If Knut had been diagnosed, he might still be alive today.

Journal reference: Nature, DOI: 10.1038/srep12805