Cerebral white matter alterations in idiopathic restless legs syndrome, as measured by diffusion tensor imaging

In search for the pathoanatomical correlate of the restless legs syndrome (RLS), various neuroimaging and electrophysiological techniques have demonstrated partly conflicting results of cortical, subcortical, brainstem, and spinal alterations. In a novel approach, the delineation of potential cerebral white matter tract disruption was investigated by application of quantitative whole brain-based diffusion tensor imaging (DTI) to a well characterized group of 45 patients with idiopathic RLS. The data of patients and 30 healthy controls were statistically compared including computation of regional fractional anisotropy (FA) as a quantitative marker of white matter integrity by use of the tensor imaging and fiber tracking software. In the patient group, multiple subcortical areas of significantly reduced FA were observed bihemispherically in close proximity to the primary and associate motor and somatosensory cortices, in the right-hemispheric thalamus (posterior ventral lateral nucleus), in motor projectional fibers and adjacent to the left anterior cingulum. Together with the results of a recent study by use of an MRI-based gray matter analysis, which localized RLS-associated changes in the sensorimotor cortices, these findings gave support to an altered subcortical network, with the major component of altered cerebral sensorimotor pathways, within a hodological concept of the RLS pathoanatomy.