Lou Gehrig may not have had amyotrophic lateral sclerosis:

A peer-reviewed paper to be published Wednesday in a leading journal of neuropathology, however, suggests that Gehrig’s demise — and that of some other athletes and soldiers given a diagnosis of amyotrophic lateral sclerosis, commonly known as Lou Gehrig’s disease — might have been catalyzed by injuries only now becoming understood: concussions and other brain trauma.

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The finding’s relevance to Gehrig is less clear. But the Yankee legend had a well-documented history of significant concussions on the baseball field, and perhaps others sustained as a battering-ram football halfback in high school and at Columbia University. Given that, it’s possible that Gehrig’s renowned commitment to playing through injuries like concussions, which resulted in his legendary streak of playing in 2,130 consecutive games over 14 years, could have led to his condition.

This may be a reason it was so difficult to cure, doctors were looking at two different things, a disease and an injury.