Amnesia indicates loss of memories such as information, facts and experiences. Otherwise known as the amnestic syndrome, amnesia causes difficulties in learning new information and forming new memories.
Amnesia is typically caused by damage to the brain in the areas for memory processing. Amnesia can be permanent unlike temporary memory loss (transient global amnesia).
There is no specific treatment for amnesia; however, memory enhancing techniques and psychological support can help manage the condition.
The main symptoms of amnesia include:
- Impaired ability to learn new information (anterograde amnesia)
- Impaired ability to remember past events and previously known information (retrograde amnesia)
The common issues with amnesia are short-term memory loss or inability to retain new information. Recent memories are usually lost while deep memories remain intact. Isolated memory loss does not affect intelligence, awareness, general knowledge, personality, attention span or judgment. People suffering from amnesia have no difficulties understanding simple communication and can learn new skills. They may also understand they have a problem with memory.
Further signs of amnesia:
- False recollections or confabulation (completely invented or made of genuine misplaced memories)
- Confusion or disorientation
Any disease or injury that affects the brain can interfere with memory features since normal memory functions involve multiple parts of the brain.
Damage to the brain structures that form the limbic system (system that controls emotions and memories) can cause amnesia. The structures of the limbic system include the thalamus (located deep in the center of the brain) and the hippocampal formations (located within the temporal lobes of the brain).
Amnesia caused by brain damage or injury is defined as neurological amnesia.
Causes of neurological amnesia include:
- Brain inflammation: Brain inflammation or encephalitis can occur as a result of: an infection with a virus, an autoimmune reaction to cancer in the body (paraneoplastic limbic encephalitis) or an autoimmune disorder without the presence of cancer
- Lack of oxygen in the brain: This can be caused be a heart attack, respiratory distress or carbon monoxide poisoning.
- Long-term alcohol abuse: Alcohol abuse can lead to thiamin (vitamin B-1) deficiency (Wernicke-Korsakoff syndrome
- Tumors: Tumor growths in the parts of the brain that control memory can cause neurological amnesia.
- Degenerative brain diseases: Alzheimer’s disease or other forms of dementia
- Medications: Specific medications such as benzodiazepines can cause amnesia.
Another type of amnesia known as dissociative (psychogenic) amnesia can be caused by trauma or emotional shock such as being a victim of a violent crime. In these rare cases, a person can lose personal memories and information usually for a brief period of time.
Factors that increase the risk of amnesia include:
- Brain injury or trauma or surgery
- Alcohol abuse
Amnesia varies in severity and scope; however, even mild amnesia affects daily activities and can interfere with work, school or social life.
Another complication resulting from amnesia may be the inability to regain lost memories. People suffering from a severe case of amnesia mat require constant supervision or a care facility.
A common cause of amnesia can be damage to the brain; therefore, the following steps may reduce the risk or prevent a brain injury:
- Wearing a helmet when riding a bike or motorcycle
- Wearing a seatbelt when driving
- Avoiding excessive use of alcohol
- Quick treatment of any type of infection to prevent it from spreading to the brain
- Request immediate medical help for symptoms of a stroke or a brain aneurysm (severe headache or one-sided paralysis or numbness)