Injury to the brain caused by a blow or jolt to the head, or by penetration, affecting physical and cognitive function.

In a personal injury case:
May arise from car accidents, falls, or assaults; symptoms range from mild concussion to severe disability.

What to know:

• Symptoms can include headaches, memory problems, mood changes, and sleep issues.

• Diagnosis may involve CT scans, MRIs, and neuropsychological testing.