Mental retardation

MENTAL RETARDATION

CONTENTSIntroduction

Classification

Etiologies

Diagnosis

Prognosis

Differential diagnosis

Treatment

INTRODUCTION

• DEFICITS IN COGNITIVE ABILITIES, AS WELL AS IN BEHAVIOURS REQUIRED FOR SOCIAL & PERSONAL SUFFICIENCY, KNOWN AS ADAPTIVE FUNCTIONING

• Both social adaptation & IQ is necessary to determine the level of mental retardation

• Highest incidence at ages 10-14yrs (school age children)

• 1.5x common in men than women

CLASSIFICATION• ICD-10 (F70-F79)

• Condition of arrested or incomplete developmental of the mind which is especially characterized by impairment of skills manifested during the developmental period, which contribute to the overall level of intelligence,i.e. cognitive, language, motor & social abilities

• F70mild

• F71moderate

• F72 severe

• F73 profound

MILD ( 50-69) MODERATE ( 35-49) SEVERE ( 20-34 ) PROFOUND ( BELOW 20 )

Acquired language with some delayed

BUT achieve the ability to use speech for everyday purpose

Achieve full independence in self care, practical & domestic skills

Difficulties main in academic school work

Can be helped by education designed to dev their skills

Demand work practically rather than academic abilities

Slow in developing comprehension & use of language

Achievement of selfcare & motor skills is retarded

Some need supervision thruoutlife

School work progress is limited

But learn the basic skills for reading, writing & counting

Majority show evidence of social devin their ability to establish contact, communicate & engage in simple social activities

Features broadly similar to moderate

Most people in this category suffer from a marked degree of motor impairment

Limited in their ability to understand or comply with request or instructions

Posses little or no ability to care for their own basic needs & require constant help & supervision

ETIOLOGIES

ETIOLOGIES

GENETICS ACQUIRED & DEVELOPMENTAL

ACQUIRED CHILDHOOD ENVIRONMENTAL &SOCIOCULTURAL

1) CHROMOSOMAL ABNORMALITIES

Down syndrome Fragile X

syndrome Prader- Willi

syndrome Cri du chat

1) MATERNAL INFECTIONS

Rubella Cytomegalic inclusion

disease Syphilis Toxoplasmosis Herpes simplex AIDS

1) INFECTIONS Encephalitis Meningitis

Poor medical care Poor maternal

nutrition Teenage pregnancies Poor postnatal medical

care Malnutrition Exposure to toxic Physical trauma Family instability

2) INBORN ERROR METABOLISM

Phenylketonuria Lesch nyhan

syndrome

2) MATERNAL SUBSTANCE ABUSE

Fetal alcohol syndrome

Prenatal drug exposure

2) HEAD TRAUMA Seizures Vehicle accident Household accidents

3) SINGLE GENE DISORDER

Tuberous sclerosis Neurofibromatosis

3) COMPLICATION OF PREGNANCY

3)Others

Cerebral palsy Cretinism

DOWN SYNDROME

• Aka mongoloid

• Most common

• Both mental & physical retardation

• Moderate or severe retardation

• Causes

Trisomy 21

Mosaicism

Translocation btwn chromosome 21 & 15

• They are placid, cheerful, cooperative and easily adapt at home

• Strengths- sociability & social skills

• Weakness- language function

Clinical features

Small skull & brachycephalic

Flat facies

Small ears & dysplastic

Slanted eyes

Epicanthic fold

Small nose with flat nasal bridge

Narrow short palate

Small teeth

Protruding toungue

Hands short & broad

Simian crease

Sandle gap toe

FRAGILE X SYNDROME

• 2nd most common

• Mutation on the X chromosome at fragile site (Xq27.3)

• 1/1000 males, 1/2000 females

• Females carriers are less impaired

• Mild to severe mental retardation

• Clinical features

Large, long head & ears

Short stature

Hyperextensible joints

Postpubertal macroorchidism

High rate ADHD,

Learning disorder,

Pervasive dev disorder,

Deficit in language fx (rapid preservative speech with abnormalities in combining words into phrases & skills)

