A

David

Darling

amnesia

Amnesia is a total loss of memory for a period of time or for events. In cases of concussion, retrograde amnesia is the permanent loss of memory for events just preceding a head injury while post-traumatic amnesia applies to a period after injury during which the patient may be conscious but incapable of recall, both at the time and later. Similar behavior to the latter, termed fugue, occurs as a psychiatric phenomenon.