Amnesia is loss of memory that occurs due to psychological trauma or other conditions causing damage to the brain. Such a type of condition essentially does not cause loss of self identity.
Individuals with amnesia face problems with forming new memories and remembering the old ones. With age, memory loss is a common phenomenon. However, when individuals experience significant loss of memory, then it is an indication of amnesia. It is a permanent condition that essentially occurs as a result of damage to the major areas of the brain. Unlike other form of amnesia, such as transient global amnesia, which causes temporary memory loss, amnesia is a permanent condition  .
Amnesia is attributable to all those factors that lead to brain damage. Such conditions include:
Amnesia is of several types such as transient global amnesia, anterograde amnesia and retrograde amnesia. Transient global amnesia occurs in about 5.2 cases per 100,000 populations. The incidence is higher amongst those aged 50 years and above. It has been estimated that in individuals over 50 years, the condition strikes 23.5 cases per 100,000 populations .
Under normal conditions, the function of memory employs several parts of the brain. Any type of situation, such as diseases, or trauma to these parts, significantly hampers the memory of the individual. The limbic system in the brain is responsible for memory functioning. This system includes the thalamus and the hippocampus. The hippocampus part of the brain is responsible for forming new memories and recovery of old memories. The cells of this part gets easily damaged and disrupted by diseases, trauma, injury, drugs and anoxia. In addition, stroke and infections can cause permanent damage to the brain  .
So far there is no specific treatment for amnesia. Affected individuals are treated for underlying disease conditions to manage the symptoms. Prognosis of the condition would greatly depend on the underlying disorder. Individuals who have developed amnesia due to brain injury, show signs of recovery over a period of several weeks to months. However, those with severe head injury have a poor prognosis.
Individuals with amnesia usually find problems with short term memory. They are unable to remember recent or new information. Such individuals usually have sound memory about their childhood days or history. For example; such individuals can recall name of past presidents, but would unable to tell names of current ones. Also, they would find difficulty in telling what they had for breakfast.
Individuals with retrograde amnesia are unable to recall past events or memories and those with anterograde amnesia find difficulty in learning new things . However, individuals with such a kind of memory loss are still able to understand written and spoken words. In addition, affected individuals present with the following signs and symptoms:
At the preliminary level, various tests will be done to rule out underlying conditions that can be a cause of memory loss such as Alzheimer disease, dementia, brain tumor or depression. Thereafter, the following tests would be done to diagnose amnesia :
The following methods are employed for treating amnesia :
Brain injury or damage to the brain from other disease is the root cause of amnesia. In view of this, it becomes necessary to adopt all steps to avoid brain damage. The following steps can be taken:
Amnesia is a condition characterized by memory loss due to damage to the parts of the brain that are responsible for memory function. There are several types of amnesia which include transient global amnesia, anterograde amnesia and retrograde amnesia. All these types define memory loss, but with different characteristics.
Damage to the thalamus and hippocampus region of the brain, are responsible for the memory function. Any damage to these parts, significantly affects the memory of the individuals. Factors such as underlying disease condition, brain injury, tumor, poor oxygen supply, alcohol abuse, trauma and stress can lead to amnesia.
Symptoms of amnesia include impaired ability of the individual to recall recent information, along with confusion and confabulation. Affected individuals can recall old information to a certain extent, but are pretty bad with new or recent information.
A detailed medical history of the affected individual is gathered. Following this, neurological tests are carried out, to assess the extent of memory loss. In addition, CT scan and MRI are also done to determine damage to the brain.
Affected individuals are treated through occupational therapy, and technological assistance to help them cope with memory loss. Certain medications are also given to treat the underlying condition.