Corticospinal Tract MR Signal-Intensity Pseudonormalization on Magnetization Transfer Contrast Imaging: A Potential Pitfall in the Interpretation of the Advanced Compromise of Upper Motor Neurons in Amyotrophic Lateral Sclerosis We read the article by Car

spinal Tract and Diffusion Tensor Imaging Analysis, ” with great in-terest. The possible recognition of a distinct phenotype of amyotro-phic lateral sclerosis (ALS) based on typical corticospinal tract (CST) hyperintensity on T1-weighted images with magnetization transfer contrast (T1MTC) reinforces the applicability ofMR imaging in con-firming upper motor neuron (UMN) involvement in ALS. However, previous reports have described false-negative MR imaging results that were attributed to progressive CST degeneration in the advanced stages of the disease.2,3Nevertheless, to the best of our knowledge, this theoretic “pseudonormalization ” has never been documented in the MR imaging follow-up of a patient with ALS. We describe imaging follow-up of a young-adult patient with ALS (a 20-year-old woman) who was examined in the 6th and 30th months after the initial clinical manifestations of UMN involvement. The MR imaging protocol included T1 MTC (TR/TE, 512 ms/mini