Pervasive Developmental Disorders and Mental Retardation



Pervasive Developmental Disorders and Mental Retardation

U of A College of Medicine, Social and Behavioral Sciences

Wednesday, October 13, 2004

Jaswinder Kaur Ghuman, M.D.

Objectives

1. Discuss definitions, classification, prevalence, and etiologies of pervasive developmental disorders (PDD) and mental retardation (MR)

2. Discuss long-term outcome and prognosis for individuals with PDD and MR

3. Discuss how to differentiate between PDD and MR

4. Understand the basic approach to working with people with PDD and mental retardation

Required reading: Textbook: Fadem B. Behavioral Science Medicine, (pp. 30-32 and 32-35)

What is Autism/PDD?

Definition

Group of neuropsychiatric disorders

▪ Social dysfunction

▪ Communicative deviance

▪ Restricted and repetitive behaviors

Kanner (1943) - “Inborn Autistic Disturbance of Affective Contact”

▪ Autistic aloneness

▪ Abnormalities of language

▪ Maintenance of sameness

▪ Limited variety of spontaneous activity

DSM-IV (1994)

▪ Autistic disorder

▪ Asperger’s disorder

▪ Childhood disintegrative disorder

▪ Rett’s disorder

▪ PDD NOS

DSM IV criteria for autistic disorder - Total of at least 6 items

Qualitative impairment in reciprocal social interaction: (at least 2 items)

▪ Marked impairment in nonverbal behaviors

▪ Failure to develop peer relationships

▪ Lack of spontaneous seeking to share enjoyment, interests, or achievements with other people

▪ Lack of socio-emotional reciprocity

Qualitative Impairments in Communication: (at least 1 item)

▪ Delay in, or total lack of, the development of spoken language and failure to compensate through alternative modes of communication (such as gesture or mime)

▪ Marked impairment in the ability to initiate or sustain a conversation with others

▪ Stereotyped and repetitive use of language or idiosyncratic language

▪ Lack of varied, spontaneous make believe play or social imitative play appropriate to developmental level

Restricted repetitive and stereotyped patterns of behavior, interests, and activities: (at least 1 item)

▪ Encompassing preoccupation with one or more stereotyped and restricted patterns of interest that is abnormal in intensity or focus

▪ Apparently inflexible adherence to specific, nonfunctional routines or rituals

▪ Stereotyped and repetitive motor mannerisms

▪ Persistent preoccupation with part of objects

Delays or abnormal functioning with onset prior to age 3: (at least 1 area)

▪ Social interaction

▪ Language as used in social communication

▪ Symbolic or imaginative play

▪ No Other PDDs

Asperger’s Disorder

Asperger (1944) "autistic psychopathy"

▪ motor deficits

▪ later onset

▪ speech being less commonly delayed

DSM Criteria

▪ Social dysfunction and repetitive behaviors similar to autistic disorder

▪ No clinically significant delay in language and cognitive development

Rett’s Disorder

▪ Apparently normal pre and perinatal development

▪ Apparently normal psychomotor development through 1st 6 months

▪ Normal head circumference at birth

▪ Onset between 5 and 48 months:

o Deceleration of head growth

o Loss of previously acquired hand movements, with the development of stereotyped hand movements

o Loss of social skills early in the course

o Appearance of poorly coordinated gait or trunk movements

o Marked delays and impairment of expressive and receptive language and severe psychomotor retardation

▪ PDD NOS: subthreshold cases

Childhood Disintegrative Disorder

▪ Apparently normal development for first 2 years

▪ Clinically significant loss of previously acquired skills in at least 2 areas:

o Expressive or receptive language

o Social skills

o Bowel or bladder control

o Play

o Motor skills

▪ Abnormalities in at least 2 areas: social dysfunction, deviant communication, repetitive behaviors

Epidemiology

▪ 4-5 cases per 10,000.

▪ Recently higher rates: up to 34-63 per 10,000

▪ PDD NOS: 1 per 600

▪ Reason for higher rate: nature of case definition, early case recognition, issues of diagnosis in extreme ranges of the condition (in severe MR or non-retarded individuals)

▪ M:F = 4 to 1.

▪ Girls with autism:

o more severely affected

o more likely to have a family history of learning and language problems.

Cognitive development

About 75% mentally retarded

▪ most moderate MR (IQ 35-50)

▪ uneven development: marked deficits in verbal skills especially comprehension

▪ much better on tasks requiring mechanical (block design) or rote memory skills

▪ May have islets of unusual ability-with numbers, maps etc.

Seizures

▪ incidence of seizures is 25-35%

▪ onset in early childhood with a second peak during adolescence

▪ deterioration during adolescence may be explained by the onset of seizures

Etiology

Psychological basis

▪ parental role in the pathogensis despite Kanner's emphasis on a constituionally based inborn disturbance in autism.

Biological basis

▪ Cerebellar, cortical and intracerebral, brainstem and EEG abnormalities; neurochenmistry (serotonin, neuropeptide function)

Prenatal and Perinatal Factors:

▪ association between congenital rubella and autism, and between Congenital cytomegalovirus infection and autism

Genetic Influence:

▪ prevalence in the siblings estimated to be 50-100 times greater than expected (2-3/100 vs. 4-5/10,000)

▪ 36% concordance for autism in monozygotic pairs compared to no concordance in dizygotic pairs

▪ Some genetic conditions, fragile X syndrome, tuberous sclerosis, untreated phenylketonuria, are associated with autism

Diagnostic assessment

▪ interdisciplinary comprehensive diagnostic assessment and evaluation

▪ individualized treatment plan

▪ educational, behavioral, psychosocial, pharmacological and medical interventions

Management

▪ No specific biological marker identified as cause

▪ No treatment modality specifically based on cause

▪ Comprehensive early intervention is effective

▪ Educational program is the main focus of management

▪ Active parent participation in the child's Rx program

▪ Speech Therapy

▪ Social skills training

▪ Behavioral therapy

▪ Supportive family therapy and counseling

▪ Pharmacotherapy

o to reduce/eliminate maladaptive behaviors

o to help enhance child’s availability for interventions

o only in conjunction with a comprehensive ITP

o symptomatic for aggressive, ritualistic/ stereotypic/ self-injurious behavior, attentional problems, mood liability and seizures

Prognosis

▪ lifelong disorder, about two- thirds of adults with autism remain severely handicapped.

