intellectual disabilities lecture

1. Intellectual Disabilities
Dr. Reza Parker (MD Romania)

2. What’s with the Name Calling?
• Idiot
• Moron
• Feeble Minded
• Mentally Retarded
• Intellectual Disability

3. Definition
Intellectual disability is disability
characterized by significant limitations
in both intellectual functioning and in
adaptive behaviour, which covers
many everyday social and practical
skills.
This disability originates before the
age of 18.

4. Definition cont.
• Deficits in IQ of 70 or below (intellectual
Functioning)
• Impairments in Adaptive Functioning
– Effective coping with common life demands
– Ability to meet standards of independence
– Measured by standard scales

5. Adaptive Behaviour
is the collection of conceptional, social, and practical
skills that are learned and performed by people in
their everyday lives.
• Conceptual skills—language and literacy; money,
time, and number concepts; and self-direction.
• Social skills—interpersonal skills, social
responsibility, self-esteem, gullibility, naïveté (i.e.,
wariness), social problem solving, and the ability to
follow rules/obey laws and to avoid being
victimized.
• Practical skills—activities of daily living (personal
care), occupational skills, healthcare,
travel/transportation, schedules/routines, safety,
use of money, use of the telephone.

6. • Children with intellectual disability can and do learn
new skills, but they develop more slowly than children
with average intelligence and adaptive skills.
• A family may suspect mental retardation if the child’s
motor skills, language skills and self-help skills do not
seem to be developing, or developing at a slower rate
than child's peers.
• Failure to adjust to new situations (adaptation) and
grow intellectually may become apparent early in
child's life. Milder cases are only recognizable at
school age or later

7. Degrees of Severity
• Mild Mental Retardation
– IQ: 50-55 to approximately 70
• Moderate Mental Retardation
– IQ: 35-40 to 50-55
• Severe Mental Retardation
– IQ: 20-25 to 35-40
• Profound Mental Retardation
– IQ: Less than 20-25

8. Mild Mental Retardation
• Previously referred to as “educable”
• Largest segment of those with MR (85%)
• Typically develop social/communication skills
during preschool years, minimal impairment in
sensorimotor areas, often indistinguishable from
“typicals” until later age
• By late teens acquire skills up to approximately
the 6th grade level

9. Moderate Mental Retardation
• Previously referred to as “trainable”
• About 10% of those with MR
• Most acquire communication skills during early
childhood years
• Generally benefit from social/vocational training and
with moderate supervision can attend to personal care
• Difficulties recognizing social conventions which
interferes with peer relations in adolescence
• Unlikely to progress beyond the 2nd grade academically
• Often adapt well to life in the community in supervised
settings (performing unskilled or semiskilled work)

10. Severe Mental Retardation
• 3 – 4% of those with MR
• Acquire little or no communicative speech in
childhood; may learn to talk by school age and be
trained in elementary self-care skills
• Can master sight reading “survival” words
• 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

11. Profound Mental Retardation
• 1 – 2% of those with MR
• Most have an identifiable neurological
condition that accounts for their MR
• Considerable impairments in sensorimotor
functioning
• Optimal development may occur in a highly
structured environment with constant aid

12. Prevalence
• 1% (1 – 3% in developed countries)
• The prevalence of MR due to biological factors is
similar among children of all SES; however, certain
etiological factors are linked to lower SES (e.g.,
lead poisoning & premature birth)
• More common among males (1.5:1)
• In cases without a specifically identified biological
cause, the MR is usually milder; and individuals
from lower SES are over-represented

13. Predisposing Factors
• No clear etiology can be found in about 75%
of those with Mild MR and 30 – 40% of those
with severe impairment
• Specific etiologies are most often found in
those with Severe and Profound MR
• No familial pattern (although certain illnesses
resulting in MR may be heritable)

14. Predisposing Factors (2)
• Heredity (5% of cases)
– Autosomal recessive inborn errors of metabolism (e.g.,
Tay-Sachs, PKU)
– Single-gene abnormalities with Mendelian inheritance
and variable expression (e.g., tuberous sclerosis)
– Chromosomal aberrations (e.g., Fragile X)
• Early Alterations of Embryonic Development (30%
of cases)
– Chromosomal changes (e.g., Downs)
– Prenatal damage due to toxins (e.g., maternal EtOH
consumption, infections)

15. Predisposing Factors (3)
• Environmental Influences (15-20% of cases)
– Deprivation of nurturance, social/linguistic and other
stimulation
• Mental Disorders
– Autism & other PDDs
• Pregnancy & Perinatal Problems (10% of cases)
– Fetal malnutrition, prematurity, hypoxia, viral and
other infections, trauma
• General Medical Conditions Acquired in Infancy or
Childhood (5% of cases)
– Infections, trauma, poisoning (e.g., lead)

16. Etiology
• At least 500 causes now known
• 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 (accounts for 40% of all X-
linked syndromes; most common inherited cause)
(3) Fetal EtOH Syndrome (most common attributable
cause)
together these 3 account for 30% of all identified
cases of MR

17. Clinical Symptoms as a whole.
• Speech
• Perception
• Cognition
• Concentration
• Memory
• Emotion
• Movement
• Behavior

18. Clinical Symptoms as a whole.
Speech
• Children with ID usually have delayed language
development and difficulties speaking and
expressing themselves.
• The degree of severity varies with the level of
impairment of intellectual ability. Mild cases can
achieve language skills that are only a little
poorer than children in the normal range of
development.
• Severe or profound cases can’t communicate at
all or speak only a few words.

