Dementia: general information

, medical expert
Last reviewed: 23.04.2024

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Dementia is a chronic, extensive, usually irreversible impairment of cognitive activity.

The diagnosis of dementia is established clinically; laboratory and neuroimaging studies are used for differential diagnosis and detection of curative diseases. Treatment of dementia is supportive. In some cases, cholinesterase inhibitors temporarily improve cognitive function.

Dementia can develop at any age, but affects mainly the elderly (about 5% of them aged 65-74 years and 40% - over the age of 85). More than half of these patients need outside medical care. At least 4-5 million people in the United States have dementia.

According to the most common definition that can be used in practice, dementia is a memory disorder and, at least, one more cognitive function. Cognitive functions include: perception (gnosis), attention, memory, account, speech, thinking. It is possible to speak about dementia only on condition that these violations of cognitive functions lead to noticeable difficulties in everyday life and in professional activity.

According to DSM-IV, dementia is diagnosed in memory disorders that lead to a functional defect and are combined with at least two of the following disorders: aphasia, apraxia, agnosia and violation of the highest regulatory (executive) functions. The presence of delirium excludes the diagnosis of dementia (American Psychiatric Association, 1994).

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Causes of dementia

Dementia can be classified in several ways: distinguish dementia of the Alzheimer's and non-Algeyme type, cortical and subcortical, irreversible and potentially reversible, widespread and selective. Dementia can be a primary neurodegenerative disorder or may arise as a consequence of other conditions.

The most common are Alzheimer's disease, vascular dementia, dementia with Levy bodies, frontotemporal (frontotemporal) dementia, HIV-associated dementia. Other conditions associated with dementia include Parkinson's disease, Huntington's chorea, progressive supranuclear palsy, Creutzfeldt-Jakob disease, Heretmann-Shtroysler-Sheinker syndrome, other prion diseases and neurosyphilis. Determining the cause of dementia is difficult; the final establishment of a diagnosis often requires postmortem patho- anatomical investigation of the brain. Patients may have more than 1 type of dementia (mixed dementia).

Classification of dementia



Primary neurodegenerative (cortical)

Alzheimer's disease

Front-Temporal Dementia

Mixed dementia with Alzheimer's component


Lacunar disease (eg, Binswanger's disease)

Multi-infarct dementia

Associated with Levy bodies

Disease of diffuse Levi bodies

Parkinsonism in combination with dementia

Progressing supranuclear palsy

Corticobasal ganglionic degeneration

Associated with intoxication

Dementia associated with chronic alcohol use

Dementia associated with prolonged exposure to heavy metals or other toxins

Associated with infections

Dementia associated with a fungal infection (eg, cryptococcal)

Dementia associated with spirochete infection (eg syphilis, lime-borreliosis)

Dementia associated with a viral infection (eg, HIV, postencephalitic)

Associated with prion contamination

Creutzfeldt-Jakob disease

Associated with structural damage to the brain

Tumors of the brain

Normotensive hydrocephalus

Subdural hematoma (chronic)

Some organic brain diseases (such as normotensive hydrocephalus, subdural chronic hematoma), metabolic disorders (including hypothyroidism, vitamin B 12 deficiency ) and intoxication (eg, lead) can lead to a slow loss of cognitive functions, which, however, are improved under the influence of therapy. These conditions are sometimes called reversible dementia, but some experts limit the use of the term "dementia" solely to situations of irreversible loss of cognitive functions. Depression can mimic dementia (and, by formal signs, was called pseudodegmentation); these two pathological conditions often coexist together. Changes in cognitive activity inevitably occur with age, but they can not be considered dementia.

Any disease can exacerbate cognitive deficits in patients with dementia. Dementia often develops in dementia patients. Drugs, especially benzodiazepines and anticholinergic drugs (in particular, some tricyclic antidepressants, antihistamines and antipsychotics, benztropine), can temporarily aggravate the symptoms of dementia, it can also be alcohol, even in moderate doses. Occurred or progressing renal or hepatic insufficiency can reduce the clearance of drugs and lead to the development of drug intoxication after many years of use of drugs in a standard dosage (eg, propranolol).

