Amnesia is a clinical manifestation that involves the loss or alteration of memory, and can occur due to multiple causes, such as trauma, neurological disease or mental disorder. This condition may be part of another condition known as dementia, a clinical condition that includes cognitive, motor and functional alterations that go beyond just memory loss. And although they share some characteristics, There are several differences between amnesia and dementia
Throughout the article we explain what both amnesia and dementia consist of, and we address the main differences between one and the other.
amnesia is a condition in which a person’s memory is lost or altered This condition may have organic or neurological causes (due to brain damage, physical injuries, neurological diseases or the use of certain substances) or due to functional or psychogenic causes (psychological factors, mental disorders, post-traumatic stress or psychological defense mechanisms).
There are two main types of amnesia: anterograde amnesia (where the ability to memorize new things is impaired or lost because data is not transferred correctly from conscious short-term memory to permanent long-term memory); and retrograde amnesia (where a person’s pre-existing memories are lost in conscious recollection, beyond an ordinary degree of forgetting, even though they can memorize new things that occur after the onset of amnesia).
Anterograde amnesia is the more common of the two. Sometimes these two types of amnesia can occur together and are called total or global amnesia. Another type of amnesia is post-traumatic amnesia, a state of confusion and memory loss that occurs after a traumatic brain injury. Amnesia that occurs due to psychological factors is generally known as psychogenic amnesia.
Many types of amnesia are associated with damage to the hippocampus and other related areas of the brain which are used in the encoding, storage and retrieval of memories. If there is a blockage in the pathways along which information travels during memory encoding or retrieval processes, or if entire regions of the brain are missing or damaged, then the brain may be unable to form new memories or recover some old ones.
Dementia: what is this disorder?
Dementia is the term used to define a class of disorders characterized by the progressive deterioration of thinking ability and memory as the brain is damaged. Generally, when memory loss is so severe that it interferes with normal daily functioning, the condition is called dementia. Less severe memory loss is known as mild cognitive impairment.
Dementia is characterized by a severe loss of memory and cognitive ability (primarily in the areas of attention, language, and problem solving), along with one or more of the following: aphasia (loss of the ability to produce or understand language), apraxia (inability to carry out learned movements), agnosia (difficulties in recognizing and identifying objects or people without damage to the senses) or executive dysfunction (inability to plan, organize or reason).
The most common type of dementia is Alzheimer’s disease, which represents 50-75% of all dementias. The second most common type, accounting for up to 20% of dementia cases, is vascular dementia, which has symptoms similar to Alzheimer’s disease but usually results from damage caused to the brain by a blood clot or hemorrhage that cuts the brain’s blood supply due to trauma.
Dementia can be caused by specific events such as a traumatic brain injury or stroke, or it can develop gradually as a result of a neurodegenerative disease that affects neurons in the brain or as a secondary symptom of other disorders such as Parkinson’s disease. Some drugs used to treat other age-related diseases and conditions can also have a harmful effect on memory and accelerate the onset of dementia.
Differences between amnesia and dementia
To address the differences between amnesia and dementia we must look at what defines each of these clinical conditions. Amnesia is a symptom that can occur in many situations and for different causes and this is something that differentiates it from a condition such as dementia, since the latter is defined as a set of disorders that can lead to other diseases or more serious conditions, and not only as a symptom or a clinical manifestation.
Another clear difference between amnesia and dementia is the variety of cognitive symptoms that occur in one condition or another. In amnesia, memory is generally the only cognitive function that is altered, while in dementia, as we have seen previously, alterations in language, attention or the ability to solve problems may occur, apart from the problems memory that the dementia patient may present.
People who suffer from dementia have their ability to adequately perform the tasks of daily life impaired, something that does not usually occur so obviously in subjects who present amnesic symptoms. Additionally, dementia typically worsens over time and cognitive abilities progressively decline; However, the vast majority of amnesias are reversible, except for those that occur precisely as a clinical sign of ongoing dementia.
In short, amnesia is rather a symptom that can occur as part of dementia, but does not have to be the result of it, and usually includes only memory loss in its different forms; and, for its part, dementia is a much more global alteration in the functioning of the brain and involves the alteration of multiple cognitive areas that go beyond memory abilities, and include alterations at a motor and functional level.
