He Mild cognitive impairment (DCL) is a syndrome that may present cognitive deficits beyond what is considered normal, where it may or may not interfere with daily life and does not meet the dementia criteria.
In other words, DCL, as the name implies, is a type of cognitive impairment characterized as mild (deficits are minor), but Are notorious enough not to be explained by the normal aging of the brain.
And it is that people, as we get older, we lose our mental faculties.
We lose thinking speed, we are becoming less agile mentally, our learning capacity diminishes, it can cost us more to remember the things…
However, this slight cognitive decline is not considered any type of disease, and is classified as"cognitive impairment associated with age" (DECAE).
The DECAE is considered as a relatively benign phenomenon, and practically all people present it (to a greater or lesser extent) as we That we are getting older. No one gets rid of losing faculties with age.
However, the DCL does not refer to this benign aging of the human brain , But it is considered a type of deterioration greater than that Presence in a DECAE.
Therefore, LBD would constitute those types of cognitive declines that are not purely associated with age and therefore are not considered as "Normal"but as pathological.
Usually when we talk about pathological cognitive impairment, we are often talking about dementia, such as Alzheimer's dementia or dementia
Parkinson's disease.
However, the DCL is not a dementia , Is a type of cognitive impairment lower than that presented in any type of dementia syndrome.
Thus, mild cognitive impairment refers to those individuals who are neither cognitively normal (they have a greater deterioration than Wait for age) or demented (they have a deterioration less than those present with people with Dementia).
In fact, the term DCL was coined by Peterson in 1999 to refer to such minor cognitive disorders, with the aim of achieving a Early diagnosis of Dementia.
This author argued that the criteria for diagnosing dementia syndromes (especially Alzheimer disease ) Were too strict, and only Allowed to detect dementias when they had long existed.
Put another way: for Peterson when a person had the deficits needed to diagnose Alzheimer's dementia, it was already a long time ago Time that was manifested in a lower intensity.
In this way, Petersen considered DCL as a degenerative process that sooner or later would eventually become Dementia.
However, it has been shown that not all people with mild cognitive impairment end up suffering from a dementia syndrome.
More specifically, taking into account the data provided by Iñiguez in 2006, only between 10% and 15% of patients with DCL end up developing an Demential syndrome
Thus, by way of summary, DCL is a type of deterioration greater than that considered as"normal"but lower than that referring to dementia syndromes.
In addition, this disease increases the probability of end up suffering from a dementia syndrome of 1-2% (for healthy people) up to 10-15% (for people With DCL).
Subtypes of mild cognitive impairment
Although DCL deficits are mild, the presentation of this disorder may vary and the type of cognitive decline may be in several ways.
Thus, at present, 4 subtypes of mild cognitive impairment have been described, each with certain characteristics. Let's review them quickly.
1. Single domain amnesic DCL
A patient whose only cognitive complaint related to a memory deficit would be labeled in this subtype.
It is the most frequent subtype and is characterized by the fact that the person does not present any type of cognitive deficit beyond a slight loss of memory.
For some authors, this subtype of DCL could be considered as a stage prior to Alzheimer's disease.
2. Amnestic DCL with involvement in multiple areas
A patient with memory loss and complaints in other cognitive areas such as problem solving, word naming or Difficulty of attention Y Concentration would be framed in this subtype.
Multiple cognitive deficits can be present but all of them of low intensity, reason why it could not be considered a demential syndrome.
3. Non-amnesic DCL with involvement in multiple areas
A patient without any alteration in his memory but with difficulties in other cognitive areas such as attention, concentration , Language, calculation or Problem solving would be diagnosed as non-amnesic DCL with affectations in multiple areas.
In this subtype, as in the previous one, multiple low-intensity cognitive deficits can be present, but with the difference that there is no memory loss.
4. Single-domain non-amnesic DCL
Finally, a patient who as in the previous case does not present memory loss and presents only one of the other cognitive deficits previously Described, would be encompassed within this DCL subtype.
Diagnostic criteria
The diagnosis of cognitive impairment Carrying is usually complex since there are no precise and universally established criteria to detect this disorder.
The main requirement for the diagnosis is to present a cognitive impairment that can be evidenced by neuropsychological Mental performance) without these meeting the dementia criteria.
Although there are no stable diagnostic criteria for detecting mild cognitive impairment, I will now comment on those proposed by the International Psychogeriatric Association , Which in my opinion clarify several concepts:
Decreased cognitive ability at any age.
Decreased cognitive ability affirmed by the patient or informant.
Gradual decrease of minimum duration of six months.
Any of the following areas may be affected.
Memory and Learning.
