Could Brain Scans Help Diagnose Dyslexia Early in Children?

Statistics show that Dyslexia is one of the most common causes for reading, writing and spelling difficulties, counting for poor reading skills in 70 to 80 percent of those who have the disorder. As many as one in five students, or 15 to 20 percent of the population, also has a language based learning disability and nearly the same percentage of males and females are affected by dyslexia from different ethnic and socioeconomic backgrounds.

Yet a new study from MIT suggests that there may be an earlier way to identify the disability and help students better succeed in the learning environment through brain imaging tests.

According to researchers at Boston Children's Hospital, they found a correlation between poor pre-reading skills in kindergartners and the size of a brain structure that connects to two language-processing areas.

The arcuate fasciculus has been found to be smaller in adults with poor reading skills, a white-matter fiber tract that links the lateral temporal cortex with the frontal cortex via a dorsal projection through the arches around the Sylvain fissure. Yet scientists are uncertain whether this difference causes reading difficulties or is simply a result from lack of reading experience.

"We were very interested in looking at children prior to reading instruction and whether you would see these kinds of differences," said senior study author, John Gabrieli, the Grover M. Hermann Professor of Health Sciences and Technology, professor of brain and cognitive sciences and a member of MIT's McGovern Institute for Brain Research, via a press release.

The study looked at approximately 1,000 children from various schools in Massachusetts and Rhode Island. During kindergarten, children whose parents were given permission to participate were assessed for pre-reading skills, including putting sounds and words together.

"From that, we're able to provide - at the beginning of kindergarten - a snapshot of how that child's pre-reading abilities look relative to others in their classroom or other peers, which is a real benefit to the child's parents and teachers," one of the lead study authors, Elizabeth Norton said, via the release.

Forty children were then asked to participate in brain scans using a technique based on magnetic resonance imaging (MRI), with the researchers placing an emphasis on the following: the arcuate fasciculus, the inferior longitudinal fasciculus (ILF) and the superior longitudinal fasciculus (SLF). 

They were also tested for their ability to name a series of familiar objects as quickly as they could identify the letters for those objects. While they did not find any correlation between this skill set, there was a strong correlation between the size and organization of the arcuate fasciculus and performance on various phonological tests.

As this part of the brain is contained in the Broca's region, otherwise known as the tissue containing neurons controlled in the involvement of speech, researchers are hoping that working with this area of the brain could help children suffering from this disorder succeed more in learning and life.

However, senior author of the study, Gabrieli, concludes with the following, via the release: "We don't know yet how it plays out over time, and that's the big question: Can we, through a combination of behavioral and brain measures, get a lot more accurate at seeing who will become a dyslexic child, with the hope that that would motivate aggressive interventions that would help these children right from the start, instead of waiting for them to fail?"

More information regarding the study can be found in the Journal of Neuroscience.