Introduction

What is Autism?
Autism develops before 30 mo of age. It is characterized by a qualitative impairment in verbal and nonverbal communication in imaginative activity and in reciprocal social interactions.

Synonyms
Pervasive Developmental Disorders and Childhood Psychosis

Introduction:
Kanner (1943) described a syndrome characterized by failure to establish communication with others, obsession to continue "sameness," failure of language communication, aloofness, preoccupation with handling small objects, and an inability to anticipate with appropriate body positioning the likelihood of being picked up.

Incidences
The prevalence is 3-4/10,000 children. The disorder is much more common in males than in females (3-4:1). Autism can be associated with other neurologic disorders, particularly turberous sclerosis, seizure disorders, and to a lesser extent, fragile X syndrome.

Causes
Poorly understood, but probable suggestions are:

• Underlying encephalopathy, as well as brain injury during gestation and the perinatal period.
• Known to be associated with known hereditary conditions, including tuberous sclerosis and other conditions, such as infantile spasms

The attempts at identifying genetic factors and chromosomal abnormalities that are associated with autism have been relatively unsuccessful.

Clinical Menifestation

The characteristic set of behaviors include:

• Qualitative impairment in reciprocal social interaction,
• Qualitative impairment of verbal and nonverbal communication and imaginative activity,
• Markedly restricted repertoire of activities and interests.

9-10 Month of age
Abnormal behaviors in form of diminution in crying, general motor activity, and feeding. Language development is usually delayed, and children do not respond appropriately to noises. Motor milestones are often normal.

18 to 24 months
Some children appear normal until 18 to 24 months of age when loss of social and language milestones and a relative lack of communication occur.

Children with autism continue to eat, poorly, particularly solid foods. They may become fascinated with particular toys while rejecting others. Before the age of 13 months, stereotypic behavior and gestures are often manifest. Affected children seek repetitive tactile, visual, vestibular, and auditory stimulation. The autistic child may forcefully refuse any tactile interaction with others.

The movements of autistic children are varied, including flapping of the hands and arms, head-banging, rhythmic head movements, rocking from the pelvis while seated, whirling in place, or rapid flicking of the nose or ears. The frequency in intensity of these movements varies. The activities described often are associated with children who have mental retardation, including behavioral abnormalities and repetitive movements.

Autistic children usually have better nonverbal than verbal skills. Delay in development of language skills is one of the most common reasons for parents seeking professional help for their affected child. Children may perseverate or have persistent and dismaying echolalia. In addition to expressive problems, comprehension difficulties may be severe.

Autistic children who learn to read rarely have significant understanding of the meaning of the material. Unfortunately, nonverbal communication also is usually deficient.

Many suffer from seizures.

Mental efficiency

Mental deficiency may be severe, but at the same time approximately 25% to 33% have IQs in the normal range. However, the deficits in language and socialization make it difficult to obtain an accurate estimate of the autistic child's intellectual potential. Occasionally, an autistic child may have an isolated, remarkable talent, analogous to that of the adult savant.

Neuropathology

Pathologic abnormalities have not been conclusive, but in brain increased cell-packing density and reduced neuronal cell size, and an absence of obvious gliosis are suggestive of abnormal development of portions of the limbic system and cerebellar circuits. Autopsy studies have shown cerebellar developmental hypoplasia in many autistic patients

Biological studies

• Dysfunction of association cortex and decreased brain cellular metabolism has been observed on PET, SPECT, MRI, and EEG and evoked potential studies.
• Aberrant dopamine functioning ahs been implicated, and abnormalities have been suggested in a number of catecholamine pathways. Increased levels of serotonin have also been noted.