Amnesia is a form of memory loss. Some people with amnesia have difficulty forming new memories. Others can’t recall facts or past experiences. People with amnesia usually retain knowledge of their own identity, as well as motor skills.
Mild memory loss is a normal part of aging. Significant memory loss, or the inability to form new memories, may indicate the presence of an amnestic disorder.
The primary symptom of amnesia is memory loss or inability to form new memories. If you have amnesia, you will have difficulty recalling facts, events, places, or specific details. The details can range from what you ate this morning to the name of the current president. You will still retain your motor skills, such as your ability to walk, as well as fluency in any languages you speak.
There are multiple types of amnesia, including retrograde amnesia, anterograde amnesia, and transient global amnesia.
When you have retrograde amnesia, you lose existing, previously made memories. This type of amnesia tends to affect recently formed memories first. Older memories, such as memories from childhood, are usually affected more slowly. Diseases such as dementia cause gradual retrograde amnesia.
When you have anterograde amnesia, you can’t form new memories. This effect can be temporary. For example, you can experience it during a blackout caused by too much alcohol. It can also be permanent. You can experience it if the area of your brain known as your hippocampus is damaged. Your hippocampus plays an important role in forming memories.
Transient global amnesia
Transient global amnesia (TGA) is a poorly understood condition. If you develop it, you will experience confusion or agitation that comes and goes repeatedly over the course of several hours. You may experience memory loss in the hours before the attack, and you will probably have no lasting memory of the experience. Scientists think that TGA occurs as the result of seizure-like activity or a brief blockage of the blood vessels supplying your brain. It occurs more frequently in middle-aged and older adults.
Most people can’t remember the first three to five years of life. This common phenomenon is called infantile or childhood amnesia.
A memory’s location in your brain is thought to depend on its age. To lose old memories, you must have widespread brain deterioration. This can be caused by Alzheimer’s disease or other forms of dementia. People with dementia usually lose more recent memories first and keep older memories longer.
A depletion of oxygen levels can also affect your entire brain and lead to memory loss. This condition is called anoxia. If the anoxia isn’t severe enough to cause brain damage, the memory loss can be temporary.
Damage to the hippocampus
Your hippocampus is a part of the brain and limbic system responsible for memory. Its activities include forming memories, organizing memories, and retrieving them when needed. Its cells are some of your brain’s most energy-hungry and fragile. They’re most easily disrupted by anoxia and other threats such toxins.
When your hippocampus is impaired, you will have difficulty forming new memories. If your hippocampus is damaged in both halves of your brain, you can develop complete anterograde amnesia. Read More