dementia

Introduction

Introduction to dementia Dementia refers to the declining occupational and social activity skills and obstacles, cognitive decline, memory loss and loss, visual skills impairment, orientation, computational power, judgment, etc. Loss, and successive obstacles such as personality, emotion and behavior change, and a progressive process of aggravation. basic knowledge The proportion of illness: 0.003%, the elderly can reach 0.8% Susceptible people: no specific people Mode of infection: non-infectious Complications: depression, urinary tract infection

Cause

Cause of dementia

Various infectious diseases of the brain (35%):

Dementia is a clinical syndrome, which can be caused by more than 60 diseases. The most common one is dementia of Alzheimer's type (DAT or AD), which accounts for about 60%, followed by vascular dementia (VaD). %20%, brain occupying lesions, especially frontotemporal tumors accounted for 4% to 5%, as well as Huntington's disease, Parkinson's disease, progressive supranuclear palsy, Pick disease, multiple sclerosis, and brain accumulation Water, various infectious diseases of the brain, nutritional metabolic diseases, etc.

Age (old age), low economic level, etc. (25%):

The main risk factors for dementia are: age (old age), gender (female), low education level and low economic level. In addition, recent studies have found that the elderly have loneliness, lack of work and social activities, cultural and sports activities, etc. Also for the risk factors for dementia, the survey conducted in Shanghai showed that after the case-normal control study, narrow interest, lack of exercise and vitality, and certain environmental factors such as low economic status were risk factors for dementia. .

Family history (25%):

Some physical illnesses and family history are also risk factors for dementia.

According to the etiology and prognosis, dementia syndrome can be roughly divided into three categories:

1. Irreversible progressive dementia, such as AD.

2. Dementia that can partially retard its development, such as VaD.

3. Can remove the cause of dementia to reduce or even stop, such as hydrocephalus, brain occupying lesions, drug poisoning, hypothyroidism, liver and kidney dysfunction, encephalitis.

Pathogenesis

Human intelligence is related to the normal structure and physiological functions of the brain. There are 8 billion to 20 billion neurons and hundreds of millions of glial cells in the brain. With the accumulation of life experiences and the acquisition of information, each neuron is formed. About 100,000 intrinsically associated dendrites and axons, which serve as informational and exchange functions, constitute the material basis of human intelligence. Normal intelligence is the sum of thinking, imagination, creativity, analysis and comprehensive ability, as well as with good vision. As a result of the interaction of hearing, special feelings and momentary feelings, intelligence is the foundation of learning ability. People have the strongest learning ability when they are young, but they lose tens of thousands of neurons every day after adulthood. About 30% of nerves are lost when they are 65 years old. Yuan, intelligence declines with age.

Dementia can be caused by more than 60 diseases, and its pathogenesis is still unclear, but the common feature is that the normal structure and physiological function of the brain are impaired. The cause of dementia is not fully understood, and some are degenerative diseases of the nervous system, and the cause of dementia Most of the clearer brain diseases are not neurodegenerative diseases, such as metabolism caused by systemic medical diseases, poisoning and brain trauma.

Prevention

Dementia prevention

There is no effective prevention method. Symptomatic treatment is an important part of clinical medical care. For the early diagnosis and early treatment of certain dementia, the symptoms of dementia will improve or slow down the irreversible process.

Complication

Dementia complications Complications depression urinary tract infection

With the development of the disease, patients often have depression, mental behavior abnormalities, etc. In addition, attention should be paid to secondary lung infections and urinary tract infections.

Symptom

Dementia Symptoms Common Symptoms Spatial Perception Disorder Cognitive Dysfunction Near-forgotten Phenomenon Memory Disorder Anxiety Eyes Depression Depressor Physique Wood Zombie Forgetting Dementia

Clinical classification

According to the different parts of the brain, dementia syndrome can be divided into cortical dementia, subcortical dementia, cortical and subcortical mixed dementia and other types of dementia syndrome.

(1) Cortical dementia:

1 Alzheimer's disease.

2 prefrontal degenerative disease (Pick disease).

(2) Subcortical dementia:

1 extrapyramidal syndrome (Parkinson's disease, Huntington's disease, etc.).

2 hydrocephalus (such as normal intracranial pressure hydrocephalus).

3 depression (pseudo-dementia).

4 white matter lesions (multiple infarction, human immunodeficiency virus disease).

5 cerebral vascular dementia (cavity state, multi-infarction type, etc.).

(3) Cortical and subcortical mixed dementia:

1 multi-infarct infarct dementia.

2 infectious dementia (viral dementia, etc.).

3 poisoning and metabolic encephalopathy.

(4) Other dementia syndrome (after brain trauma and after hypoxia, etc.):

2. The main clinical manifestations of dementia

Clinical manifestations vary with the cause of dementia, and their symptoms vary at different times. The following are general clinical manifestations of dementia.

(1) cognitive dysfunction:

1 memory disorder: for the most prominent early symptoms, especially AD, manifested as retrograde and antegrade two forms of forgetting, such as missing common items, forgetting to cook food on the stove, forgetting appointments, etc., late stage of dynamism I don't even remember my birthday, family members and my own name.

2 language barriers or aphasia: manifested as naming difficulties, verbal empty, cumbersome, understanding of language, writing and retelling are also obstacles, in the late period, few words or imitate language.

3 intentional misuse: the performance is not able to perform sports activities to do some simple actions, such as combing hair, dressing and so on.

4 Loss of recognition: Loss of ability to recognize objects and even family members, but also tactile loss of recognition, that is, the objects in the hands (such as coins) cannot be identified by touch.

