Pediatrics notes about "Intellectual Disability/ Mental Retardation". These notes were published in 2018. You can download them also from - Telegram: https://t.me/pediatric_notes_2018 - Mediafire: http://www.mediafire.com/folder/u5u60m184t9z7/Pediatric_Notes_2018

1. Mental Retardation
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Intellectual Disability (Mental Retardation)
* Traditional Nomenclature
❖ According to DSM-IV-TR, a diagnosis of mental retardation can be made only when both:
- the IQ, as measured by a standardized test, is sub average ( IQ = 70 )
- and a measure of adaptive function reveals deficits in at least two of the areas of adaptive
function.
► Adaptive functioning can be measured by using a standardized scale, such as the Vineland
Adaptive Behavior Scale.
► IQ= Mental age/Chronological age x 100
* New Nomenclature
• Mental retardation (MR) is a developmental disability that first appears in children under
the age of 18.
• The term MR as offensive & the term intellectual disability (ID) or intellectually
development disorder (IDD) is now preferred by most advocates in most English-speaking
countries.
 The most prominent organization in this field is the American Association on Mental
Retardation (AAMR), which has been most influential in educating the public about mental
retardation and in supporting research relating to mental retardation.
A. Significantly subaverage intellectual functioning: an IQ of approximately 70 or below on an
individually administered IQ test (for infants, a clinical judgment of significantly subaverage
intellectual functioning).
B. Concurrent deficits or impairments in present adaptive functioning
(i.e., the person's effectiveness in meeting the standards expected for his or her age by his or her
cultural group) in at least two of the following areas:
communication, self-care, home living, social/interpersonal skills, use of community resources,
self-direction, functional academic skills, work, leisure, health, and safety.
C. The onset is before age 18 years.
DSM-IV criteria for Mental Retardation

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( 5 grades )
I. Mild II. Moderate III. Severe IV. Profound
Other name Educable Trainable Dependent Life Support
IQ 50–70 35–49 20–34 <20
Proportion in
people with
MR
85% 10% 3-4% 1-2%
Self care - Most live
independently with
appropriate support
- Raise their own
families
- Usually need
supported
accommodation or
live with family
- need mild
supervision
- Often adapt well to
life in the community
in supervised settings
(performing
unskilled or
semiskilled work)
- need much support
- has minimal self care
- Very limited skills
- Able to perform
simple tasks as adults
in closely supervised
settings
- Most adapt well to
life in the community,
living in group homes
or with families
- Non trainable
- NO self care
- need total
supervision.
- Optimal development
may occur in a highly
structured
environment with
constant aid
Language &
social skills
- Typically develop
social/communication
skills during
preschool years
- Most acquire
communication skills
during early
childhood years
- Difficulties in
recognizing social
conventions which
interferes with peer
relations in
adolescence
- Unlikely to progress
beyond the 2nd
grade
academically
- Acquire little or no
communicative
speech in childhood;
a) may learn to talk by
school age
b) maybe trained in
elementary self-care
skills
motor &
sensory
abnormalities
- Minimal impairment
in sensorimotor areas
- Often
indistinguishable
from “typicals” until
later age
- Most have an
identifiable
neurological
condition that
accounts for their MR
- Considerable
impairments in
sensorimotor
functioning
- Death may occur d.2
variety of problems or
complications
Classification :

