Late-onset restless legs syndrome evaluated at night-hours with resting-state fMRI of the brain and voxel-based morphometry

Purpose: The aim of the study was to investigate the resting state networks and brain volumetric changes in patients with late onset restless legs syndrome (lRLS).   Material and Methods: Nine untreated lRLS patients (mean age 65.2 +/- 7.7; mean disease duration 4.2 +/- 2.6 years) and 9 age and sex matched controls were evaluated at night hours with resting state fMRI (rs-fMRI) and a 3D T1-weighted sequence. The evaluation of rs-fMRI data was performed using the independent component analysis model. Volumetric changes were evaluated with voxel based morphometry (VBM). Results: The fMRI analysis revealed eight resting state networks. Patients compared to controls showed significant greater activation of the supplementary motor area and the premotor cortex in the right hemisphere. VBM analysis did not reveal any significant volume change in brain white and grey matter. Conclusions: Untreated patients with lRLS do not have any regional brain volume alterations. Activation in the presymtomatic period of the supplementary motor cortex and the premotor cortex may represent anticipation of the forthcoming sensorimotor symptoms.