CONTEXT: Dr. Joanne Kurtzberg, Dr. James M. Provenzale, and colleagues at Duke University prospectively evaluated diffusion-tensor MRI (DTI) anisotropy measurements of white matter regions in Krabbe disease patients treated with stem cell transplantation, a promising new therapeutic approach for a condition that previously had no cure. They compared anisotropy values in infants who underwent stem cell transplantation in the first month of life (before development of clinical signs of Krabbe disease) with those who had the procedure after development of clinical signs of the disease at approximately six months of age.
RESULTS: Anisotropy values in all patients were compared with those of five age-matched normal children with no neurologic disease. Anisotropy values in the early-treatment group were near normal at the time of transplantation and were substantially higher than anisotropy values at the time of transplantation in the late-treatment group (which ranged from 55% to 74% of normal). Over the next two years, anisotropy values remained at 80% to 90% of normal values in the early-transplant group but decreased to 36% to 39% of normal in the late-transplant group. Early-transplant children had mild or moderate neurologic disability, whereas late-transplant children had severe neurologic disability.
IMAGE: Fractional anisotropy values appear in the posterior limb of the internal capsule in the image (left). They correspond (right) with abnormal signal in the same region. (Provided by J. Provenzale. Reprinted from Radiology 2005;236:221-230)
IMPLICATIONS: Good concordance was seen between the DTI values and clinical outcome. The results indicate that DTI might be a useful means of assessing disease progression in Krabbe disease and other white matter disorders. Maintenance of anisotropy values in the mildly or moderately decreased range in children who underwent early transplantation probably represents amelioration of the disease process in this demyelinating condition.