Posted: January 10th, 2023

How do different forms of amnesia damage brain activity?

How do different forms of amnesia damage brain activity?
Amnesia is a general term used to describe memory loss. There are many different forms of amnesia, each of which can be caused by a variety of factors, including brain injury, infection, disease, or psychological trauma. Each type of amnesia can affect different areas of brain activity, leading to different symptoms and forms of memory loss.
One of the most well-known types of amnesia is anterograde amnesia, which is the inability to form new memories after the onset of the condition. This type of amnesia is typically caused by damage to the hippocampus, a region of the brain that plays a key role in the formation of new memories. This type of amnesia can be caused by a variety of factors, including head injury, infection, or stroke. An example is Korsakoff’s syndrome, which is caused by prolonged alcohol abuse, which is known to damage the hippocampus. This can lead to difficulties remembering recent events, and also creating vivid confabulations, also known as false memories.
Retrograde amnesia is the loss of memories before the onset of the condition. This can occur as a result of brain damage or injury, such as a head injury, infection, or stroke. This type of amnesia can affect memories from a specific time period, such as memories from the time immediately before the injury, or it can affect memories from a longer time period, such as memories from childhood. The causes can be various, from head injury, infection, or stroke, to degenerative conditions such as Alzheimer’s disease. An example is the case of “H.M” (Henry Molaison) who had a surgery called lobotomy that was supposed to cure him of his epilepsy, it ended up damaging his hippocampus, resulting in a severe retrograde amnesia, where he lost all memories of his life before the surgery, and could not form new memories.
Another type of amnesia is known as transient global amnesia, which is characterized by a sudden, temporary loss of memory, often accompanied by confusion, disorientation, and difficulty forming new memories. This type of amnesia typically lasts for several hours or days, after which the person’s memory typically returns to normal. The causes of transient global amnesia are still not fully understood, but it is thought to be related to blood flow in the brain, and most commonly affects older adults, who have more blood vessels issues.
Another less common type is called dissociative amnesia, it is related to psychological traumas. It’s associated with memories being blocked by the brain as a way of coping with traumatic experiences. This type of amnesia can result in the inability to recall specific memories or time periods, and can be triggered by stressful events, such as war, physical or sexual abuse, or natural disasters. People with dissociative amnesia may also develop multiple personality disorder.
Lastly, there is congenital amnesia, which is a rare form of amnesia that is present from birth. This type of amnesia is typically caused by a genetic disorder that affects the development of the hippocampus, and people with congenital amnesia are unable to form new memories or recall past events.
Different forms of amnesia can damage brain activity in a variety of ways, depending on the type of amnesia and the specific area of the brain that is affected. While some forms of amnesia can be caused by traumatic events or injury, others are related to disease or genetic disorders. The specific symptoms of amnesia can also vary depending on the type, ranging from difficulty forming new memories to an inability to recall past events. Each type of amnesia requires a specific diagnosis, treatment and management.