Causes of dementia


Symptoms of dementia

With dementia, all cognitive functions suffer. Often, the loss of short-term memory may be the only symptom. Despite the fact that the symptoms exist in a certain time interval, they can be divided into early, intermediate and late. Personality and behavioral changes can develop in the early or late stage. Motor and other focal neurological deficit syndromes occur in different stages of the disease, depending on the type of dementia; most early they develop with vascular dementia and later with Alzheimer's disease. The frequency of convulsive seizures is partly increasing in all stages of the disease. Psychoses - hallucinations, manic states or paranoia - occur in about 10% of patients with dementia, although a significant percentage of patients appear temporary symptoms.

Early symptoms of dementia

Early appearance of signs of memory loss; it becomes difficult to train and retain new information. Language problems (especially in the selection of words), mood swings, the development of personal changes. Patients may have progressive problems with daily self-care (manipulation of a checkbook, finding a route, forgetting the location of things). Abstract thinking, insight, reasoning can be reduced. Patients can react to loss of independence and memory by irritability, hostility and arousal.

Agnosia (loss of ability to identify objects with safety of sensory functions), apraxia (loss of ability to perform a pre-planned and known motor act despite the preservation of motor function) or aphasia (loss of understanding ability or speech production) may subsequently limit the patient's functional capabilities.

Although early symptoms of dementia may not reduce sociability, family members report unusual behavior amidst emotional lability.

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Intermediate symptoms of dementia

Patients become incapable of learning and learning new information. Memory for distant events is reduced, but not lost in the least. Patients may need help in maintaining daily life activity (including bathing, eating, dressing, physiological needs). Personal changes are increasing. Patients become irritable, aggressive, focused on their personality, uncompromising and very easily embittered, or they become passive with the same type of reactions, depression, incapable of making a final judgment, bezinitsiativnymi and eager to escape from social activity. Behavioral disorders may develop: patients may get lost or become suddenly inappropriately agitated, hostile, uncommunicative or physically aggressive.

At this stage of the disease, patients lose the sense of time and space, as they are unable to effectively use the usual environment and social signals. Patients are often lost, they can not independently find their bedroom and bathroom. They remain walking, but with an increased risk of falls, injuries due to misalignment. Changes in perception or understanding can accumulate and transform into psychosis with hallucinations and paranoia and mania. The rhythm of sleep and wakefulness is often disorganized.

Late (severe) symptoms of dementia

Patients are unable to walk, eat or exercise any other daily activities, they develop urinary incontinence. Short-term and long-term memory is completely lost. Patients may lose the ability to swallow. They develop a risk of malnutrition, pneumonia (especially caused by aspiration) and pressure sores. As they become absolutely dependent on the help of others, placing them in hospitals for long-term care becomes absolutely necessary. Eventually, mutism develops.

Since such patients are unable to report any symptoms to the doctor and because often elderly patients do not develop fever and leukocytosis in response to infection, the physician must rely on his own experience and insight when the patient appears signs of a physical illness. In the final stages, a coma develops, and death usually comes from an infected infection.

Symptoms of dementia

Diagnosis of dementia

Diagnosis focuses on the distinction between delirium and dementia and the establishment of those areas of the brain that have become the object of injury, and an assessment of the likely reversibility of the cause of the disease. The difference between dementia and delirium is decisive (since delirium symptoms with immediate treatment are usually reversible), but it can be difficult. First of all, attention must be paid attention. If the patient is inattentive, delirium is likely to occur, although progressive dementia may also be accompanied by a pronounced loss of attention. Other signs that distinguish delirium from dementia (for example, the duration of cognitive impairment) are specified in the collection of anamnesis, physical examination, assessment of specific causes of the disease.

Dementia should also be separated from age-associated memory problems; old people have memory impairments (in the form of information reproduction) compared to younger ones. These changes are not progressive and do not significantly affect daily activities. If such people have enough time to learn new information, their intellectual effectiveness remains good. Moderately expressed cognitive impairments are represented by subjective complaints of memory; memory is weaker than the age reference group, but other cognitive spheres and daily activities are not violated. More than 50% of patients with mild cognitive impairment develop dementia within 3 years.

Dementia should also be separated from cognitive impairment against a background of depression; these cognitive impairments are resolved in the treatment of depression. Elderly patients who are depressed are showing signs of cognitive decline, but unlike patients with dementia, they tend to exaggerate (underestimate) memory loss and rarely forget important current events or personal reference points.

With a neurologic examination, signs of psychomotor delay are revealed. In the process of examination, patients with depression make little effort to respond, while patients with dementia often expend considerable effort, but they respond incorrectly. With simultaneous coexistence in a patient of depression and dementia, treatment of depression does not contribute to the complete restoration of cognitive functions.

