How do you manage Moya-Moya disease medically for patients that are unable to receive EC-IC bypass?

It depends on the cause. Usually for patients either moya moya disease (in contrast to moya moya syndrome where symptomatic patients would benefit from EDAS or surgical management ) due to atherosclerosis or radiation induced if someone has continued ischemic events or silent infarcts on aspirin monotherapy (no evidence that 325 mg daily is superior to efficacy than 81 mg daily once the levels are built and if the aspirin assay also is showing optimal platelet inhibition at 81 mg daily- I then don’t use a higher dose) then I may add Plavix 75 mg daily (or brilinta if they are a non responder to Plavix).

I will also do a CTP with Diamox to look for baseline auto-regulatory reserve. If the baseline reserve is normal, then will continue medical...

I would say that there is no clear evidence for the best medical therapy for Moya Moya; the treatment is mainly surgical, either direct EC/MC bypass or an EDAS procedure. If surgery is not an option, the usual medical treatment for secondary stroke prevention would be appropriate, including antiplatelet therapy, BP management, etc.