They are among war’s invisible wounds: the emotional and cognitive problems that many troops experience years after combat explosions sent huge shock waves through their brains. Whereas the link between concussions and post-traumatic stress disorder has become clearer in recent years, a specific connection between PTSD and blast waves has remained elusive.

Now, a prominent neuropathologist who researches brain injuries among military personnel says his team has identified evidence of tissue damage caused by blasts alone, not by concussions or other injuries. The team’s study was published on Thursday in The Lancet Neurology.

The discovery could eventually lead to better treatments and to improved head and body protection for troops exposed to high-energy blasts, some experts said. Other researchers advised that these initial findings should be bolstered by more studies before veterans and their families read too much into them.

“We talk about PTSD being a psychiatric problem — how people responded to the horror of warfare,” said Dr. Daniel P. Perl, the neuropathologist who led the study. “But at least in some cases, no — their brain has been damaged.”