Posts tagged autism
Articles and news from the latest research reports.
New Definition of Autism in Updated Psychiatric Clinical Manual Will Not Exclude Most Children with Autism
Parents should not worry that proposed changes to the medical criteria redefining a diagnosis of autism will leave their children excluded and deemed ineligible for psychiatric and medical care, says a team of researchers led by psychologists at Weill Cornell Medical College.
Their new study, published in the October 1 issue of the American Journal of Psychiatry, is the largest to date that has tried to unpack the differences between the diagnostic criteria for autism spectrum disorders in the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) and the proposed revision in the fifth edition (DSM-5), which is expected to be published in May 2013. These manuals provide diagnostic criteria for people seeking mental-health-related medical services.
"I know that parents worry, but I don’t believe there is any substantial reason to fear that children who need to be diagnosed with autism spectrum disorders, and provided with vital services, will not be included in the new criteria in this updated manual," says the study’s senior investigator, Dr. Catherine Lord, director of the Center for Autism and the Developing Brain at NewYork-Presbyterian Hospital’s Westchester campus, along with its affiliated medical schools Weill Cornell Medical College and Columbia University College of Physicians and Surgeons.
At issue is whether DSM-5 will “capture” the same individuals diagnosed with different forms of autism by the DSM-IV. The DSM-5 proposal redefines autism as a single category — autism spectrum disorder (ASD) — whereas DSM-IV had multiple categories and included Autistic Disorder, Asperger’s Disorder, and Pervasive Developmental Disorder, Not Otherwise Specified (PDD-NOS).
Critics have particularly worried that among the excluded will be children now diagnosed with PPD-NOS and Asperger’s disorder. That isn’t the case, says Dr. Lord, who is also a DeWitt Wallace Senior Scholar at Weill Cornell and an attending psychologist at NewYork-Presbyterian Hospital. The study, the largest to date and arguably, the most rigorous, finds that when relying on parent report, 91 percent of the 4,453 children in the sample currently diagnosed with a DSM-IV autism spectrum disorder would be diagnosed with ASD using DSM-V.
Many of the remaining nine percent would likely be reincluded once a clinician can offer input, says Dr. Lord, who is also a member of the American Psychiatric Association’s DSM-5 Neurodevelopmental Disorders Work Group.
The study researchers also concluded that DSM-5 has higher specificity than DSM-IV—in their study, DSM-5 criteria resulted in fewer misclassifications.
(Source: weill.cornell.edu)
University of Miami researchers find that babies’ non-verbal communication skills can help predict outcomes in children at high risk of developing Autism
Approximately 19 percent of children with a sibling diagnosed with Autism Spectrum Disorder (ASD) will develop Autism due to shared genetic and environmental vulnerabilities, according to previous studies. For that reason, University of Miami (UM) psychologists are developing ways to predict the occurrence of ASD in high-risk children, early in life, in hopes that early intervention will lead to better outcomes in the future. Their findings are published in the journal Infancy.
The study is one of the first to show that measures of non-verbal communication in children, as young as eight months of age, predict autism symptoms that become evident by the third year of life. The results suggest that identifying children, who are having difficulties early enough, can enhance the effects of interventions.
Georgia Tech Creating High-Tech Tools to Study Autism
Researchers in Georgia Tech’s Center for Behavior Imaging have developed two new technological tools that automatically measure relevant behaviors of children, and promise to have significant impact on the understanding of behavioral disorders such as autism.
One of the tools—a system that uses special gaze-tracking glasses and facial-analysis software to identify when a child makes eye contact with the glasses-wearer—was created by combining two existing technologies to develop a novel capability of automatic detection of eye contact. The other is a wearable system that uses accelerometers to monitor and categorize problem behaviors in children with behavioral disorders.
Both technologies already are being deployed in the Center for Behavior Imaging’s (CBI) ongoing work to apply computational methods to screening, measurement and understanding of autism and other behavioral disorders.
Boosting natural marijuana-like brain chemicals treats fragile X syndrome symptoms
UCI study points to role endocannabinoids play in common genetic cause of autism
American and European scientists have found that increasing natural marijuana-like chemicals in the brain can help correct behavioral issues related to fragile X syndrome, the most common known genetic cause of autism.
The work indicates potential treatments for anxiety and cognitive defects in people with this condition. Results appear online in Nature Communications.
Daniele Piomelli of UC Irvine and Olivier Manzoni of INSERM, the French national research agency, led the study, which identified compounds that inhibit enzymes blocking endocannabinoid transmitters called 2-AG in the striatum and cortex regions of the brain.
