Latest update: August 21st, 2012
Distant mothers. MMR vaccines. Genetic mutations. Contaminated drinking water. These are just a few of the many factors that scientists and doctors have attributed to the cause of autism throughout the last 50 years, since autism was first established as a separate diagnosis in the late 1960’s. In recent years the prevalence of autism spectrum disorders in American children has risen to one in every one 150. Yet, despite these attempts none have proved successful in isolating a definite cause. In fact, from diagnosis to treatments, autism research is rife with uncertainties and trial-and-error theories, many of which have thus far been disproved and fallen to the proverbial wayside.
Unfortunately, without a definite cause, the hope to cure autism is also hampered. While there is no known cure for autism, those diagnosed have the option of undergoing treatments that, at best, lessen the deficits associated with autism and improve the quality of life and functional independence. While the goal of these therapies is to correct the developmental disability that mostly affects a person with autism – the ability to communicate and interact with others socially – the key to completely eradicating the presence of autism altogether is in determining its origins.
Attempting just that, research scientists at Albert Einstein College of Medicine (Yeshiva University) have proposed a new theory focusing on the neurological make-up of people with autism that could lead to groundbreaking changes in the treatment and overall knowledge of autism. The theory – co-authored by Dr. Mark F. Mehler, M.D., chairman of neurology and director of the Institute for Brain Disorders and Neural Regeneration at Einstein, and Dr. Dominick P. Purpura, M.D., dean emeritus and professor of neuroscience at Einstein – arose from an observational study of autistic children that illuminated a recurring phenomenon. The researchers noticed that during bouts of fever, children with the disorder displayed a behavioral improvement that suddenly reverts once the fever subsides. This observation has led the proposal that the brain of an individual with autism is normal, but “dysregulated,” and the symptoms can therefore be reversed.
The theory pinpoints the locus coeruleus-noradrenergic (LC-NA) system as the part of the brain that is involved in causing autism. “The LC-NA system is the only brain system involved both in producing fever and controlling behavior,” Purpura said.
The locus coeruleus-noradrenergic, a Latin name literally defined as ‘blue spot’ due to its shading, plays a key role in our concentration and focusing attention, skills that those with autism have great difficulty cultivating. Additionally, the LC-NA activates other areas of the brain related to complex cognitive tasks. In an autistic child, according to Mehler and Purpura, it is a combination of genetic and environmental factors (particularly stress while the fetus is in the later stages of development, a time that renders the fetal brain especially sensitive to disturbances) that causes the dysregulation in this area of the brain.
Support for this theory came from a 2008 study published in the Journal of Autism and Developmental Disorders that found a higher frequency of autism in children whose mothers were exposed to hurricanes during pregnancy. Fever activates the locus coeruleus, and the stimulation allows it to do its job, regulating reactions and centering attention. The fundamental element to this finding is that fever allows the autistic child to behave normally, “This could not happen if autism was caused by a lesion or some structural abnormality of the brain,” Purpura said.
“If the locus coeruleus is impaired in autism, it is probably because tens or hundreds, maybe even thousands, of genes are dysregulated in subtle and complex ways,” Mehler said. “The only way you can reverse this process is with epigenetic therapies, which, we are beginning to learn, have the ability to coordinate very large integrated gene networks.”
Epigenetics refers to gene changes that occur that have been hypothesized to be passed from parent to fetus. Epigenetics has largely been associated with diseases, and epigenetic theory seeks to correct these gene changes.
The central theorists warn that this advance is no sudden cure to autism, a disease which has baffled the medical field for some time; it is, however, a door opening into better understanding autism and finding more effective treatment.
Mehler and Purpura’s publication on their theory, entitled “utism, fever, epigenetics and the locus coeruleus” was featured in the March issue of the journal Brain Research Reviews.Jasmine Weg
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