mental retardation
Introduction
Introduction to mental retardation Mental retardation (MR): refers to a group of factors that are caused by genetic factors, environmental factors or psychosocial factors during the developmental stage before the age of 18, and whose clinical manifestations are characterized by markedly low intelligence and social adaptability. disease. The past few decades have been commonly referred to as brain hypoplasia, mental retardation, mental irritation, and mental retardation. For more than a decade, the education sector has tended to use feeble-mindedness, while the civil affairs department has used mental handicap. These names actually refer to the same group of people. basic knowledge The proportion of illness: 0.15% Susceptible people: no specific population Mode of infection: non-infectious Complications: neurodevelopmental delay brain atrophy
Cause
Cause of mental retardation
Causes
The etiology of mental retardation is complex and involves a wide range of factors, such as biological factors, psychosocial factors and other factors, which may lead to brain function development blockage or damage to brain tissue structure. With the development of modern medical science, some cases The cause can be identified, but many cases have not yet been able to detect the cause of the disease.
Genetic abnormality (40%)
Mainly refers to nervous system dysplasia caused by genetic or chromosomal abnormalities, malformation or congenital metabolism Down syndrome, Turner syndrome; phenylketonuria, galactosemia, familial black sputum dementia; neurofibromatosis, Nodular sclerosis and congenital hydrocephalus, brain penetrating malformation, microcephaly and so on. The first three months of pregnancy is the initial stage of the formation of the fetal nervous system, which is susceptible to damage from pathogenic factors and leads to obvious deformities. In the fetal period of maternal infection (virus, spirochete, toxoplasma), abdominal trauma or radiation, psychoactive substance poisoning, hypothyroidism and other endocrine diseases, pregnancy toxemia, malnutrition, hypoxia and other serious diseases are mental development One of the causes of delay.
Perinatal disease (25%)
Including premature birth, dystocia, brain damage during childbirth, neonatal asphyxia and nuclear jaundice.
Other factors (15%)
Such as infection (especially infection of the central nervous system), craniocerebral trauma, poisoning, epilepsy, malnutrition, endocrine or metabolic diseases and encephalitis after vaccination.
Psychosocial factors (15%)
Psychosocial factors have a significant impact on children's intellectual development. Because of poverty or neglect, abuse, children's early isolation from society, lack of benign environmental stimulation, lack of cultural and educational opportunities can lead to mental retardation.
Prevention
Mental retardation prevention
Mainly to eliminate the cause, to carry out genetic counseling, to avoid marriage of close relatives, strengthen pregnancy care, pay attention to nutrition during pregnancy, avoid exposure to harmful chemicals, quit smoking, abstain from alcohol, absolutely prohibit the intake of drugs, avoid taking teratogenic drugs, avoid exposure to radiation Prevent virus and protozoal infections; do prenatal checkups, prevent pregnancy complications, improve obstetric techniques, and avoid pathological delivery. Do a good job in child health care, implement planned immunization, prevent infectious diseases, especially nervous system infections, pay attention to nutrition and health, prevent poisoning, and avoid brain trauma. Promote parenting knowledge and improve parental culture.
Complication
Mental retardation complications Complications, neurodevelopmental delay, brain atrophy
Due to the etiology and the severity of the disease, the lightness and moderateness of the moderate, the intelligence can gradually improve, but still lower than the normal age, the prognosis and brain disorders, low resistance, low living adaptability and other factors The heavy ones usually die young.
Symptom
Symptoms of mental retardation Common symptoms Severe mental retardation Moderate mental retardation Hearing disorder Mild mental retardation End finger short inward bending... Extremely severe mental retardation Eating abnormalities Post-morning amnesia Cortical amnesia Mental age is less than physiological age
The clinical manifestations of mental retardation are closely related to the degree of mental retardation. The degree of mental retardation is determined through clinical examinations including intelligence tests and social fitness assessment results. IQ is used as an indicator for assessing mental retardation, IQ (IQ) It refers to the ratio of the intelligence age to the actual age measured by an individual through a certain intelligence scale, that is, IQ=(intellectual age/actual age) X100, IQ (IQ) is in the normal range of 100±15, IQ (IQ) 70 Or less than 70 are mentally retarded, clinically classified mental retardation into 4 grades: mild ( IQ is 50 to 70), moderate ( IQ is 35 to 49), severe ( IQ is 20 to 34), extremely severe (The IQ is below 20), and the clinical features of different degrees are now described as follows:
(1) Mild mental retardation: the most common, but because of the light degree, it is often difficult to be identified, the body is generally not abnormal, the language development is retarded, the social ability is lower than the normal level, social interaction is possible, and practical skills are available. Self-care, can engage in simple labor or technical operations, but learning ability, skills and creativity are worse than normal people. Reading, writing, computer and abstract thinking skills are worse than children of the same age, showing learning difficulties, special education can make their intelligence Levels and social adaptability have improved.
