What is retrograde amnesia?
Amnesia is a kind of memory loss in which your capacity to create, store and recall memories is affected. Retrograde amnesia affects memories created before the onset of amnesia. Someone who suffers from retrograde amnesia following a severe brain injury may be unable to recall events that occurred years, even decades, before the injury.
Damage to memory-storage portions of the brain in multiple brain regions causes retrograde amnesia. A catastrophic accident, a major sickness, a seizure or stroke, or a degenerative brain disease can all cause this type of damage. Retrograde amnesia can be intermittent, permanent or progressive, depending on the cause (getting worse over time).
Memory loss in retrograde amnesia generally concerns information rather than abilities. Some may forget whether or not they possess a car, what kind it is, and when they purchased it, but they will still be able to drive.
Retrograde amnesia vs Anterograde amnesia
Retrograde amnesia and anterograde amnesia are the two primary types of amnesia.
Anterograde amnesia affects the ability to form new memories following the start of amnesia. Retrograde amnesia makes it difficult to access memories from before the beginning of the condition.
These two types of amnesia may and frequently do coexist in the same person.
Types of retrograde amnesia
Temporally graded retrograde amnesia
Retrograde amnesia is generally temporally graded, which means that it affects your most recent memories first and spares your oldest memories. This is referred to as Ribot’s law.
The severity of retrograde amnesia varies greatly. Some people may only forget memories from the year or two before they were injured or diagnosed with an illness. Others may have a loss of decades of memories. Even when people lose decades, memories from childhood and adolescence are often retained.
Among the signs and symptoms are:
- Not being able to recall events that occurred before the start of amnesia
- Forgetting names, faces, locations, facts and general information before the onset of amnesia
- Preserving earlier memories, particularly from childhood and adolescence
- Recalling abilities like as playing the piano, riding a bike and driving a car
Making new memories and learning new abilities may or may not be possible for someone with this disease.
Focal retrograde amnesia
Focal retrograde amnesia, also referred to as isolated or pure retrograde amnesia, occurs when a person solely has the disorder and no anterograde amnesia symptoms. This indicates that the ability to create new memories is preserved. This type of memory loss has no impact on a person’s IQ or capacity to learn new abilities, such as how to play the piano.
Dissociative amnesia (psychogenic)
Dissociative amnesia is an uncommon type of retrograde amnesia that occurs as a result of emotional trauma. It is not caused by brain injury, as other kinds of retrograde amnesia are. It’s just a psychological reaction to a traumatic event. It’s generally brought on by a violent crime or other forms of severe trauma, and it’s just transitory. Among the signs and symptoms are:
- Being unable to recall events that occurred before a terrible incident
- Being unable to recollect facts from one’s own life
Causes of retrograde amnesia
Damage to various parts of the brain important for regulating emotions and memories can cause retrograde amnesia. These consist of the thalamus, which is located deep in the brain’s center and the hippocampus, which is located in the temporal lobe.
This disorder can be caused by a variety of factors. These are some of them:
Traumatic brain injury
The majority of minor traumatic brain injuries result in concussions. However, a severe injury to the head, such as a concussion, might impair the memory-storing regions of the brain, resulting in retrograde amnesia. The amnesia might be temporary or permanent, depending on the severity of the injury.
Wernicke encephalopathy is a disease induced by thiamine deficiency, which is usually caused by prolonged alcohol abuse or severe malnutrition. Wernicke encephalopathy can develop to Korsakoff psychosis, which manifests as both anterograde and retrograde amnesia if left untreated.
Encephalitis is a kind of brain inflammation caused by a viral infection like herpes simplex. A cancer-related or non-cancer-related autoimmune response can also cause it. The memory-storing areas of the brain may be damaged as a result of this inflammation.
Retrograde amnesia can be a symptom of Alzheimer’s disease and other degenerative dementias. This illness has no cure or therapy at the moment.
Large strokes and a series of minor strokes can also harm the brain. Memory difficulties may arise depending on where the injury occurs. Strokes can result in memory difficulties and even dementia. Verbal memory and visual memory are two forms of memory that might be impaired after a stroke.
Seizures of any kind can damage the brain and create memory difficulties. Some seizures impact the entire brain, while others just affect a small portion of it. In patients with epilepsy, seizures in specific regions of the brain, particularly the temporal and frontal lobes, are a major cause of memory difficulties.
Cardiac arrest leads patients to cease breathing, denying their brain oxygen for many minutes. This can result in severe brain injury, resulting in retrograde amnesia or other cognitive problems.
How is it diagnosed?
Your doctor will need to do a complete medical check to rule out any other probable causes of memory loss before diagnosing retrograde amnesia. It’s advisable to enlist the help of a loved one when speaking with the doctor, especially if you’re forgetting or muddled about your medical history.
Your doctor will have to know what drugs you’re taking as well as any previous health issues you’ve had, such as seizures, infections or strokes.
Your doctor may do a variety of diagnostic tests, including:
- CT or MRI scans are used to search for brain injuries or abnormalities
- Blood testing for nutritional deficits and infections
- A neurological examination
- Cognitive tests to assess short- and long-term memory
- An electroencephalogram (EEG) to diagnose seizure activity
Treatment for retrograde amnesia
Retrograde amnesia is not treated with any specific medicines. The primary focus of your treatment will be on the underlying cause of your forgetfulness. For example, if you really have epilepsy, you and your specialist will work together to minimize the number of seizures you experience.
Alzheimer’s disease and other degenerative dementias currently have no treatments. However, certain medicines have been shown to decrease the development of Alzheimer’s disease. Other kinds of dementia are often treated with an emphasis on support and coping.
Some persons with amnesia work with an occupational therapist to learn new skills and replace what they’ve forgotten. They work with the therapist to store new memories using their previous, intact memories as a foundation.
Therapists can assist clients in developing organizing techniques that make new knowledge simpler to recall. Conversational strategies that can assist people to enhance their social functioning can also be developed.
Psychotherapy may help in the recovery of memories that have been lost as a result of traumatic situations. It may also aid people suffering from other types of amnesia in coping with memory loss.
Learning to utilize modern technology, such as smartphones and tablets, can help many persons with amnesia. People with severe amnesia can utilize technology to help them organize and store information if they are trained. Smartphones and similar devices are very useful for those who have difficulty generating new memories.
They may be used as a means of archiving old memories. Photographs, movies, and papers may all be useful sources of information.
What is the prognosis?
Depending on the cause, retrograde amnesia can get better, worse, or stay the same throughout life. It’s a serious disease that can be difficult to manage, so loved ones’ assistance and support are frequently crucial. Depending on the severity of the amnesia, the patient may regain independence or require further care.