title: Functional connectivity alternation of the thalamus in restless legs syndrome patients during the asymptomatic period: a resting-state connectivity study using functional magnetic resonance imaging.
abstract: BACKGROUND
  Restless legs syndrome (RLS) is a primary sensory disorder with a secondary motor component (e.g., urge to move), and the thalamus is known to play a central role in RLS. The purpose of our study was to explore the intrinsic changes in the thalamocortical circuit in RLS patients using a resting-state functional magnetic resonance imaging (fMRI) paradigm.
  
  
  METHODS
  Resting-state fMRIs were obtained in the morning from 25 idiopathic RLS patients who were not using RLS medications and 25 controls. Resting-state connectivity was analyzed by a seed-based method using Analysis of Functional NeuroImages (AFNI) software with the bilateral thalami (ventroposterolateral nucleus [VPLN]). The connectivity characteristics of RLS patients were compared to those of the controls.
  
  
  RESULTS
  We found that RLS patients showed reduced thalamic connectivity with the right parahippocampal gyrus, right precuneus, right precentral gyrus, and bilateral lingual gyri; however, the right superior temporal gyrus, bilateral middle temporal gyrus, and right medial frontal gyrus showed enhanced connectivity with the thalamus. RLS severity was negatively correlated with connectivity between the thalamus and right parahippocampal gyrus (r = -0.414; P = .040).
  
  
  CONCLUSIONS
  Our results suggest that the characteristics of the connectivity changes may reflect the pathways involved in producing RLS symptoms and indicate that RLS patients may have deficits in controlling and managing sensory information, which supports the act of viewing RLS as a disorder disrupting somatosensory processing.
authors.affiliation: Department of Biomedical Engineering, Dongsan Medical Center, Keimyung University School of Medicine, Daegu, South Korea.
authors.forename: Jeonghun
authors.initials: J
authors.lastname: Ku
authors.affiliation: Department of Neurology, Dongsan Medical Center, Keimyung University School of Medicine, Daegu, South Korea. Electronic address: neurocho@gmail.com.
authors.forename: Yong Won
authors.initials: YW
authors.lastname: Cho
authors.affiliation: Department of Neurology, Dongsan Medical Center, Keimyung University School of Medicine, Daegu, South Korea.
authors.forename: Yeong Seon
authors.initials: YS
authors.lastname: Lee
authors.affiliation: Department of Neurology, Dongsan Medical Center, Keimyung University School of Medicine, Daegu, South Korea.
authors.forename: Hye-Jin
authors.initials: HJ
authors.lastname: Moon
authors.affiliation: Department of Radiology, Dongsan Medical Center, Keimyung University School of Medicine, Daegu, South Korea.
authors.forename: Hyukwon
authors.initials: H
authors.lastname: Chang
authors.affiliation: Department of Neurology, Johns Hopkins University, Hopkins Bayview Medical Center, Baltimore, MD, USA.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Earley
authors.affiliation: Department of Neurology, Johns Hopkins University, Hopkins Bayview Medical Center, Baltimore, MD, USA.
authors.forename: Richard P
authors.initials: RP
authors.lastname: Allen
mesh_terms: D001921:Brain / Q000503:physiopathology; 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*; D013788:Thalamus / Q000503:physiopathology*
keywords: Central pain; Connectivity; MRI; Resting fMRI; Restless legs syndrome (RLS); Thalamus