What is Transient Global Amnesia (TGA)?
Transient global amnesia (amnesia means loss of memory) is a clinical syndrome characterized by sudden onset of anterograde loss of memory (anterograde means inability to remember events after onset of memory loss) and learning abilities.
The period of memory loss lasts for a few hours from onset of an attack, therefore, the term transient is used here.
Transient global amnesia has the following features
- It generally affects middle-aged or elderly people, above the age of 50 years.
- Triggering factors for transient global amnesia are postulated to be the following:
- Emotional or mental stress
- History of a migraine, stroke and epilepsy
- Recent sexual activity
- Physical exertion
- Psychological disturbances.
- The sudden change of temperature
- Individuals with transient global amnesia are alert and communicative and there is a complete absence of neurological signs and symptoms.
- The patient may seem confused and asks about recent events repeatedly.
- There is disorientation in relation to time, place and person.
- There is a temporary inability to form new memories.
- Symptoms such as a headache, nausea, vomiting and dizziness are seen in nearly 10% of cases of transient global amnesia.
- Chest pain, tingling and numbness of extremities, the coldness of extremities and sweating have also been reported during attacks.
How Is It Diagnosed?
Transient global amnesia is a clinical diagnosis. There are no specific tests or scans to confirm the diagnosis.
A Computed Tomography (CT scan), Magnetic Resonance Imaging (MRI) or An Electroencephalogram (EEG) may be advised by the treating doctor to diagnose possible underlying conditions which may be responsible for attacks of transient global ischemia.
It can be tested by the doctor at the bedside by asking the patient about his/ her activities before the onset of amnesia. Hodge and Warlow in 1990 formed diagnostic criteria to diagnose TGA. The following points are considered in the diagnostic criteria
- The attack must be witnessed by a capable observer who was present throughout the attack.
- Anterograde amnesia must be present during the attack.
- Cognitive impairment is limited to amnesia without loss of consciousness or alertness.
- No accompanying focal neurological symptoms are to be present during and after the attack
- There should be the absence of epileptic features
- Resolution of attack must occur within 24 hours
- Patients with recent head injury or active epilepsy are not to be included
Transient Global Amnesia After Effects
- Transient global amnesia is a benign condition which usually resolves by itself within 24 hours from onset of amnesia without the need for any medical assistance or intervention.
- Since there is a temporary loss of memory, the patient cannot recollect events that happened during the episode of amnesia.
- Most patients do not experience recurrence. About one-fourth of patients who encounter a transient global ischemia develop the risk of having recurrent attacks.
- There may be partial loss of long-term memory. Patients may have difficulty in recalling events that occurred in the past few hours, days or months before the attack of amnesia.
- Rare instances of complete and permanent loss of memory have been reported in patients having recurrent attacks of transient global amnesia.
- Some cases have reported persistence of memory dysfunction even after the condition has resolved.
- Some patients even report mild cognitive impairment after attacks of amnesia, which means that they have difficulty in learning new things, concentrating on work or taking decisions of day-to-day activities.
- A proportion of patients with recurrent attacks of transient global amnesia have reported impaired visuoperceptual functions, which means that although patients can see the surroundings well, yet they are unable to understand them.
- Studies have found that patients with transient global amnesia are at an increased risk for coronary artery diseases and myocardial infarction as compared to the general population.
- Studies have also found that patients with TGA are at an increased risk for strokes and seizures.
Transient Global Amnesia Treatment
- There are no specific evidence-based medicines in allopathy for treatment of transient global amnesia. As evident from the name, TGA is a self-limiting condition and the patient experiences spontaneous improvement usually within 24 hours of its onset without any medical intervention.
- Treatment can, however, be directed towards controlling or eliminating the causative factors.
- Memory plays a significant role in shaping an individual’s personality and identity. It also influences a person’s learning process. Therefore, transient global amnesia can be a fairly frightening experience for any person.
Keeping these pointers in mind, psychological support and counseling of patients, as well as relatives, is as important as diagnosing it.
- Treatment can be aimed at optimizing cardiovascular and cerebrovascular function by managing blood pressure, heart rates and rhythms and blood cholesterol levels.
- Alternative medicine treatment options can be used to manage transient global amnesia. These include
- Homeopathy – This system of medicine aims to treat the person as a whole. It considers signs and symptoms, constitution and thermal state of each patient individually. It is known to treat the root cause of any illness.
- Acupuncture – This therapy aims at improving the body’s physiological (natural) process by stimulation of acupoints resent all over the body. This system of medicine also uses cupping as a part of treatment. Clinical researches in the field of acupuncture have proved its ability in the management of neurological conditions like stroke, TIA and TGA.
There are no ways by which one can prevent a transient global amnesia or avoid its recurrence. Continuous mental and emotional support and counseling helps the patient deal with each attack of TGA.
It might be considered a good practice for patients and their relatives to keep a diary to keep track of such attacks. Patients who experience recurrent episodes of transient global amnesia are advised to keep a regular follow up with their treating doctor or neurologists and not just pay visits at the time of emergency.