(2) Moderate mental retardation: can partially take care of daily simple life, can do simple housework, language, motor function and skill ability obviously lag behind normal children of the same age, reading, computing ability is poor, understanding ability is poor, right The school's homework lacks the ability to learn. Adults cannot live completely independently. A small number of patients are accompanied by signs of physical developmental defects and abnormalities of the nervous system.
(3) Severe mental retardation: social adaptability is obviously flawed. Everyday life needs other people's care, no danger and defense, obvious obstacles in speech development, or can only learn some simple words, can't understand other people's words, and develop motor function. Restricted, serious people can not sit, stand and walk, can not accept learning and education, often accompanied by epilepsy, congenital malformation.
(4) Extremely severe mental retardation: less common, most of them have obvious congenital malformations at birth, completely lacking the ability to take care of themselves, need others to care for life, do not speak, do not walk, can not receive training.
Mental retardation Physical characteristics: prenatal dysfunction and severe mental retardation often have congenital abnormal signs, such as small head, facial deformity, low ear, cleft lip, cleft palate, limb and genital malformation, etc., visual, auditory and congenital Heart damage and the like are more common.
Special type of mental retardation: This disease is a group of diseases caused by various causes. Some cases are caused by chromosomal abnormalities, congenital metabolic disorders, etc., and the clinical composition is a special type.
Psychological characteristics of mental retardation
The psychological activity characteristics of patients with this disease are closely related to the degree of central nervous system damage and mental retardation. Here is a brief description of the psychological characteristics of mentally handicapped children:
(1) Speech and thinking, often showing slow speech development, poor expression ability, slow thinking and understanding, lack of abstraction, generalization ability, loss of verbal ability of severe or extremely severe, almost no thinking ability.
(2) Perceptual aspect; the perception is slow, the scope of perception is narrow, and it is difficult to distinguish the small differences in shape, size, and color of objects.
(3) Attention and memory: often attention is not concentrated, attention is widely narrow, memory is poor, recognition speed is slow and reproduction is not accurate.
(4) Emotional aspects: performance is naive, immature, emotionally unstable, lack of self-control, easy to impulsive, often timid, isolated, shy, retreating.
(5) Sports and behavioral aspects: common body shape is uneven, sports are not coordinated, poor flexibility, or excessive activity, destruction, aggressive behavior or other bad behavior.
Examine
Examination of mental retardation
1, do routine physical examination, including neurological examination, growth and development, such as height, weight, head circumference, head shape, with or without deformity, vision, hearing and skin, hair with or without abnormalities.
2, laboratory tests, including EEG, skull imaging, brain evoked potentials, biochemical tests and genetic cytology.
Diagnosis
Diagnosis and diagnosis of mental retardation
diagnosis
Diagnosis should be based on a combination of medical history, physical and neurological examinations, mental examinations, intelligence and social fitness assessments.
Diagnostic points include: 1 onset before the age of 18; 2 IQ below 70; 3 have varying degrees of social adaptation difficulties. The IQ standards at all levels are as follows: mild 50-69, moderate 35-49, severe 20-34, and extremely severe below 20.
The necessary auxiliary examinations, such as chromosomal examination, CT or MRI, and genetic metabolic disease screening, should be performed to make an etiological diagnosis as much as possible.
With the diagnostic criteria for mental retardation in DSM-IV:
A. Intelligence is significantly lower than the general level: IQ 70 (if it is a baby, for clinical judgment, no measurement).
B. At present, the adaptation function is defective or defective (patients do not meet the level of their cultural background and age), at least in the following two: speech communication, self-care, family life, social or interpersonal skills, community facilities Application, self-direction, learning and skills, work, amateur, health, and safety.
