OP raises a good question.
I did a google search using "Medical problems experienced by Helicopter Pilots" and numerous links were surfaced.
None seemed titled to show a relevance to his question but there was some interesting studies done on several different military service pilots.
As the US Veterans Administration and/or the military service offers compensation or pensions for disabilities incurred while in the service it might be a good idea for Veterans to look through some of those studies.
You might have a valid claim even well after leaving the military service.