Intellectual disability

Introduction Distractance of intelligence is a group of clinical syndromes that can have at least three impairments in memory, cognition (generalization, calculation, judgment, etc.), language, visual spatial function, and personality. Often caused by nervous system diseases, mental illnesses and physical diseases. The main symptoms include: 1 memory disorder; 2 thinking and judgment disorders; 3 personality changes; 4 affective disorders. The general clinical manifestations of congenital mental retardation (mental retardation), memory disorder (amnesia syndrome) and dementia are mainly described here.

Cause

The causes include biomedical factors and psychosocial reasons. The former refers to various unfavorable factors that the brain receives during development (prenatal and perinatal), which can make the development of the brain unable to reach the required level and ultimately affect intelligence. The latter refers to factors such as cultural deprivation, improper parenting, and feeling deprivation, which can make the information of the day after tomorrow insufficient or inappropriate, thus affecting the intelligence level. According to the WHO 1985 classification and the results of the National Collaborative Group, the causes were classified into the following categories.

1. Infection, poisoning: 12.3%. Infections indicate brain infections before and after birth, such as rubella, cytomegalovirus, toxoplasma, herpes simplex virus and many other viral infections. Poisoning includes hyperbilirubinemia, toxemia, lead poisoning, alcoholism, and long-term overdose of phenytoin or phenobarbital.

2. Mechanical damage and hypoxia of the brain: 19.6%. Brain damage, such as birth trauma and craniocerebral trauma, can occur due to physical or mechanical factors before, after, and during childbirth. Perinatal or postnatal hypoxia can also damage brain tissue, such as severe blood loss, anemia, heart failure, lung disease and neonatal asphyxia, intracranial hemorrhage, as well as drowning, anesthesia, and epileptic brain Hypoxia.

3. Metabolic, nutritional and endocrine disorders: 5.8%. The metabolism of amino acids, carbohydrates, fats, mucopolysaccharides, sputum and other substances in the body can affect the development and function of nerve cells, such as phenylketonuria and galactosemia. Insufficient nutrition during and after birth, especially the lack of protein, iron and other substances will reduce the number of brain cells in the fetus and infant or reduce their function. Endocrine disorders also affect mental development, such as hypothyroidism.

4. Brain major diseases: 0.7%. These include tumors, degenerative diseases of unknown origin, neurocutaneous syndrome, cerebrovascular diseases, and the like.

5. Congenital malformations or hereditary syndrome of the brain: 9.5%. Congenital malformations include hydrocephalus, hydrocephalus malformation, small head deformity, neural tube insufficiency, and my brain deformity. Hereditary syndromes such as adrenal white matter malnutrition.

6. Chromosome aberration: 5.1%. Chromosomal aberrations include changes in the number or structure of autosomes or sex chromosomes, such as congenital, trisomy 18, trisomy C, meow syndrome, fragile X syndrome, congenital testicular hypoplasia syndrome, Congenital ovarian hypoplasia syndrome.

7. Other factors during the perinatal period: 11.8%. Including premature infants, low birth weight infants, intrauterine growth retardation, maternal nutritional diseases, pregnancy-induced hypertension.

8. Accompanied by mental illness: such as infant autism, childhood schizophrenia.

9. Social psychological factors: 8.2%. Such children do not have organic lesions of the brain, mainly caused by adverse environmental factors such as neuropsychological damage and sensory deprivation, such as severe lack of early appropriate stimulation and education.

10. Special sensory defects accounted for 5.1%. Including special sensory defects such as sputum, dumb, and blindness.

11. The cause of unknown is 21.9%. After detailed examination and no clues to the cause, the cause is unknown.

an examination

Related inspection

Brain MRI examination of nervous system examination

Laboratory inspection

Laboratory tests include blood, urine, brain, spinal fluid biochemical tests, cranial X-ray and CT examination, cerebral angiography, EEG, evoked potentials, audiometry, chromosome analysis, pituitary, thyroid, gonads, adrenal function tests, viruses (such as cytomegalovirus, rubella virus), protozoa (such as toxoplasma) and antibody testing. The relevant items should be selected according to the diagnostic needs.

Intelligence test and behavioral judgment

Mild MR multi-use intelligence test, severe MR above the use of intelligence test methods are often difficult, must rely on the behavior rating scale, and the rating scale is not as reliable as the intelligence test for the identification of mild MR. Therefore, the two methods should be used together, and the results must be comprehensively analyzed.

