Intellectual disability (ID), once called mental retardation, is characterized by below-average intelligence or mental ability and a lack of skills necessary for day-to-day living. People with intellectual disabilities can and do learn new skills, but they learn them more slowly. The DSM-IV definition utilizes four degrees of severity that reflect the level of intellectual impairment: IQ levels between 50–55 to approximately 70 characterize mild mental retardation, 35—40 to 50–55 characterize moderate mental retardation, 20–25 to 35–40 characterize severe mental retardation,

1. Mental RetardationMental Retardation

2. ContentsContents::
 DefinitionDefinition
 PrevalencePrevalence
 ClassificationClassification
 CausesCauses
 Clinical EvaluationClinical Evaluation
 InvestigationInvestigation
 ManagementManagement

3. DefinitionDefinition
 Mental retardation (MR) is a generalizedMental retardation (MR) is a generalized
disorder appearing before adulthood,disorder appearing before adulthood,
characterized by significantly impairedcharacterized by significantly impaired
cognitive functioning and deficits in two orcognitive functioning and deficits in two or
more adaptive behaviorsmore adaptive behaviors..
 It has historically been defined as anIt has historically been defined as an
Intelligence Quotient score under 70Intelligence Quotient score under 70

4. Intelligence Quotient (IQ)Intelligence Quotient (IQ)
 An intelligence quotient, or IQ, is a scoreAn intelligence quotient, or IQ, is a score
derived from one of several differentderived from one of several different
standardized tests designed to assessstandardized tests designed to assess
intelligence.intelligence.

5. 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 intelligence90 to 109 Normal or average intelligence
 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

6. The Classical definition comprisesThe Classical definition comprises
3 components3 components::
1- subaverage intellectual function .1- subaverage intellectual function .
2- that result from an injury , disease or2- that result from an injury , disease or
abnormality before the age of 18 years .abnormality before the age of 18 years .
3- resulting in impaired ability to adapt to the3- resulting in impaired ability to adapt to the
environment .environment .

7. PrevalencePrevalence::
Mental retardation is present in about 2 toMental retardation is present in about 2 to
3% of the population3% of the population..

8. Mental RetardationMental Retardation
PrevalencePrevalence
Slightly more males than femalesSlightly more males than females
More prevalent in lower SES and in minorityMore prevalent in lower SES and in minority
groupsgroups

9. IQ classification:IQ classification:
I.Q.(intelligence quotient) is 100; normal ranges from 90 to 110I.Q.(intelligence quotient) is 100; normal ranges from 90 to 110
1-Border line { IQ 70-80 }1-Border line { IQ 70-80 }
2-mild MR { IQ 55-70 }2-mild MR { IQ 55-70 }
3-moderate MR{ IQ 40-55 }3-moderate MR{ IQ 40-55 }
4-sever MR { IQ 25-40 }4-sever MR { IQ 25-40 }
5-profound MR { IQ below 25 }5-profound MR { IQ below 25 }

11. EtiologyEtiology
 UnknownUnknown ““ 30-40 %30-40 % ““
 GeneticGenetic ““ 5%5% ““
 Early embryonic ( prenatal )Early embryonic ( prenatal ) ““ 30%30% ““
 Prematurity , IUGR (perinatal)Prematurity , IUGR (perinatal) ““ 10 %10 % ““
 Acquired medical condition (trauma ,Acquired medical condition (trauma ,
infection ..)infection ..) ““ 5%5% ““
 EnvironmentEnvironment ““ 5-20%5-20% ““

12. Etiology classificationEtiology classification::
 PrenatalPrenatal
 PerinatalPerinatal
 PostnatalPostnatal

13. 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

14. Prenatal causesPrenatal causes::
»»Genetic Disorders :Genetic Disorders :
Fragile X syndrome FXS :Fragile X syndrome FXS :most common cause .most common cause .
Klinefelter syndrome :Klinefelter syndrome :male with extra x chromosomemale with extra x chromosome 47,XXY47,XXY
Down syndrome :Down syndrome :
Metabolic disorders:Metabolic disorders: PKU, GalactosemiaPKU, Galactosemia
Skin disorders :Skin disorders : neurofibromatosis and Tubererous sclerosis .neurofibromatosis and Tubererous sclerosis .
Endocrine :Endocrine : hypothyroidismhypothyroidism

