Autism/Pervasive Developmental Disorder (PDD) Spectrum
Autism/Pervasive Developmental Disorder (PDD) Spectrum: Excerpt from The 5-Minute Pediatric Consult
Jeanne Greenblatt, MD, MPH
Autism/Pervasive Developmental Disorder Spectrum - BASICS
Autism/Pervasive Developmental Disorder Spectrum - description
- Neuropsychiatric syndromes characterized by:
- Delays/impairments in development of social, communication, play, and behavioral skills
- Onset in 1st years of life
- Frequent association with mental retardation
- Increased risk of seizure disorder
- Spectrum of related disorders:
- Autistic disorder: Symptoms prior to age 3 years, impairments in social relatedness, communication, and play, and restricted interests/activities
- Pervasive developmental disorder not otherwise specified: Subthreshold autism
- Asperger syndrome: Social deficits, restricted range of interests, relatively stronger language development, average to above-average cognitive abilities
- Childhood disintegrative disorder: Developmental deterioration after 24 months of age
- Rett syndrome: Females; hand-washing/wringing movements, head-growth deceleration before 48 months of age
Autism/Pervasive Developmental Disorder Spectrum - epidemiology
Autism/Pervasive Developmental Disorder Spectrum - incidence
- Observation of higher rates of autism have led to concern that autism may be increasing.
- Increased rates most likely related to changes in definition and, better diagnosis and awareness
Autism/Pervasive Developmental Disorder Spectrum - prevalence
- Autistic disorder: 13 cases/10,000
- Pervasive developmental disorder not otherwise specified: 20–50 cases/10,000
- Asperger syndrome: 2.6 cases/10,000
- Childhood disintegrative disorder: 0.11 cases/10,000; as of 1999, 106 cases reported
- Autistic disorder: Male:Female ~4:1
- Females have more severe symptoms:
- 50% of cases exhibit severe to profound mental retardation.
- 30% of cases have mild to moderate mental retardation.
- 20% of cases have normal cognitive abilities.
- Asperger syndrome: More common in boys
- Rett disorder: 0.83 cases/1,000 females
- Childhood disintegrative disorder: Occurs predominately in males
Autism/Pervasive Developmental Disorder Spectrum - etiology
- No single cause of autism identified, syndrome likely has multiple etiologies; toxic factors are controversial, dysimmune causes under research
- Neuroimaging reveals increased brain size
- Elevated serotonin (research)
- Twin genetic studies implicate genetic factors
- Siblings of proband at higher risk
- Monozygotic twins have higher concordance rate than dizygotic twins
- ~1/100 persons with autism exhibit fragile X anomaly
- Rett disorder caused in a majority of cases by mutations in the MeCP2 gene
- Rate of autism in tuberous sclerosis elevated
- No proof that environmental agents such as mercury or gluten cause autism, but many claims have been made.
Autism/Pervasive Developmental Disorder Spectrum - associated conditions
- Prenatal: Toxemia, rubella, cytomegalovirus, toxoplasmosis
- Perinatal: Anoxia, trauma, hyperbilirubinemia
- Genetic/Chromosomal: Angelman syndrome, ring chromosome 15, Prader-Willi syndrome, fragile X syndrome, trisomy 21, XYY syndrome, tuberous sclerosis, other
- Metabolic: Phenylketonuria, hyperthyroidism, histidinemia, lipidosis
- Microcephaly, hydrocephalus, cerebral dysgeneses
- Infantile spasms, meningitis, encephalitis
Autism/Pervasive Developmental Disorder Spectrum - DIAGNOSIS
Autism/Pervasive Developmental Disorder Spectrum - signs & symptoms
- Delays/impairments in language development:
- Rare cases present with “acquired epileptic aphasia” (paroxysmal electroencephalogram in sleep)
- Marked inability to initiate and sustain conversation (when speech is present)
- Cognitive delays
- Impairment in eye contact, facial expression, nonverbal social behaviors
- Impaired social interactions
- Impaired peer relationships
- Stereotypies (e.g., rocking, hand flapping)
- Restricted range of interests/activities
- Attachment to unusual objects, fascination with parts of objects
- Behavioral rigidity, distress with changes in routine
- Lack of imaginary play appropriate to developmental level
- In Rett disorder: Scoliosis, breathing problems, seizures, motor problems
Autism/Pervasive Developmental Disorder Spectrum - history
- Prenatal, neonatal, developmental, medical, family, and social history essential
- Diagnosis based on significant impairments in: Verbal/nonverbal communication, social skills, presence of restrictive/repetitive behaviors
