What is Amnesia?
Amnesia refers to the loss of memories, such as facts, information and experiences. Though forgetting your identity is a common plot device in movies and television, that’s not generally the case in real-life amnesia.
Instead, people with amnesia — also called amnestic syndrome — usually know who they are. But, they may have trouble learning new information and forming new memories.
Amnesia can be caused by damage to areas of the brain that are vital for memory processing. Unlike a temporary episode of memory loss (transient global amnesia), amnesia can be permanent.
There’s no specific treatment for amnesia, but techniques for enhancing memory and psychological support can help people with amnesia and their families cope.
Signs and Symptoms of Amnesia
The two main features of amnesia are:
- Difficulty learning new information following the onset of amnesia (anterograde amnesia)
- Difficulty remembering past events and previously familiar information (retrograde amnesia)
Most people with amnesia have problems with short-term memory — they can’t retain new information. Recent memories are most likely to be lost, while more remote or deeply ingrained memories may be spared. Someone may recall experiences from childhood or know the names of past presidents, but not be able to name the current president, know what month it is or remember what was for breakfast.
Isolated memory loss doesn’t affect a person’s intelligence, general knowledge, awareness, attention span, judgment, personality or identity. People with amnesia usually can understand written and spoken words and can learn skills such as bike riding or piano playing. They may understand they have a memory disorder.
Amnesia isn’t the same as dementia. Dementia often includes memory loss, but it also involves other significant cognitive problems that lead to a decline in daily functioning.
A pattern of forgetfulness is also a common symptom of mild cognitive impairment (MCI), but the memory and other cognitive problems in MCI aren’t as severe as those experienced in dementia.
Additional signs and symptoms
Depending on the cause of the amnesia, other signs and symptoms may include:
- False memories (confabulation), either completely invented or made up of genuine memories misplaced in time
- Confusion or disorientation
Causes of Amnesia
Normal memory function involves many parts of the brain. Any disease or injury that affects the brain can interfere with memory.
Amnesia can result from damage to brain structures that form the limbic system, which controls your emotions and memories. These structures include the thalamus, which lies deep within the center of your brain, and the hippocampal formations, which are situated within the temporal lobes of your brain.
Amnesia caused by brain injury or damage is known as neurological amnesia. Possible causes of neurological amnesia include:
- Stroke
- Brain inflammation (encephalitis) as a result of an infection with a virus such as herpes simplex virus, as an autoimmune reaction to cancer somewhere else in the body (paraneoplastic limbic encephalitis), or as an autoimmune reaction in the absence of cancer
- Lack of adequate oxygen in the brain, for example, from a heart attack, respiratory distress or carbon monoxide poisoning
- Long-term alcohol abuse leading to thiamin (vitamin B-1) deficiency (Wernicke-Korsakoff syndrome)
- Tumors in areas of the brain that control memory
- Degenerative brain diseases, such as Alzheimer’s disease and other forms of dementia
- Seizures
- Certain medications, such as benzodiazepines or other medications that act as sedatives
Head injuries that cause a concussion, whether from a car accident or sports, can lead to confusion and problems remembering new information. This is especially common in the early stages of recovery. Mild head injuries typically do not cause lasting amnesia, but more-severe head injuries may cause permanent amnesia.
Another rare type of amnesia, called dissociative (psychogenic) amnesia, stems from emotional shock or trauma, such as being the victim of a violent crime. In this disorder, a person may lose personal memories and autobiographical information, but usually only briefly.
Treatment of Amnesia
Treatment for amnesia focuses on techniques and strategies to help make up for the memory problem, and addressing any underlying diseases causing the amnesia.
Occupational therapy
A person with amnesia may work with an occupational therapist to learn new information to replace what was lost, or to use intact memories as a basis for taking in new information.
Memory training may also include different strategies for organizing information so that it’s easier to remember and for improving understanding of extended conversation.
Technological assistance
Many people with amnesia find it helpful to use smart technology, such as a smartphone or a hand-held tablet device. With some training and practice, even people with severe amnesia can use these electronic organizers to help with day-to-day tasks. For example, smartphones can be programmed to remind them about important events or to take medications.
Low-tech memory aids include notebooks, wall calendars, pill minders, and photographs of people and places.
