MENTAL RETARDATION. Definition Mental retardation (MR) is a generalized disorder appearing before adulthood, characterized by significantly impaired cognitive

MENTAL MENTAL RETARDATIONRETARDATION

DefinitionDefinition

Mental retardation (MR) is a Mental retardation (MR) is a generalized disorder appearing generalized disorder appearing before adulthood, characterized by before adulthood, characterized by significantly impaired cognitive significantly impaired cognitive functioning and deficits in two or functioning and deficits in two or more adaptive behaviorsmore adaptive behaviors..

It has historically been defined as an It has historically been defined as an Intelligence Quotient score under 70 Intelligence Quotient score under 70

Intelligence Quotient Intelligence Quotient (IQ)(IQ) An intelligence quotient, or IQ, is An intelligence quotient, or IQ, is

a score derived from one of a score derived from one of several different standardized several different standardized tests designed to assess tests designed to assess intelligence.intelligence.

Grades of IQGrades of IQ

140 + Genius140 + Genius 120 to 140 Very superior intelligence120 to 140 Very superior intelligence 110 to 119 Superior intelligence110 to 119 Superior intelligence 90 to 109 Normal or average 90 to 109 Normal or average

intelligenceintelligence 80 to 89 Dull80 to 89 Dull 70 to 79 Borderline deficiency70 to 79 Borderline deficiency Under 70 Definite feeble mindednessUnder 70 Definite feeble mindedness

ClassificationClassification: :

It is classified as:It is classified as:

1-1-Down`s syndrome.Down`s syndrome.

2-2-Phenylketonuria (PKU).Phenylketonuria (PKU).

3-3-Cretinism (Thyroid Deficiency).Cretinism (Thyroid Deficiency).

4-4-Cranial Anomalies.Cranial Anomalies.

5-5-Microcephaly.Microcephaly.

6-6-Hydrocephalus.Hydrocephalus.

Down SyndromeDown Syndrome

Down syndrome is a Down syndrome is a chromosomal condition chromosomal condition characterized by the presence of characterized by the presence of an extra copy of genetic material an extra copy of genetic material on the on the 21st chromosome, either , either in whole (in whole (trisomy 21) or part 21) or part (such as due to translocations).(such as due to translocations).

Down Syndrome (cont)Down Syndrome (cont)

The incidence of Down syndrome The incidence of Down syndrome is estimated at 1 per 733 births, is estimated at 1 per 733 births, although it is statistically more although it is statistically more common with older parents due common with older parents due to increased mutagenic to increased mutagenic exposures upon some older exposures upon some older parents' reproductive cells. Other parents' reproductive cells. Other factors may also play a role.factors may also play a role.


Often Down syndrome is associated Often Down syndrome is associated with some impairment of cognitive with some impairment of cognitive ability and physical growth, and a ability and physical growth, and a particular set of facial particular set of facial characteristics. Individuals with characteristics. Individuals with Down syndrome tend to have a Down syndrome tend to have a lower-than-average cognitive lower-than-average cognitive ability, often ranging from mild to ability, often ranging from mild to moderate disabilities.moderate disabilities.


The average IQ of children with The average IQ of children with Down syndrome is around 50, Down syndrome is around 50, compared to normal children with compared to normal children with an IQ of 100.an IQ of 100.[5][5] A small number A small number have a severe to high degree of have a severe to high degree of intellectual disability.intellectual disability.


Phenylketonuria (PKU)Phenylketonuria (PKU)

Phenylketonuria is a rare metabolic Phenylketonuria is a rare metabolic disorder. In PKU the baby appears disorder. In PKU the baby appears normal at birth but lacks an enzyme normal at birth but lacks an enzyme needed to break down needed to break down phenylalanine, an amino acid found phenylalanine, an amino acid found in protein foods. When this condition in protein foods. When this condition is undetected, the phenylalanine is undetected, the phenylalanine builds up in the blood and leads to builds up in the blood and leads to brain damage.brain damage.

Phenylketonuria (PKU)Phenylketonuria (PKU)(cont)(cont)

The disorder usually becomes The disorder usually becomes apparent between 6 and 12 apparent between 6 and 12 months after birth, although such months after birth, although such symptoms as vomiting, a peculiar symptoms as vomiting, a peculiar odor, infantile eczema, (a skin odor, infantile eczema, (a skin disorder in infants), and seizures disorder in infants), and seizures (fits) may become apparent (fits) may become apparent during the early weeks of life.during the early weeks of life.


