Morphometric study of the corpus callosum in young children with different types of communication disorders

Objective: The corpus callosum plays an important role in the development of human cognition, verbal as well as non-verbal. Developmental language disorder (DLD), autistic spectrum disorder (ASD), and mental retardation (MR) are the common causes of communication disorders in children. This study tested the hypothesis that there are differences in the area of the corpus callosum and its subregions in young children with DLD, ASD and MR. Patients and Methods: Thirty-three patients with verbal intelligence quotients below 70, were included in the study. There were 11 patients in each group. The mean age (± SD) in the DLD (39.5 ± 11.0 months), ASD (30.6 ± 8.1 months) and MR (36.3 ± 11.8 months) groups at MRI examination were comparable. A semi-automated, computer-assisted procedure was used to measure the total brain areas, and the total area of the corpus callosum and its five subregions on the midsagittal T1-weighted magnetic resonance imaging. Results: The total brain areas (Mean ± SD, cm²) in the DLD, ASD and MR groups were 127.6 ± 17.8, 127.5 ± 13.7, 118.6 ± 20.1, respectively. After standardization with respect to total brain area, there was no significant difference in the total corpus callosum area (cm²) between the three groups (4.24 ± 1.38, 3.55 ± 0.67, and 2.83 ± 1.63 for DLD, ASD and MR, respectively), although the MR group had the smallest total area of corpus callosum among the three groups. After comparing the 5 different subregions of the corpus callosum among the three groups, a significant difference was observed only in the posterior body of the corpus callosum (p = 0.01), with the smallest area in the MR group. A significant difference in the posterior body of the corpus callosum was observed only between the DLD and MR groups (p <0.05). Conclusions: We found that there are differences in the subregions of the corpus callosum, especially in its posterior body, between children with DLD, ASD and MR. This preliminary study suggests that a decrement in the development of the corpus callosum occurs more often in young children with mental retardation than in children with communication disorders.