Dyslexia: MRI Brain Scans Spot Early Signs

Instead of waiting for a child to experience reading delays, scientists now say they can identify the reading problem even before children start school, long before they become labeled as poor students and begin to lose confidence in themselves.

Although typically diagnosed during the second or third grade of school - around age 7 or 8 - a team from Children's Hospital Boston said they could see signs of the disease on brain scans in children as early as 4 and 5, a time when studies show children are best able to respond to interventions.

"We call it the dyslexia paradox," said Nadine Gaab of the Laboratories of Cognitive Neuroscience at Children's, whose study was published in Proceedings of the National Academy of Sciences.

Gaab said most children are not diagnosed until third grade, but interventions work best in younger children, hopefully before they begin to learn to read.

"Often, by the time they get a diagnosis, they usually have experienced three years of peers telling them they are stupid, parents telling them they are lazy.

We know they have reduced self esteem. They are really struggling," Gaab said in a telephone interview.

Her study builds on an emerging understanding of dyslexia as a problem with recognizing and manipulating the individual sounds that form language, which is known as phonological processing.
In order to read, children must map the sounds of spoken language onto specific letters that make up words. Children with dyslexia struggle with this mapping process.

"The beauty is spoken language can present before written language so people can look for symptoms," said Dr. Sally Shaywitz, a director of the Center for Dyslexia and Creativity at Yale University.

Signs of early dyslexia might include difficulty with rhyming, mispronouncing words or confusing similar-sounding words.

"Those are all very early symptoms," Shaywitz said.

Dyslexia affects roughly 5 percent to 17 percent of all children and up to 1 in 2 children with a family history of the disorder will struggle with reading, have poor spelling and experience difficulty decoding words.

In her study, Gaab and colleagues scanned the brains of 36 preschool children while they did a number of tasks, such as trying to decide if two words start with the same sound.

They found that during these tasks, children who had a family history of dyslexia had less brain activity in certain regions of the brain than did children of similar ages, intelligence and socioeconomic status.

Older children and adults with dyslexia have dysfunction in these same areas of the brain, which include the junctions between the occipital and temporal lobes and the temporal and parietal lobes in the back of the brain.

Gaab said the study shows that when children predisposed to dyslexia did these tasks, their brains did not use the area typically used for processing this information. This problem occurred even before the children started learning to read.

"The important point of this paper is it shows the need to look for signs of dyslexia earlier," said April Benasich, director of the Carter Center for Neurocognitive Research at Rutgers, the State University of New Jersey, who was not part of the study.

Benasich studies language processing in even younger children - babies who have a family history of learning disorders.

"There is evidence to suggest that what is thought to be reading failure is there before the kids fail," she said.

Gaab said her study is too small to form the basis of any test for dyslexia but her team has just won a grant from the National Institutes of Health to do a larger study.

Ultimately, she hopes parents will be able to go to their pediatrician and ask for their child to be assessed.

"Families often know that their child has dyslexia as early as kindergarten, but they can't get interventions at their schools," she said in a statement.

"If we can show that we can identify these kids early, schools may be encouraged to develop programs," she said.

Low birthweight Infants at risk from Autism (5x)

Autism researchers at the University of Pennsylvania School of Nursing have found a link between low birthweight and children diagnosed with autism, reporting premature infants are five times more likely to have autism than children born at normal weight.

The children, some born as small as about a pound, were followed for 21 years making this study, published in the prestigious journal Paediatrics, one of the most remarkable of its kind.

The infants were born between September 1984 through July 1987 in Middlesex, Monmouth, and Ocean counties in New Jersey at birthweights from 500 to 2000 grams or a maximum of about 4.4 pounds.

“As survival of the smallest and most immature babies improves, impaired survivors represent an increasing public health challenge,” wrote lead authorJennifer Pinto-Martin, MPH, PhD, director of the Center for Autism and Developmental Disabilities Research and Epidemiology (CADDRE) at Penn Nursing.

“Emerging studies suggest that low birthweight may be a risk factor for autism spectrum disorders.”

Links between low birthweight and a range of motor and cognitive problems have been well established for some time, but this is the first study that establishes that these children are also at increased risk for autism spectrum disorders (ASD).

