Eric Courchesne (2), a leading scientist whose studies of the cerebellum have opened a new field of belief for the region's potential functions, suggested that autistics have a marked propensity for cerebellar lesions and Purkinje neuron loss, leading to an inability to "rapidly and accurately" change attention from one focus to another, particularly in the areas of visual and auditory stimuli.
Dr. Margaret Bauman, (Dept. of Neurology, Harvard Medical School and a child neurologist at Massachusetts General Hospital in Boston), and Dr. Thomas Kemper (Depts. of Neurology, Anatomy, and Pathology, Boston University School of Medicine) have a different hypothesis (3) which nonetheless correlates with Courchesne's theory. They believe that a dysfunctional neural structure may result in autistic behavior. Bauman and Kemper have discovered that the amygdala and hippocampus (parts of the limbic system which regulate memory and emotional reactions) are packed densely with neurons in the dissected brains of autistics. This complements Courchesne's idea that there are fewer Purkinje neurons in the cerebral regions of autistic children. Because Purkinje neurons are responsible for programmed cell death, a lack of them could result in an overabundance of neurons in the brains of autistic infants. If it is to be believed that humans develop many more neurological connections than are needed (the unnecessary neurons undergoing cell suicide in early development), then it stands to reason that a high neural density will result if there is an insufficient number of Purkinje cells. Likewise, the overabundance of neurons in the amygdala and hippocampus can potentially explain why autistics have difficulty responding to too much stimulus at a given moment: their systems overreact to the given input, and they respond by simply not reacting at all. These theories imply that autism has a genetic origin.
Studies of a Massachusetts town have attributed autism to congenital environmental causes. In Leomenster, a high proportion of autistic patients were found in homes "down-wind from the factory smokestacks" (4). Another statistic states that a pregnant woman who either contracts rubella or is given a vaccine for the disease, carries a greater likelihood of having a child affected with autism. It has also been suggested that the pertussis portion of the DPT vaccination may contribute to autism.
Genetic connections to autism must also be considered: there appears to be a sex linkage (it is four times as prevalent in males than in females). Fathers with autism had a 25% chance of passing the disorder onto their children, and in the case of identical twins, it was much more likely that both would suffer from autism because of their identical genetics (5).
Another suggested cause of autism involves Candida albicans, a bacteria which is commonly found in the body, but can develop into an overgrowth which results in thrush and various yeast infections. These attacks have been linked to depression, cystitis, and severe food and environmental allergies. Although humans all have a certain amount of this bacteria in their digestive tracts from infancy, usage of an antibiotic can upset the delicate balance and cause Candida albicans (6) to mutate into a form which can permeate mucous membranes and enter the bloodstream. This abundance of bacteria in the blood may be responsible for a series of allergies and sensitivities connected to autism. These hyper-sensitivities include allergies to wheat, corn, milk, sugar, and citrus fruit. It has also been suggested (8), "the most successful therapy has been the use of a combination of magnesium, vitamin B6, vitamin B5, DMG (dimethyl-glycine), and certain amino acids including 5-hydroxytryptophan (if tryptophan isn't available)." However, as this website disclaimed, "none of these theories change the fact that the basic process occurring is a neurochemical one, dealing with abnormal dopamine metabolism" (8).
Dr. Bernard Rimland of the Autism Research Institute in San Diego (9), cautioned parents about the use of mega-vitamin treatments, citing examples of children who were poisoned from an overdose of vitamin B-6. He also discussed studies done in which "children showed a remarkably wide range of benefits from the vitamin B6. There was better eye contact, less self-stimulatory behavior, more interest in the world around them, fewer tantrums, more speech, and in general the children became more normal, although they were not completely cured...(however) The children who showed improvement under B6 improved because they needed extra B6. Autism is thus in many cases a vitamin B6 dependency syndrome" (9). The Autism Reseach Institute advocates the usage of 60 to 2,000 mg of DMG per day, depending on how fast an individual metabolizes the food supplement. It has been suggested that folic acid (250 mcg per lb of body weight per day) has been seen to work in some cases (9). Vitamin C was also cited as a useful dietary supplement which might help the body regulate systems and might improve concentration and awareness. Rimland suggests using a B-complex vitamin and magnesium to attempt to control some of the more physically apparent symptoms of autism. However, although many websites advocated the use of various vitamins and minerals to treat autism, none portended to have found a cure, or even plausible reasons for the benefits. Although research is still in the beginning stages, and many treatments are mere shots in the dark, autistics and their families continue to hope that cures and qualified treatments are not far-off. There are many available resources including group home projects (10), family support (11), and a wide-range of literature (12), much of it written by survivors themselves.
2. Information about Eric Courchesne's lab.
3. Autism and the Limbic System from autism.org
4. Overview of Autism: Causes from autism.org
6. The Candida Albicans Mystery from the Environmental & Preventive Health Center of Atlanta
7. Allergy-induced Autism Network homepage
8. Environmental & Preventive Health Center of Atlanta's autism page
9. Nutrients useful in autism from autism.org
10. A Circle of Children helps raise autistic kida in the Toronto area.
11. On-The-Same-Page... An Asperger Syndrome and autism resource
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