Mental retardation in children

Mental retardation is a condition caused by congenital or early acquired underdevelopment of the psyche with a pronounced lack of intelligence, which makes it difficult or completely impossible for an adequate social functioning of the individual.

The term "mental retardation" has become generally accepted in the world of psychiatry over the past two decades, replacing the term "oligophrenia", which has long been common in our and some other countries.

The term "oligophrenia" is more narrow, it is used to refer to a state that meets a number of clear criteria.

• The totality of mental underdevelopment with the prevalence of weakness in abstract thinking. The severity of violations of the prerequisites of the intellect (attention, memory, working capacity) is less, underdevelopment of the emotional sphere is less rude.
• Uncertainty of intellectual insufficiency and irreversibility of the pathological process that caused maldevelopment.

The concept of "mental retardation" is broader and more correct, since it includes diseases with congenital or early acquired underdevelopment of mental functions, in which the progression of the brain lesion is noted. Clinically, this is detected only with prolonged observation.

Mental retardation is characterized by a marked decrease in intellectual abilities compared to the average (often expressed as an intelligence factor below 70-75) combined with the restriction of more than 2 functions of the following: communication, independence, social skills, self-service, use of public resources, maintaining personal security. Treatment includes training, working with the family, social support.

It is incorrect to assess the severity of mental retardation only on the basis of the intelligence factor (IQ) (for example, light 52-70 or 75, moderate 36-51, severe 20-35 and deep less than 20). The classification should also take into account the level of care and care that the patient needs, ranging from support from time to time to high-level, high-level care in all activities. This approach focuses on the strengths and weaknesses of the individual and the relationship between them and the needs of the patient's surroundings, as well as expectations and attitudes from the family and society.

Approximately 3% of the population lives with an IQ of less than 70, which is at least 2 standard deviations below the mean IQ in the general population (IQ is less than 100); if you take into account the need for care, only 1% of the population has severe mental retardation (UO). Severe mental retardation is noted in children in families of all socioeconomic groups and educational levels. Less severe mental retardation (in which the patient needs intermittent or limited care) is more common in groups with lower socioeconomic status, similar to the observation that IQ is more likely to correlate with school successes and socioeconomic status than specific organic factors. Nevertheless, recent studies have suggested the role of genetic factors in the development of mild violations of cognitive functions.

ICD-10 codes

In ICD-10, mental retardation is codified under the heading F70, depending on the severity of intellectual impairment. As the first diagnostic reference point, a common intellectual indicator is used, determined using the Wechsler technique. The following IQ indicators for assessing mental retardation have been adopted:

• indicator in the range of 50-69 - mild mental retardation (F70);
• an indicator in the range 35-49 - moderate mental retardation (F71);
• an indicator in the range 20-34 - severe mental retardation (F72);
• the indicator below 20 is deep mental retardation (F73).

The fourth sign is used to determine the severity of behavioral disorders if they are not caused by a concomitant mental disorder:

• 0 - the minimum value of violations or their absence;
• 1 - significant behavioral disorders requiring treatment;
• 8 - other behavioral disorders;
• 9 - behavioral disorders are not defined.

If the etiology of mental retardation is known, an additional code from ICD-10 should be used.

Epidemiology of Mental Retardation

The prevalence of mental retardation among different age groups of the population is largely different, which explains the significance of the criterion of social adaptation in the diagnosis. The maximum values of this indicator are.on the age of 10-19 years, in which the society makes high demands on the cognitive abilities of the population (schooling, call-up for the army service, etc.).

The incidence of mental retardation in the world is 3.4-24.6 per 1000 people.

Screening

For early diagnosis of mental retardation due to impaired metabolism, screenings are used. Along with phenylketonuriei, screening can be directed to the detection of homocystinuria, histidemia, "maple syrup" disease, tyrosinemia, galactosemia, lysinemia, mucopolysaccharidosis. A special diet allows you to avoid or significantly reduce the severity of an intellectual defect. Preventive measures include improving care for pregnant women, including obstetrics, prevention of neuroinfections and craniocerebral trauma in young children, and iodine prophylaxis in people living in iodine-deficient areas.

[1], [2], [3], [4], [5], [6], [7], [8], [9], [10],

Causes of mental retardation

Intellect is determined by both genetic and environmental factors. Children whose parents are mentally retarded are at higher risk of a number of mental (psychological) development disorders, but a purely genetic transmission is infrequent. Despite the advances in genetics, which increased the probability of determining the cause of the patient's intellectual disability, in 60-80% of cases, a certain cause still can not be established. More often the cause is revealed in severe cases. Violations of speech and personal and social skills, rather, may be the result of emotional problems, psychosocial deprivation, developmental disorders of school skills or deafness, rather than mental retardation.