Often the first symptoms noticed are Often the first symptoms noticed are signs of mental retardation, which may signs of mental retardation, which may be moderate to severe, depending on be moderate to severe, depending on the degree to which the disease has the degree to which the disease has progressed. Motor incoordination and progressed. Motor incoordination and other neurological manifestations other neurological manifestations relating to the severity of brain damage relating to the severity of brain damage are also common, and often the eyes, are also common, and often the eyes, skin, and hair of untreated PKU patients skin, and hair of untreated PKU patients are very pale.are very pale.


PKU is thought to result from PKU is thought to result from metabolic alterations involving metabolic alterations involving recessive genes, and 1 person in recessive genes, and 1 person in 70 is thought to be a carrier.70 is thought to be a carrier.

Cretinism (Thyroid Cretinism (Thyroid Deficiency)Deficiency)

Cretinism provides a dramatic illustration of Cretinism provides a dramatic illustration of mental retardation resulting from endocrine mental retardation resulting from endocrine imbalance. In this condition, the thyroid imbalance. In this condition, the thyroid either has failed to develop properly or has either has failed to develop properly or has undergone degeneration or injury. In either undergone degeneration or injury. In either case, the infant suffers from a deficiency in case, the infant suffers from a deficiency in thyroid secretion. Brain damage resulting thyroid secretion. Brain damage resulting from this insufficiency is most marked from this insufficiency is most marked during the prenatal and early postnatal during the prenatal and early postnatal periods of rapid growth.periods of rapid growth.


Typical descriptions of cretins involve Typical descriptions of cretins involve cases in which there has been a severe cases in which there has been a severe thyroid deficiency from an early age, thyroid deficiency from an early age, often even before birth. Such a cretin often even before birth. Such a cretin has a dwarflike, thick-set body and has a dwarflike, thick-set body and short, stubby extremities. His height is short, stubby extremities. His height is usually just a little over 3 feet, the usually just a little over 3 feet, the shortness accentuated by slightly bent shortness accentuated by slightly bent legs and a curvature of the spine.legs and a curvature of the spine.


He walks with a shuffling gait that is He walks with a shuffling gait that is easily recognizable. His head is large, easily recognizable. His head is large, with abundant black, wiry hair; his with abundant black, wiry hair; his eyelids are thick, giving him a sleepy eyelids are thick, giving him a sleepy appearance; his skin is dry and appearance; his skin is dry and thickened and cold on the touch. Other thickened and cold on the touch. Other pronounced physical symptoms include pronounced physical symptoms include a broad, flat nose, large and flappy ears, a broad, flat nose, large and flappy ears, a protruding abdomen, and failure to a protruding abdomen, and failure to mature sexually.mature sexually.


The cretins reveal a bland personality, The cretins reveal a bland personality, and his thought processes tend to be and his thought processes tend to be sluggish. Most cretins fall within the sluggish. Most cretins fall within the moderate and severe categories of moderate and severe categories of mental retardation, depending on the mental retardation, depending on the extent of brain damage. In cases with extent of brain damage. In cases with less pronounced physical signs of less pronounced physical signs of cretinism, the degree of mental cretinism, the degree of mental retardation is usually less severe.retardation is usually less severe.


Cranial AnomaliesCranial Anomalies

Mental retardation is associated with a number of Mental retardation is associated with a number of conditions in which there are relatively gross conditions in which there are relatively gross alterations in head size and shape, and where the alterations in head size and shape, and where the causal factors have not been definitely causal factors have not been definitely established. In established. In macrocephalymacrocephaly ("large ("large headedness"), for example there is an increase in headedness"), for example there is an increase in the size and weight of the brain, an enlargement the size and weight of the brain, an enlargement of the skull, and visual impairment, convulsions, of the skull, and visual impairment, convulsions, and other neurological symptoms resulting from and other neurological symptoms resulting from the supporting structure for brain tissue. Other the supporting structure for brain tissue. Other cranial anomalies include cranial anomalies include microcephaly microcephaly and and hydrocephalushydrocephalus..

MicrocephalyMicrocephaly

The term The term microcephalymicrocephaly means "small means "small headedness". It refers to a type of mental headedness". It refers to a type of mental retardation resulting from impaired retardation resulting from impaired development of the brain and a development of the brain and a consequent failure of the cranium to consequent failure of the cranium to attain normal size. The most obvious attain normal size. The most obvious characteristics of microcephalic is his characteristics of microcephalic is his small head, the circumference of which small head, the circumference of which rarely exceeds 17 inches, as compared rarely exceeds 17 inches, as compared with normal of approximately 22 inches.with normal of approximately 22 inches.