19. Perception
• Children with ID are slow in reacting and
perceiving environmental stimuli.
• They have difficulties distinguishing small
differences in the shape, size and color.

20. Cognition
• Capacity to analyze, reason, comprehend and
calculate, and for abstract thinking is often
impaired to a greater or lesser extent according
to severity.
• Children with mild ID are capable of achieving
reading and mathematics skills to approximately
the level of a typical child aged 9 to 12
• Individuals with severe or profound ID lack the
capacity to read, calculate or even understand
what others say.

21. Concentration and memory
• Ability to concentrate is low and narrow. By
and large, memory is poor and they are slow
at remembering although there are exceptions
(e.g., savants).
• They have difficulties recalling and their
memories are often inaccurate.

22. Emotion
• Emotions are often naive and immature but
may improve with age.
• Capacity for self-control is poor and impulsive
and aggressive behavior is not uncommon.
Some are timid, withdrawn and shy.

23. Movement and behavior
• Children with ID often lack coordination, may be
clumsy or show excessive movement.
Meaningless or stereotyped movements (e.g.,
rocking, head-banging, teeth-biting, shouting,
tearing clothes, pulling hair, playing with the
genitals) are frequent in severe ID. Destructive,
aggressive or violent behavior can also be
observed.
• Self-injurious behavior (e.g. self-slapping or
biting) may occur in moderate and severe ID.

24. Behavior problems:
• Symptoms like restlessness (continuously moving
around, unable to sit in one place), poor concentration,
impulsiveness, temper tantrums, irritability and crying
are common.
• Other disturbing behavior, like aggression, self-
injurious behavior (such as head banging) and
repetitive rocking may also be seen (see section on
challenging behaviors below). When such behavior is
severe and persistent, it can become a major source of
stress for families.
• Therefore, attention should be paid to reduce such
behavior while providing treatment and care

25. Down’s Syndrome
• Most common chromosomal abnormality leading to MR
(1:600-800 births)
• Nondysjunction of chromosome 21 (trisomy 21)
• Relative strengths:
– Visual (vs. auditory processing)
– Social functioning
• Relative weaknesses:
– Language expression and pronunciation
• Generally viewed to suffer less severe psychopathology
than other developmentally delayed groups
• After 40 years of age, affected individuals nearly always
demonstrate postmortem neuronal defects
indistinguishable from Alzheimer’s Disease

26. Clinical Manifestation
• Cranium- Flat Occiput
• Eyes- Inner Epicanthal Folds, Brushfield spots,
strabismus, Nystagmus
• Ears- over folded upper helix
• Facial- Protruding Tongue, Large cheeks, Flat
nasal fold, small nose.4
• Skeletal- short, excess nuchal skin, dysplastic
hips, vertebral anomalies.

27. Down’s Syndrome

28. Clinical Manifestation
• Cardiac-Atrioventricular-Septal Defect
• CNS- Hypotonia,low IQ,
Developmental Delay, Hearing
problems, Development of
Alzheimers in 40s.

29. Behavior & Psychiatric Illness in Down Syndrome.
• Recent population based survey of social and
healthcare records found:
– Females had better cognitive abilities and speech
production compared with males
– Males had more behavioral troubles
– ADHD symptoms were often seen in childhood across
gender
– Depression was diagnosed more often in adults with
mild/moderate intellectual impairment
– Autistic behavior was most common in those with profound
intellectual disability
– Elderly often showed a decline in adaptive behavior
consistent with Alzheimer’s

30. Assessment
• Per Guidelines (Health Supervision of Children
with Down syndrome)
– chromosomal analysis, CBC, echo,
– yearly thyroid test(t3/t4/tsh)
– atlanto-occipital x-ray at 2 yr,
– sleep study(EEG)
– hearing test
– ophthalmology assessment

31. Fragile X Syndrome
• FMR-1 gene (>200 trinucleotide CGG repeats, Xq27.3)
• 1:3600 males , 1:6000 females
• Most common Heritable cause of ID in boys.
• General problems: MR, mild CT dysplasia, & macro-orchidism
• Only 50% of females with the full mutation demonstrate IQs in
the borderline/mild MR range (vs. 100% of males)
• Increases the risk for ADHD, autism (20-60%) & social phobia
• Increasing deficits in adaptive and cognitive functioning with age
• Relative strengths:
– Verbal long-term memory
• Relative weaknesses:
– ST memory, VM integration, sequential processing, math & attn

