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Symptoms of dementia
Last reviewed: 23.04.2024
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Dementia can be manifested by increased forgetfulness, personality change, decreased initiative, weakened criticism, difficulty in performing routine tasks, difficulty in word selection, violation of abstract thinking, behavioral disorders and mood. To "non-cognitive" manifestations of dementia include sleep disorders, wandering, depression, psychosis and other behavioral disorders. "Non-negative" symptoms of dementia often disrupt the life of the patient and are the main reason for going to the doctor.
If there is a suspicion of dementia, the anamnesis should be collected from the patient himself and from those who are well informed about the patient. In the early stages, the doctor's main focus should be on identifying the patient's particular difficulties in everyday household activities, since it is here that the first signs of mental insufficiency usually appear and therefore it is noticed before by careful relatives and not by doctors.
The earliest and permanent sign of dementia is a short-term memory disorder. Forgetfulness of orders and instructions, the growing tendency to put things out of place, small inconsistencies in some seemingly ordinary actions - all these behavioral features are noticed first and foremost by close people. There are difficulties when calculating (for example, money), inability to use household appliances (for example, a telephone) or other difficulties in work or home activities that were previously not at all characteristic of the patient. As dementia progresses, there is a narrowing of the range of interests, a decrease in activity, a growing memory impairment, and a reduction in criticism. The patient may have difficulty in trying to find a way to a known place, revealing a partial disorientation in place and time. There may be deceptions of feelings, hallucinations, a decrease in control in behavior, which is manifested by episodes of excitement and impulsive behavior. This explains the acts of violence, alcohol excesses, sexual deviations, antisocial behavior. Patients become careless in clothes and untidy; In the final stage of incontinence develops. There are motor and speech perseverations. Sometimes speech is subject to progressive decay. Any form of aphasia, to which agnosia and apraxia often joins, can develop. Violated gait - dysbasia. In severe cases, amnestic disorientation in space, time, surrounding the subject situation, in one's own personality (the patient does not recognize himself in the mirror), mutism.
The presence or absence of somatic manifestations depends on the etiology of dementia, but in any case there is a general physical exhaustion, a decrease in body weight, suppression of endocrine functions. Dementia can reach the final stage of disintegration of mental functions - the stage of marasmus. Most of the time the patient spends in bed and dies from pneumonia or other intercurrent diseases.
It must be remembered that in the clinical diagnosis of dementia there are two important limitations. First, the diagnosis of dementia should not be made if the patient is in a confused state of consciousness. In other words, it is necessary to be sure that the deterioration of mental functions is not due to a violation of consciousness. Secondly, the term "dementia" is not applicable to individual ablation of complex brain functions, such as amnesia, aphasia, agnosia or apraxia. Although dementia may well be combined with these syndromes.
Dementia is always a syndrome, not a disease. Differential diagnosis of the causes of dementia, always indicative of organic brain damage, is difficult due to the very large number of diseases that can lead to the development of dementia. For successful orientation in the circle of these diseases, a convenient diagnostic algorithm is proposed, according to which a differential diagnosis is made between the three groups of diseases. We are talking about depression, toxic-metabolic encephalopathies and actually brain diseases. At the second stage, diagnostic search is significantly narrowed, which greatly facilitates differential diagnosis.
Clinical experience suggests that depression is sometimes mistakenly interpreted as dementia. This is due to the fact that depression, accompanied by a decrease in memory, a violation of attention, a narrowing of the range of interests and motivations, may resemble dementia. Here everyday everyday activity is also hampered, which together can serve as an excuse for suspicion of dementia. This form of depression is called pseudodementia and is reversible under the influence of antidepressants.
