Transient global amnesia is a condition which makes the sufferer unable to form new memories or recall the recent past. It is important to rule out other causes of amnesia when dealing with TGA. Symptoms of transient global amnesia are:
• A dramatic onset of memory loss, which is verified by a reliable witness
• The sufferer retains their personal identity despite this loss of memory
• They still retain normal cognition, such as the ability to recognize and name familiar objects and follow simple directions
• There is an absence of any signs indicating damage to any area of the brain, such as limb paralysis, involuntary movement or impaired word recognition
• The duration lasts no more than 24 hours
• There is a gradual return of memory
• There is no evidence of any kind of seizures during the period of amnesia
• The sufferer has no recorded history of active epilepsy or has suffered any recent head injury
Another feature of transient global amnesia includes the sufferer saying the same question over and over again, such as: "What am I doing here?" or "How did we get here?"
You should seek out immediate medical attention for a sufferer who suddenly goes from a normal awareness of present reality to confusion about what has 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 more life-threatening illnesses that are also responsible for 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 proper medical evaluation will be the only way of determining a sudden cause of any loss of memory.