Possible Concussion Outcomes

Natural History

Concussion will usually improve significantly within a 7 to 10 day period. However, ignoring or failing to recognize concussion signs and symptoms can result in potentially catastrophic consequences. Acute brain swelling, traditionally referred to as “Second Impact Syndrome” is usually fatal. Prolonged symptoms, recurrent concussion, learning difficulties, and personality problems have also been reported.

The following conditions can evolve from the initial concussion injury:

Post-Concussion Syndrome (PCS)

Post-concussion syndrome is a complication arising from concussion. Little is known of why it occurs and persists and why it affects some people and not others.
Unlike other forms of concussion, symptoms do not clear up within a relatively short period and can even become permanent.

Second-Impact Syndrome (SIS)

Experiencing a second concussion before the symptoms of the first concussion have resolved can prove fatal. With SIS, the brain usually swells rapidly due to its inherent vulnerability following the original first blow.

The secondary event, together with the altered levels of brain chemicals typical of concussion, can hamper the brain’s ability to self-regulate the amount of blood to the brain.

SIS can therefore cause an increase in brain blood flow which can result in rapid brain swelling, particularly amongst young athletes.

Chronic Traumatic Encephalopathy

Chronic Traumatic Encephalopathy (CTE) is a progressive degenerative disease of the brain found predominately in boxers. Persons with a history of repetitive brain trauma, including symptomatic concussions as well as asymptomatic subconcussive hits to the head may be at risk of CTE.

The repeated trauma to the brain triggers a progressive degeneration of the brain tissue containing clumps of Tau protein. Memory loss, confusion, impaired judgment, impulse control problems, aggression, depression, and, eventually, progressive dementia have all been shown to be possible symptoms of the disorder. CTE has also been linked to suicide in high profile NFL players.

The onset of disease can begin long after (10-20 years) the last brain concussion, and has typically only been diagnosed after the death of the patient (post mortem).

Recently, a study in the USA has utilized brain scan technology to develop a potential test for CTE. At this stage, no definite cause and effect can be drawn between concussion in sport and CTE. Research is ongoing in Australia and the United States.

The Sports Concussion Programme concussion tests can quickly and effectively detect concussion after an injury, allowing for immediate removal from play and referral to a medical doctor.