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V. Severity unspecified :
- This type is for persons who are strongly suspected of having mental retardation, but who
cannot be tested by standard intelligence tests OR are too impaired or uncooperative to be
tested.
- This type may be applicable to infants whose significantly sub-average intellectual
functioning is clinically judged but for whom the available tests do not yield numerical IQ
values (e.g., Bayley Scales of Infant Development and Cattell Infant Scale)
o Prevalence : 1- 3%.
o Highest incidence : school age children with the peak at the ages 10 - 14 years.
o 1.5 times more common among men than among women.
o 40.7 % of MR children between 4 and 18 years of age met criteria for at least one psychiatric
disorder.
o The severity of retardation affected the type of psychiatric disorder.
o The mental disorders among mentally retarded persons include;
( mood disorders, schizophrenia, ADHD and conduct disorder ).
o Approximately 1/3 also had autistic disorder OR an autistic- like condition.
- No clear etiology can be found in about 75% in mild MR & 30 – 40% in severe impairment
- Specific etiologies are most often found in those with Severe & Profound MR
- No familial pattern (although certain illnesses resulting in MR may be heritable)
- Over 150 MR syndromes have been related to the X-chromosome
❖ Most common cause of MR:
1. Down’s Syndrome (most common genetic cause)
2. Fragile X Syndrome (40% of all X-linked syndromes; most common inherited cause)
3. Fetal Alcohol Syndrome
Epidemiology :
Comorbidity Prevalence :
Etiology:
N.B. these 3 account for 30% of all identified cases of MR

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❖ Other Causes of MR :
1. Heredity 2. Early Alterations of
Embryonic Development
5% of cases 30% of cases
1. Autosomal recessive inborn errors of
metabolism (e.g., Tay-Sachs, PKU)
2. Single-gene abnormalities with Mendelian
inheritance and variable expression
(e.g., tuberous sclerosis)
3. Chromosomal aberrations (e.g., Fragile X)
1. Chromosomal changes (e.g., Down)
2. Prenatal damage due to toxins
(e.g., Maternal Alcohol Consumption, infections)
3. Environmental
Influences
4. Pregnancy
& Perinatal Problems
5. Acquired conditions
in Infancy or Childhood
15-20% of cases 10% of cases 5% of cases
1. Deprivation of nurturance,
social/linguistic and other
stimulation
2. Mental Disorders
e.g. Autism
3. Cultural deprivation
4. Low socio-economic status
5. Inadequate caretakers
6. Child abuse
1. Fetal malnutrition,
prematurity, hypoxia,
infections, trauma
2. Metabolic :
- Congenital hypothyroidism
- Amino acid disorders e.g
Phenylketonuria
- Carbohydrate disorder e.g.
Galactosemia
1. Infections
2. Trauma
3. poisoning (e.g., lead)

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Fragile X Syndrome
• Most common cause of inherited mental retardation
• Mutation on the X chromosome at what is known as the fragile site (Xq27.3).
i. The typical phenotype includes :
- large, long head with prominent ears
- Short stature
- hyper-extensible joints
- post-pubertal macroorchidism (enlarged testes) “fertile”
ii. Developmental features
- Relative strengths:
Verbal long-term memory “ Expressive language ability “
- Relative weaknesses:
Short Term memory, sequential processing, math & attention.
iii. Cognitive features
- The mental retardation ranges from mild to severe.
- Increasing deficits in adaptive & cognitive functioning with age
iv. Neuropsychological features
- Increases the risk for ADHD, autism (20-60%) & social phobia
Etiology :
C/P :
Definition
:

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Fetal Alcohol Syndrome (FAS)
❖ Incidence : 1:1000
1. Growth
- prenatal and/or postnatal growth retardation
2. Facial deformities “ Midface hypoplasia “ (from abnormal frontal lobe development)
- Smooth philtrum
- Thin, smooth vermilion border of the upper lip
- Short palpebral fissures
- ptosis of eyelid
- microphthalmia
- Epicanthic folds
- flattened nasal bridge, Short upturned nose
- cleft lip ( + palate)
- micrognathia, retrognathia
- protruding ears
3. CNS deformities
- Developmental delay
- Irritability in infancy
- Hyperactivity in childhood (ADHD)
- Mental retardation
- microcephaly
- meningomyelocele
- hydrocephalus
4. Cardiac deformities
- tetralogy of Fallot
- coarctation of aorta
5. Skeletal abnormalities (Neck deformities)
- cervical vertebral & rib abnormalities
- mild neck webbing
Characteristic
C/P

