“Transient amnesia” refers to repeated attacks of memory loss.
There are a number of well recognised causes of transient amnesia, including head injury, transient global amnesia, migraine, drugs and rarely, transient ischemic attacks (“mini strokes”). It has recently been recognised that transient amnesia can also be caused by epilepsy.
“Transient epileptic amnesia” (TEA) refers to repeated attacks of memory loss caused by epilepsy.
We recently conducted a study looking at the clinical features of a group of 50 TEA patients. We found that TEA tends to present in late adulthood (average age 62). Men are twice as likely to suffer from the condition. The attacks often occur on waking and typically last for 30 to 60 minutes. During an attack there is usually a combination of problems in remembering recent events and in laying down a memory for events occurring during the attack. Problems with memory may be the only symptom during an attack. However some patients report hallucinations of smell during the episode, and some briefly lose touch with their surroundings. The attacks generally respond very well – stop altogether – when an appropriate anti-epileptic drug is prescribed.
TEA is often misdiagnosed as either transient global amnesia (TGA) or psychogenic amnesia. Distinguishing TEA from other causes of amnesic attacks is an important step in developing successful treatment programmes for this form of amnesia and its associated memory deficits.