A Longitudinal Study Of Diffusion Tensor Imaging In Als Patients

OBJECTIVE: To assess changes in white matter tracts integrity in ALS patients and controls, early and at 6 months using DTI. BACKGROUND: The role of DTI in Amyotrophic Lateral sclerosis is not clearly understood, prior studies were hindered by their small sample size and provided conflicting results they also focused on the diagnostic value of DTI. The use of DTI as a marker of disease progression has not been investigated. DESIGN/METHODS: 12 patients with ALS and 12 healthy controls were enrolled in the study. ALSFRS-R, FVC and manual muscle testing were performed at baseline and at 6 months. Patients and controls underwent two structural MRI scans at baseline and at 6 months that included a high resolution T1 and a DTI scan. RESULTS: All ALS patients exhibited a significant DTI abnormalities at baseline and at 6 months. The area of corticospinal tract caudal to the thalamus bilaterally exhibited the most significant lower FA value at baseline. However the anisotropy for this region did not exhibit a significant change at 6 months. The change in FA correlated with the change in FVC. For the area where ALS patients showed a significant difference from control, there was a difference in radial but not in axial diffusivity suggesting that disrupted myelin tracts may be at the root of the drop in FA noted in the patients. CONCLUSIONS: DTI seems to be a sensitive tool for detecting early corticospinal tract degeneration and may help establish early diagnosis in ALS patients, however longitudinal analysis did not reveal significant change in FA values overtime. It seems that upper motor neuron damage in ALS happen very early on. DTI could be used as a surrogate marker of UMN degeneration but may not be a good marker of disease progression. Getting repeated scans in ALS patients is limited by the patient functional decline. Disclosure: Dr. Ajroud-Driss has nothing to disclose. Dr. Mansour has nothing to disclose. Dr. Herrmann has nothing to disclose. Dr. Casey has nothing to disclose. Dr. Allen has nothing to disclose. Dr. Sufit has nothing to disclose. Dr. Heller has nothing to disclose. Dr. Siddique has nothing to disclose. Dr. Apkarian has nothing to disclose.