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 No known cause Possible causes: Neurological Characteristics Hyperactivity Perceptual-motor impairments Emotional Lability Coordination deficits Attention disorders Impulsivity Memory & thinking disorders Specific learning disabilities Speech & hearing disorders Equivocal neurological signs No known cause Possible causes: Neurological Genetic Environmental Prenatal Perinatal Postnatal

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 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   Child's development Milestones Physical difficulties Family history Mental retardation Physical anomalies,hypothyroidsm, hyperbilrubiaemia. Consanguinity of parents

  Examination General Overall health Weight ,height ,head circumference Physical anomalies & stigmata Neurological Tone ,power ,posture,reflexes Cranial nerves Motor skills Comprehension & use of language Neuropsychological testing Intelligence quotient(IQ) Language development Lab. Investigation Karyotyping& genetic testing Biochemical studies Brain imaging (parenting testing ,amniocentesis, chorionic villus sampling)

Conditions associated with mental retardation Chromosomal abnormalities Down's syndrome 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

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 . 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 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

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.