[11], [12], [13], [14], [15], [16], [17],

Prenatal factors

Mental retardation can cause a number of chromosomal abnormalities and genetic metabolic and nervous diseases.

Congenital infections that may cause mental retardation include infections caused by the rubella virus, cytomegalovirus, Toxoplasma gondii, Treponema pallidum and HIV.

Effects on the fetus of drugs and toxins can cause the development of mental retardation. Fetal alcohol syndrome is the most common cause in this group. Also, the reasons for the development of mental retardation are anticonvulsants, such as phenytoin or valproate, chemotherapeutic drugs, exposure to radiation, lead and methylmercury. Severe hypotrophy during pregnancy can affect the development of the fetal brain, leading to mental retardation.

Intratinal factors

Complications associated with prematurity or immaturity, CNS hemorrhage, periventricular leukomalacia, breech delivery, forceps application, multiple pregnancy, placenta previa, preeclampsia and intranatal asphyxia may increase the risk of mental retardation. Increased risk is noted in children, small to the term of gestation; the violation of intelligence and low body weight have the same causes. In children with very low and extremely low birth weights, there is a different degree of increased risk of developing mental retardation, which depends on the gestational age, the features of the intranatal period, and the quality of care for the child.

Chromosomal and genetic causes of mental retardation

Chromosomal diseases	Genetic metabolic diseases	Genetic diseases of the nervous system
Cats Syndrome Down Syndrome Syndrome of a fragile X chromosome Klinefelter Syndrome Mosaicism Trisomy on the 13th chromosome (Patau's syndrome) Trisomy on the 18th chromosome (Edwards syndrome) Syndrome Turner (Shereshevsky-Turner)	Autosomal recessive: Aminoaciduria and acidemia Peroxisomal diseases: Galactosemia Maple Syrup Disease Phenylketonuria Lysosomal defects: Gaucher's disease The syndrome of Hurler (mucopolysaccharidosis) Niemann-Pick disease Thea-Sachs disease X-linked recessive diseases: Lesch-Nihan syndrome (hyperuricemia) Hunter syndrome (variant of mucopolysaccharidosis) Okouco-cerebral sin syndrome	Autosomal dominant: Myotonic dystrophy Neurofibromatosis Tuberous sclerosis Autosomal recessive: Primary microcephaly

Postnatal factors

Insufficient nutrition and psychoemotional deprivation (lack of physical, emotional and cognitive support necessary for growth, development and social adaptation) in children of the first years of life can be the most common causes of mental retardation throughout the world. Mental retardation can be the result of viral and bacterial encephalitis (including AIDS-associated neuroencephalopathy) and meningitis, poisoning (eg, lead, mercury), severe hypotrophy, as well as accidents in which head trauma or asphyxia occurs.

Causes and pathogenesis of mental retardation

Symptoms of mental retardation

The first manifestations include a delay in intellectual development, immature behavior, as well as limited self-service skills. In some children with mild mental retardation, recognizable symptoms may not develop until preschool age. However, often mental retardation is diagnosed early in children with severe and moderate severity, as well as when combined with physical anomalies and malformations or signs of a condition (for example, cerebral palsy) that can be associated with a specific cause of mental retardation (for example , intranatal asphyxia). The delay in development usually becomes apparent to preschool age. Among the older children, the distinguishing features are low IQ combined with limitations of adaptive behavioral skills. Despite the fact that the features of development can vary, it is much more often in children with mental retardation, there is a slow progression, rather than a halt in development.

Some children may have cerebral palsy or other motor impairment, delayed speech development or loss of hearing. Such motor or sensory disturbances may resemble cognitive impairments, but they are not their own independent causes. With growth and psychological maturation, some children develop anxiety or depression if other children reject them or if they are concerned about the realization that others see them as different and defective. Well-organized school curricula that allow such children to be included in the communication and educational process can contribute to maximizing social integration, thereby minimizing negative emotional reactions. In patients with mental retardation, the reason for the majority of calls to the psychiatrist and hospitalizations are behavioral disorders. Behavioral disorders often have a situational nature, as a rule, one can detect a provoking factor. Factors that predispose to unacceptable behavior are the following: lack of training in socially responsible behavior, unstable discipline, reinforcement of wrong behavior, impaired ability to communicate, and discomfort due to concomitant physical disorders and mental disorders such as depression or anxiety. When the patient is in a hospital, additional unfavorable factors are overcrowding, insufficient number of staff, and lack of activity.

Symptoms of mental retardation

Classification of mental retardation

There are many authorial classifications of mental retardation, which are presented in the relevant publications. With clinical and pathogenetic differentiation of mental retardation, it is expedient to divide it into the following groups:

• exogenously conditioned, hereditary forms of brain damage that are not primarily associated with the formation of the anatomical and physiological basis of the intellect;
• light forms of mental retardation, due to the genetic variability of intelligence in the norm.

