A brain injury will often show up on brain scans as a well-defined area of damage. But often the changes to the brain extend far beyond the visible injury.
While the short-term symptoms of concussion are reversible, research suggests that even a single knock to the head can have severe consequences later in life.
Visualising concussion-related changes in the brain is particularly challenging. Unlike the bleeding inside the brain that might occur with a severe head impact, no obvious structural changes accompany concussion.
