How can an individual with a noncommunicable disease apply for an EB-5 visa and are there any special requirements?

This is not a ground of inadmissibility, but it may result in public charge concerns, so need to set up a trust to show he will not be a burden on the state.

Applying either for a green card inside the US (Adjustment of Status) or for an immigration visa outside of the US (Consular Processing) requires a health examination by an approved physician from a list maintained by the US government. Usually, a medical condition that is not contagious and which does not put the public at danger, is less likely to jeopardize a green card or immigrant visa application.

Yes, there are health requirements pertaining to a residence application. You can read about health grounds of inadmissibility here: https://www.uscis.gov/policy-manual/volume-8-part-b Some health conditions, while not a ground of inadmissibility per se, can spill into other grounds of inadmissibility, such as public charge etc.

There should be no issue applying for a green card for someone with multiple sclerosis as it does not fall under a communicable disease of public health significance.

I do not believe this disease is on the CDC list of medical conditions that exclude one from admission to the U.S. The individual would still have to prove they can afford their medical care in the U.S. and will not become a public charge.