A research team in the United States may have solved a mystery that has haunted soldiers and veterans for more than a century: how blast force from battlefield explosions injures the human brain.

The findings, published Thursday in the medical journal the Lancet Neurology, reveal a unique and consistent pattern of damage in the autopsied brains of eight military service members who had served in Iraq, Afghanistan, and elsewhere in the Middle East.

All had suffered trauma after exposure to blast force on the battlefield, mostly from improvised explosive devices (IEDs)—the signature injury of recent campaigns, just as shell shock from exploding artillery shells had been the signature injury of World War I, a hundred years before.

In medical terminology, traumatic