SymptomsBy Mayo Clinic staff
Transient global amnesia is identified by its main symptom, which is the inability to form new memories and to recall the recent past. Once that symptom is confirmed, ruling out other possible causes of amnesia is important.
Necessary symptoms for diagnosis
Doctors base a diagnosis of transient global amnesia on the following signs and symptoms:
- Sudden onset of memory loss, verified by a witness
- Retention of personal identity despite memory loss
- Normal cognition, such as the ability to recognize and name familiar objects and follow simple directions
- Absence of signs indicating damage to a particular area of the brain, such as limb paralysis, involuntary movement or impaired word recognition
- Duration of no more than 24 hours
- Gradual return of memory
- No evidence of seizures during the period of amnesia
- No history of active epilepsy or recent head injury
Along with these signs and symptoms, a common feature of transient global amnesia includes repetitive questioning, usually of the same question — for example, "What am I doing here?" or "How did we get here?"
When to see a doctor
Seek immediate medical attention for anyone who quickly goes from normal awareness of present reality to confusion about what just happened. If the person experiencing memory loss is too disoriented to call an ambulance, call one yourself.
Although transient global amnesia isn't harmful, there's no easy way to distinguish the condition from the life-threatening illnesses that can also cause sudden memory loss. In fact, sudden amnesia is much more likely to be caused by a stroke or a seizure than by transient global amnesia. A medical evaluation is the only way to determine the cause of sudden memory loss.
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