32. Fragile X Syndrome

33. Fragile X Syndrome

34. Fetal Alcohol Syndrome
• Incidence > 1:1000
• Irritable as infants, hyperactive as children (ADHD)
• Teratogen amount: 2 drinks/day (smaller birth size), 4-6
drinks/day (subtle clinical features), 8-10 drinks/day (full
syndrome)
• General problems: prenatal onset of growth deficiency,
microcephaly, short palpebral fissures
• Syndrome can include:
– Facial deformities (ptosis of eyelid, microphthalmia, cleft lip [+/- palate],
micrognathia, flattened nasal bridge and phfiltrum, & protruding ears)
– CNS deformities (meningomyelocele, hydrocephalus)
– Neck deformities (mild webbing, cervical vertebral & rib abmormalities)
– Cardiac deformities (tetralogy of Fallot, coarctation of aorta)
– Other abnormalities (hypoplastic labia majora, strawberry hemangiomata)

35. Fetal Alcohol Syndrome

36. Prader-Willi Syndrome
• Deletion in chromosome 15 (15q11-13);
• freq 1:15000 cases
• H30- Hypotonia, hyperphagia, Obsessive Hyperphagia,
morbid Obesity
– Short stature, almond shaped eyes, small hands/feet, mild to
moderate MR, Hypopigmentation.
• Relative stability in adaptive functioning during
adolescence and early adulthood
• Relative strengths:
– Expressive vocabulary, LT memory, visual/spatial integration
and visual memory (unusual interest in jigsaw puzzles)
• Relative weaknesses:
– Temper tantrums, emotional lability, mood symptoms , anxiety,
skin picking, OCD symptoms (>50% OCD)

37. Prader-Willi Syndrome

38. Prader-Willi Syndrome

39. Angelman Syndrome
• Deletion in chromosome 15 (15q11-13)
• Severe MR, seizures, ataxia & jerky arm
movements (puppet-like gait), absence of
speech, and bouts of laughter (aka “happy
puppet”)
• In contrast to PWS, all identified cases of
deletion traced to maternal chromosome 15
– Illustrating “genomic imprinting,” (the fact that the
parent of origin of the deletion at the same locus
impacts the phenotype; that is, deletion of paternal
15q11-13 results in Prader-Willi but deletion of
maternal 15q11-13 results in Angelman.)

40. Angelman Syndrome
• Ataxia with severe intellectual disability.
• Seizures
• Tremulousness
• Hypotonia midface hypoplasia
• Fair hair
• Uncontrollable laughter.

41. Angelman Syndrome

42. Williams Syndrome
• Deletion of elastin gene (7q11.23)
• MR, supravalvular aortic stenosis, “elfin-like”
facies, infantile hypercalcemia, and growth
deficiency
• Relative strengths:
– Remarkable facility for recognizing facial features
– Loquacious, pseudo-mature “cocktail party speech”
• Relative weaknesses:
– Increased risk for ADHD, Anxiety D/O

43. Williams Syndrome

44. Assessment
• Mild Mental Retardation
IQ: 50-55 to approximately 70
• Moderate Mental Retardation
IQ: 35-40 to 50-55
• Severe Mental Retardation
IQ: 20-25 to 35-40
• Profound Mental Retardation
IQ: Less than 20-25

45. Treatment
• The primary goal of treatment is to develop the
person’s potential to the fullest.
• Special education and training may begin as early
as infancy. This include social skills to help the
person function as normal as possible.
• The patient must be evaluated for the presence or
absence of other effective disorders.
• Behavioral approaches are important for patients
with intellectual disabilities.

46. • There are specific programs that people with
developmental disabilities can take part in
wherein they learn basic life skills.
• These "goals" may take a much longer
amount of time for them to accomplish, but
the ultimate goal is independence.
• People with developmental disabilities learn
throughout their lives and can obtain many
new skills even late in life with the help of
their families, caregivers, clinicians and the
people who coordinate the efforts of all of
these people.

47. • Family psychoeducation
 explain problem to carers
 give parents skills to support child development
 promote participation in family, school and community life
 address psychosocial needs of carers
• Advice for teachers
• Manage risk/contributing factors
 hearing and vision problems
 nutrition
 maternal depression
 lack of stimulation
• Manage co-occurring epilepsy, depression and
behaviour problems

48. Prevention
• Primary (preventing occurrence of ID):
– Prenatal: (toxins, infections incl. HIV)
– Peri-natal: (delivery, neo-natal screening)
– Post-natal: (immunization, treatment for infections, safe
and enriching environment)
• Secondary (halting disease progression):
– Discover ID early, provide stimulation for optimal
development
• Tertiary (maximizing functioning)
– Support for families
– Stimulation, training, vocational opportunities