“Cognitive problems in these children may mask underlying autism,” said Dr. Pinto-Martin. “If there is suspicion of autism or a positive screening test for ASD, parents should seek an evaluation for an ASD.

Early intervention improves long-term outcome and can help these children both at school and at home.”

In future studies, Penn researchers will investigate possible links between brain hemorrhage, a complication of premature birth, and autism by examining brain ultrasounds taken of these children as newborns.

The researchers, including a team at The Children’s Hospital of Philadelphia, followed 862 children from birth to young adulthood finding that five percent (5%) of the children were diagnosed with autism, compared to one percent (1%) of the general population in what researchers called “the first study to have estimated the prevalence of ASD . . . using research validated diagnostic instruments.”

The $3 million study was funded by the National Institute of Mental Health.(NIMH)

ADHD: Brain scans reveal drugs' effects on attention

Scientists have developed a way to use PET scans to test if drugs are helping mice that have been genetically engineered to have a form of attention deficit.

In the brain of the altered mouse (right), low dopamine levels result in a brighter image. 

(Credit: David Gutmann, MD, PhD)

Scientists have developed a way to evaluate new treatments for some forms of attention deficit disorder.

Working in mice, researchers at Washington University School of Medicine in St. Louis showed that they can use brain scans to quickly test whether drugs increase levels of a brain chemical known as dopamine.

In a study published last year, the same group found that raising dopamine levels in mice alleviates attention deficits caused by neurofibromatosis type 1 (NF1), a condition that affects more than 100,000 people in the United States. Approximately 60 percent to 80 percent of children with NF1 have some type of attention deficit problem.

"Many kids with NF1 really struggle in school, and finding ways to help alleviate attention problems is a high priority," says David H. Gutmann, MD, PhD, the Donald O. Schnuck Family Professor of Neurology.

"The technique we've refined may make it possible to match specific treatments to the patients with NF1 and attention deficit who are most likely to benefit from those treatments."

The results appear online in Experimental Neurology.

Symptoms of NF1-related attention deficits are similar to those that affect children in the general population. But it's unclear whether the brain changes that underlie these problems in children with NF1 are similar to the brain changes that cause attention deficits in the general population.

"This mouse model may not be a perfect model for all forms of attention deficit, but it is a terrific model for one type of attention system dysfunction," Gutmann says. "Greater understanding of what goes wrong in some children with NF1 could lead to new insights into a broader variety of attention problems."

Gutmann is director of the Washington University Neurofibromatosis (NF) Center, a national referral center for patients with all forms of neurofibromatosis. The center is active in basic science research and clinical trials, with the goal of developing innovative new approaches for treating patients with NF.

Gutmann and his colleagues have developed genetically engineered mice that develop NF1-related attention problems and brain tumours.

Last year, Gutmann showed that one of these lines of mice had lower levels of dopamine in part of the brain. Following treatment with the drug Ritalin, both the brain dopamine levels and the attention deficits in these mice were restored to normal.

"Prior to our study, there was no molecular basis for using Ritalin to treat children with NF1 and attention deficits, so its use depended on the pediatrician's practice, the severity of the attention deficit and how comfortable the parents were with the use of medication," Gutmann says.

"In general, only the most severely affected kids are being treated, but that may change in the future."

Read more at Science Daily

Further Evidence that Parents' smoke damages children

Children who are around smokers face a higher risk of early emphysema when they become nonsmoking adults, perhaps because their lungs never totally recovered from secondhand smoke exposure, new research suggests.

Researchers reached their conclusions after conducting CT scans on 1,781 non-smokers from six communities in the United States. About half of them grew up in homes with at least one smoker.

"We were able to detect a difference on CT scans between the lungs of participants who lived with a smoker as a child and those who did not," Gina Lovasi, an assistant professor of epidemiology at Columbia University's Mailman School of Public Health, said in a university news release. "Some known harmful effects of tobacco smoke are short-term, and this new research suggests that effects of tobacco smoke on the lungs may also persist for decades."

The researchers didn't find a link between childhood exposure to tobacco smoke and lung function. "However, emphysema may be a more sensitive measure of damage compared with lung function in this relatively healthy cohort," Lovasi noted.

The findings are published in the December 2009 issue of the American Journal of Epidemiology.