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This essay discusses an important view concerning the differential diagnosis of infantile autism. As you will see, the symptomology common to autistic infants mimics that of severely retarded children in the early months of life. In addition, the identification of autism as a "disease" in infants is impeded by the lack of biological evidence to support such a diagnosis.
Autism has, in multiple studies, been related to a multitude of organic dysfunction’s. These include everything from genetic markers to metabolic diseases. A few of these dysfunction’s, be they associated or causative, are discussed in this essay.
At present, physicians can base their early diagnoses only on the emotional and physical symptoms present in nearly 82% of all autistic children. However, the term "autism" as a disease should not be used to describe one disorder characterized by a certain core deficit, but rather should be considered an umbrella term to be used to describe a variety of associated disorders.
The early diagnosis of autistic disorders in infants is crucial for the success of treatment programs that have proven somewhat effective in recent years. There is no cure for autism, and no wonder drugs that are corrective of autistic behavior. Treatment therefore is directed on an emotional level which must begin in the early years of life to be successful. It has been shown that the period of psychological attachment plays a crucial role in predetermining autistic behavior.
The Early Onset of Autism
As previously discussed, the onset of infantile autism is characterized by a set of classic symptoms common to nearly all autistic children. Most often, it is not the physician who notices these symptoms, but rather the responsibility falls on the primary caregiver to recognize that something is not quite right with the infant. By relying on the perceptiveness of the non-professional, the early diagnosis of infantile autism is hindered even further.
Within the first 30 months of life, the autistic infant will show emotional deficits and uncommon reactions to certain stimuli that is the mark of "classic", or "Kanner’s Autism". These symptoms can be, and most often are, easily confused with the symptoms presented by severely retarded children. From the sources cited in this essay, I have compiled a list of 20 common findings of researchers in autism that are manifested in autistic children by the age of 30 months. Once again, it is essential at this stage to be familiar with these symptoms, and to be available to the possibility that your patient or child may be autistic. The classic symptoms are summarized below. They are sub-grouped into four categories including Social, Communication, Play-Behavior, and Perception. The most prevalent and easily recognizable of these symptoms are typed in italics. Of these symptoms, the ones that arise from the Perception subgroup are the most manifest and most often reported of the symptoms.
Social Symptom’s Communication Deficit’s
*Appears to be isolated from surroundings *Content with own act-ivity
*Doesn’t smile when expected *Difficulty imitating movements
*Difficulty in making eye contact *Late speech development
*Indifferent to presence of parents in room *Doesn’t point to objects
*Requires non-disruptive environment for satiety *Doesn’t comprehend language
*Can’t indicate own wishes
Play Behavior Perception Deficits
*Doesn’t play "like other children" *Suspicion of deafness
*Occupies self only when alone *Empty gaze
*Plays only with hard objects *Interested only in certain parts of
certain objects
*Odd-looking" gazes
*Interested in objects in motion
*Overexcited when tickled
*Strange reactions to sound
These symptoms were present in 82% of the children diagnosed in 1991. Upon viewing the list, one has to speculate the credibility of these symptoms as true indications of infantile autism. A suspicion should arise bearing in mind the fact that of all the cases diagnosed in 1989, nearly 59% were later diagnosed as not autistic, but had other related disorders. However, of the authors from which I compiled this list, many reported their diagnoses to remain accurate in about three-quarters of all cases.
As I mentioned, these symptoms are considered common to autistic children as well as severely retarded children. This presents yet another problem in making a differential diagnosis. Such a problem in fact that many pediatricians are reluctant to make a distinction until later in life. This is detrimental as I said to the treatment programs that are focused on the early emotional attachment period of life, which is around one to two years of age in most cases.
Searching for An Organic Basis of Autism
The search for a biological basis of autism has followed a tortuous path throughout the past thirty years. Nearly every area of the brain has, at one time or another, been believed to be the origin of autism. Many sophisticated studies has been performed, many with great success. These studies has relied on neurobiological techniques such as immunocytochemistry, CT scans, MRI’s, PET scans, and differential staining techniques. A huge variety of conclusions have been drawn from these studies. The most important conclusion that has been elucidated, is that no one knows yet where autism originates. A more practical approach in research has lead to the convention that "autism" as a disease is a term that actually encompasses a variety of associated cognitive disorders with varying biological foundations. Children that have been diagnosed with autism are in reality afflicted with one or more disorders that to date have not been classified and named. These children therefore, are thrown into a generic grouping and labeled autistic. Obviously, this fact illustrates that much more research is needed in autism to help discover the true identity of these diseases and their organic origins. Some studies on neurotransmitters have shown some success. Serotonin is elevated in body fluids in a substantial subgroup of autistic patients, but this could be due to concomitant mental retardation rather than autism. Dopamine may be dysfunctional in many patients as well. Endorphin fraction II might be raised in the CNS, in at least some cases. This has been linked to those patients that display self-injurious behavior in particular.
Autism has been linked to a variety of metabolic disorders as well. Many authors have shown a connection between PKU and autism. Animal studies have shown that experimental hyperphenylalaninemia which imitates PKU interferes with myelination of the brain. Abnormalities in purine metabolism and lactic acidosis have also been associated with autism.
Many infectious diseases, such as congenital rubella and post-natal herpes have been associated with autism. In isolated cases, congenital cytomegalovirus infection has lead to autism.
There is a substantial amount of evidence that also points to a genetic origin of autism. Studies with monozygotic twins suggest that autism, or at least an autistic-like disorder, is inherited. There is also strong evidence of the Fragile X Syndrome as being extremely associated with infantile autism. Also, a nearly four to one ratio of autistic boys to girls points to a sex-linked inheritance. It is the convention that genetic predisposition at least, is evident in many cases. Siblings are 50 to 100 times as likely to illustrate autistic symptoms than non-sibling relatives. The search for the genetic marker, or markers, as the case may be, is fast and furious at present. Many avenues are being pursued in many different directions. Perhaps history will repeat itself and someone will stumble across the answer to this puzzling disease.