Attention and Concentration.
Thought.
Language.
Visuospatial Function.
Decreased assessment of mental status or neuropsychological tests.
This situation can not be explained by the presence of a dementia or other medical cause.
Thus, the criteria for establishing the diagnosis of LBD are to present complaints of a decline in cognitive abilities that are detectable Through mental performance tests that are less severe than those of Dementia.
This is why differentiating mild cognitive impairment from dementia is especially important, let's see how we can do it.
Main differences with dementia
In order to be able to clarify the differences between DCL and dementia, first let's see what the diagnostic criteria are for the d Ementials.
According to him Diagnostic and Statistical Manual of Mental Disorders (DSM-IV), are as follows:
TO. The presence of multiple cognitive deficits that are manifested by:
1. Impairment of memory (impaired ability to learn new information or recall previously learned information).
2. One (or more) of the following cognitive impairments:
(A) aphasia (altered language)
(B) apraxia (impaired ability to perform motor activities, despite motor function intact).
(C) agnosia (failure to recognize or identify objects, even though the sensory function is intact).
(D) alteration of the execution (eg, planning, organization, sequencing and abstraction.
B. Cognitive deficits in each of the A1 and A2 criteria cause significant cognitive impairment of work or social activity and Represent a significant reduction of the previous level of activity.
C. Deficits are not due to other medical or psychiatric illnesses.
As we can see, the demential syndromes are characterized by the deterioration of memory and other cognitive alterations such as language, Planning, solving problems, apraxias or agnosias.
The characteristics of DCL are practically the same as those of dementia, since in mild cognitive impairment both Memory as the other cognitive deficits just mentioned.
Thus, it is not possible to differentiate DCL from dementia by the type of alterations that the person presents, since they are the same in both pathologies, for Therefore, differentiation can only be made through the severity of these.
Thus, the keys to differentiate DCL from dementia are as follows:
Unlike dementia, the deterioration that occurs in the DCL does not usually modify excessively the functionality of the person, which can Continue to carry out the activities autonomously and without difficulties (except tasks that require a very high cognitive performance).
In dementias, the learning capacity is usually null or very limited, whereas in the DCL, although it has decreased, it can remain certain Ability to learn new information.
People with dementia are often unable or difficult to perform tasks such as handling money, go shopping, Orienting yourself on the street, etc. On the other hand, people with DCL tend to be more or less well-off for this type of task.
The most typical deficits of CDL are loss of memory, denomination problems and diminution of the verbal fluency, reason why the presentation The only one of these 3 deficits (low severity) makes the diagnosis of DCL more difficult than that of Dementia.
All DLC deficits are much less serious. To quantify it, a useful screening tool is the Mini-Mental State Examination (MMSE) . A score between 24 and 27 in this test would support a diagnosis of MCI, a score lower than 24 in the diagnosis of dementia.
Markers of mild cognitive impairment
Since mild cognitive impairment increases the risk of developing Alzheimer's dementia, current research has focused on determining Markers of both DCL and Alzheimer's.
Although there are no clear markers yet, there are several biological, behavioral, psychological and neuropsychological markers that allow Differentiate both pathologies and predict which patients with MCI can develop dementia.
Biological markers
One of the major biological markers of Alzheimer's disease (AD) is peptides in the cerebrospinal fluid .
In the neurons of people with Alzheimer's, greater amounts of Beta-amyloid, T-Tau and P-Tau proteins have been detected.
When patients with DCL have high levels of these proteins in their brain, they are more than likely to develop AD, but if they present Normal levels of these proteins the evolution towards EA becomes very unlikely.
Behavioral and psychological markers
A study by Baquero in 2006 estimates that 62% of patients with DCL present some psychological or behavioral symptoms. The most frequent They are depression And irritability.
Likewise, authors such as Lyketsos, Apostolova and Cummings argue that symptoms such as apathy , the anxiety And agitation (typical of depressions) Increase the likelihood of developing AD in patients with mild cognitive impairment.
Neuropsychological markers
According to Íñieguez, those patients with DCL who present a significant impairment of language and implied memory or a marked alteration of the Episodic memory And work, are more likely to develop AD than the DCL patients with another pattern of deficits.
Thus, by way of conclusion, it seems that the boundaries between mild cognitive impairment and dementia are not clearly defined.
The DCL could be defined as a low-intensity cognitive decline that does not diminish excessively in the person's daily life, but which in some cases may Suppose a phase prior to a severe, progressive and chronic dementia.
And what do you know about DCL? Explain to me how you interpret this disorder. I am interested in your opinion. Thank you!
References
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- Image source.