One of the frustrations of researchers who study chronic traumatic encephalopathy, the degenerative brain disease linked to repeated head hits, is that it can be detected only in autopsies, and not in the living.

Researchers, though, have been trying to solve this problem in two primary ways: by identifying biomarkers linked to the disease that show up on imaging tests in certain locations in the brain, and by trying to locate in the blood the protein that is the hallmark of the disease.

On Monday, two groups of researchers said they had made what they considered small steps in developing both methods.

The announcements are small parts of much larger studies that will take years to bear fruit, if they ever do. Both methods have been questioned by detractors, some of whom say the hype is getting ahead of the science. Scientists, these critics note, have spent decades trying to find ways to accurately diagnose Alzheimer’s disease, which has some of the same characteristics as C.T.E.