Symptoms and Signs of Sports-Related Concussion The most obvious disturbance of brain function with a concussion is Loss of consciousness However, many patients do not lose consciousness but instead manifest symptoms and signs such as Confusion: Appears dazed or stunned, is unsure of opponent or score, answers slowly Memory loss: Does not know plays or assignment, does not recall events before the injury (retrograde amnesia) or afterward (anterograde amnesia) Vision disturbance: Has double vision or light sensitivity Dizziness, clumsy movements, impaired balance Headache Nausea and vomiting Tinnitus Loss of smell or taste Postconcussive symptoms are symptoms that may be present for a few days to weeks after concussion; they include Chronic headaches Short-term memory difficulties Difficulty concentrating Fatigue Difficulty sleeping Personality changes (eg, irritability, mood swings) Sensitivity to light and noise Postconcussive symptoms typically resolve in a few weeks to several months.