Even if you don’t experience a loss of consciousness, the few hours that follow your injury are still critical, and you’ll need to watch for symptoms such as:Headache: Headache is a prevalent symptom following TBI. Slurred speech: This includes speaking extremely slow or fast.Restlessness: Restlessness and agitation are two of the most problematic and striking behaviors when you have TBI, even for your family or caregivers.