1. Mental Retardation
Dr. Kalpana Malla
MD Pediatrics
Manipal Teaching Hospital
Download more documents and slide shows on The Medical Post [ www.themedicalpost.net ]

2. Definition (AAMD)
• American Association on Mental Deficiency :
Mental retardation refers to significantly
sub average general intellectual
functioning, existing concurrently with deficits
in adaptive behavior and manifested during
the developmental period

3. • Intellectual functioning is defined by
Intelligent Qutient (I.Q)
IQ = Mental Age/Chronological Age X100

4. Wechsler Adult Intelligence Scale
(WAIS)
Class IQ
• Profound MR --------------------- <20
• Severe MR ----------------------- 20-34
• Moderate MR ------------------- 35-49
• Mild MR -------------------------- 50-69
• Boderline MR --------------------70-79
• Low average---------------------80-89
• Average --------------------------90-109
• High average ------------------110-119
• Superior -------------------------120-129
• Genious ------------------------ > 130

5. Revised definition -1992
• Does not consider IQ
• Considers defects in adaptive skills- It is
characterized by significantly subaverage
intellectual functioning, existing concurrently with
related limitations in two or more of the following
applicable adaptive skill areas:
1.Communication
2. Self-Care- getting dressed, using the bathroom, and
feeding oneself
3. Home Living

6. Revised definition -1992
4. Social Skills - peers, family members, spouses,
5. Community Use
6. Self-Direction
7. Health And Safety
8. Functional Academics
9. Leisure And Work
• Mental retardation manifests before age 18.

7. • Two areas of deficits - intellectual functioning and
adaptive skills :
• Intellectual skills, the ability to solve problems
related to academics; usually estimated by an IQ
test
• Adaptive skills, skills needed to adapt to one’s
living environments; usually estimated by an
adaptive behavior survey

8. Alternative terms
• Developmental delay
• Developmental disability
• Intellectual disability
• Mental handicap
• Learning difficulty
• Idiots
• Morons
• Mental Defectives
• Feeble-minded
• Fools
• Evolutionary Degenerates

9. Causes by time.
• Prenatal (12%) -occurs during fetal
development
• Perinatal (6%) -causes at birth
• Postnatal (4%) - occurring after birth, can
be biological or psychosocial
• 78% unknown

10. • Prenatal :
A)Structural defects – hydrocephalus,spina
bifida,craniosynostosis, microcephaly
B)Genetic conditions
1. chromosomal disorders –down
syndrome ,fragile X syndrome
Klinfelters syndrome

11. Prenatal
2.Inborn errors of metabolism –
a) Amino acid - Phenylketonuria, Maple syrup urine
Ds,Homocystinuria,Hartnup ds
b) Carbohydrate metabolism –glactosemia,Fructose
intolerance, Glycogen storage ds, MPS
c) Lipid metabolism - lipidosis, Tay sachs Ds,
C. Endocrine – cretinism

12. Prenatal
D) Maternal – TORCH infection
- Fetal alcohol syndrome,
Teratogenic agents, irradiation,
Toxemia of pregnancy

13. Causes by time
Perinatal
• Birth Asphyxia
• Birth trauma
• Intracranial hge
• Low birth weight
• Prematurity
• Torch
• Meningitis at birth

14. Causes by time
Postnatal-
• Infection -Meningitis, Encephalitis
• Toxic – kernicterus ,Lead intoxication
• Trauma - Head injuries ,ICHge ,Child abuse and
neglect
• Endocrine –hypoglycemia ,hypocalcemia,
dyselectrolytemia,hypothyroidism
• Gross PEM

15. Postnatal……..
• Behavioral injuries - Social and family,
interactions
• Educational availability & supports that
promote mental development of adaptive
skills
• Social, behavioral, and educational often
overlap these are sometimes referred to as
cultural-familial mental retardation

16. Causes by severity
• Mild MR is more influenced by cultural and
family environment – PHYSIOLOGICAL MR
• More severe MR is more likely to stem from
genetic and other organic factors –
PATHOLOGICAL MR

17. Syndromes associated MR
• Down syndrome -MR, slanted eyes, single
palm crease, hypotonia, short stature
• Fragile X Syndrome – in males, thought to be
most common hereditary cause of MR
• Tay-Sachs Disease - inherited metabolic
disorder which leads MR, paralysis, dementia,
or blindness