- Absence of verbal or nonverbal communication joining parent and child’s attention, stereotyped behavior, behavioral rigidity, tactile defensiveness, apraxia, anorexia, narrow diet
- Comorbidities: Epilepsy, attention problems, sleep disturbances, obsessive-compulsive disorder traits, tics, anxiety, depression, epilepsy, mood instability, aggression, lack of fear, mistreatment of animals, self-injury
Autism/Pervasive Developmental Disorder Spectrum - physical exam
- Evaluate for growth disturbance
- Signs of self-injurious behavior
- Stereotypical behavior, involuntary movements, motor coordination abnormalities, mirror/overflow movements
- Ophthalmologic/audiologic evaluations to rule out visual or hearing deficits
- Long, thin face, prominent ears: Fragile X (macro-orchidism may not be present until after puberty
- Pigmented lesions: Neurocutaneous syndromes, hypopigmented macules/fibromas suggest tuberous sclerosis
- Microcephaly: Toxoplasmosis, other viruses, rubella, cytomegalovirus, herpes virus (TORCH) infection, Angelman syndrome, Rett disorder
- Macrocephaly: Neurocutaneous disorder, storage disease, hydrocephalus, or no identifiable cause
- Presence of spasticity, visual loss, ataxia: Leukodystrophy
Autism/Pervasive Developmental Disorder Spectrum - tests
Autism/Pervasive Developmental Disorder Spectrum - lab
- Neurodiagnostic tests not useful unless specific neurologic disorders suspected
- Routine neuroimaging: Limited diagnostic or practical value, consider if child is retarded:
- Electroencephalogram if epilepsy is suspected (~25%).
- Chromosome studies: If child is retarded
- Inborn error screen: Detects phenylketonuria, other amino acid disorders
- Head MRI/CT: If focal neurologic deficit, suspect neurocutaneous disease, or retardation is present
- Toxoplasma, other viruses, rubella, cytomegalovirus, herpesvirus titers: Setting of microcephaly
- CBC: Evaluation of growth delay and/or pica
- Blood lead level: R/O lead intoxication
- Thyroid function tests: R/O hyper/hypothyroidism
- Audiogram/brainstem auditory evoked response: Recommended for children with speech and language delay
Autism/Pervasive Developmental Disorder Spectrum - differencial diagnosis
- Mental retardation: MAY not have pervasive developmental disorder/autism IF communication, behavior, play, and social skills appropriate to developmental age
- Deafness: Delayed/absent oral language acquisition; behavioral/social difficulties may relate to language delays
- Mixed receptive-expressive language disorder: No deficits in social interactions or restricted range of interests
- Selective mutism
- Anxiety, obsessive-compulsive disorder, or PTSD
Autism/Pervasive Developmental Disorder Spectrum - TREATMENT
Autism/Pervasive Developmental Disorder Spectrum - general measures
- Psychoeducational assessment: Support cognitive, developmental, adaptive, functional, communication, and social needs:
- Intensive educational/behavioral interventions should target acquisition of communicative, social, cognitive skills
- Early sustained structured behavioral intervention using applied behavior analysis (ABA) and behavior modification highly beneficial in many children
- Vocational training important for some adolescents and adults
- Social skills training especially for higher-functioning patients is essential
- Education and support for parents and siblings integral to treatment
- Psychotherapy not indicated to address core features of autism and pervasive developmental disorder
- Screening and diagnostic tests:
- Checklist for Autism in Toddlers (CHAT)
- Autism Diagnostic Interview - Revised (ADI-R)
- Childhood Autism Rating Scale (CARS)
- Autism and the pervasive developmental disorder spectrum disorders vary greatly in symptom presentation. Discordancy among clinicians’ diagnoses, and under- and overdiagnoses of these disorders are common.
- Symptom presentation differs at different stages of development.
- Medication often not helpful, patients often develop side effects
- Subclinical seizure types may be detected only on electroencephalogram.
Autism/Pervasive Developmental Disorder Spectrum - diet
No proof that glutenfree diets are helpful, but there are many claims of effectiveness of glutenfree diets.
Autism/Pervasive Developmental Disorder Spectrum - medication
- Pharmacotherapy does not treat most core symptoms of autism.
- Medication helps treat comorbid symptoms/behaviors that interfere with patient’s ability to function at highest potential in educational/social activities.