15. »Cranial»Cranial Malformations :Malformations :
Anencephaly :Anencephaly :
microcephaly :microcephaly :
Hydrocephaly :Hydrocephaly :

16. »Congenital Factors :»Congenital Factors :
Maternal :Maternal : Rubella , congent. Syphilis & Rh incompitabilityRubella , congent. Syphilis & Rh incompitability
Toxins :Toxins : drugs , fetal alcohol syndrom ..drugs , fetal alcohol syndrom ..

17. Perinatal CausesPerinatal Causes::
 Low Bwt :Low Bwt : premature , teen pregnancy , poor nutrition ..premature , teen pregnancy , poor nutrition ..
21 % with MR21 % with MR
Birth AnoxiaBirth Anoxia :: breech presentation , knotted umbilical cord.breech presentation , knotted umbilical cord.

18. Natal
Third trimester
( late pregnancy)
Complications of
pregnancy
Diseases in mother
such as heart and
kidney
disease and diabetes
Placental dysfunction
Labour
(during delivery)
Severe prematurity,
very low birth weight,
birth asphyxia
Difficult and/or
complicated delivery
Birth trauma
Neonatal
(first four weeks
of life)
Septicemia, severe
jaundice,
hypoglycemia

19. Postnatal CausesPostnatal Causes::
Child abuse and neglect :Child abuse and neglect :
Traumatic brain injury :Traumatic brain injury :
Infection :Infection : meningitis and encephalitismeningitis and encephalitis
Nutritional deficiencies :Nutritional deficiencies :
Cultural and familial :Cultural and familial :

20. Postnatal
(in infancy and
childhood)
Brain infections such as
tuberculosis, Japanese
encephalitis, and bacterial
meningitis
Head injury
Chronic lead exposure
Severe and prolonged malnutrition
Gross understimulation

21. 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 adaptiveDelays in the development of adaptive
behaviors such as self-help or self-carebehaviors such as self-help or self-care
skills .skills .

22. DiagnosisDiagnosis::
 According to the latest edition of theAccording to the latest edition of the
Diagnostic and Statistical Manual ofDiagnostic and Statistical Manual of
Mental Disorders (DSM-IV), three criteriaMental Disorders (DSM-IV), three criteria
must be met for a diagnosis of mentalmust be met for a diagnosis of mental
retardation:retardation:

23.  1/ an IQ below 701/ an IQ below 70
 2/ significant limitations in two or more2/ significant limitations in two or more
areas of adaptive behavior (as measured byareas of adaptive behavior (as measured by
an adaptive behavior rating scale, i.e.an adaptive behavior rating scale, i.e.
communication, self-help skills,communication, self-help skills,
interpersonal skills, and more)interpersonal skills, and more)
 3/ evidence that the limitations became3/ evidence that the limitations became
apparent before the age of 18 .apparent before the age of 18 .

24. Grades of MRGrades of MR::
 According to IQ :According to IQ :
 Profound mental retardation Below 20Profound mental retardation Below 20
 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--84Borderline intellectual functioning70--84

25. Clinical EvaluationClinical Evaluation
 Complete History :Complete History :
 Examination :Examination :

26. HistoryHistory
»complete and detailed history«»complete and detailed history«
complete systemic reviewcomplete systemic review
surgical history :surgical history : trauma , accidentstrauma , accidents
medical illnesses :medical illnesses : hospitalization , general heathhospitalization , general heath
pregnancy history :pregnancy history : maternal age , parity , infections..maternal age , parity , infections..
birth :birth : type , wt . GA ,complications , apgar scoretype , wt . GA ,complications , apgar score
Postnatal :Postnatal : incubator , ventilator , disease ..incubator , ventilator , disease ..