PRADER WILLI SYNDROME

• Small deletion in chromosome 15

• Less 1/10000

• Features:

Compulsive eating behaviour

Obesity

Mental retardation

Hypogonadism

Small stature

Hypotonia

Small hands & feet

Oppositional & defiant behaviour

CRI DU CHAT SYNDROME

• Cats cry (laryngeal abnormality)

• Deletion in chromosome 5

• Severe retardation

• Clinical features

Microcephaly

Low set ears

Oblique palpebral fissures

Hypertelorism

microagnathia

PHENYLKETONURIA

• Inborn error metabolism• 1 of every 10000 to 15000 LB• Common in North europion• Causes:Phenylalanine ParatyrosineAbsence of phenylalanine

hydroxylase

• Clinial featuresMost severe retardationSome borderline or normal IQHyperactiveTemper tantrumsBizarre mvements of upper bodyTwisting hand mannerismImpaired verbal & non verbal

communicationPoor coordinationEczema, vomiting, & convulsion

LESCH NYHAN SYNDROME

• Rare disorder- X linked

• Inborn error metabolism of purine

• Deficiency of enzyme

Clinical features

Mental retardation

Microcephaly

Seizures

Choreoathetosis

Spasticity

Gout

SEVERE COMPULSIVE SELF MUTILATION BY BITTING MOUTH & FINGERS

FETAL ALCOHOL SYNDROME

• Prenatal factors

• Mother ingest large amount of alcohol

• Clinical features

Mental retardation

Dysmorphism

Hypertelorism

Microcephaly

Short palpebral fissure

Inner epicanthal fold

Short turned up nose

CEREBRAL PALSY CRETINISM

GOITRE DWARFISM MENTAL

RETARDATION COARSE SKIN LARGE TONGUE POT BELLY HYPOTONIA HYPERTELORISM

PSYCHOSOCIAL FEATURES1. Negative self-image

2. Poor self-esteem

3. Communication difficulties

4. Isolation & feelings of inadequacy

5. Anxiety

6. Anger

7. Dysphoria

8. Depression

DIAGNOSIS• History taking

• Psychiatric interview

• Physical examination

• Neurological examination

• Mental status examination

LAB INVESTIGATIONS• Electroencephalography• Neuroimaging • Hearing & speech evaluation• Chromosome studies• Urine & blood analysis• Psychological assessment (perceptual, motor, linguistic, cognitive)Visual motor coordination- Goodenough draw a person test, Kohs block

testEvaluate mental retardation- Gesell & Bayley scale, Cattel infant

intelligence scaleLanguage test – Peabody vocab test

COURSE & PROGNOSIS

• The infants with the poorest prognosis are those who

manifest a combination of inactivity, general hypotonia,

and exaggerated response to stimuli.

• In older children, hyperactivity, short attention span,

distractibility, and low frustration tolerance are often

signs of brain damage.

DIFFERENTIAL DIAGNOSIS

• Must according to onset of age (before or after age of 18)

1. Pervasive developmental disorders

2. Brain damage

3. Autistic disorder

4. Schizophrenia with childhood onset

5. Heller's disease

Many children when evaluated display similar bizarre & stereotyped behaviour -> mutism, echolalia, or functioning on a level of retardation.

TREATMENT• 1' prevention : To eliminate/reduce condition that lead to dev of dis

Increase general public's knowledge & awareness of mental retardation, continuing efforts of health professionals to ensure & upgrade public heatlh policies, provide optimal MCHC, family & genetic councelling

Various supplementary enrichment for children & mothers of low socio-economic status

• 2' prevention : to shorten the course of illness

• 3' prevention : to minimize the sequalae @ consequent disabilities

• Education for the child

• Behavioural, cognitive, & psychodynamic therapies

• Social intervention

REFERENCES