Tricky situation for sure, if his health insurance is through work then diagnosing a seizure disorder could shut down his climber job. It would be worth contacting his primary doctor and find out what the confidentiality guidelines are as far as disclosures to the employer. It may turn out he is completely protected and there will be no disclosures of specific health issues to an employer.
If not then seek medical assistance off the insurance dime, even though that is expensive.
The reality though is that this is not all about losing a job, stoicism and even denial in the face of difficulty is one of the hallmarks of the working climber mindset, it has to be.
Another way to go is look at the big picture and talk to a counselor to help clarify where the fears might really be coming from and try to work to a good solution from there. No fault in seeking support to solve a difficult conundrum.
-AJ