Abnormal age-related cortical folding and neurite morphology in children with developmental dyslexia.
Eduardo Caverzasi, Maria Luisa Mandelli, Fumiko Hoeft, Christa Watson, Marita Meyer, Isabel E Allen, Nico Papinutto, Cheng Wang, Claudia A M Gandini Wheeler-Kingshott, Elysa J Marco, Pratik Mukherjee, Zachary A Miller, Bruce L Miller, Robert Hendren, Kevin A Shapiro, Maria Luisa Gorno-Tempini
Author Information
Eduardo Caverzasi: Dyslexia Center, University of California, San Francisco, San Francisco, CA, USA; Department of Neurology, University of California, San Francisco, San Francisco, CA, USA; Biomedical Sciences PhD, Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy. Electronic address: eduardo.caverzasi@ucsf.edu.
Maria Luisa Mandelli: Dyslexia Center, University of California, San Francisco, San Francisco, CA, USA; Memory and Aging Center, Department of Neurology, University of California, San Francisco, San Francisco, CA, USA.
Fumiko Hoeft: Dyslexia Center, University of California, San Francisco, San Francisco, CA, USA; Department of Psychiatry and Weill Institute for Neurosciences, University of California, San Francisco, CA, USA.
Christa Watson: Dyslexia Center, University of California, San Francisco, San Francisco, CA, USA; Memory and Aging Center, Department of Neurology, University of California, San Francisco, San Francisco, CA, USA.
Marita Meyer: Dyslexia Center, University of California, San Francisco, San Francisco, CA, USA.
Isabel E Allen: Department of Epidemiology and Biostatistics, University of California, San Francisco, San Francisco, CA, USA.
Nico Papinutto: Department of Neurology, University of California, San Francisco, San Francisco, CA, USA.
Cheng Wang: Dyslexia Center, University of California, San Francisco, San Francisco, CA, USA; Memory and Aging Center, Department of Neurology, University of California, San Francisco, San Francisco, CA, USA; Department of Psychiatry and Weill Institute for Neurosciences, University of California, San Francisco, CA, USA.
Claudia A M Gandini Wheeler-Kingshott: Queen Square MS Centre, Department of Neuroinflammation, UCL Institute of Neurology, Russel Square House, London, United Kingdom; Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy; Brain MRI 3T Mondino Research Center, C. Mondino National Neurological Institute, Pavia, Italy.
Elysa J Marco: Department of Neurology, University of California, San Francisco, San Francisco, CA, USA; Department of Psychiatry and Weill Institute for Neurosciences, University of California, San Francisco, CA, USA; Department of Pediatrics, University of California, San Francisco, San Francisco, CA, USA.
Pratik Mukherjee: Neuroradiology Section, Department of Radiology and Biomedical Imaging, University of California, San Francisco, USA.
Zachary A Miller: Dyslexia Center, University of California, San Francisco, San Francisco, CA, USA; Memory and Aging Center, Department of Neurology, University of California, San Francisco, San Francisco, CA, USA.
Bruce L Miller: Department of Neurology, University of California, San Francisco, San Francisco, CA, USA; Memory and Aging Center, Department of Neurology, University of California, San Francisco, San Francisco, CA, USA.
Robert Hendren: Dyslexia Center, University of California, San Francisco, San Francisco, CA, USA; Department of Psychiatry and Weill Institute for Neurosciences, University of California, San Francisco, CA, USA.
Kevin A Shapiro: Dyslexia Center, University of California, San Francisco, San Francisco, CA, USA; Department of Neurology, University of California, San Francisco, San Francisco, CA, USA.
Maria Luisa Gorno-Tempini: Dyslexia Center, University of California, San Francisco, San Francisco, CA, USA; Memory and Aging Center, Department of Neurology, University of California, San Francisco, San Francisco, CA, USA.
There is increasing recognition of a relationship between regional variability in cerebral gyrification and neurodevelopment. Recent work in morphometric MRI has shown that the local gyrification index (lGI), a measure of regional brain folding, may be altered in certain neurodevelopmental disorders. Other studies report that the lGI generally decreases with age in adolescence and young adulthood; however, little is known about how these age-dependent differences in brain maturation occur in atypical neurodevelopment and mechanisms underlying gyrification, such as synaptic pruning. Organization and optimization of dendrites and axons connections across the brain might be driving gyrification and folding processes. In this study, we first assessed lGI differences in the left hemisphere in a cohort of 39 children with developmental dyslexia (DD) between the ages of 7 and 15 years in comparison to 56 typically developing controls (TDC). To better understand the microstructural basis of these changes, we next explored the relationship between lGI differences and cortical thickness and neurite morphology by applying neurite orientation dispersion and density imaging (NODDI). We identified significant differences in lGI between children with DD and TDC in left lateral temporal and middle frontal regions. Further, DD failed to show the expected age-related decreases in lGI in the same regions. Age-related differences in lGI in DD were not explained by differences in cortical thickness, but did correlate with NODDI neurite density and orientation dispersion index. Our findings suggest that gyrification changes in DD are related to abnormal neurite morphology, and are possibly an expression of differences in synaptic pruning.
References
Neuropsychologia. 2016 Jan 29;81:68-78
[PMID: 26679527]
