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About Autism Spectrum Disorder: "Classic" Autism

Autism is a complex developmental disability that typically appears during the first three years of life. Autism impacts the normal development of the brain in the areas of social interaction and communication skills. Children and adults with autism typically have difficulties in verbal and non-verbal communication, social interactions, leisure activities, and imaginative play. The disorder makes it difficult for them to communicate and relate to the outside world. People with autism may exhibit, aggressive and/or self injurious behavior, repeated body movements, unusual responses to people, resistance to changes in routine, and unusual attachments or interests in objects. Autism is a spectrum disorder; symptoms can vary greatly from mild to severe

Autism is the 2nd leading childhood developmental disorder behind Down’s syndrome. It is a complex neurodevelopmental disorder that is present throughout the lifespan. It is part of a group of disorders known as Autism Spectrum Disorders (ASD), including PDD-NOS and Asperger's syndrome. Although the classic form of autism can be distinguished from other forms of autism spectrum disorder, the terms are often used interchangeably.

Some people believe that there might be two manifestations of classical autism, regressive autism and early infantile autism. Early infantile autism is present at birth while regressive autism begins before the age of 3 and often around 18 months. It appears that approximatelty 30% of cases of classic autism are of the regressive type.

Fragile X Syndrome
Fragile X syndrome is the most common single gene cause of autism spectrum disorders with mental retardation. It was so named because one part of the X chromosome has a defective piece that appears pinched and fragile when under a microscope. Fragile X syndrome affects about two to five percent of people with ASD. As an inherited disorder, it is important for families to be aware of any history of Fragile X in family members. Fragile X can be detected through genetic testing.

Tuberous Sclerosis
Tuberous sclerosis (TSC) is a rare genetic disease that causes benign tumors to grow in the brain and on other vital organs such as the kidneys, heart, eyes, lungs, and skin. It commonly affects the central nervous system. In addition to the benign tumors that frequently occur in TSC, other common symptoms include seizures, mental retardation, behavior problems, and skin abnormalities. TSC may be present at birth, but signs of the disorder can be subtle and full symptoms may take some time to develop. Together with Fragile X syndrome, tuberous sclerosis is one of the two known, single gene causes of autism spectrum disorders.

Sensory problems
Some level of sensory problems and difficulties with sensory integration are common to 95% of children with autism spectrum disorders. This may include both over- and under-reponsiveness to a variety of sensory stimuli and well as responses to sensory stimuli that are not proportional to the stimulation. For example, many children with autism are highly attuned or even painfully sensitive to certain sounds, textures, tastes, and smells. Some people find the feel of clothes, or certain kind of fabrics, touching or rubbing against their skin to be almost unbearable. Some 'everyday' sounds—a vacuum cleaner, a ringing telephone, a sudden storm, even the sound of waves lapping the shoreline—may cause them to cover their ears or scream.

Mental Retardation
Some level of mental retardation is thought to occur in 30 – 70% of children with classic autism. Mental retardaion is much less common in other forms of autism spectrum disorders – PDD-NOS and does not occur in person’s with Asperger’s disorder. Diagnosis of mental retardation in autism can be difficult of the child is nonverbal and is unable to immitate as these children cannot respond to standardized intellecutal testing. Many individuals on the spectrum display “splinter skills” which means some areas of ability may be normal or superior, while others may be especially weak.

Seizures
It is thought that approximately one in four children with autism and mental retardation develops seizures, often starting either in early childhood or adolescence. Seizures, caused by abnormal electrical activity in the brain, can produce a temporary loss of consciousness (a "blackout"), a body convulsion, unusual movements, or staring spells. In most cases, seizures can be controlled by medicines called anticonvulsants.

Hyperactivity and Attention Disorders
Attention-deficit hyperactivity disorder (ADHD) is one of the most commonly diagnosed childhood disorders. Its symptoms include inattention, hyperactivity, and impulsivity. According to the CDC, the causes are currently unknown, and it is thought that the term covers a variety of related disorders. Symptoms of autism and the underlying cognitive deficits that are part of the autism spectrum are in some ways similar to those seen in ADHD. These include problems with attention, executive functioning, and problem solving. While ADHD may be co-morbid (occur together) with an autism spectrum disorder, ADHD-like symptoms are a common part of autism spectrum disorder symtomatology.

Depression and Anxiety Disorders
Depression and its cousin, anxiety, may be the most common comorbid disorders accompanying autism, affecting over half of all people with Asperger syndrome (AS). Often, depression is contributed to by lack of social acceptance of those with autism spectrum disorders.

Obsessive-Compulsive Disorder
Obsessional thoughts are ideas, images or impulses that enter the individual's mind again and again. Typically obsessive thought/action patterns are thought to be distressing and the sufferer often tries to resist them. Children with autism spectrum disorders often have a strong need for sameness, rigidity in following a routine, and repetitive behaviors and mannerisms. Both OCD and obsessive-like symptoms seen in autism may be driven (in part) by anxiety. However, for children with autism, the rigidity and need for sameness appears to be related to underlying neurocognitive deficits seen in autism and not to obsessive thought patterns.

Gastrointestival problems
While consensus panel recommendations from the American Academy of Pediatrics and other medical groups do not recognize bowel problems as occuring more often in children with an autism spectrum disorder than in children in the general population, it has been claimed by some that up to fifty percent of children with autism experience persistent gastrointestinal tract problems, ranging from mild to moderate degrees of inflammation in both the upper and lower intestinal tract.

Neuroinflammation and Immune Disorders
The role of the immune system in the development of autism is controversial. Until recently, there was scant evidence supporting immune hypotheses, but research into the role of immune response and neuroinflammation may have important clinical and therapeutic implications. Recent studies indicate the presence of heightened neuroimmune activity in both the brain tissue and the cerebrospinal fluid of persons with autism. The role of the immune system in the onset of autism or in the symptoms and neurocognitive deficits seen in autism is unknown.

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