Corpus Callosum Size on Magnetic Resonance Imaging and Its Association With Developmental Delays in Children: A Retrospective Case-Control Study

Introduction Developmental delay (DD) encompasses a heterogeneous group of conditions that present with a delay in development or an abnormal pattern of developmental progression. The corpus callosum (CC) is the largest white matter structure in the human brain and connects the cerebral hemispheres. The association between DD and CC thickness is poorly documented. Objectives The main objective of this study is to compare the thickness of various regions of the CC in children with and without DD, using magnetic resonance imaging (MRI). Material and methods This retrospective case-control study included 70 children aged two to six years (35 children each with DD and normal development). The thickness of the CC was measured on mid-sagittal T1-weighted images according to Witelson's method. Associations between the mean sizes of the different regions of the CC in the case and comparison groups were assessed. Results Delayed speech was the most common presentation of DD, followed by delayed fine motor skills. A significant difference (p < 0.005) was observed between the mean thickness of the CC subdivisions in the case and comparison groups. The difference was most pronounced in the regions of the splenium, anterior body, and genu, with effect sizes of 1.59, 1.33, and 1.15, respectively (Cohen's d values). Significant differences were also observed between the thickness of the genu and splenium in participants who predominantly displayed language delay (p = 0.013). Conclusion Corpus callosal thinning is associated with various DDs in the pediatric age group, and the presence of a thin CC on MRI should trigger evaluation for DD.