The Providentia psychology blog has an excellent post about old-time champion boxer ‘The Michigan Wildcat’ Wolgast who fought on despite clear neurological damage and eventually suffered boxer’s dementia. He could apparently be found shadow boxing invisible opponents in the sanatorium.
Wolgast won the world lightweight title in 1912 but sustained continuous damage throughout his career and continued way past the point that would be permitted in modern times.
He progressed from minor neurological impairment to ‘dementia pugilistica‘ – a form of dementia caused by repetitive low level damage to the brain.
When his condition gradually deteriorated, Ad Wolgast was readmitted to hospital in 1927. While he remained there for the rest of his life, Ad continued to train in his room.; According to his obituary, that typically involved frequent shadowboxing, bobbing, and uppercuts against imaginary opponents. Ad Wolgast seemed largely unaware of his surroundings except on rare occasions when he would plaintively ask where he was and when he would be allowed to leave. His boxing career may have been long over but it still took two hospital attendants to restrain him whenever he was forced to do something he didn’t want to do. By all reports, his “tough guy” reputation and violent temper earned him numerous beatings in hospital but he always recovered quickly enough. He went blind in the final few years of his life.
Link to Providentia on ‘The Michigan Wildcat’.