Microcephalics differ considerably from Microcephalics differ considerably from each other in appearance, although there each other in appearance, although there is a tendency for the skull to be coned is a tendency for the skull to be coned shaped, with a receding chin and shaped, with a receding chin and forehead. Microcephalics fall within the forehead. Microcephalics fall within the moderatemoderate, , severesevere, and , and profoundprofound categories of mental retardation, but the categories of mental retardation, but the majority shows little language majority shows little language development and is extremely limited in development and is extremely limited in mental capacity.mental capacity.


HydrocephalusHydrocephalus

Hydrocephalus is a relatively rare condition in Hydrocephalus is a relatively rare condition in which the accumulation of an abnormal which the accumulation of an abnormal amount of cerebrospinal fluid within the amount of cerebrospinal fluid within the cranium causes damage to the brain tissues cranium causes damage to the brain tissues and enlargement of the cranium. In and enlargement of the cranium. In congenital cases of hydrocephalus, the head congenital cases of hydrocephalus, the head is either already enlarged at birth or begins is either already enlarged at birth or begins to enlarge soon thereafter, presumably as a to enlarge soon thereafter, presumably as a result of a disturbance in the formation, result of a disturbance in the formation, absorption, or circulation of the cerebrospinal absorption, or circulation of the cerebrospinal fluid.fluid.


The disorder can also develop in infancy The disorder can also develop in infancy or early childhood following the or early childhood following the development of a brain tumor, subdural development of a brain tumor, subdural hemetoma,(clot in the brain covering), hemetoma,(clot in the brain covering), meningitis,(infection of brain covering) or meningitis,(infection of brain covering) or other such conditions. Here the condition other such conditions. Here the condition appears to result from a blockage of the appears to result from a blockage of the cerebrospinal pathways and an cerebrospinal pathways and an accumulation of fluid in certain brain accumulation of fluid in certain brain areas.areas.


The clinical picture of hydrocephalus depends on The clinical picture of hydrocephalus depends on the extent of neural damage, which, in turn, the extent of neural damage, which, in turn, depends on the age at onset and the duration depends on the age at onset and the duration and severity of disorder. In chronic cases the and severity of disorder. In chronic cases the chief symptom is the gradual enlargement of the chief symptom is the gradual enlargement of the upper part of the head out of all proportion to the upper part of the head out of all proportion to the face and the rest of the body. While the face and the rest of the body. While the expansion of the skull helps minimize destructive expansion of the skull helps minimize destructive pressure on the brain, serious brain damage pressure on the brain, serious brain damage occurs nonetheless, leading to intellectual occurs nonetheless, leading to intellectual impairment and such other effects as convulsions impairment and such other effects as convulsions and impairment or loss of sight and hearing.and impairment or loss of sight and hearing.

Causes Of Mental Causes Of Mental

RetardationRetardation::

PrenatalPrenatal NatalNatal PostnatalPostnatal

Prenatal

Chromosomal disorders

Downs syndrome, Fragile X syndrome,

Klinefelters syndrome

Single gene disorders

Inborn errors of metabolism, such as

galactosemia, phenylketonuria.

Brain malformations such as genetic microcephaly, hydrocephalus

Adverse material /

environmental influences

Deficiencies , such as iodine deficiency

and folic acid deficiency

Using substances such as alcohol

Exposure to other harmful chemicals such as pollutants,

heavy metals, harmful medications

Infections e.g. TORCH HIV

Natal

Third trimester ( late

pregnancy)

Complications of pregnancy

Diseases in mother such as heart and

kidney disease and

diabetesPlacental

dysfunction

Labour (during

delivery)

Severe prematurity, very low birth weight, birth

asphyxiaDifficult and/or

complicated delivery

Birth trauma

Neonatal (first four

weeks of life)

Septicemia, severe jaundice,

hypoglycemia

Postnatal(in infancy

and childhood)

Brain infections such as tuberculosis, Japanese

encephalitis, and bacterial meningitisHead injury

Chronic lead exposureSevere and prolonged

malnutritionGross understimulation

Common featuresCommon features

Delays in oral language developmentDelays in oral language development Deficits in memory skillsDeficits in memory skills Difficulty learning social rulesDifficulty learning social rules Difficulty with problem solving skillsDifficulty with problem solving skills Delays in the development of Delays in the development of

adaptive behaviors such as self-help adaptive behaviors such as self-help or self-care skills .or self-care skills .