5 Motor dysfunction: refers to the obstacles that occur when performing more complex tasks or completing more complex behavioral activities. This is one of the most common symptoms of dementia patients, and it is also one of the manifestations of social adaptability decline.

(2) Non-cognitive dysfunction:

1 Spatial awareness barriers: the obstacles to spatial orientation and the implementation of spatial awareness activities.

2 Judgement and anticipation of dysfunction: manifested as overestimating your ability and status, or underestimating the risk of certain activities.

3 Personality changes: if you don't talk about hygiene, don't trim the margins, and you are not excessively close to the stranger.

4 gait changes: frequent falls, can also be accompanied by ambiguity and other basal ganglia lesions, common in VaD, Lewy body dementia (DLB) and Parkinson's disease (PD) and amyotrophic lateral beam sclerosis (ALS) combined Dementia.

5 mental and behavioral disorders: This is one of the prominent symptoms of dementia, especially in DLB and frontotemporal dementia (FTD), common symptoms are anxiety, depression, emotional abnormalities, mental and behavioral abnormalities, the latter including hallucinations, delusions , irritability, aggressive behavior (language and action), ill-conditioned collection of worthless objects.

3. Clinical stage of dementia

Many of the above symptoms may occur in a particular patient, or may occur as the condition progresses. The clinical generalization is divided into three stages.

(1) Forgetting period: This period is mainly characterized by memory impairment, and its content is as above. The memory change in this period is often neglected because the patient and his family mistakenly believe that it is a common degenerative change in the elderly, so it needs to be related to age. Memory impairment, also known as "benign memory disorder", the latter's memory loss is mainly due to the decline of mechanical memory ability, while the ability to understand memory is acceptable, the ability to recall is reduced, and the recognition function is relatively reserved.

(2) Disorder period: In addition to the memory disorder continues to increase in this period, there are thinking and judgment disorders, personality changes and affective disorders, patient work, learning (new knowledge) and social contact ability decline, and even personality changes may occur. Some focal brain and personality aphasia, aphasia or physical inconvenience.

(3) Dementia period: The above-mentioned symptoms of patients in this period are getting worse, so that they can not complete simple daily life events, such as dressing, eating, etc., staying bedridden all day long, gradually losing contact with relatives and friends and the outside world, limbs and rigidity Or flexion sputum, sphincter dysfunction, and ultimately death due to systemic complications such as lung and urinary tract infections, pressure sores and systemic failure.

As a group of syndromes, dementia has not yet been diagnosed as the "gold standard". The main reason is that there are many causes of dementia, and most patients cannot make the necessary pathological examinations in the clinic. The clinical diagnosis is based on clinical diagnosis. Performance, auxiliary examinations (including imaging studies) and neuropsychological tests.

Examine

Dementia check

1. Determination of cerebrospinal fluid, serum ApoE polymorphism: Many studies have shown that ApoE polymorphism is associated with the occurrence of Alzheimer disease (AD), 2 gene seems to not only protect people from AD, but also related to longevity.

2. Determination of Tau protein quantitation, amyloid beta fragment, also has diagnostic and differential significance.

3. Imaging examination: CT can be seen brain atrophy, ventricular enlargement, cerebral infarction, can provide the basis for the nature and type of dementia, MRI examination shows bilateral temporal lobe, hippocampal atrophy provides a strong basis for AD, has been used in clinical in recent years The functional MRI suggests a good specificity and sensitivity for the early diagnosis of AD. According to the principles of glucose metabolism and cerebral blood flow distribution, the images shown by 18F-FDG can be seen in the parietal lobe, temporal lobe and frontal lobe. In particular, the blood flow and metabolism of the bilateral temporal lobe hippocampus were reduced, consistent with the atrophy zone indicated by CT and MRI.

4. Electrophysiological examination: such as EEG, negative correlation evoked potential P300 analysis.

5. Neuropsychological test: commonly used tools are the Wechsler Adult Intelligence Scale (WAIS-CR), the Wechsler Memory Scale (WMS-CR), the Mini Mental State Scale (MMSE), and the Daily Living Function Scale (ADL). , Alzheimer's Dementia Scale (ADAS), Alzheimer's Dementia Cognitive Scale (ADAS-cog), Blessed Behavioral Scale and Cognitive Ability Discrimination Scale (CAS I), etc., the above scales can be used in combination It can also be applied alone, mainly based on clinical needs and patient compliance. Neuropsychological tests are mainly used to identify dementia and non-dementia in cognitive function, but can not make dementia based on a certain test result alone. diagnosis.

Diagnosis

Dementia diagnosis

The current international diagnostic criteria for dementia is the fourth edition of the American Diagnostic and Statistical Guidelines for Mental Disorders (DSM-IV) (Table 2). The diagnosis of AD is mostly based on the NINCDS/ADRDA standard recommended by the United States (1984), while the diagnosis of VaD is mostly in the United States. NINDS-AIREN standard.

According to the accuracy of the diagnosis, the above criteria are diagnosed, possibly and suspicious. The criteria for diagnosis are in addition to clinical manifestations. The biopsy or autopsy is required for histopathological basis. The possible standard is further divided into diagnostic criteria. The basis for supporting the diagnosis is in accordance with the basis of diagnosis and the evidence for eliminating the diagnosis. The clinically diagnosed dementia (AD or VD) is mostly "probable".

In terms of differential diagnosis, in addition to the "benign memory disorder" mentioned above, it is necessary to exclude sputum, depression and other mental disorders that can also manifest as cognitive decline, several common dementia such as AD, VD, DLB It also needs to be identified between the FTD and the FTD.

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