In some cases you may not realize that you or someone you know has sustained a traumatic brain injury. The symptoms are sometimes difficult to identify unless you know what you are looking for and ask the right questions. Typical symptoms of TBI such as memory loss or difficulty concentrating may be mistaken for old age or side effects from medication. Some of these symptoms may also be very subtle. In some cases, an emergency room physician may suspect a brain injury and order an MRI or CT Scan. Unfortunately, these tests may not show subtle changes in function due to traumatic brain injury. The patient is then left to wonder about what is causing the symptoms but has already been told that they did not suffer a brain injury. The fact that these tests are normal would not preclude a finding of traumatic brain injury. In these situations, a neuropsychological evaluation may be helpful in identifying functional problems such as memory loss, difficulty concentrating or other cognitive functions.