Aberrant Course of the Corticospinal Tracts in the Brain Stem Revealed by Diffusion Tensor Imaging/Tractography

Aberrant CSTs refer to collateral pathways separating from the original CST at the midbrain, descending through the pontine ML, and re-entering the original CST at the upper medulla. We report conventional MR imaging, DTI, and FT of a child with a completely aberrant right CST. Only FT revealed the completely aberrant course of the CST, whereas conventional MR imaging and color-coded FA-maps suggested the absence of the right CST. This case shows the ability of FT to study the abnormal course of white matter tracts.