Duration of PTA may be difficult to gauge accurately; it may be overestimated (for example, if the patient is asleep or under the influence of drugs or alcohol for part of the time) or underestimated (for example, if some memories come back before continuous memory is regained) [REF].
An alternative to the GOAT is the Westmead Post-Traumatic Amnesia Scale (WPTAS)[REF][REF] which examines not only orientation to person, place and time, but also crucially the ability to consistently remember new information from one day to the next.