Neuroimaging such as fMRI has been used primarily as a research tool. However researchers from Stanford have now used fMRI as a prognostic tool to determine which of those children with dyslexia are likely to improve over time. Moreover it is highly accurate.
Dyslexia is a common brain based learning difficulty affecting between 5-15% of all children. The severity of the condition and the effectiveness of intervention varies enormously as well. It is estimated that only around 20% will benefit from interventions so that they develop adequate reading levels by adulthood.
Neuroimaging has shown that children with dyslexia use a different part area of the brain for reading (part of the frontal lobe called the inferior frontal gyrus) from those without dyslexia.
The researchers took a small group of twenty-five 14 year olds with dyslexia (and 20 non-dyslexics in a control group) and firstly assessed their reading ability using standardised tests. They then performed fMRI and diffusion tensor imaging as they read. By repeating the tests after 30 months they ascertained that the fMRI (rather than the other imaging technique) scans were able to show and predict with 90% accuracy, which children would show future gains in their reading ability over time.
Knowing that these children are using different neural pathways when reading will hopefully lead to new and effective therapies in the future.
The study was only small but shows great promise for future work in this area. Longer-term outcomes need to be looked at and it would also be useful to see what was happening in the brains of younger children with dyslexia.
Ref: Fumiko Hoeft, Bruce D. Mccandliss, Jessica M. Black, Alexander Gantman, Nahal Zakerani, Charles Hulme, Heikki Lyytinen, Susan Whitfield-Gabrieli, Gary H. Glover, Allan L. Reiss, and John D. E. Gabrieli. Neural systems predicting long-term outcome in dyslexia. Proceedings of the National Academy of Sciences, 2010; DOI: 10.1073/pnas.1008950108