18. Syndromes associated MR
• Williams syndrome –mild to mod MR (social
deficits in special
skills, reading, math, writing), heart
defects, elfin facial features
• Prader-Willi syndrome - MR varies, mostly
mild MR, obesity

19. Signs
• Have trouble speaking
• Find it hard to remember things
• Have trouble understanding social rules
• Have trouble learn specific subject
• Have trouble solving problems
• Have trouble thinking logically
• Disable to self care
• Persistence of infantile behaviour
• Unable to take higher education

20. Mild MR
• Learning disabilities ,hyperactivity, short
attention span, distractibility, poor
concentration, poor memory, impulsiveness,
clumsy movements, disturbed sleep
• Emotional instability, low frustration tolerance

21. • Mild disability –
May not be obvious in early childhood
In School - have poor academic performance (
learning disability)
In adults - considered as "slow" rather than retarded

22. Moderate MR
• Academic skills – 2nd grade level
• Problem with social work
• Behaviorable age -8 yrs
obvious within 1st year of life
- will face difficulty in school, at home, and in the
community
- Need special school, but they can still progress to
become functioning members of society. As adults
they may live with their parents, in a supportive
group home

23. Severe MR
• Little or no speech
• Limited abilities to manage self care
• Require high supervision
• Behaviourable age – 3 yrs

24. Diagnosis
• According to the latest edition of the
Diagnostic and statistical Manual of Mental
Disorders there are three criterias
1. IQ below 70
2.Significant limitations in two or more areas of
adaptive behavior
3. Evidence that the limitations became
apparent in childhood

25. Assessment
• Assess intellectual and adaptive skills
• Professional administered IQ tests
- Stanford-Binet – 2yrs - adult
- Wechsler Intelligence Scale for
Children (WISC-III) – 6- 17 yrs
- Kaufman Assessment Battery for
Children (K-ABC)

26. Prenatal Screening
• Amniocentesis (fluid)
• Chorionic villus sampling (CVS) (tissue)
• Sonography (visual)
• Maternal serum screening (MSS) (blood)

27. Investigations
• No routine workup
• Clinical judgement
• No identifyable cause in most cases
• Some – chromosomal, metabolic, encephalopathy
• Investigations – TORCH screening
Karyotyping
thyroid function test
metabolic screening
CT/MRI
EEG

28. Treatment
• Require patience, good will, unlimited time
• Caring rather than curing
• Educating rather than medicating

29. Instruction Using Behavioral
Principles
• Caregivers are trained to teach children
positive behaviors and reduce
negative behaviors effectively
and humanely

30. Drug Therapies
• No specific drugs but some symptoms can be
controlled
• Neuroleptic drugs to reduce aggressive and
antisocial behavior (phenothiazines)
• antipsychotic drugs( risperidone)
• Antidepressant drugs can improve sleep, possibly
help reduce self-injurious behavior, reduce
depression

31. Mainstreaming
• Placing children with MR in regular classrooms
to “normalize” their behavior and give them
more opportunities
• Students with MR achieve high academic gains
where they are more fully included in general
classrooms

32. Institutionalization
• Reserved for the least capable children with
the gravest disabilities

33. Milder MR is usually More severe MR is
treated with treated by:
• 1. Behavioral • 1. Behavior Therapy
Instruction • 2. Drugs to control
• 2. Early Intervention aggression and self-
Programs injurious behavior
• 3. Special Education • 3. Either home care or
• 4. Mainstreaming institutionalization

34. Treatable /Preventable causes of MR
• Hypothyroidism
• Severe PEM
• Perinatal asphyxia
• Preterm /LBW
• Meningitis, encephalitis

35. Prevention
• Primary intervention before it
occurs…(vaccines for rubella)
• Secondary intervention soon after detection
(lead screening, PKY screening)
• Tertiary intervention to reduce long term
effects (early education intervention)

36. ASSOCIATED PROBLEMS
• Self injury • Eating problems
• Pica • Poisoning
• CP • Sexual abuse
• Epilepsy • Learning disorders
• Toilet probs • Behavior problems
• Sleep disorders

37. Thank you
Download more documents and slide shows on The Medical Post
[ www.themedicalpost.net ]