Prevetable cause of mental retardation
Prevetable cause of mental retardation
Published on: Mar 4, 2016
Transcripts - Prevetable cause of mental retardation
Guide: Dr. Deepak Dwivedi Dr.Priyank Patel
Mental retardation is defined as subaverage general
intelligence, manifesting during early developmental period.
The child has diminished learning capacity and does
not adjust well socially.
Now the term mental retardation has been replaced by
It is calculated according to the formula
Mental Age divided by chronological age, multiplied
Diagnostic criteria for intellectual
A Significantly subaverage intellectual functioning: an IQ
score of 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 and
interpersonal skills, use of community resources,self-
direction, functionalacademic skills, work,leisure,
health, and safety.
C The onset is before age of 18 years.
Grading of intellectual disability:
Mild intellectual disability: IQ 50-55 to 70
Moderate intellectual disability IQ 35-40 to 50-55
Severe intellectual disability IQ 20-25 to 35-40
Profound intellectual disability IQ below 20-25
Intellectual disability, Severity unspecified, when there is
strong presumption of intellectual disability but the person’s
intelligence is untestable by standard tests.
Causes of Intellectual disability
Aminoacidopathies: Organic acidemia, Phenylketonuria,
hompcystinuria, histidinemia, organic aciduria
Carbohydrate disorder: Glycogen storage disorder, glucose
transport defect, galactosemia
Chromosomal disorder: Down syndrome, fragile X syndrome,
Neuroectodermal dysplasia: Tuberous sclerosis
Developmental defects: Microcephaly, craniostenosis,
porencephaly, cerebral migration defect
Use of teratogens in first triamaster of pregnancy
Placental deficiency, toxemia of pregnancy, antepartum
Radiation during prenancy
Hypoxic ischemic encephalopathy
Post natal factor:
Infection of central nervous system
Thrombosis of cerebral vessels
Malnutrition , child abuse
Phatak’s Baroda screening test:
This is India’s best known development testing
system but meant to used by child psychologist rather
Denver development screening test:
It has 4 domain i.e. gross motor, fine motor
adaptive, language and personal social behavior
Trivandrum development screening chart:
it is simplified adaptation of Baroda development
applicable to children up to 2 year of age
useful as a mass screening test.
•Goodenough-Harris drawing test
•Clinical adaptive test and clinical linguistic and auditory
milestone scale (CAT/CLAMS)
Bayley scale for infant development II
it is the most commonly used scale.
usually takes 30-60 min to assess
Assesses language behavior, fine motor,gross motor,
and problem solving skill, provides mental
development index and psychomotor development
Wechsler intelligence scale for children IV:
The most commonly used psychological test for children
>3 year of age
Assesses verbal and performance skill
Provide full scale IQ and indices of verbal
comprehension perceptual reasoning workig memory
and processing speed
Other test like
Stanford-Binet intelligence scale 5th edition
Factors affecting Development along with
preventble cause of intellectual disability
•Genetic factors: Intelligence of parents has direct
correlation on the final IQ of the child.
There are several genetic causes for development
Delay and subsequent mental retardation.
There are few neuro metabolic disorder which if
diagnosed and treated timely can be prevent
developmental delay in child.
This disorder is caused by deficiency of enzyme phenyl
The affected infant is normal at birth.
Profound mental retardation develop gradually if the
infant remains untreated.
Vomiting may be an early symptom.
The infant are lighter in their complexion than unaffected
Neurological symptom include seizure, spasticity, hyperreflexia,
Prominent maxillae with widely spaced teeth.
Quantitative measurement of plasma phenylalanine
Should be treated with a phenyl restricted diet.
Formula low or free of phenyalanine ar e commercially
Denotes elevated level of galactose in blood.
caused mainly due to deficiency of
(i) galactose-1-phosphate uridyl transferase
(iii) uridine diphosphate galactose-4-epimerase
Poor weight gain
The preliminary diagnosis is made by demonstrating a
reducing substance in several urine specimens collected while
the patient is milk or any other formula containing lactose.
For confirmation quantitative measurement can be done
Non lactose containing diet
All inborn error of metabolism
should be diagnosed at the earliest
and should be treated.
deficiency of various micronutrient can
adversely affect development of fetus and later on can
have influence on infant development
(ii)Exposure to drug and toxin:
use of alcohol during pregnancy can affect
mental development of infant.
Fetal Alcohol syndrome
Occurs because of high level of alcohol ingestion during
Prenatal onset and persistence of growth deficiency
facial abnormality including short palpebral fissure,
epicanthal fold, maxillary hypoplasia,
micrognathia, smooth philtrum, smooth upper lip
Cardiac defect primarily septal defect
Minor joint and limb abnormalities
No specific therapy exists
By eliminating alcohol intake after conception.
Maternal smoking causes decreases in birth weight. Along
with this it also cause defect in brain, heart and face,
Use of cocaine and opioid during pregnancy can cause
serious problem in fetus.
Valproic acid can have severe defects in child
Maternal exposure to radiation also have deleterious effect
upon fetal developments
Maternal diseases and infection :
Pregnancy induced hypertension
Feto-placental insufficiency due to any cause
Acquired infection e.g. toxoplasmosis,
Rubella, CMV, herpes, Chorio-amniotis
Among various infection one of the most imp. Is
caused by Toxoplasma gondii, an obligate
There is a wide variety of manifestation:
May lead to hydrops foetalis and perinatal death
Classical triad is
diagnosis can be done by culture or serological tests
Cytomegalo virus infection
Congenital infection can manifest as
blueberry muffin like rash
definitive method of diagnosis is virus isolation or
demonstration of CMV DNA by PCR.
