By: Dr. Stacey Naito – Physician and IFBB Pro
Zoo veterinarians were astonished and puzzled when Knut, the polar bear at the Berlin Zoo who rose to celebrity status, died suddenly in 2011 after suffering from a seizure and collapsing into the pool in his enclosure. Knut’s death at the young age of four was a complete surprise, since polar bears can live up to 20 years in the wild and even longer in captivity, so researchers were determined to find out the cause of his bizarre demise.
Researchers have finally discovered what killed Knut. The reason for his death was an autoimmune disorder called anti-NMDA receptor encephalitis, a type of brain inflammation in which the body attacks its own brain cells and causes them to malfunction. Anti-NMDA receptor encephalitis strikes one in 200,000 people and is the main cause of non-infectious encephalitis. Initial symptoms are nausea, fever, headaches and hallucinations, later progressing to motor abnormalities, seizures and death if untreated. Until Knut’s cause of death was discovered, scientists believed that this form of encephalitis only occurred in humans.
Anti-NMDA receptor encephalitis is treated in humans with high-dose steroids and plasma exchange. Now that scientists have determined that the disease affects other creatures in the animal kingdom, zoo veterinarians are optimistic that zoo animals who exhibit signs of encephalitis without a clear cause can be treated with the same medications. The knowledge of what killed Knut has also made scientists aware that anti-NMDA receptor encephalitis may be undertreated, which can aid in the development of earlier intervention and more effective treatments for this disease.