AUTISTIC SPECTRUM DISORDERS

AUTISTIC SPECTRUM DISORDERS (ASDs)

ASDs/Pervasive developmental disorders (PDDs) include autism, Asperger’s syndrome and Rett’s syndrome and are characterized by the three major features, namely:

      1.       Impaired social interaction

      2.       Impaired communication

      3.       Impaired imagination

Asperger’s disorder is characterized by impaired social interaction though communication and cognitive function are preserved. The child interacts with others but in an appropriate way. He approaches others in endless monologues on a topic of interest to him but without appreciating that the other party is disinterested.

Rett’s syndrome is characterized by regression of motor milestones and language (after 1 year of age; invariably in females), ataxic gait or fine tremors of hands, sighing respiration with intermittent apneic spells, repetitive hand-wringing movements and autistic behavior.

Autism is a complex developmental disability appearing in first 3 years of life. It is a sort of poorly understood psychosis in which the child is highly withdrawn and seemingly living in an isolated world of his own with complete failure to react to other people, communication problems, extreme aloofness and obsessive desire for sameness in routine and surroundings. In addition, there may be mental retardation, seizures or learning disabilities. Autism is not caused by bad parenting.

The following details pertain to autism.

Epidemiology

Prevalence of classical autism is estimated to be around 4-5 in 10,000 population. Most cases are first born or late born (fourth or more in sibling rank). Boys suffer more often than girls.

Etiology

Various hypothesis about its etiology include:

1.       Genetic predisposition in view of its occurrence in pairs of identical and fraternal twins. Sueceptibility locus is on long arm of chromosome 13 and 17.

2.       Neurologic theory in the form of damage to reticular formation of brainstem about fifth week of intrauterine life(rubella), leading to “a widow of vulnerability” for autism.

3.       Organic theory, based on abnormal brain rhythms in EEG, bames a neurologic dysfunction (PKU, infantile spasms, herpes simplex encephalitis) as the cause of autism.

4.       Psychological theory that totally blames parents for autism in the child is not widely accepted.

Clinical features

The autistic child may have an organic brain disease as in blindness, deafness or mental retardation, or from emotional deprivation. He may, however, be of normal intelligence, some gifted with “islands of brilliance”. The child’s potential is masked and not low or absent.

The child takes no interest in environments and is negativistic. He fails to develop normal relationship with others, including his mother , and does not react to a situation in an expected manner. Lack of eye contact, facial expression and gestures is missing. Speech is either poorly developed or not developed at all. About 60% patients develop highly individualized language. They insist on following same routine everyday. Some children may be attracted by spinning or rotating objects. Response to stimuli may also be unusual.

Seizure are more likely in autistic children.

Diagnosis

Early identification, based by and large on clinical grounds, is of paramount  importance. Role of investigation is limited to determining the existence of predisposing or accompanying factors.

Management

General

The cornerstone of management is to establish contact and communication with the child so as prevent him from sliding into utter isolation. Providing a structured predictable environment employing play, language therapy and interpersonal  exercises helps. It should revolve around the following three strategies.

1.       Management of abnormal behavior( behavior modification)

2.       Help for the family

3.       Arrangement for educational and social services

Pharmacotherapy

There is no medication to treat autism such. However ,  specific symptoms(aggression, temper tantrum) may warrant medication. Neuroleptics (olanzapine, risperidone), dopamine antagonists (haloperidol) may be selectively employed to relieve comorbidity.

Prognosis

Prognosis is guarded. Only a small proportion  of the children grow up to acquire language and social skills and have self-sufficient (independent) existence in the community. Most end up in institutions sooner or later.