▪ social relatedness and communication may improve, but rarely normal (quality or quantity)

▪ 40-50% acquire useful speech early on but continue to show language abnormalities

▪ The best prognosis is in the cases with the presence of communicative speech by age 5, and normal nonverbal intellectual skills and communicative language.

Summary

▪ Autism is a chronic life long condition with significant impairment in useable communication and adaptive social skills requiring in at least two third of the cases life long structured living assistance. Autism truly represents a serious and persistent mental illness.

Mental retardation

Definition

▪ IQ < 70

▪ Adaptive functioning deficits

▪ Onset before 18 years

Classification

▪ Average IQ: IQ 100 + 15

▪ Borderline IQ: IQ 70 to 85

▪ Mild MR: IQ 55 to 70 (85%)

▪ Mod MR: IQ 40 to 50-55 (10%)

▪ Severe MR: IQ 25 to 35-40 (4%)

▪ Profound MR: IQ < 25 (1-2%)

Clinical features

▪ Vary depending on the level of retardation

▪ Severe and profound MR recognized early and may have more dysmorphic and associated behavior and psychiatric disorders

Assessment

▪ Psychiatric Assessment

▪ Work-up for organic causes

▪ Cognitive and adaptive assessment

Associated psychiatric and behavioral disorders

▪ 25% of clinically referred persons may have psychiatric problems

▪ lower rates (10-15%) in population-based studies

▪ Same range of psychiatric problems as the general population, but rates vary

▪ More people with MR have psychosis and autism, and less apt to have substance abuse and affective disorders

Etiology and Pathogenesis

▪ 50% may have known organic causes

▪ Most mild MR-no clearly defined cause of MR

▪ Biological and environmental causes

▪ Genetic causes: Down’s syndrome and Fragile X syndrome most common

Down syndrome

• 1/600; 1/100 for maternal age of 40

▪ Trisomy/translocation 21 (95%)

▪ Moderate-severe MR

▪ Deceleration in development in 1st year

▪ Slanted palpebral fissures, epicanthal folds

▪ Protruding tongue, flat facies

▪ Small stature, thick neck, small ears

▪ Single palmer transverse crease

▪ Hypotonia

▪ Pleasant

▪ Congenital heart defects

▪ Higher risk of premature aging, Alzheimer’s by 35

Fragile X syndrome

• Long arm of chromosome at Xq27 (fragile site)

▪ 1/1250 males vs 1/2500 females

▪ Males with MR (10-12%), X-linked MR (20-50%)

▪ Moderate-severe MR

▪ IQ declines through early adolescence

▪ Delayed language

▪ Large prominent jaw and ears

▪ Long face

▪ Hyperextensible joints

▪ Short stature

▪ Post-pubertal macroorchidism

▪ ADHD, PDD, hand flapping, social anxiety, gaze aversion

Other biological causes

▪ Chromosomal disorders: Turner, Klinefelter

▪ Inborn errors of metabolism: Phenylketonuria, Glyogen storage disorders

▪ Developmental disorders of brain formation: Anencephaly, spina bifida, hydrocephalus, microcephaly

▪ Environmental influences: maternal malnutrition, placental insufficiency, gestational diabetes, in-utero ETOH or cocaine exposure

▪ Head injuries

▪ Infections: Herpes simplex, HIV, hemophilus influenza, meningitis, malaria, measles, rubella, toxoplasmosis

▪ Other disorders: Neurofibromatosis, tuberous sclerosis, muscular dystrophies

Medical assessment

▪ Genetic conditions, e.g., family Hx

▪ Evolution of condition, e.g., Rett’s

▪ Hx of significant birth trauma, exposure to environmental toxins

▪ Exposure to marked psychosocial adversity

▪ Physical exam: assessment of growth and development

▪ Dysmorphic features

▪ Hearing and visual screening

▪ Screening for metabolic, chromosomal, organic aciduria, heavy metal screening

▪ EEG if Sxs suggestive of seizures

▪ Neurology assessment, neuroimaging

Treatment

▪ Adequate and appropriate support

▪ Appropriate educational services including individualized educational planning, speech therapy, environmental manipulation (type of classroom, seat assignment)

▪ Extension of educational services to 21 years

▪ Rx of associated psychiatric disorders

▪ Behavioral intervention

▪ Quality of life issues

▪ Structured programs

▪ Sheltered employment

Additional Information

▪ Harinder S. Ghuman, Jaswinder K. Ghuman and Laurence W. Ford: Pervasive developmental Disorders and Learning Disorders, Chapter 16, pp 197-212. In HS Ghuman and RM Sarles (eds.) Handbook of Child and Adolescent Outpatient, Day Treatment and Community Psychiatry. Brunner/Mazel, 1998

▪ James C. Harris: Developmental Neuropsychiatry: Volume II, Oxford University Press, 1995: Mental Retardation; Chapter 5, pp. 91-126

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