Differential diagnosis

Evaluation of the patient's state of intelligence is an essential part of the neurological examination. It includes the evaluation of consciousness, demeanor, behavior, emotion, content of thinking and coherence, and the potential of intelligence.

Traditional smart state checks include:

1 General information: such as "Where were you born? What is the name of the mother?"

2 orientation function: such as "Where is this? Today is the number? What time is it?"

3 Concentration: use the order reversal method, such as the month of the year from "December"

4 Calculation: If you do some simple arithmetic conversion: 110 consecutively minus 7.

5 Reasoning judgment and memory: If you identify 3 objects, then ask the patient to repeat their names or let the patient listen to a story. After a few minutes, ask the patient to try to repeat. The most important ones may be the orientation of time, the reversal of sequence, and Memories of paragraph sentences.

In addition to this, it is necessary to test some advanced intelligence functions when checking the intelligence state, including language disorders (speech difficulty); structural disability; left and right orientation obstacles; unable to complete complex instructions, etc., especially required Difficulties in doing midline crossovers, such as touching the left ear with the right finger; unimaginative thinking activities (ie, intentional misuse; telling the patient "if you have a box of matches how to draw it" and ask him to use the action demonstration One side ignores; or can't notice double stimuli, which are usually accompanied by more limited brain lesions, but may also be seen in patients with delirium or dementia.

The differential diagnosis of dementia requires accurate medical history, neurological examination, and physical examination.

In Alzheimer's disease, the typical symptoms are insidious onset. In other aspects, the course of healthy people slowly progresses, but the disease develops relentlessly. On the contrary, the history of patients with vascular dementia may have sudden onset of memory loss. The history of stroke, or the performance of hypertension and heart disease; patients with a history of alcoholism should be highly suspected of the possibility of Korsakov's mental illness.

In addition to extrapyramidal symptoms such as slow posture changes and some primitive reflexes (such as pout reflexes), physical examination of patients with Alzheimer's disease is generally normal; conversely, vascular dementia syndrome may include mild Hemiplegia, or other symptoms of the focal nervous system.

The diagnosis of dementia syndrome must take three steps: Step 1 First, clinically determine whether the patient has dementia, and use the Folstein Short Mental State Checklist (MMSE) or the revised Hasegawa Intelligence Scale to measure intelligence for screening. Step 2 to determine the brain lesions of dementia requires a series of examinations, such as EEG, EEG topography, single photon emission computed tomography (SPECT), CT, magnetic resonance and positron emission tomography (PET), etc. . The third step is the differential diagnosis involving dementia. AD must be differentiated from vascular dementia, the Hachinski ischemic scale is commonly used.

First, according to IQ and adaptive behavior and age of onset, determine whether there is MR, and then further find the cause of MR.

In the process of diagnosis, the child's growth and development history should be collected in detail, and physical and neuropsychiatric examinations should be comprehensively conducted. The growth and development indicators of children of different ages at different developmental stages should be compared and compared with normal children of the same age to determine their intelligence level and adaptability. , making clinical judgments. At the same time, with the appropriate intelligence test method, the diagnosis can be made and the severity of MR can be determined.

Medical history collection

(1) Family history: It is necessary to know whether parents are married to close relatives, and whether there are blind, dumb, epilepsy, cerebral palsy, congenital malformations, MR and mental illness in the family.

(2) History of maternal pregnancy: ask the mother if there is any viral infection, miscarriage, hemorrhage, injury, taking chemical drugs, exposure to poison, radiation, whether there is hypothyroidism, diabetes and severe malnutrition, and whether there are multiple births or amniotic fluid. Excessive, incomplete placental function, maternal and child blood type incompatibility.

(3) Birth history: Whether it is premature or expired, whether there is abnormal production mode, whether the birth weight is low birth weight, whether there is suffocation, birth injury, intracranial hemorrhage, severe jaundice and congenital malformation.

(4) History of growth and development: including neuropsychiatric episodes, such as the time when the big movements such as raising the head, sitting up, walking, etc., the use of fingers to detect the completion of fine movements such as small toys and daily necessities, shouting father and mother, listening to speech, etc. The developmental state of language function, as well as other intellectual behaviors such as feeding, dressing, and controlling bowel movements.

(5) Past and present disease history: whether there is craniocerebral trauma, hemorrhage, central nervous system infection, severe systemic infection, seizures, etc.

The material in this site is intended to be of general informational use and is not intended to constitute medical advice, probable diagnosis, or recommended treatments.