Ganciclovir, foscarnet, cidofovir
Neonatal Risk factor
Intrauterine growth restriction:
Adversely affect development
Chances of developmental impairment
increases with prematurity. More the child is premature
more will be the risk. Mainly because of complications like
intracranial bleed, white matter injury, hypoxia, hyper-
bilirubinemia and hypoglycemia
Various metabolic derangement can affect child
Studies have indicated that over 40%
of survivor of significant asphyxia suffer from
major neurocognitive disabilities.
Incidence can be decreased by Institutional delivery, proper
resuscitation, early stimulation therapy
Post natal factors :
Infant and child nutrition:
Early growth faltering (<24 month ) seems
to be more detrimental to childhood development.
Calorie deficeincy associated with multiple micronutrient
and vitamins like zinc, vitamin A, B12, D, E contribute to
Associated with delayed brain maturation, poorer
cognitive, motor and social emotional development
it can lead to congenital hypothyroidism and
irreversible mental retardation, making it the most common
preventable cause of mental retardation.
Diarrhoea, malaria, other parasitic infection and HIV
Like lead, arsenic, pesticide, mercury, and polycyclic aromatic
Exposure may be prenatally through maternal exposure or
postnatally through breast milk, food, water, house dust, soil
Acquired insult to brains:
traumatic or infectious insult like meningitis,
encephalitis, cerebral malaria and other factor like near
drowning, trauma particularly during early years of life can
have a permanent adverse effect on brain development.
impairment particularly those involving sensory inputs
from the eyes or ears can have a significant impact on
attainment of milestone.`
cognitive stimulation, caregiver’s sensitivity and affection
have important role in child development.
Higher level of maternal warmth and responsiveness are
associated with higher cognitive ability and reduced level of
behavioral problems in young children.
this is possibly the most common underlying
factor for impaired child development.
Lack of stimulation:
Social and emotional deprivation and lack of
adequate interaction and stimulation is an important cause
of developmental impairment.
Violence and abuse:
Domestic and community violence can have
profound psychological effect on the child.
it is negatively associated with child
Institutional care like orphanages during
early life increases the risk of poor growth, ill health,
have protective and promotive effect on child
has protective effect
•It is the most common preventable cause of mental
•Iodine deficiency is the most common cause of congenital
Most infant with congenital hypothyroidism are
asymptomatic at birth due to transplacental passage of
Despite having maternal thyroxine infant have low level
of serum T4 and elevated TSH.
Twice common in girls than boys
Birth weight and Height are normal but head size may be
Prolongation of physiologic jaundice may be the earliest
Feeding difficulties especially sluggishness, lack of
interest, somnolence and choking spell during nursing
are often present.
Respiratory difficulty due to large tongue
Poor appetite, constipation
Temperature is subnormal.
Edema of the genital and extremities
Pulse is slow, heart murmur, cardiomegaly, pericardial effusion
Congenital anomaly mostly cardiac
Widely opened anterior and posterior fontenelle
Neck short thick
Hands are broad and fingers are short
Myxedema mainly in skin of eyelids, the back of the hands,
and external genitalia.
Development is delayed
For Newborn Screening blood is obtained between 2 and
5 day of life by heel-prick.
Serum level of T4 or free T4 are low; serum level of T3 may be
normal and not helpful in diagnosis.
If the defect is primarily in thyroid level TSH are elevated.
• Retardation of osseous development can be seen.
• The distal femoral epiphysis, normally present at
birth, is often absent.
• the epiphysis often have multiple foci of ossification.
• Deformity of T12,L1, L2 is common.
may show low voltage P and T wave with diminished
Amplitude of QRS complex and suggest poor left ventricular
Pericardial effusion may be seen.
often shows low voltage
Levothyroxine given orally is treatment of choice.
the recommended initial starting dose is 10-
Neonate with more severe hypothyroidism should be
started at the higher end of dosage range.
Thyroid function test should be done at recommended
interval usually monthly in first 6 month of age then at
2- 3 month interval.
Thyroid replacement should be stopped for one month at
the age of 3 yr in suspected transient hypothyroidism.
Treatment may be discontinued in the absence of persistent
Abnormality on investigation and normal level of thyroid
Early diagnosis and adequate treatment from the first
weeks of life result in normal linear growth and
Most severely affected children can have retarded
skeletal maturation and have reduced IQ and can have
other neurological consequences like hypotonia,
hypertonia, incoordination, short attention span and
Prevention and control:
Iodine disorder are best prevented as treatment
is usually ineffective. Iodinated salt and iodized oil are
highly efficacious in preventing iodine deficiency.
The National Goiter Control Program of the Ministry
of Health in India began in 1962 with establishment of
Prevention of Mental Retardation
Examples of primary program to prevent intellectual
Increasing the public’s awareness of the adverse effect of
alcohol and other drugs of abuse on the fetus.
Preventing teen pregnancy and promoting early prenatal care
Preventing Traumatic injury: Encouraging the use of guards
and railing to prevent fall and other avoidable injuries in the
Home ; using appropriate seat restraints when driving and
wearing a safety helmet when biking ; teaching firearm safety
Preventing Poisoning: Teaching parents about locking up
medications and potential poison.
Implementing immunization programs to reduce the risk of
intellectual disability due to encephalitis, meningitis and
Newborn hearing screening programs.