AUTISM AS A DEVELOPMENTAL DISORDER OF BRAIN FUNCTION
Rapin I
Albert
Einstein College of Medicine, Bronx NY, USA
Earlier viewed as the behavioral response of
toddlers or preschool children to inadequate parenting, we know today that
autism is a developmental disorder of the immature brain that affects (1)
sociability, (2) verbal and
nonverbal communication and imaginative play, and (3) cognitive and
behavioral flexibility. It has
a wide range of severity and is not rare. It has many non-genetic and genetic etiologies. Single
gene defects are rare as recurrence within sibships is under 10%. Some children may inherit excess
vulnerability to particular--as yet undefined--trivial, usually easily
tolerated environmental insults.
As autism is behaviorally
defined, it has no exclusionary etiologic or physical criteria: what counts
is what brain circuits are dysfunctional, not what made them so. Stereotypic purposeless movements,
joint laxity, toe walking, and apraxia and a mixture of hyper- and hypo-reactivity
to sensory stimuli in any modality are common. Sleep disorders and difficulty attending to activities
introduced by another person are troublesome. Cognition ranges from mental retardation to normal IQ,
with uneven underlying skills and concreteness. A third will have experienced at least two unprovoked
epileptic seizures by adolescence or have had subclinical EEG epileptiform
activity in slow sleep. All children who do not speak well require definitive
assessment of hearing. For
clinical purposes, if the history and clinical examination do not suggest a
diagnosable biologic condition, results of powerful research tools like
extensive cytogenetic, molecular, biochemical, and imaging tests rarely
modify management. The most
effective interventions are early intensive education of the child that
addresses both language and behavior, and training of parents in behavior
management strategies.
Medications do not alter outcome but may help some troublesome
behaviors.