Blasts from explosives have long been known to cause mild traumatic brain injury in combat veterans, but a new study by Seattle experts sheds light on how — and where — lasting harm may occur. Using brain scans from dozens of former soldiers, plus similar research in mice, scientists have identified the cerebellum — the area of the brain critical for coordinating movement, balance and certain cognitive skills — as particularly vulnerable to repeated blasts. “What’s interesting is that these types of TBI wouldn’t be on most people’s radar,” said James Meabon, an expert in psychiatry and geriatrics at UW.
More than 40 veterans who participated in the study experienced an average 21 mild traumatic brain injuries as a result of explosions, with some enduring more than 100 such injuries. The more blasts they were exposed to, the more they showed lower levels of glucose metabolism, a marker of brain activity, in the cerebellum, the study found. Further neuroimaging in both mice and humans showed additional structural changes in the cerebellum, including damage to the fibers that connect regions across the brain.