Traumatic brain injury (TBI) can result from trauma to the head caused by an accident. The accident could involve a defective product, fall, construction site accident, train accident, or motor vehicle accident. TBIs can be difficult to diagnose because many brain injuries do not involve an outward sign of injury. You can sustain a brain injury because you suffered whiplash from a fall or car crash. Most physicians begin with a physical examination and a rating on the Glasgow Coma Scale (GCS). Physicians rely on their observations of the patient and the patient’s reported symptoms to make an initial diagnosis.