C. Onset before the age of 18.
317 Mild IQ: 50 or 55--70;
318.0 Moderate IQ: 35 or 40 - 50 or 55;
318.1 Severe IQ: 20 or 25-35 or 40;
318.2 Extremely severe IQ is less than 20 or 25;
319 Indicated at the end of the severity.
Diagnostic step
1. Collect medical history in detail. Comprehensively collect the child's maternal and perinatal conditions, personal growth and development history, maintenance history, past disease history, family culture and economic status to find out whether there are any adverse factors related to the physical and psychological development of the child.
2. Comprehensive physical examination and related laboratory examinations. An indispensable step in the analysis of the cause of mental retardation, including: examination of growth and development indicators (such as height, weight, head circumference, skin palm fingerprint, etc.), related endocrine and metabolic tests, EEG, EEG topographic map, Head X-ray, CT and MRI examination, chromosome analysis and fragile site examination.
3. Mental development assessment
(1) Intelligence test: It is one of the main reasons for diagnosing mental retardation. Intelligence tests should be used with caution by trained technical personnel. Collective or screening methods should not be used for diagnosis, but diagnostic tests should be used for individual tests. The commonly used scales in China include: Gesell Developmental Diagnostic Scale, Wechsler Preschool Intelligence Scale (WPPSI), and Wechsler School Age Children's Intelligence Scale Revision ( WISC-R), China Binet Test Scale, etc.
(2) Assessment of social adaptive behavior: The judgment of social adaptive behavior is another important basis for diagnosing mental retardation. At present, for children aged 4-12 years, the social adaptability scale (Yao Shuqiao et al.) can be used to assess the social adaptability of children. If it is not suitable for use, it can also be judged by the same age and people with the same cultural background to judge the independent living ability and the degree of fulfilling its social functions. Reference can also be made to the use of the Infant-Junior High School Students' Adaptive Behavior Scale (revised by Zuo Qihua et al.), the AAMD Adaptive Behavior Scale and the Vineland Adaptive Behavior Scale compiled by the American Association for Mental Defects.
(3) Clinical development assessment: In the clinical work or unconditional intelligence test, the clinical development assessment method can be used, that is, according to the clinical manifestations of mental retardation and developmental characteristics of the children, the developmental level of the child can be estimated. evaluation of.
Differential diagnosis
Mental retardation should be clinically differentiated from the following diseases:
(1) Temporary delay in mental development: children with chronic physical illness, post-illness state, malnutrition, taking sedative drugs or poor environment, lack of learning conditions, etc., can cause children to be sluggish, poor thinking, easy to be mistaken for intelligence Low and mental retardation.
If you improve your living conditions and learning conditions or physical recovery, your intelligence can recover quickly.
(2) epilepsy: frequent seizures and taking phenobarbital, carbamazepine, valproic anti-epileptic drugs, can make children sleepy, sluggish, similar to mental retardation.
(3) Children with schizophrenia: There may also be low academic performance, indifference, contact with the surrounding environment and maladaptation, but most children do not have real mental retardation.
(4) Vision, hearing impairment, adapting to the environment and learning difficulties: In early years, people with severe deafness often have language development disorders. Do not mistake these situations for mental retardation. Some aphasias cause aphasia, misuse, and loss of writing. Learning and language skills, but their general intelligence is good.
(5) Children with ADHD: lack of concentration, poor academic performance, non-compliance with discipline, and poor social ability, similar to mental retardation, but the intelligence is often within the normal range, and the academic performance can be significantly improved. The medication can be improved, and these manifestations can be differentiated from mental retardation.
(6) Normal children also have some verbal ability, and their ability to exercise is slow, but their ability to understand and adapt to the environment is still normal. Once the function develops, they can quickly catch up with normal children, and they are not significantly backward in all aspects, and mental development. The delay is different.
(7) Attention deficits and hyperactivity disorder due to inattention affecting learning and social adaptation, seemingly mental retardation, but the developmental delay in these children's medical history is not obvious, there are typical symptoms of attention deficit and hyperactivity disorder, intelligence test results For normal or marginal intelligence levels, learning difficulties often have varying degrees of improvement after improving attention and reducing hyperactivity.
(8) Children with autism Children with autism are often accompanied by mental retardation. If the child meets the diagnostic criteria for mental retardation and autism, both diagnoses need to be made. Children with high-functioning autism with normal mental development may be misdiagnosed as mental retardation because of their poor social adaptability. At this time, the intelligence test results are helpful for differential diagnosis.