The best test for detecting dementia is to assess short-term memory (for example, memorizing 3 subjects and the ability to name them after 5 minutes); patients with dementia forget the simple information after 3-5 minutes. Another evaluation test can serve as an assessment of the ability to name objects of various categorical groups (for example, a list of animals, plants, furniture). Patients with dementia have difficulty in naming even a small number of objects, the same ones for which dementia is absent, easily call more of them.

In addition to the loss of short-term memory, the diagnosis of dementia requires the establishment of at least the following cognitive impairments: aphasia, apraxia, agnosia, or loss of ability to plan, organize, follow a sequence of actions or think abstractly (violations of executive or governing, regulatory functions). Each type of cognitive deficiency can significantly affect the loss of functional activity and represent a significant loss of pre-existing level of functioning. In addition, cognitive impairment can only manifest itself against the background of delirium.

The history and physical examination should focus on the signs of systemic diseases, which may indicate a possible cause of delirium or for curative diseases that can cause cognitive impairment (vitamin B12 deficiency, developing syphilis, hypothyroidism, depression).

A formalized study of mental status should be performed. In case there is no delirium, the score less than 24 confirms dementia; correction to the level of education increases the accuracy of diagnosis. If there is no doubt in the diagnosis of dementia, patients should be subjected to complete neuropsychological testing, which will help to identify specific deficiency syndromes inherent in dementia.

The examination should include SHS, assessment of liver function and thyroid hormone level, vitamin B12 concentration. If the clinical study confirms the presence of specific disorders, other studies are shown (including HIV testing, syphilis). Lumbar puncture is rarely performed, but it can be indicated if there is a chronic infection or if there is a suspicion of neurosyphilis. Other surveys may be used to eliminate the causes of delirium.

CT or MRI should be performed at the beginning of the examination of a patient with dementia or after a sudden change in cognitive or mental status. Neuroimaging can reveal reversible structural changes (namely normotensive hydrocephalus, brain tumors, subdural hematoma) and metabolic disorders (including Galloworlden-Spatz disease, Wilson's disease). Sometimes EEG is useful (for example, with periodic falls and eccentric, bizarre behavior). Functional MRI or single-photon emission CT can provide information on cerebral perfusion and help with differential diagnosis.

Diagnosis of dementia

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Prognosis and treatment of dementia

Dementia usually has a progressive course. However, the rate (rate) of progression varies widely and depends on a number of reasons. Dementia shortens the expected life expectancy, but the survival score varies.

Activities that provide security and provide appropriate environmental conditions of life are extremely important in the treatment, as well as the care of the guardian. Some medications may be helpful.

Patient safety

Occupational therapy and physiotherapy determine the safety of the patient at home; The aim of these measures is to prevent accidents (especially falls), manage behavioral disorders and plan corrective actions in case of progressing dementia.

It should be evaluated to what extent the patient can function in different circumstances (in the kitchen, in the car). In case the patient is found unable to perform these actions and he remains in the previous situation, some protective measures (including not included gas / electric stove, restriction of access to the car, confiscation of keys) may be necessary. Some situations may require the doctor to inform the Department of Traffic Management about a patient with dementia, because under certain circumstances such patients can no longer continue driving. If the patient has a tendency to leave home and wander, installation of a monitoring alarm system is necessary. Ultimately, assistance (home helpers, home health care services) or changing the environment (providing daily activities without stairs and steps, assisting devices, assistance of professional nurses) may be required.

Measures to modify the environment

Providing suitable for a patient with dementia environmental conditions can help in gaining a sense of confidence in the ability to self-service and in his own personality. Such activities include orientation training in the room; bright lighting, bright, familiar environment, minimizing new influences and regular, with a small number of stresses, the patient's activity.

A large calendar and clock should become the usual condition for daily activity and help with orientation; Medical personnel should have a large registered badge and be presented repeatedly to the patient. Changes in the patient's environment, established (established) order must be carefully and simply explained to the patient, while avoiding emergency procedures. Patients need time to comprehend and familiarize themselves with the changes that have occurred. Explaining to the patient the sequence of his actions (for example, visiting a bath or eating food) is necessary to prevent resistance or wrong reactions. Often visits by medical personnel and familiar people support patients in a socially adapted state.

The room should be sufficiently illuminated and contain sensory stimuli (including radio, television, night lighting) in order to help the patient stay focused and concentrate his attention. It is necessary to avoid silence, darkness, placing the patient in isolated rooms.

