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Showing posts with label rdi. Show all posts
Showing posts with label rdi. Show all posts

Autism Treatment : ABA, RDI, and Sensory Treatment

Saturday, 8 February 2014
Autism Treatment : ABA, RDI, and Sensory Treatment

Autism


Autism is a disorder of neural development characterized by impaired social interaction and verbal and non-verbal communication, and by restricted, repetitive or stereotyped behavior. The diagnostic criteria require that symptoms become apparent before a child is three years old. Autism affects information processing in the brain by altering how nerve cells and their synapses connect and organize; how this occurs is not well understood. It is one of three recognized disorders in the autism spectrum (ASDs), the other two being Asperger syndrome, which lacks delays in cognitive development and language, and pervasive developmental disorder, not otherwise specified (commonly abbreviated as PDD-NOS), which is diagnosed when the full set of criteria for autism or Asperger syndrome are not met.
Autism has a strong genetic basis, although the genetics of autism are complex and it is unclear whether ASD is explained more by rare mutations, or by rare combinations of common genetic variants. In rare cases, autism is strongly associated with agents that cause birth defects.Controversies surround other proposed environmental causes, such as heavy metals, pesticides or childhood vaccines; the vaccine hypotheses are biologically implausible and lack convincing scientific evidence. The prevalence of autism is about 1–2 per 1,000 people worldwide, and it occurs about four times more often in boys than girls.The Centers for Disease Control and Prevention (CDC) report 20 per 1,000 children in the United States are diagnosed with ASD as of 2012, up from 11 per 1,000 in 2008. The number of people diagnosed with autism has been increasing dramatically since the 1980s, partly due to changes in diagnostic practice and government-subsidized financial incentives for named diagnoses;the question of whether actual prevalence has increased is unresolved.

Causes


It has long been presumed that there is a common cause at the genetic, cognitive, and neural levels for autism's characteristic triad of symptoms. However, there is increasing suspicion that autism is instead a complex disorder whose core aspects have distinct causes that often co-occur.
Three diagrams of chromosome pairs A, B that are nearly identical. 1: B is missing a segment of A. 2: B has two adjacent copies of a segment of A. 3: B's copy of A's segment is in reverse order.
Deletion (1), duplication (2) and inversion (3) are all chromosome abnormalities that have been implicated in autism.[50]
Autism has a strong genetic basis, although the genetics of autism are complex and it is unclear whether ASD is explained more by rare mutationswith major effects, or by rare multigene interactions of common genetic variants. Complexity arises due to interactions among multiple genes, the environment, and epigenetic factors which do not change DNA but are heritable and influence gene expression.[20] Studies of twins suggest thatheritability is 0.7 for autism and as high as 0.9 for ASD, and siblings of those with autism are about 25 times more likely to be autistic than the general population.[40] However, most of the mutations that increase autism risk have not been identified. Typically, autism cannot be traced to a Mendelian(single-gene) mutation or to a single chromosome abnormality, and none of the genetic syndromes associated with ASDs have been shown to selectively cause ASD. Numerous candidate genes have been located, with only small effects attributable to any particular gene. The large number of autistic individuals with unaffected family members may result from copy number variations—spontaneous deletions or duplications in genetic material during meiosis.Hence, a substantial fraction of autism cases may be traceable to genetic causes that are highly heritable but not inherited: that is, the mutation that causes the autism is not present in the parental genome.
Several lines of evidence point to synaptic dysfunction as a cause of autism. Some rare mutations may lead to autism by disrupting some synaptic pathways, such as those involved with cell adhesion. Gene replacement studies in mice suggest that autistic symptoms are closely related to later developmental steps that depend on activity in synapses and on activity-dependent changes. All known teratogens (agents that cause birth defects) related to the risk of autism appear to act during the first eight weeks from conception, and though this does not exclude the possibility that autism can be initiated or affected later, it is strong evidence that autism arises very early in development.
Although evidence for other environmental causes is anecdotal and has not been confirmed by reliable studies, extensive searches are underway.Environmental factors that have been claimed to contribute to or exacerbate autism, or may be important in future research, include certain foods, infectious disease, heavy metals, solvents, diesel exhaust, PCBs, phthalates andphenols used in plastic products, pesticides, brominated flame retardants, alcohol, smoking, illicit drugs, vaccines, and prenatal stress, although no links have been found, and some have been completely disproven.
Parents may first become aware of autistic symptoms in their child around the time of a routine vaccination. This has led to unsupported theories blaming vaccine "overload", a vaccine preservative, or the MMR vaccine for causing autism.The latter theory was supported by a litigation-funded study that has since been shown to have been "an elaborate fraud". Although these theories lack convincing scientific evidence and are biologically implausible, parental concern about a potential vaccine link with autism has led to lower rates of childhood immunizations,outbreaks of previously controlled childhood diseases in some countries, and the preventable deaths of several children




Many children with autism and related disorders exhibit unwanted behaviors, such as head-banging or slapping others. For parents and other caregivers, trying to reduce these behaviors can be difficult and frustrating. In fact, efforts at discouragement often end up making the behaviors more frequent.
One approach for dealing with these issues is applied behavior analysis, or ABA, training. One of the most widely accepted autism therapies, 32 out of the 50 states in the U.S. have laws that require health insurers to cover it.

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