"Tests showed that the man’s spinal cord was markedly inflamed. The cause seemed to be an autoimmune reaction: his immune system was mistakenly attacking his own nerves as if they were a foreign body or a germ. Doctors could not figure out why it had happened, but the standard treatment for inflammation — a steroid drug — seemed to help
Neurological illnesses sometimes defy understanding, Dr. Lachance said, and this seemed to be one of them. At the time, it did not occur to anyone that the problem might be related to the patient’s occupation.
By spring, he went back to his job. But within weeks, he became ill again. Once more, he recovered after a few months and returned to work — only to get sick all over again."