These transmitters allow for the efficient transport of electrical signals at synapses, structures through which information passes between neurons. In fragile X syndrome, regional synapse communication is severely limited, giving rise to certain cognitive and behavioral problems.
Fragile X syndrome is caused by a mutation of the FMR1 gene on the X chromosome. People born with it are mentally disabled; generally experience crawling, walking and language delays; tend to avoid eye contact; may be hyperactive or impulsive; and have such notable physical characteristics as an elongated face, flat feet and large ears.
The researchers stress that their findings, while promising, do not point to a cure for the condition.
“What we hope is to one day increase the ability of people with fragile X syndrome to socialize and engage in normal cognitive functions,” said Piomelli, a UCI professor of anatomy & neurobiology and the Louise Turner Arnold Chair in the Neurosciences.
The study involved mice genetically altered with FMR1 mutations that exhibited symptoms of fragile X syndrome. Treated with novel compounds that correct 2-AG protein signaling in brain cells, these mice showed dramatic behavioral improvements in maze tests measuring anxiety and open-space acceptance.
While other work has focused on pharmacological treatments for behavioral issues associated with fragile X syndrome, Piomelli noted that this is the first to identify the role endocannabinoids play in the neurobiology of the condition.
About endocannabinoids
Endocannabinoid compounds are created naturally in the body and share a similar chemical structure with THC, the primary psychoactive component of the marijuana plant, Cannabis. Endocannabinoids are distinctive because they link with protein molecule receptors — called cannabinoid receptors — on the surface of cells. For instance, when a person smokes marijuana, the cannabinoid THC activates these receptors. Because the body’s natural cannabinoids control a variety of factors — such as pain, mood and appetite — they’re attractive targets for drug discovery and development. Piomelli is one of the world’s leading endocannabinoid researchers. His groundbreaking work is showing that this system can be exploited by new treatments to combat anxiety, pain, depression and obesity.
(Source: today.uci.edu)
Neuroscientists at New York University have devised a method that has reduced several afflictions associated with Fragile X syndrome (FXS) in laboratory mice. Their findings, which are reported in the journal Neuron, offer new possibilities for addressing FXS, the leading inherited cause of autism and intellectual disability.
Those afflicted with FXS do not possess the protein FMRP, which is a suppressor of protein synthesis. Absent this suppressor, protein synthesis is exaggerated, producing a range of mental and physical disorders.
Previous research has indirectly targeted protein synthesis by seeking to temper, but not block, this process. The NYU researchers, by contrast, sought a more fundamental intervention—removing the enzyme, p70 ribosomal S6 kinase 1, or S6K1, which has previously been shown to regulate protein synthesis in FXS mice. By addressing this phenomenon at the molecular level, they hoped to diminish many of the conditions associated with FXS.
Findings Offer New Opportunity To Understand Connection Between Primary Brain Functions and Behavioral Patterns in Autism
New research led by Carnegie Mellon University neuroscientists takes the first step toward deciphering the connection between general brain function and the emergent behavioral patterns in autism. Published in the journal Neuron, the study shows that autistic adults have unreliable neural sensory responses to visual, auditory and somatosensory, or touch, stimuli. This poor response reliability appears to be a fundamental neural characteristic of autism.
"Within the autism research community, most researchers are looking for the location in the brain where autism happens," said Ilan Dinstein, a postdoctoral researcher in Carnegie Mellon’s Department of Psychology and lead author of the study. "We’re taking a different approach and thinking about how a general characteristic of the brain could be different in autism - and how that might lead to behavioral changes."
The eyes may be windows into the soul, but following their movement also could allow doctors to make quick, accurate diagnoses for disorders like autism, schizophrenia, or attention deficit hyperactivity disorder, various research projects suggest.
Eye tracking, which records where subjects focus when watching visual displays, could diagnose brain disorders more accurately than subjective questionnaires or medical examinations do, researchers say. Exams are expensive and time-consuming, and subjective tests have been known to wrongly identify healthy people or misdiagnose disorders.
To make sense of all that people see, the brain filters huge amounts of visual information, fills in gaps and focuses on certain objects. That complex task uses many mental circuits, so differences in what people choose to look at ― differences so subtle that only a computer can spot them ― could provide unprecedented insight into common neurological problems.