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Phenylketonuria (PKU)
- The most common inborn error of amino acid metabolism
- It is an autosomal recessive disorder
- occurs in about 1 of every 10,000 to 15,000 live births.
- Normally , Phenylalanine hydroxylase (PAH) enzyme catalyzes the conversion of
L-phenylalanine to L-tyrosine
L − phenylalanine
𝐏𝐡𝐞𝐧𝐲𝐥𝐚𝐥𝐚𝐧𝐢𝐧𝐞 𝐡𝐲𝐝𝐫𝐨𝐱𝐲𝐥𝐚𝐬𝐞
→ L − tyrosine
- mutations in the PAH gene → impaired PAH expression → impaired ability to metabolize
phenylalanine “ essential amino acid “ → its accumulation in blood and tissues
Skin findings
- Fair skin and hair : most characteristic (Due to impairment of melanin synthesis )
- Eczema (including atopic dermatitis)
- Musty or mousy odor
Neurologic signs:
- Intellectual disability (the most common finding overall)
- Seizures ( in about 25% of cases ) & tremors
- Spasticity, hypertonia & hyperreflexia
- Irritability & Hyperactivity
- Microcephaly
Other manifestations
- Vomiting , may be an early symptom
- prominent maxillae with widely spaced teeth, enamel hypoplasia
- Growth retardation
Etiology :
C/P If untreated :
Definition
:
Incidence :
N.B. Most patients are severely retarded (but some reported to have borderline or normal intelligence)

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- PKU is diagnosed through newborn screening on blood samples during 1st
week of life
- In positive screening results, diagnosis should be confirmed by quantitative measurement
of plasma phenylalanine concentration
- The mainstay of treatment of PKU is a low–phenylalanine diet for life
- The goal of therapy is to reduce phenylalanine levels in the plasma and brain.
- The diet should be started as soon as the diagnosis is established.
- Discontinuation of therapy, even in adulthood, may cause deterioration of IQ and cognitive
performance
- Because phenylalanine is not synthesized endogenously, small amounts of phenylalanine
should be added to the diet to prevent phenylalanine deficiency.
✓ Formulas free of or low in phenylalanine are commercially available.
✓ Essential amino acids, vitamins, and minerals must be supplemented by using medical foods
✓ Energy and variety are provided by low-protein foods, including fruits and non-starchy
vegetables .
 The diet requires elimination of all high-protein foods, such as meat, dairy, nuts, & legumes.
 Starches, including bread, potatoes, corn, and beans, also must be restricted
Diagnosis :
Treatment :

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Diagnosis
• Multidisciplinary evaluation should be individually tailored to the child.
A team of professionals like pediatric neurologist, developmental pediatrician, psychologist,
social scientist, speech therapist, physical therapist, special educator, social worker and
nurse will evaluate the child.
• Complete history is collected from family members and care takers.
• Mental history
• Physical examination to exclude physical illness.
• Neurological assessment
• Assessment of milestones like intellectual levels, cognitive ability, language pattern and
communication skills, hearing, behavior.
Investigations
1. Chromosome Studies
- Amniocentesis- Chronic villi sampling (CVS) is a screening technique to determine fetal
chromosomal abnormalities.
- 8 to 10 weeks of gestation
2. Molecular cytogenetics techniques:
- FISH (Fluorescent In Situ Hybridization) for diagnosis of microdeletion syndromes.
3. Molecular techniques: PCR
4. Urine chromatography for amino acids, and MPS, Reducing Substances as Galactose.
5. Plasma chromatography: for Amino acids, T4 & TSH estimation, serum lactate, ammonia.
6. Serologic investigations: for antenatal infections: IgM at birth.
7. X-ray Skull: for cranial anomalies, and intra-cranial calcifications.
8. Neuroimaging: MRI can show abnormalities in the brain such as myelination patterns.
9. Fundus examination: sTORCH, optic atrophy
10.Screening for visual and auditory acuity.
11.Psychological Assessment:
- For infants :
✓ The Bayley Scales of Infant Development (BSID)
✓ The Gesell Developmental Schedules
✓ The Cattell Infant Intelligence Scale
- For children :
✓ The Stanford–Binet Intelligence Scales
✓ The 3rd
edition of the Wechsler Intelligence Scale for Children (WISC-III)

