Abnormal Brain Structures Observed in
Children with Attention Deficit Disorder and Learning Disabilities
University of South Florida Graduate Research Project - Special Education Department
Environmental Causes of Learning Disabilities and Attention Deficit Disorder
Information Compiled by Richard W. Pressinger, M.Ed.
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There has been a growing amount of medical research identifying various types of brain damage in children with attention deficit disorder, hyperactivity and learning disabilities. The nationwide increases being observed in these child disorders is being explained by many scientists as resulting from environmental and chemical exposures during pregnancy. These include the obvious culprits such as alcohol and cigarette use, but serious new concerns are being raised by government and university research showing many common household chemicals can also contribute to subtle damage to the developing brain during pregnancy. These include cleaning chemicals, home pesticide use, cosmetic chemicals, prescription medications, artificial food additives, chemicals in plastics, synthetic perfume and cologne ingredients, job chemicals, and the pesticide chlordane (found as a contaminant in the air of most U.S. homes built before 1988). In a summary report entitled the Principles of Developmental Neurotoxicity, from the National Center for Toxicological Research (7), it was stated:
If we are to agree with this research that repeated exposure to certain consumer chemicals can weaken or damage brain growth and result in increases in mental retardation, learning disabilities or behavior disorders, then it is quite plausible to expect a corresponding subtle decrease in mental function of our above average students, but detecting such effects will be extremely difficult. Also, it is important to realize that a decrease in mental capacity is not strictly limited to academic function. The human brain is also responsible for all other mental functions including talent, personality, sense of humor, articulation skills and even conscience oriented behavior. Therefore, it is quite realistic to suspect the potential for these areas of the human brain to be compromised by the same compounds being found to cause learning disabilities and attention deficit disorder. Many researchers now agree, as will be addressed in this paper, that subtle brain disorders can be the cause of learning disabilities, hyperactivity, attention deficit and even propensity toward behavior problems such as aggression and behavior "void of conscience." In fact, it has been only recently that abnormalities in brain structure have been found in people with learning disabilities and attention deficit disorders. Damage to Brain Structure Found in Students
At age 20, six days after beginning his first paying job, the patient died suddenly as the result of an accidental fall from a great height. The cause of death was multiple internal injuries producing massive bleeding. An autopsy of the brain showed no evidence of trauma or other gross abnormalities according to the researchers. After receiving permission from the man’s parents, the physicians conducted a thorough examination of the man’s brain structure. The results are seen in the picture at left. The top photograph shows a normal brain with good column organization and larger cells. The bottom (learning disabilities) brain shows poor organization and smaller cells. The researchers stated the area of the learning disability brain shows abnormalities also to a location in the brain called the "Wernicke’s Speech Area," and appears to play a particularly important role in language function. The researchers concluded by saying,
Learning Disability & Attention
Deficit Children Have A method for determining abnormalities in the brains of living learning disability (LD) and attention deficit disorder (ADD) children was used in a study of 13 LD and ADD children at the Department of Neurology, Kennedy Institute in Denmark (13). The study was conducted using a method called emission computed tomography which takes a picture of a "slice" of the brain after the child inhales a very small amount of a radioactive substance called xenon 133. The picture then allows the scientists to visually see how much blood is being used by different parts of the brain (a greater illumination in the picture represents increased blood flow). This also represents the level of metabolic activity in the brain areas. After comparing the photographs taken of all children the investigators stated,
To bring this into perspective and without the multi-syllable medical terms, the investigators found lower levels of blood in Attention Deficit Disorder children in the area of the brain that is just behind the central forehead going in about an inch or two. When ritalin was given and measurements taken again, normal blood flow was created, thereby providing a biological explanation of why children improve after taking Ritalin. Glucose Metabolism Defective in In a study of hyperactive students conducted at the National Institute of Mental Health, reported in the November 15, 1990 New England Journal of Medicine, researchers found the brain cells of these individuals were using lower levels of glucose than other non-hyperactive people (glucose is the primary fuel used by the brain cells which enables them to function). In a study of hyperactive students conducted at the National Institute of Mental Health, reported in the November 15, 1990 New England Journal of Medicine, researchers found the brain cells of these individuals were using lower levels of glucose than other non-hyperactive people (glucose is the primary fuel used by the brain cells which enables them to function). In conclusion, the investigators stated:
Since there is common agreement among researchers and medical professionals that learning disabilities and attention deficits can, in fact, result from subtle brain damage caused by a variety of common environmental chemical exposures in today's "modern" society, it is imperative to organize this information into an easy to read format. This will give couples who desire to have children a far better chance of having a child that is neurologically healthy without the complications accompanied by attention deficit disorder or learning disabilities. This has been the goal of this research project.
In the 1975 Canadian Psychiatric Association Journal, Dr. R. Denson discusses the increase society has observed in children with hyperactive disorders.
For more information on how environmental exposures and www.chem-tox.com/pregnancy/learning_disabilities.htm
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Examples of visually detected brain
damage in learning disability and attention deficit individuals are discussed in three
different research projects below. One incident reported by Dr. Albert Galaburda at
Harvard Medical School (9), investigated the unfortunate accidental death of an individual
with known serious reading learning disabilities in school. At age 18 he had a reading
level of fourth grade despite a 105 intelligence score on the Stanford- Binet test.
Because of this discrepancy in intelligence and reading level, he was given the diagnosis
of Developmental Dyslexia. He also had moderate math difficulties and mild
difficulties with right-left orientation and finger recognition.