Another diagnostic alternative in the presence of dementia are toxic-metabolic encephalopathies. A variety of possible causes (drug intoxication, lack of any body) require screening metabolic disorders. In addition to knowledge of the clinical picture, it is important to remember two important, but often underestimated, markers of toxic-metabolic encephalopathy. First, for the latter, transient states of confusion are very typical. Sometimes, confusion states develop as an initial manifestation of dysmetabolic encephalopathy. Secondly, another important marker concerns the EEG picture in these diseases. According to many experts, if the EEG shows no signs of slowing bioelectric activity, that is, a shift in the wave spectrum toward a decrease in normal alpha activity and an increase in the representation of slow waves (theta and delta bands), then the presence of toxic metabolic encephalopathy as a cause of dementia may be called into question. This important detail in the general picture of the EEG can be observed in other pathological conditions, but its absence makes the diagnosis of toxic metabolic encephalopathy very unlikely. Quite often, simply canceling a suspected drug as a possible "culprit" of intoxication ex juvantibus confirms the diagnosis, as it leads to the reverse development of the state of confusion and dementia in the elderly.
Finally, the third group of diseases that can be the cause of dementia is represented by diseases directly (primarily) affecting the brain tissue. They can be unifocal (for example, a tumor or subdural hematoma) or multifocal (for example, multiple infarctions).
Clarification of the cause of dementia within this group of diseases of the nervous system requires a complete examination. The absence of neurological signs in a number of cases makes the etiological diagnosis very difficult. Lumbar puncture and CT usually help to correctly recognize the nature of the pathological process, but there are exceptions. For example, some lacunar infarcts may be too small for their detection; Similarly, CT manifestations of brain atrophy in many degenerative diseases can be indistinguishable from age-related changes in healthy individuals of the same age at certain stages of the disease. Neither magnetic resonance imaging, nor positron emission tomography or EEG mapping can often help in the differential diagnosis in this group of patients. At the same time, the correct diagnosis of brain disease leading to dementia is very important, since its treatment can sometimes lead to the reverse development of dementia (for example, the evacuation of subdural hematoma or the elimination of risk factors for certain forms of vascular dementia).
In "degenerative" dementias (ie, dementias in degenerative diseases of the nervous system), forms occur where dementia may be the only manifestation of a neurological disease (Alzheimer's disease, Pick's disease). They can therefore be called "pure" dementias (exceptions to this rule are described when the disease is combined with extrapyramidal or pyramidal signs). They are mainly cortical. Alzheimer's disease is associated with a primary lesion of predominantly posterior (parietal) brain regions. Pick's disease is a much more rare disease, affecting primarily the anterior parts of the hemispheres ("fronto-temporal lobar degeneration"). But there are forms in which dementia is accompanied by motor disorders (eg, Parkinson's disease, Huntington's chorea, progressive supranuclear palsy, etc.). This is mainly "subcortical" dementia.
Among the degenerative variants, Alzheimer's disease is the most common cause of dementia in the population over 65 and accounts for about 50-60% of all dementia in general.
The disease begins in middle or old age, very rarely - at the age of 45 years. The most important symptom is gradually progressive deterioration of memory, mainly short-term. Memory impairment is accompanied by a decrease in efficiency, narrowing of the circle of interests, emotional lability. Gradually, along with cognitive disorders develop speech disorders, disorders of visual-spatial functions, which significantly complicates the daily routine of the patient.
Currently, the following categories of diagnosis are used in Alzheimer's disease: a possible, probable and reliable disease.
Behavioral disorders in dementia
Behavioral disorders often occur in patients with dementia and may be represented by psychotic disorders, speech or psychomotor agitation, sleep disorders, wandering, personality changes. These manifestations bring suffering to the patients, create problems for the caregivers, make them use health resources more often. They are the main reason for seeking outpatient or emergency medical care. Behavioral disorders are very common, heterogeneous and have a different prognosis. Personality changes are manifested at an early stage of the disease and are often described as a "sharpening" of premorbid personality traits. They can also be represented by irritability, apathy, detachment and estrangement from others. At a later stage of the disease, personality changes are detected in more than half of the patients placed in care institutions.