27. History (contHistory (cont.(.(
drugs:drugs: mother and childmother and child
developmental Hx :developmental Hx : mile stones , loss it , speech ..mile stones , loss it , speech ..
educational Hx :educational Hx : schooling , IQ testsschooling , IQ tests
behavioral Hx :behavioral Hx : skills , attention , activityskills , attention , activity
family Hx :family Hx : consanguinity , inherited ds ..consanguinity , inherited ds ..
social Hx :social Hx :

28. ExaminationExamination
»complete and detailed examination«»complete and detailed examination«
• Growth parameters :Growth parameters :
• Dysmorphic features :Dysmorphic features :
• CNS examination :CNS examination :
• Other system and skin exam :Other system and skin exam :
• IQ tests :IQ tests :
• Developmental testing :Developmental testing :

29. InvestigationsInvestigations
»» there is no specific investigation for MR»» there is no specific investigation for MR
but good hx and physical examinationbut good hx and physical examination
guide us toward the proper one ««guide us toward the proper one ««
 DNA analysis:DNA analysis: chromosomeschromosomes
 Metabolic labs:Metabolic labs: plasma a.a. , urine organic a. , ckplasma a.a. , urine organic a. , ck
 Imaging :Imaging : brain MRI , CT , skeleton filmsbrain MRI , CT , skeleton films
 Psychological Assesment:Psychological Assesment:
 Electrophysiology :Electrophysiology : EEG , auditory & visual evokedEEG , auditory & visual evoked
potentialspotentials

30. ManagementManagement::
 Management of mental retardation (MR)Management of mental retardation (MR)
begins with breaking the news to parentsbegins with breaking the news to parents
of affected children sensitively,of affected children sensitively,
compassionately, and culturallycompassionately, and culturally
appropriatelyappropriately

31. TreatmentTreatment
Early intervention isEarly intervention is criticalcritical
Optimal time: Preschool yearsOptimal time: Preschool years
Encourage explorationEncourage exploration
Teach basic skillsTeach basic skills
Celebrate achievementsCelebrate achievements
Rehearsal, rehearsal, rehearsalRehearsal, rehearsal, rehearsal
Protection from teasing/social rejectionProtection from teasing/social rejection

32. ««««there is no specific Rx for MRthere is no specific Rx for MR»»»»
««General rulesGeneral rules::
--Identify the cause then initiate aIdentify the cause then initiate a
comprehensive plancomprehensive plan
--Special school programsSpecial school programs
--Community servicesCommunity services

33.  Special educators, languageSpecial educators, language
therapists, behavioral therapists,therapists, behavioral therapists,
occupational therapists, andoccupational therapists, and
community services that provide socialcommunity services that provide social
support and respite care for familiessupport and respite care for families
affected by MR.affected by MR.

34. PreventionPrevention::
 Genetic:Genetic:
 Prenatal screening for genetic defectsPrenatal screening for genetic defects
and genetic counseling for families at riskand genetic counseling for families at risk
for known inherited disorders canfor known inherited disorders can
decrease the risk of inherited mentaldecrease the risk of inherited mental
retardationretardation..

35.  Social:Social:
 Government nutrition programs areGovernment nutrition programs are
available to poor children it can reduceavailable to poor children it can reduce
retardation associated withretardation associated with
malnutrition.malnutrition.

36. ToxicToxic::
 Environmental programs to reduceEnvironmental programs to reduce
exposure to lead, mercury, and otherexposure to lead, mercury, and other
toxins will reduce toxin-associatedtoxins will reduce toxin-associated
retardation.retardation.
 Increased public awareness of the risks ofIncreased public awareness of the risks of
alcohol and drugs during pregnancy canalcohol and drugs during pregnancy can
help reduce the incidence of retardationhelp reduce the incidence of retardation

37.  Infectious:Infectious:
 The prevention of congenital rubellaThe prevention of congenital rubella
syndrome.syndrome.