'Pig Brain Mist' Mystery Disease Solved
A little over a year ago, The New York Times reported on a curious phenomenon. Workers at a Hormel-affiliated pork processing plant in Austin, Minnesota were developing a mysterious neurological symptoms — fatigue, numb legs, pain, and difficulty walking — and no one knew why. The one thing all the patients had in common was that the worked with pig brains; specifically, "blowing brains," a gruesome procedure in which a metal hose hooked to an air compressor was inserted into the animal's skull, and the brain was essentially forced out of the head in a fine mist.
With no clear explanation for what was going on, medical investigators had to come up with something.
The Times reported:
The investigators had begun leaning toward a seemingly bizarre theory: that exposure to the hog brain itself might have touched off an intense reaction by the immune system, something akin to a giant, out-of-control allergic reaction. Some people might be more susceptible than others, perhaps because of their genetic makeup or their past exposures to animal tissue. The aerosolized brain matter might have been inhaled or swallowed, or might have entered through the eyes, the mucous membranes of the nose or mouth, or breaks in the skin.
Last week, Wired's Science blog told us that we have an answer. The theory of hog brain as a massive allergic reaction held up, the brain matter cuing the workers' immune systems to target their own nervous system.
"When you're breathing in pig brain tissue, your body develops an antibody against it," said Mayo Clinic neurologist James Dyck, who helped treat the workers. Antibodies are chemicals used by the immune system to tag foreign bacteria and substances. "There's enough overlap between pig brains and human brains that it was a problem."
Fortunately, most responded to treatment with immunotherapy and steroids, and six improved without any treatment at all. None of the workers, however, have recovered fully.
The complete report on the workers' complaint, treatment, and recovery will be presented at the American Academy of Neurology's annual conference, which will be held in Seattle in April.