Default mode network disturbances in restless legs syndrome/Willis-Ekbom disease.
The unusual sensations of restless legs syndrome/Willis-Ekbom disease (RLS/WED) are induced by rest or a low arousal state with a circadian variation in the threshold for induction. It has been suggested that the emergence of RLS/WED symptoms relates to abnormal brain functions dealing with internally generated stimuli. The purpose of this study was to investigate the changes in the default mode network (DMN) in RLS/WED subjects.



Sixteen drug-naïve, idiopathic, RLS/WED subjects, and 16 age-matched and gender-matched healthy subjects were scanned in an asymptomatic resting state. A comparison of the DMN was conducted between the two groups. Resting state functional magnetic resonance imaging (MRI), Korean versions of the International RLS scale, and other sleep questionnaires were used.



The results showed reductions in the DMN connectivity in the left posterior cingulate cortex, the right orbito-frontal gyrus, the left precuneus, and the right subcallosal gyrus of the RLS/WED subjects. The DMN connectivity was increased in sensory-motor-associated circuits, which included the right superior parietal lobule, the right supplementary motor area, and the left thalamus. In addition, the connectivity between the DMN and thalamus was negatively correlated with that in the orbito-frontal gyrus and the subcallosal gyrus in the subjects.



The results showed disturbances of the DMN in RLS/WED subjects that influence the thalamic relay sensory-motor-associated circuit. These findings may underscore the fact that RLS/WED subjects have disturbances in default mode network functions involving internal stimuli in the resting state. This may be related to compensatory changes to maintain resting.
Department of Biomedical Engineering, Dongsan Medical Center, Keimyung University School of Medicine, Daegu, South Korea.
Jeonghun
J
Ku
Department of Neurology, Dongsan Medical Center, Keimyung University School of Medicine, Daegu, South Korea.
Yeong Seon
YS
Lee
Department of Radiology, Dongsan Medical Center, Keimyung University School of Medicine, Daegu, South Korea.
HyukWon
H
Chang
Department of Neurology, Johns Hopkins University, Hopkins Bayview Medical Center, Baltimore, MD, USA.
Christopher J
CJ
Earley
Department of Neurology, Johns Hopkins University, Hopkins Bayview Medical Center, Baltimore, MD, USA.
Richard P
RP
Allen
Department of Neurology, Dongsan Medical Center, Keimyung University School of Medicine, Daegu, South Korea. Electronic address: neurocho@gmail.com.
Yong Won
YW
Cho
D001921:Brain / Q000503:physiopathology*; D016022:Case-Control Studies; D005260:Female; D059907:Functional Neuroimaging; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009434:Neural Pathways / Q000503:physiopathology*; D012148:Restless Legs Syndrome / Q000503:physiopathology*; D011795:Surveys and Questionnaires
Default mode network; Restless legs syndrome; Thalamic circuit