- Symptoms/medications to consider:
- Self-injurious behavior: Risperidone (now FDA approved for this indication), atypical/typical antipsychotics, guanfacine, clonidine
- Sleep disturbances: Melatonin, clonidine, trazodone
- Seizures: Newer anticonvulsants, carbamazepine, phenytoin, valproate, barbiturates often worsen hyperactivity
- Hyperactivity/attention difficulties: Psychostimulants, Strattera, bupropion, venlafaxine, clonidine, guanfacine
- Obsessive-compulsive disorder symptoms/perseveration: SSRIs, clomipramine
- Tic disorders: Guanfacine, clonidine, atypical/typical antipsychotics
- Depression: SSRIs, bupropion, venlafaxine
- Anxiety: SSRIs, buspirone, venlafaxine, benzodiazepines (rarely as may increase disorganization and agitation)
- Aggression: Risperidone, atypical antipsychotics, SSRIs, anticonvulsants, guanfacine
Autism/Pervasive Developmental Disorder Spectrum - FOLLOW UP
Autism/Pervasive Developmental Disorder Spectrum - patient monitoring
- Prognosis linked to cognitive ability and acquisition of social/communication skills
- Early provision of services can improve prognosis
- If no language by 5 years of age, language development unlikely
- Children with autism/pervasive developmental disorder often require lifelong treatment and support.
- Physician should remain active in long-term treatment planning and individual and family support
Autism/Pervasive Developmental Disorder Spectrum - bibliography
- Committee on Children with Disabilities. Technical report: The pediatrician’s role in the diagnosis and management of autistic spectrum disorder in children. Pediatrics. 2001;107(5):E85.
Jacobson JW, Foxx RM, Mulick JA. Controversial Therapies for Developmental Disabilities: Fad, Fashion and Science in Professional Practice. Mahwah, NJ: Lawrence Erlbaum Associates, 2005.- Moeschler JB, Shevell M. Committee on Genetics (2006): Clinical genetic evaluation of the child with mental retardation or developmental delays. Pediatrics. 2006;117:2304-2316
Scahill L, Martin A. Psychopharmacology. In: Volkmarr FR, Klin A, Paul R, et al. eds. Handbook of Autism and Pervasive Developmental Disorders. Hoboken, NJ: Wiley; 2005:1102–1122.- Volkmar F, Cook EH Jr, Pomeroy J, et al. Practice parameters for the assessment and treatment of children, adolescents, and adults with autism and other pervasive developmental disorders. J Amer Acad Child Adolesc Psychiatry. 1999;38(12 suppl):32S–54S.
- Walker DR, Thompson A, Zwaigenbaum L, et al. Specifying PDD-NOS: A comparison of PDD-NOS, Asperger syndrome and autism. J Am Acad Child Adolesc Psychiatry. 2004;43(2):172–180.
Autism/Pervasive Developmental Disorder Spectrum - ADDITIONAL READING
- Gutstein S, Sheely R. Relationship Development Intervention Activities for Young Children. London: Jessica Kingsley Publications; 2002.
Autism/Pervasive Developmental Disorder Spectrum - CODES
Autism/Pervasive Developmental Disorder Spectrum - icd9
299.0 Infantile autism
Autism/Pervasive Developmental Disorder Spectrum - FAQ
- Q: What are the chances of having a 2nd child with autism?
- A: In families with 1 child with autism, the recurrence risk for subsequent children is 3–7%. This is in contrast to the risk in the general population, which is 0.1–0.2%.
- Q: What is the value of brain imaging in autism?
- A: MRI may help diagnose a heritable syndrome with genetic counseling implications (e.g., leukodystrophy, tuberous sclerosis), but is usually unhelpful in high-functioning cases without focal neurological findings.
- Q: Is the prevalence of children with autism spectrum disorders increasing?
- A: The increased numbers of children with autism spectrum disorders is most likely related to a combination of: Increased awareness, better diagnostic definitions, increased diagnostic accuracy (especially at the ends of the spectrum), and diagnostic shift (e.g., cases previously diagnosed with only mental retardation are more likely to now be diagnosed with autism and mental retardation) rather than to an actual increase in prevalence of the disorder.
Book Source Details
- Book Title: The 5-Minute Pediatric Consult
- Author(s): M. William Schwartz MD; et al.
- Year of Publication: 2008
- Copyright Details: The 5-Minute Pediatric Consult, Copyright © 2008 Lippincott Williams & Wilkins.
More About Pervasive developmental disorders
More Medical Textbooks Online about Pervasive developmental disorders
Review other book chapters online related to Pervasive developmental disorders:
Copyright notice for book excerpts: Copyright © 2008 Lippincott Williams & Wilkins. All rights reserved.
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More About This Book:
Title: The 5-Minute Pediatric Consult
Authors: M. William Schwartz MD; et al.
Publisher: Lippincott Williams & Wilkins
Copyright: 2008
ISBN: 0-7817-7577-9
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