Rewiring the Autistic Brain
Signs of autism—such as impaired social skills and repetitive, ritualistic movements—usually begin to appear when a child is about 18 months old. Autism is thought to result from miswired connections in the developing brain, and many experts believe that therapies must begin during a “critical window,” before the faulty circuits become fixed in place. But a new study online today in Science shows that at least one malfunctioning circuit can be repaired after that window closes, holding out hope that in some forms of autism, abnormal circuits in the brain can be corrected even after their development is complete.
Faulty wiring. Shutting off the Nlgn3 gene in mice (right panel) results in miswired synaptic connections, which may be fixable. Credit: S. J. Baudouin et al., Science
According to developmental neurobiologist Peter Scheiffele of the University of Basel in Switzerland, autism doesn’t result from a handful of “culprit” genes that point to a treatable flaw. Instead, patients appear to carry mutations in one out of dozens, even hundreds of risk genes. “This genetic complexity is a huge issue with respect to developing treatments [for autism],” Scheiffele says. To complicate the picture further, autism is not always an isolated disorder; it’s often a common feature in syndromes that otherwise differ drastically. For example, in fragile X syndrome, a form of mental retardation, about 25% of patients are also autistic.
Scheiffele and colleagues were studying a gene called neuroligin-3 (Nlgn3), involved in building the contact points, called synapses, between neurons. Many researchers believe that autism begins at the synapse, and mutations in Nlgn3 have appeared in some forms of the disorder. Sheiffele’s team was focusing on synapses in the cerebellum, a part of the brain that controls movement, but, according to recent research, may also be involved in social behavior. Abnormalities in this region may contribute to both the unusual movements and the social problems seen in autistic patients.
To get a better handle on the role of Nlgn3, the scientists studied mice whose Nlgn3 genes were engineered with an on-off switch, called a promoter region, that is controlled by the antibiotic doxycycline. The animals were raised with the drug in their drinking water, which kept the switch in the off position. With the Nlgn3 gene disabled in the mice, neurons in their cerebellum made the abnormal connections seen in the autistic brain.
Specifically, and much to the researchers’ surprise, the lack of Nlgn3 led to the overactivation of a receptor abbreviated as mGluR1α. This receptor is a component of a pathway that is also disrupted in fragile X syndrome, though it results from mutations in an entirely different gene. In the mice, the overabundance of these receptors led the neurons to make synaptic connections in the wrong places.
To see if turning Nlgn3 gene back on would correct these problems, the researchers withdrew the doxycycline. It worked: With Nlgn3 functioning once more, levels of the extraneous receptor receded back to normal, and the misplaced synapses began to disappear.
"Our finding demonstrates that there is still flexibility after the ‘critical window’ of brain development,” Scheiffele says. “It raises the question: To what extent can a miswired brain be corrected?” The next step, he says, is to see whether motor abnormalities, such as ladder-climbing difficulties, and social interactions can be corrected with similar treatment in the engineered mice. His team is also studying whether drugs that block the mGluR1α receptor can have the same effect as genetically controlling the Nlgn3 gene, which isn’t a treatment option for humans.
"This study holds out hope for children and even adults with developmental disorders. Maybe their conditions aren’t set in stone and can be treated," says neuroscientist Kimberly Huber of the University of Texas Southwestern Medical Center in Dallas. Huber adds that drugs that block a similar receptor, mGluR5, are in clinical trials to treat fragile X syndrome.
(Source: news.sciencemag.org)
A team of Australian researchers, led by University of Melbourne has developed a genetic test that is able to predict the risk of developing Autism Spectrum Disorder, ASD.
Lead researcher Professor Stan Skafidas, Director of the Centre for Neural Engineering at the University of Melbourne said the test could be used to assess the risk for developing the disorder. “This test could assist in the early detection of the condition in babies and children and help in the early management of those who become diagnosed,” he said. “It would be particularly relevant for families who have a history of Autism or related conditions such as Asperger’s Syndrome,” he said.
Autism affects around one in 150 births and is characterized by abnormal social interaction, impaired communication and repetitive behaviours. The test correctly predicted ASD with more than 70 per cent accuracy in people of central European descent. Ongoing validation tests are continuing including the development of accurate testing for other ethnic groups.
Can Videogaming Benefit Young People with Autism Spectrum Disorder?
Individuals with ASD have difficulty with communication and social interaction, but they often have particularly good visual perceptual skills and respond well to visual stimuli. Videogames offer opportunities for successful learning, motivation to improve skills such as planning, organization, and self-monitoring, and reinforcement of desired behaviors without the need for direct human-to-human interaction.
Autism is a growing area of interest for the gamification community, and Games for Health Journal continues to explore various aspects of how videogame technology can be beneficial in treating this complex spectrum of disorders.