Activity helps patients to function better, those with specific interests prior to dementia have a more favorable prognosis. Activity should be fun, supported by a certain stimulation, but do not involve too many choices (alternatives) and complex tasks. Physical exercises help to reduce excessive motor activity, impaired stability and maintain the necessary tone of the cardiovascular system, and therefore must be performed on a daily basis. Exercises can also help in improving sleep and reducing behavioral disorders. Occupational therapy and music therapy help maintain accurate motor control and support non-verbal stimulation. Group therapy (in this system reminiscence therapy, socialization of activity) can help to maintain conversational and interpersonal experience.

Medicines against dementia

The exclusion from use or restriction of dosages of drugs that affect the central nervous system often improves the functional state of the patient. Sedation and anticholinergics should be excluded, with a tendency to worsen the course of dementia.

Cholinesterase inhibitors such as donepezil, rivastigmine and galantamine are somewhat effective in improving cognitive function in patients with Alzheimer's disease or dementia with Levy bodies and may be useful in other forms of dementia. These drugs, by inhibiting acetylcholinesterase, increase the level of acetylcholine in the brain. Such new drugs as memantine can help slow the progression of mild or severe dementia and can be used in conjunction with cholinesterase inhibitors.

Other drugs (including antipsychotics) are used to control behavioral disorders. Patients with dementia and signs of depression should be treated with drugs from the group of non-anticholinergic antidepressants, preferably from the group of selective serotonin reuptake inhibitors.

Help the nurse

The closest family members bear great responsibility for caring for a patient with dementia. Nurses and social workers can train them and other caregivers how to better meet the needs of patients (including how to distribute day care and conduct financial calculations), training should be continuous. Other sources (including support groups, educational materials, the Internet) should be available. Nurses may experience situational stress. Stress can be caused by anxiety about protecting the patient and a sense of frustration, exhaustion, anger and resentment for having to take so much care of someone. Health care professionals should pay attention to early symptoms of stress and depression in caregivers and, if necessary, support in the provision of care (including social workers, nutritionists, nurses, and home care professionals). If patients with dementia develop unusual lesions, an assessment of possible ill-treatment of the elderly patient is necessary.

The End of Life

Due to the fact that criticism and thinking in patients with dementia are steadily deteriorating, there may be a need to appoint a family member, guardian or lawyer to manage financial affairs. In the early stages of dementia, before the patient becomes incapacitated, his wishes for custody must be clarified and his financial and legal affairs (including the reliability of the lawyer and the reliability of the lawyer leading the medical cases) brought to the necessary order. After these documents are signed, the patient's capacity should be assessed, and the results of this assessment are fixed.

Treatment of dementia


Dementia and forensic psychiatry

Dementia is defined in ICD-10 as a syndrome caused by a brain disease, which is usually chronic or progressive. In this case, there is a characteristic deficit of a number of higher cortical functions, in particular memory, thinking, orientation, understanding, counting, learning ability, language and judgments. All this happens with a clear mind. Often, in parallel, there is a decline in social behavior and emotional control. Reducing cognitive abilities usually results in significant problems in daily life, in particular related to washing, dressing, eating, personal hygiene and toilet. Classification of the types of this disorder is based on the underlying processes of the disease. Two main types: Alzheimer's disease and cerebrovascular disease. Among others, mention should be made of Pick's disease, Creutzfeldt-Jakob disease, Huntington's disease, Parkinson's disease and HIV-related illness. Lishman defines dementia as "the acquired common defeat of the intellect, memory and personality, but without the defeat of consciousness." Unlike delirium or intoxication, with dementia, consciousness should not be clouded. There must be evidence of a specific organic factor etiologically associated with this disorder, or such an organic factor may be assumed.

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Dementia and the right

The effect of dementia can be manifested in increasing the irritability of the subject, his increased aggressiveness or suspicion (which can lead to violence), as well as in disinhibition (which can lead to such crimes as unwanted sexual behavior) or forgetfulness (as a result, there may be crimes such as shop stolen by absent-mindedness). Dementia clearly falls under the definition of mental illness given in the Mental Health Act 1983. Consequently, dementia may be the basis for recommendations for treatment in accordance with certain articles of the Mental Health Act. The court is interested in the degree of dementia, and also how it affects the judgment and behavior of the offender. The severity of the disease is important for determining the degree of mitigating circumstances or responsibility.

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