I've been trying to write an article on the history of "combat fatigue," PTSD, and similar conditions amongst medieval knights when I started thinking about some other neurological conditions that may also have affected them, namely chronic traumatic encephalopathy (CTE). I'm wondering if any medievalist out there know of any sources that describe this sort of madness amongst veteran knights. Essentially, CTE (now more commonly associated with football players) is a neurodegenerative disorder caused by repeated head injuries. Tangles of detrimental tau protein begin to accumulate in the brain, similar to what we see in Alzheimer's patients. Symptoms tend to manifest as erratic behavior, violent mood swings, dementia, and even some suicidal behavior. In Blood Red Roses, archaeological records of the wounds from Towton seem to indicate that a high percentage of battlefield injuries were delivered to the head/neck, and this distribution seems to be corroborated by other archaeological findings. With all that in mind, it stands to reason that men-at-arms probably sustained a great deal of head trauma. As I said, do any historians out there know of any good sources that describe veterans as displaying CTE symptoms? Or, if not, could there be some survivor bias--that is to say, we primarily see head wounds in mass graves because they are the most deadly, whereas survivors probably didn't get hit in the head as much? Thanks!