Guest Author - Maria Hester, M.D.
Transient global amnesia (TGA) is among the most striking neurologic phenomena known to man. Several hypotheses exist regarding its cause, but there is no consensus among the experts about the underlying basis of transient global amnesia. Fortunately, the use of new and innovative imaging techniques has begun to shed light on this remarkable syndrome.
The sudden onset of amnesia can be very traumatic to patients, as well as their loved ones. Some current hypotheses about the cause include decreased blood flood to the brain (ischemia), migraine, seizures, congestion of blood flow away from the brain, and psychological disorders.
TGA was the term coined for this condition by C.M. Fisher and R.D. Adams over 40 years ago. It is characterized by a sudden inability to retain new information (anterograde amnesia). Acutely, prior memories (retrograde amnesia) can also occur and go back as far as several months.
Patients with TGA may experience the following symptoms:
1.They often ask the same questions over and over again.
2.Patients with TGA may appear disoriented in time and place.
3.Some experience symptoms like headache, vertigo, and nausea with attacks.
4.They have no change in the level of consciousness (they are not groggy) and they retain their self-awareness.
5.Mental impairment is limited to amnesia. They can perform complex tasks such as driving and cooking.
6.Symptoms resolve spontaneously within 24 hours and may be as short as an hour.
According to medical scientists, the average age of symptom onset is approximately 60 years of age and up to 11 out of 100,000 people per year may experience this syndrome.
While TGA is considered a benign disorder and is not associated with a history of recent head trauma, patients may experience persistent impairment of mental function.
While once thought to be in some respects similar to a TIA (or mini-stroke) there are some striking differences. Classically, a person experiencing a TIA has some obvious abnormality with her motor function. For instance, the facial muscles may become weak on one side causes drooping of one side of the mouth. Inability to hold on to saliva may be another manifestation, as can slurred speech. Alternatively, the person may experience weakness of one side of the body. As previously noted, with TGA the deficit is limited to amnesia. There is no impairment of muscles.
While inconclusive, some research suggests that when compared to those with a true TIA, those with TGA have fewer risk factors for cardiovascular disease (such as high cholesterol and high blood pressure). In addition, patients with TGA have a better prognosis. If you experience any peculiar memory lapses, see your doctor immediately and do not try to diagnose yourself with this benign condition. You may have something much more serious that requires immediate medical attention.