Classification of mental retardation

[18], [19], [20], [21],

Diagnosis of mental retardation

When suspected of mental retardation, psychological development and intelligence are assessed, usually with early intervention or school staff. Standardized intelligence tests can determine intellectual ability below the average, but if the result does not match the clinical data, it should be questioned, since there is a chance of error; diseases, motor or sensory impairments, a language barrier or intercultural differences may interfere with a child's performance of a test. Such tests also have a bias toward the middle class, but are usually acceptable for assessing intellectual abilities in children, especially older children.

Testing the level of neuropsychic development using tests such as the Ages and Stages Questionnaire or the Parents' Evaluation of Developmental Status (PEDS) provides an approximate assessment of the psychological (mental) development of younger children and may be performed by a doctor or other persons. Such measures should only be used for screening, and not as a replacement for standardized intelligence tests, which should be prescribed and conducted only by a qualified psychologist. It is necessary to assess the neuropsychic development immediately if there is a suspicion of its delay. All cases of moderate or severe mental retardation, progressive disorders, including disability, neuromuscular disorders, or suspected convulsive disorders, should be examined by an experienced pediatrician specializing in the neuropsychological development of children or a pediatric neurologist.

After identifying mental retardation, every effort should be made to determine its cause. Due to the precise definition of the cause, it is possible to judge the prognosis of further development for the child, plan training programs, this can be useful in genetic counseling, helps to reduce the sense of guilt of the parents. Anamnesis (including perinatal history, neuropsychological development, neurological history, and family history) may reveal the cause. An algorithm for examining a child with mental retardation (general delay of neuropsychological development) was proposed by the Society of Pediatric Neurologists. Brain imaging techniques (eg, MRI) can demonstrate the developmental defects of the CNS (observed, for example, in neurodermatoses such as neurofibromatosis or tuberous sclerosis), hydrocephalus, in which correction is possible, or more severe brain development defects such as schizencephaly. Genetic tests can help diagnose diseases such as Down's syndrome (trisomy 21) in a standard karyotype study, fission 5p (feline cry syndrome) or DiGiorgi syndrome (deletion 22q) with fluorescent in situ hybridization (FISH), fragile X chromosome syndrome with direct DNA research.

Hereditary diseases of metabolism can be assumed by clinical manifestations (for example, hypotrophy, lethargy, adynamia, vomiting, convulsions, hypotension, hepatosplenomegaly, rough features, specific smell of urine, macroglossia). Isolated delay in general movements (for example, late started to sit or walk) or small hand movements (poorly takes objects, draws, writes) may indicate neuromuscular disorders. Depending on the expected cause, special laboratory tests are carried out. The evaluation of vision and hearing should be conducted at an early age, often also justifiably an examination for intoxication with lead.

Diagnosis of mental retardation

[22], [23]

Treatment of mental retardation

Treatment and support depend on social skills and cognitive functions. Treatment and participation in the early intervention program in infancy can prevent or reduce the severity of disability due to perinatal brain damage. It is recommended to recommend realistic and affordable methods of caring for the child.

It is extremely important to support and advise the family of a sick child. Immediately upon confirming the diagnosis of "mental retardation", parents should be informed about this and give them enough time to discuss the causes, effects, prognosis, further education of the child, as well as the importance of balancing known prediction factors and negative predictions, in which low expectations lead in the future to a poor functional outcome. Sensitive counseling in the future is necessary for family adaptation. If the family doctor can not provide coordination and counseling, the child and parents should be sent to a center where children with mental retardation are examined and their families will be assisted by specialists in various fields of medicine and psychology; nevertheless the family doctor should continue to provide medical assistance.

Survey of patients with some forms of mental retardation

Supposed Cause	The survey
One developmental disorder or multiple minor developmental anomalies, a family history of mental retardation	Chromosomal analysis CT and / or MRI of the brain
Hypotrophy, idiopathic hypotension, hereditary metabolic disorders	Screening for HIV in high-risk newborns Nutritional and psychosocial history The study of amino acids in urine and / or blood, as well as the study of enzymes for the diagnosis of accumulation diseases or peroxisome diseases Research of muscle enzymes SMA12 / 60 Bone age, radiography of bones
Convulsions	EEG CT and / or MRI of the brain Determination of the level of calcium, phosphorus, magnesium, amino acids, glucose and lead in the blood
The developmental defects of the skull (for example, premature closure of seams, microcephaly, macrocephaly, craniostenosis, hydrocephalus), cerebral atrophy, brain development defects, hemorrhages in the central nervous system, tumors, intracranial calcifications due to toxoplasmosis, cytomegalovirus infection or tuberous sclerosis	CT and / or MRI of the brain Screening for TORCH infection Urine culture for viruses Chromosomal analysis