DiagnosisDiagnosis: :

According to the latest edition of According to the latest edition of the Diagnostic and Statistical the Diagnostic and Statistical Manual of Mental Disorders (DSM-Manual of Mental Disorders (DSM-IV), three criteria must be met for IV), three criteria must be met for a diagnosis of mental retardation: a diagnosis of mental retardation:

1/ an IQ below 70 1/ an IQ below 70

2/ significant limitations in two or 2/ significant limitations in two or more areas of adaptive behavior (as more areas of adaptive behavior (as measured by an adaptive behavior measured by an adaptive behavior rating scale, i.e. communication, self-rating scale, i.e. communication, self-help skills, interpersonal skills, and help skills, interpersonal skills, and more) more)

3/ evidence that the limitations 3/ evidence that the limitations became apparent before the age of became apparent before the age of 18 . 18 .

Grades of MRGrades of MR: :

According to IQ :According to IQ : Profound mental retardation Below Profound mental retardation Below

2020 Severe mental retardation 20Severe mental retardation 20––3434 Moderate mental retardation 35Moderate mental retardation 35––4949 Mild mental retardation 50Mild mental retardation 50––6969 Borderline intellectual functioning70--Borderline intellectual functioning70--

8484

ManagementManagement: :

Management of mental Management of mental retardation (MR) begins with retardation (MR) begins with breaking the news to parents of breaking the news to parents of affected children sensitively, affected children sensitively, compassionately, and culturally compassionately, and culturally appropriately appropriately

By most definitions mental By most definitions mental retardation is more accurately retardation is more accurately considered a disability rather than considered a disability rather than a disease. a disease.

Currently, there is no "cure" for Currently, there is no "cure" for an established disability, though an established disability, though with appropriate support and with appropriate support and teaching, most individuals can teaching, most individuals can learn to do many things learn to do many things

The mainstay of treatment of MR is The mainstay of treatment of MR is developing a comprehensive developing a comprehensive management plan for the management plan for the condition. The complex habilitation condition. The complex habilitation plan for the individual requires plan for the individual requires input from care providers from input from care providers from multiple disciplines, including multiple disciplines, including special educators, language special educators, language therapists, behavioral therapists, therapists, behavioral therapists, occupational therapists, and occupational therapists, and community services that provide community services that provide social support and respite care for social support and respite care for families affected by MR.families affected by MR.

PreventionPrevention: :

Genetic: Prenatal screening for Genetic: Prenatal screening for genetic defects and genetic genetic defects and genetic counseling for families at risk for counseling for families at risk for known inherited disorders can known inherited disorders can decrease the risk of inherited decrease the risk of inherited mental retardationmental retardation..

Social: Government nutrition Social: Government nutrition programs are available to poor programs are available to poor children in the first and most children in the first and most critical years of life. These critical years of life. These programs can reduce retardation programs can reduce retardation associated with malnutrition. associated with malnutrition. Early intervention in situations Early intervention in situations involving abuse and poverty will involving abuse and poverty will also helpalso help..

Toxic: Environmental programs to Toxic: Environmental programs to reduce exposure to lead, mercury, reduce exposure to lead, mercury, and other toxins will reduce toxin-and other toxins will reduce toxin-associated retardation. However, associated retardation. However, the benefits may take years to the benefits may take years to become apparent. Increased public become apparent. Increased public awareness of the risks of alcohol awareness of the risks of alcohol and drugs during pregnancy can and drugs during pregnancy can help reduce the incidence of help reduce the incidence of retardation retardation

Infectious: The prevention of Infectious: The prevention of congenital rubella syndrome is congenital rubella syndrome is probably one of the best probably one of the best examples of a successful program examples of a successful program to prevent one form of mental to prevent one form of mental retardation. Constant vigilance, retardation. Constant vigilance, such as limiting exposure to cat such as limiting exposure to cat litter that can cause litter that can cause toxoplasmosis during pregnancy, toxoplasmosis during pregnancy, helps reduce retardation that helps reduce retardation that results from this infectionresults from this infection..

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MENTAL RETARDATION. Definition Mental retardation (MR) is a generalized disorder appearing before adulthood, characterized by significantly impaired cognitive