Amnesia is a clinical manifestation involving memory loss or alteration, 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 picture that includes cognitive, motor, and functional disorders 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 amnesia and dementia consist of, and we discuss the main differences between them.
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What is amnesia?
Amnesia is a condition in which a person’s memory is lost or altered . This condition can have organic or neurological causes (due to brain damage, physical injury, 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: antegrade amnesia (where the ability to memorize new things is impaired or lost because data is not transferred correctly from short-term conscious memory to long-term permanent memory); and retrograde amnesia (where a person’s pre-existing memories are lost in conscious memory, beyond an ordinary degree of forgetfulness, even though they can memorize new things that occur after the onset of amnesia).
Antegrade 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, a state of confusion and memory loss that occurs after 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 that 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 to retrieve 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 the ability to think and memory as the brain becomes 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 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 disorders: aphasia (loss of 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 accounts for 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 to the brain caused by a blood clot or bleeding 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 neurodegenerative disease affecting brain neurons 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 an adverse effect on memory and speed up the onset of dementia.
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Differences between amnesia and dementia
To address the differences between amnesia and dementia, we must look at what defines each of these clinical pictures. 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 symptoms. serious, and not just as a symptom or a clinical manifestation.
Another clear difference between amnesia and dementia is the variety of cognitive symptoms that occur in either condition. 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, regardless of the problems. of memory that the demented patient can present.
People with dementia are impaired in their ability to adequately perform the tasks of daily life , something that does not usually occur so clearly in subjects with amnestic symptoms. Furthermore, dementia typically worsens over time and cognitive abilities are progressively reduced; however, the vast majority of amnesias are reversible, except for those that present precisely as a clinical sign of ongoing dementia.
In short, amnesia is rather a symptom that can appear as part of dementia, but it does not have to be the result of it, and usually only includes 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 capacities, and include alterations at the motor and functional level.