A change in mental status at the time of an injury signals concussion, even if there is no loss of consciousness (LOC).

• Concussion can occur without LOC.


• It's estimated that less than 10% of concussions involve LOC.


• LOC at the time of concussion must be viewed as a sign of a potentially worrisome traumatic brain injury, especially if it lasts longer than 30 minutes.


• LOC followed by more severe acute neural status abnormalities carries a greater risk of intracranial pathology.

A change in mental status at the time of an injury signals concussion, even if there is no amnesia.

• It's estimated that less than 25% of concussions involve post-traumatic amnesia.


• Concussion patients with amnesia experience more persistent symptoms than those with brief LOC.


• Amnesia can be retrograde or anterograde.

Retrograde amnesia is the loss of memory of events that took place immediately preceding an injury.

• Typically it affects short term memory centers.


• It’s noticeable in responses to questions about such topics as date, time, location, score, recent meals, or play responsibilities.

Anterograde amnesia involves a deficit in forming new memory. Post-traumatic amnesia is a type of anterograde amnesia that happens as a result of an injury. This can be evident in failure to recall details after the event in response to questioning, such as about the final score, dressing, leaving, going home, and so on.