A:A person with a mild traumatic brain injury (TBI) may remain conscious or may experience a loss of consciousness for a few seconds or minutes. Other symptoms of mild TBI include headache; confusion; lightheadedness; dizziness; blurred vision or tired eyes; ringing in the ears; a bad taste in the mouth; fatigue or lethargy; a change in sleep patterns; behavioral or mood changes; and trouble with memory, concentration, attention, or thinking.