A small study showed that FASD subjects had greater mean diffusivity (MD) in the isthmus of CC, with no significant differences in the other CC regions. MD represents average water diffusion in all directions155. In another study, WM integrity following PEA was evaluated and compared with matched controls, using DTI and T1-weighted MRI images, and their correlation with neurocognitive deficits156. Lower values for FA were observed in the FASD group in right lateral temporal lobe and bilaterally in lateral aspects of the splenium of CC. WM density was found to be low in some, but not all of these regions with low FA. The areas with low FA were confirmed to be WM using region of interest (ROI) analyses, suggesting that PEA may be associated with decreased myelination or disorganized WM tracts. The FA of the splenium, but not that of the temporal lobe correlated with scores of visuo-motor integration tests156. Another study found impairments in tasks related to interhemispheric information transfer in children with PEA, and showed that these impairments correlated with reductions in the size of CC157. These