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Treatment
I. 1ry
prevention: “Health education & Health promotion “
- Education to increase the general public’s knowledge and awareness of mental retardation
- Proper antenatal, natal, and immediate postnatal care
- Vaccination of all females against rubella before child bearing period
- Antenatal diagnosis of fetal illness in certain diseases e.g. Triple screening in DS,
chromosomal analysis of amniotic fluids
- Neonatal screening for all babies for common preventable causes of MR
e.g. PUK, Galactosemia, Cretinism
- Genetic counselling for hereditary causes after accurate diagnosis
II. 2ry
& 3ry
Prevention “2ry=Early Diagnosis & treatment, 3ry=Rehabilitation & prevent complications“
- Should be treated to shorten the course of the illness.
- To minimize the sequalae or consequent disabilities.
- Hereditary metabolic & endocrine disorders, such as PKU and hypothyroidism, can be treated
effectively in an early stage.
III. Active Treatment
- Education for the Child
- Behavioral, Cognitive, and PsychodynamicTherapies
- Family Education
- Social Intervention
IV. Pharmacology
- Some studies have focused on the use of medications for the following behavioral syndromes
that are frequent among mentally retarded persons
 Common Comorbid Psychiatric Disorders:
ADHD, Aggression and self-injurious behavior, Rage behavior, depressive behavior.
V. Parental counselling
Stage-I - Impart information regarding condition of the mentally retarded child.
- Avoid giving misleading information or building false hopes in the parents.
Stage-II - Help the parents develop right attitude towards their mentally retarded child
(to prevent overprotection, rejection, pushing the child too hard).
- Handle guilty feelings in parents.
Stage-III - create awareness in parents regarding their role in training the child.

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Attention-Deficit/Hyperactivity Disorder
(ADHD)
- It is a chronic behavioral condition that affects millions of children and may continue into
adulthood.
1. predominantly inattentive
2. predominantly hyperactive/impulsive
3. combined type.
❖ Inattention Symptoms (at least 6 symptoms required)
o Fails to give close attention to details or makes careless mistakes in schoolwork, work, etc.
o Difficulty sustaining attention
• Does not seem to listen when spoken to directly
• Does not follow through on instructions and fails to finish schoolwork, chores, etc.
o Difficulty organizing tasks and activities
o Avoids tasks requiring sustained mental effort
o Loses things necessary for tasks or activities
• Easily distracted by extraneous stimuli
• Forgetful in daily activities
❖ Hyperactivity-Impulsivity Symptoms (at least 6 symptoms required)
o Difficulty playing or engaging in activities quietly
o Always "on the go" or acts as if "driven by a motor”
• Talks excessively
• Blurts out answers
o Difficulty waiting in lines or awaiting turn
o Interrupts or intrudes on others
o Runs about or climbs inappropriately
• Fidgets with hands or feet or squirms in seat
• Leaves seat in classroom or in other situations in which remaining seated is expected
Definition
:
Types
DSM-IV criteria for ADHD

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- Symptoms present before age 7
- Clinically significant impairment in social or academic/occupational functioning
- Some symptoms that cause impairment are present in 2 or more settings
(e.g., school/work, home, recreational settings)
- Not due to another disorder (e.g., Autism, Mood Disorder, Anxiety Disorder)
❖ Medical:
a. Atomoxetine
b. Methylphenidate
❖ Psychotherapy
Autism
- It is a condition that manifests in early childhood
- Developmental regression
- Restricted repetitive & stereotyped behavior
- markedly aberrant communication skills
- Abnormal social interactions
- Abnormal reactions to environmental stimuli
 Absence of protodeclarative pointing
 Absence of symbolic play
❖ NO Medical
❖ Psychotherapy
Treatment :
Treatment :
Behavioral & developmental features:
“protodeclarative pointing : draw attention to an object to comment on it or share interest in it “
“ Symbolic Play is a type of play behavior when a child uses one thing to represent something else
e.g. holding a rectangular wooden block to his ear and talking into it like a telephone “