Initially eleven unexplained neurologic illnesses were detected among workers at a pork processing plant in Austin, Minnesota. The workers had fatigue, pain, numbness, and tingling in their arms and legs, and weakness. Laboratory tests showed evidence of inflammation of the nerves; the condition was progressive. The common link among the workers was that they had exposure to a pork brain extraction procedure involving compressed air. An autoimmune response to aerosolized pig nerve tissue was suspected. Ultimately eighteen cases were linked to the Minnesota pork processing plant. There were five similar cases at an Indiana plant and one case at a Nebraska plant. The meat processing plants have since discontinued the use of compressed air in removing pork brains. The workers' health has stabilized or improved.