Transcript Mental retardation(Learning disability)

Prof. Elham Aljammas
23/3/2014
MENTAL RETARDATION(LEARNING
DISABILITY)
LEARNING DISABILITY
LEARNING DISABILITY
Specific learning disability means a disorder in 
one or more of the basic psychological
processes involved in understanding or in using
language, spoken or written, that may manifest
in an imperfect ability to listen, think, speak,
read, write, spell, or do mathematical
calculations including conditions such as
perceptual disabilities, brain injury, minimal
brain dysfunction, dyslexia, and developmental
aphasia
LEARNING DISABILITY
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No known cause
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Possible causes:
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Neurological
Genetic
Environmental
Prenatal
Perinatal
Postnatal
Characteristics 
Hyperactivity 
Perceptual-motor impairments 
Emotional Lability 
Coordination deficits 
Attention disorders 
Impulsivity 
Memory & thinking disorders 
Specific learning disabilities 
Speech & hearing disorders 
Equivocal neurological signs 
Mental retardation is IQ =70
Impairment across a wide range of functions 
Onset during childhood 

Features of mental retardation 
Divided into mild, moderate severe & profound 
Prevalence of 2% 
with male to female ratio =3/2 
Usually untreatable 
Often accompanied by 
Psychiatric disorders 
Behavioral disturbance 
Medical problems(e.g epilepsy) 
LEARNING DISABILITY
Though there is no known cause of learning 
disabilities, there are many techniques and
strategies that teachers can use to help
students identified with learning disabilities
acquire knowledge and skills and to experience
success.
Variables
mild
moderate

------------------------------------------------------severe
--------------------------------IQ
69-50
49-35
<35 
% of cases
85%
10%
5% 
Self care
independent
needs some help
limited 
Language reasonable
limited
basic/no 
R.& Writing ===
basic
minimal/no
Ability to work semiskilled Unskilled- supervised Superv.ba.S 
Physical prob. Rare
sometime
common 
Etiology discovered sometime often
usuall 
Causes of MR 
Genetic 
Obstetric complications 
In utero infection& complications 
Perinatal complications 
Other factors 
Cerebral palsy 
Hydrocephalus 
Spina bifida 
Assessment of mental
retardation
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History 
Details of pregnancy 
Fetal growth, fetal alcohol syndrome 
Infection(rubella HIV,Toxoplasmosis,cytomegalovirus,trauma ,) 
Substance misuse, eclampsia 
Delivery 
Gestational age 
Birth Complication, placental insufficiency. Ventricular hemorrhage
Condition of baby 
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Child's development 
Milestones
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Physical difficulties 
Family history 
Mental retardation 
Physical anomalies,hypothyroidsm, hyperbilrubiaemia.
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Consanguinity of parents
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Examination 
General 
Overall health 
Weight ,height ,head circumference
Physical anomalies & stigmata 
Neurological 
Tone ,power ,posture,reflexes 
Cranial nerves 
Motor skills 
Comprehension & use of language
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Neuropsychological testing 
Intelligence quotient(IQ) 
Language development 
Lab. Investigation 
Karyotyping& genetic testing 
Biochemical studies 
Brain imaging 
(parenting testing ,amniocentesis, chorionic villus sampling)
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Conditions associated with mental 
retardation
Chromosomal abnormalities 
Down's syndrome
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Trisomy 21.commonest causes of MR .Incidence of
1/650live birth.related to maternal age.
Features 
Moderate or severe mental retardation 
Flaccid temperament 
Physical features 
Slanted eyes & epicanthic folds 
Small mouth with furrowed tongue 
Flat nose 
Flattened occiput 
Stubby hand with single transverse palmer crease
Hypotonia 
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Associated medical problems 
Cardiac septal defect 
Gastrointestinal obstruction 
Atlanto axial instability 
Susceptibility to infection 
Increased incidence of lymphoma 
& hypothyroidism 
Fragile X syndrome 
Fragile site on the long arm of the X chromosome 
seen when cells are grown in folate deficient
medium,2nd commonest cause of MR(1 in
500brths),commoner in male, gets worse with
succeeding generation
.
There is no specific treatment, Methylphenidate 
&folic acid may improve the attention deficit
Features of fragile X syndrome
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.
Mental retardation may be mild, moderate , severe, 
or
profound.
Gets worse late in childhood
Performance IQ is affected more than verbal IQ
Litany speech: repetitive lacking in themes or content 
Poor concentration& attention 
Autistic features common 
Physical features 
Large protruding ears
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long face with high arched palate
Flat feet ,lax joints, soft skin, large testis, mitral valve 
prolapsed
Single gene disorders 
Phenylketonuria(PKU) 
Is the classic inborn error of metabolism. The amino
acid phenylalanine can't be converted to Para
tyrosine because of the absence of the converting
enzyme. It is AR.affect 1 in 10000 births causing
1%of severe MR .
Features of PKU 
Severe MR 
Tantrum & unpredictable aggression 
Abnormal movement & mannerism 
Fair skin 
Short stature 
Associated medical problems 
Eczema,vomiting&seizures 
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Examples of metabolic disorders associated with MR 
Metabolic category
example 
Amino acid
homocystineuria 
Lipid
tay-sachs disease 
Mucopolysaccarides
Hurlers syndrome 
Carbohydrates
galactosaemia 
Purines
lesch- Nyhan Synd. 
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