transient amnesia causes
Transient global amnesia is a sudden, temporary loss of memory for events during, after, and sometimes before the event that caused the amnesia. What causes many cases of transient global amnesia is not known, but one type is caused by drinking too much alcohol or taking certain drugs. People with this amnesia suddenly but temporarily become unable to store new memories and to recall events that happened after the amnesia occurred.
Most people with transient global amnesia have only one episode in a lifetime, unless the cause is seizures or migraines. About 5 to 25% have repeated episodes. After an episode, the confusion usually clears quickly, and total recovery is the rule, although people may not remember what happened during the episode.