However, the definition has evolved over time to include a change in consciousness, such as amnesia, although controversy continues about whether the definition should include only those injuries in which loss of consciousness occurs.
Men denne definition har udviklet sig over tid til at inkludere en ændring i bevidsthed, såsom hukommelsestab, selvom der er uenighed om denne definition kun skal inkludere de skader hvor tab af bevidsthed opstår.