Post-concussion syndrome
About 10% of people with PCS develop sensitivity to light or noise, about 5% experience a decreased sense of taste or smell, and about 14% report blurred vision. People may also have double vision or ringing in the ears, also called tinnitus. PCS may cause insomnia, fatigue, or other problems with sleep.
Sports-related traumatic brain injury
Short-term effects deal mostly with Post-concussion Syndrome, which has no clearly defined definition. A person suffering from a single concussive incident typically has a strong recovery rate. The most common Post-concussion symptom is a persistent headache which usually disappears within 1–2 weeks. Other common short-term effects include dizziness, vomiting, nausea, sensitivity to light and sound, irritability, cognitive lapses and memory impairment. 20-90% of the persons affected develop one symptom within a month of the incident, after 3 months 40% of the affected persons show at least 3 symptoms.