Retrograde amnesia affects memories that were formed before the onset of amnesia. If one develops retrograde amnesia after a traumatic brain injury, the person may be unable to remember what happened in the years, or even decades, prior to the injury.
Retrograde amnesia is actually caused by damage to the memory storage areas of the brain in various brain regions. This type of damage results from a traumatic injury, a serious illness, a seizure or stroke, or even a degenerative brain disease. Depends on the cause, retrograde amnesia can be temporary, permanent, or progressive.
There are two main types of amnesia, they are anterograde and retrograde. People who have anterograde, always have troubles in making new memories after the onset of amnesia, while People with retrograde amnesia have trouble accessing memories before the onset of amnesia.
Types Of Amnesia
Temporally graded retrograde amnesia: This is temporally graded, which means that the most recent memories are affected first, while oldest memories are usually spared. The extent of retrograde amnesia varies significantly. Some people may lose memories from the year or two prior to having the injury or disease. Other people may lose decades of memories. Even when people lose decades, they typically hang on to memories from childhood and adolescence.
Not being able to remember things that has happened before the onset of amnesia.
Forgetting names, people, faces, places, facts, and general knowledge before the onset of amnesia.
Forgetting skills like riding a bike, playing the piano, and driving a car.
Retaining older memories, from childhood and adolescence.
Focal retrograde amnesia: This is also known as an isolated or pure retrograde amnesia, is when someone only experiences retrograde amnesia with few or no symptoms of anterograde amnesia. This means that the ability to form new memories is left intact. This isolated memory loss doesn’t affect a person’s intelligence or ability to learn new skills, like playing the piano.
Dissociative (psychogenic) amnesia: This is a very rare type of retrograde amnesia resulting from emotional shock. It is not caused by damage to the brain,unlike other types of retrograde amnesia. It is purely a psychological response to trauma and is often caused by a violent crime or trauma and is usually temporary. below are its symptoms:
Not being able to remember things that happened before a traumatic event
Unable to recall autobiographical information
Traumatic brain injury: This type of injury is usually mild, resulting in concussion. But severe injuries like a blow on the head, damages the memory storing areas of the brain which leads to retrograde amnesia. Depends on the level of damage, the amnesia could be temporary or permanent.
Thiamine deficiency: This is typically caused by alcohol abuse or serious malnutrition,which can lead to a condition called Wernicke encephalopathy. If not treated, Wernicke encephalopathy progresses into a condition called Korsakoff psychosis, which presents both anterograde and retrograde amnesia.
Encephalitis: This is an inflammation in the brain caused by a viral infection and affects the memory storing parts of the brain, such as herpes simplex. It can also be caused by a cancer related or non cancer related autoimmune reaction.
Alzheimer’s disease: This and other degenerative dementias can lead to progressively worsening retrograde amnesia. There is currently no cure for this disease.
Stroke: Large strokes and repeated small strokes can cause damage to the brain. Depending on where the damage occurs, memory problems may result. It is common for strokes to lead to dementia,The type of memory that can be affected by stroke include verbal memory and visual memory.
Seizures: Any type of seizure can cause brain damage memory loss. Some seizures affect the whole brain and some only affect a small area. Seizures in certain parts of the brain, especially the temporal and frontal lobes, are common causes of memory problems in people with epilepsy.
Cardiac arrest: This causes people to stop breathing, which means their brain has been deprived of oxygen for several minutes. It can cause damage to the brain, which may cause retrograde amnesia or other cognitive deficits.