A complete individual program is developed in cooperation with relevant specialists, including teachers. Neurologists or pediatricians specializing in the neuropsychological development of children, orthopedists, physiotherapists participate in the treatment of concomitant diseases in children with impaired motor functions. Speech therapists and defectologists, as well as audiology, provide assistance in delaying speech development or with suspected hearing loss. Nutritionists can help in the treatment of hypotrophy, social workers - to reduce isolation from the outside world. With concomitant mental disorders, such as depression, the child can be assigned appropriate psychotropic drugs in doses similar to those used in children without mental retardation. The use of psychotropic drugs without conducting behavioral therapy and changing the environment of the child is rarely effective.

All efforts should be made to ensure that the child lives at home and is not isolated from society. The situation in the family can be both favorable for the child, and negative. Family can be useful psychological support and assistance in the daily care of the child, which provides day care centers, incoming helpers or temporary help services. Living conditions and surroundings should stimulate independence and support learning the skills necessary to achieve this goal. If possible, the child must attend an appropriately adapted day care center or school with peers who are not mentally retarded. The Education for Persons with Disabilities Act (IDEA), a special law on education in the United States, stipulates that all children with disabilities should receive adequate educational opportunities, educational programs for them should be as restrictive as possible and should ensure the maximum inclusion of such children in training and social life. When people with mental retardation reach adulthood, they are provided with a number of places of residence and work. The large institutions where mentally retarded people lived and work are now replaced by places of residence for small groups or by individual apartments that correspond to their functional capabilities and needs.

Many people with mild or moderate mental retardation can provide for themselves, live independently and succeed in work that requires basic intellectual skills. Life expectancy may be reduced depending on the etiology of the disorder, but medical care improves the long-term prognosis for people with all types of mental retardation. Patients with severe mental retardation, as a rule, throughout life need help and care. The more pronounced backwardness and immobility, the higher the risk of death.

Mental retardation - Treatment

Prevention of mental retardation

Medico-genetic counseling makes it possible to give recommendations on the undesirability of pregnancy in cases of hereditary aggravation of certain forms of mental retardation due to the high risk of the birth of a sick child. In prenatal diagnosis with amniocentesis at the 14-16th week of gestation, metabolic diseases (homocystinuria, maple syrup disease, mucopolysaccharidosis) are identified, which, in the presence of a risk of chromosomal abnormalities, makes it possible to recommend abortion.

Applying for medical genetic counseling can help couples with a high risk of having a child with mental retardation understand the possible dangers. If a child is diagnosed with mental retardation, the definition of etiology can provide the family with proper information about the likelihood of a sick child being born in the future.

High-risk couples who decide to give birth to a child often undergo a prenatal examination that allows them to have an opportunity for abortion and subsequent family planning. Amniocentesis or chorion biopsy may reveal hereditary metabolic diseases and chromosomal diseases, carrier status, as well as the developmental abnormalities of the central nervous system (eg, neural tube defects, anencephaly). Ultrasonography can also detect CNS defects. Determination of alpha-fetoprotein in the mother is a good screening test for the detection of neural tube defects, Down's syndrome and other conditions. Amniocentesis is indicated for all pregnant women over 35 (since they have a higher risk of having a child with Down's syndrome), as well as women with a family history of congenital metabolic diseases.

Vaccination against rubella virtually eliminated congenital rubella as the cause of mental retardation. Methods of vaccination against cytomegalovirus infection are being developed. The incidence of mental retardation is reduced due to the continued improvement and increase in the availability of obstetric and neonatal care, as well as the use of replacement blood transfusions and Rh _o (D) immunoglobulin for the prevention and treatment of hemolytic disease in newborns; the growth of survival rate of newborns with very low birth weight maintains, however, the prevalence of mental retardation is at the same level.

Forecast of mental retardation

The prognosis depends on the etiopathogenetic variant of mental retardation and the socio-psychological conditions of upbringing.

For progrediently current forms, in which mental retardation is only one of the manifestations of the disease, the prognosis in most cases is poor. Mental development at a certain stage stops, there is a gradual disintegration of the acquired motor and mental functions. Death occurs in childhood or adolescence from infected infections.

For non-specific forms of mental retardation, positive evolutionary dynamics are characteristic with a slowed but progressive development of mental functions with the greatest lag in the higher forms of cognitive activity-generalization and abstraction. Significant role played by socio-psychological factors (family environment, the presence or absence of complicating pathocharacterological disorders, timeliness and adequacy of training, acquisition of work skills).

With mild mental retardation, not complicated by mental disorders, in adulthood, adaptation is possible in an environment that does not impose special requirements on their abstract-logical level.

[24], [25], [26], [27], [28]