Amnesia, also known as amnestic syndrome is a medical condition in which patients lose their ability to memorize data such as information, facts and experiences. People suffering from amnesia are generally lucid and have a sense of self but face trouble in forming new memories and learning new information. Amnesia is caused in a person due to functional defect or organic defect. Organic causes include usage of drugs such as sedatives, and brain damage due to injury. Amnesia is also a symptom of various degenerative brain disorders such as Alzheimer’s disease and dementia. Functional cause includes various psychological factors like defense mechanism of neurology system.
Usually patients suffering from amnesia face problems with short-term memory and are likely to forget the recent activities or actions that they were involved into. However, deeply ingrained memories such as childhood memories may be sprayed into the brain and can be recalled by the patients. Sometimes patients suffering from amnesia also show symptoms such a disorientation and confabulation (false recollection). Patients may suffer from various types of amnesia namely retrograde amnesia, infantile amnesia, anterograde amnesia, traumatic amnesia, Wernike-Korsakoff's psychosis, source amnesia, transient global amnesia, hysterical (fugue) amnesia, posthypnotic amnesia, prosopamnesia and blackout amnesia.
Anterograde amnesia is a type of amnesia in which a patient cannot remember new data or information, and is caused due to brain trauma. In retrograde amnesia, patient is not able to recall the activities that happened in the past or before trauma. In transient global amnesia, patient suffers from temporary loss of all memory. Traumatic amnesia results due to hard blow to the brain that may be caused by car accident. Wernike-Korsakoff's psychosis is caused to due extended alcohol abuse. In fugue amnesia, patients loose the memory of their identity also in combination with their past memory. In infantile amnesia, also known as childhood amnesia, patient is not able to recall events from his or his childhood. Posthypnotic amnesia is during hypnosis and events happened during this phase cannot be recalled. In source amnesia, patient forgets the source of information. Blackout amnesia is due to heavy drinking and occurs for short duration. In prosopamnesia, patient is unable to remember faces.
Amnesia can be diagnosed with physical examination and medical tests. Various physical examinations that are performed to rule out the presence of amnesia include reflexes, sensory function and balance. Medical tests include MRI scanning, CT scanning and electroencephalogram (EEG). Sometimes blood tests are also performed to reveal the presence of nutritional deficiencies or infection.
Till date no medications (drugs) specifically used for treating amnesia is present in the market however, various drugs that are used to treat diseases which result in amnesia are used for its treatment. For instance, thiamin vitamin supplements are advised to the patients suffering from Wernike-Korsakoff's psychosis. In addition, occupational therapy is also provided to the patient in which therapist helps to learn new information to replace lost memory. The market for amnesia diagnostics and therapeutics is anticipated to grow owing to rising number of accidents (road, water and air). This would increase the risk for head injury and in turn may result in organic amnesia. Aging population would also enhance the growth of amnesia diagnostics and therapeutics market as older people are at higher risk for developing amnesia due to various neurological disorders such as dementia.