Memory loss around a seizure can be one of the most unsettling parts of epilepsy. A person may remember the warning but not the seizure, remember waking up but not what happened afterwards, or lose pieces of time before and after the event.
Memory depends on brain networks that seizures can disrupt
The hippocampus and connected temporal-lobe networks are central to forming new memories. Seizures arising from or spreading through these networks can interfere with encoding and retrieval, which helps explain why some people have amnesia for the event itself or for the surrounding period.
The postictal period can add another layer
After a seizure, attention, language and memory may remain impaired while the brain recovers. A person can appear awake yet still fail to lay down reliable memories. That means witnesses may remember more of the event than the person who experienced it.
It is rarely only one factor
Longer-term memory difficulties in epilepsy can also be influenced by seizure frequency, sleep disruption, mood, underlying brain changes and antiseizure medicines. Not every memory problem is caused by the last seizure.
Why video or written records can help
If someone cannot remember an event, a seizure diary, witness account or clinically appropriate video can help reconstruct what happened. That information can be useful when discussing seizure type, injuries or recovery with the epilepsy team.
Sources
Systematic review — Signs and symptoms of the postictal period