title: T2 relaxometry using 3.0-tesla magnetic resonance imaging of the brain in early- and late-onset restless legs syndrome.
abstract: OBJECTIVE
  Previous T2 relaxometry studies have provided evidence for regional brain iron deficiency in patients with restless legs syndrome (RLS). Measurement of the iron content in several brain regions, and in particular the substantia nigra (SN), in early- and late-onset RLS patients using T2 relaxometry have yielded inconsistent results. In this study the regional iron content was assessed in patients with early- and late-onset RLS using magnetic resonance imaging (MRI), and compared the results with those in controls.
  
  
  METHODS
  Thirty-seven patients with idiopathic RLS (20 with early onset and 17 with late onset) and 40 control subjects were studied using a 3.0-tesla MRI with a gradient-echo sampling of free induction decay and echo pulse sequence. The regions of interest in the brain were measured independently by two trained analysts using software known as medical image processing, analysis, and visualization. The results were compared and a correlation analysis was conducted to investigate which brain areas were related to RLS clinical variables.
  
  
  RESULTS
  The iron index in the SN was significantly lower in patients with late-onset RLS than in controls (p=0.034), while in patients with early-onset RLS there was no significant difference. There was no significant correlation between the SN iron index of the late-onset RLS group and clinical variables such as disease severity.
  
  
  CONCLUSIONS
  Late-onset RLS is associated with decreased iron content in the SN. This finding supports the hypothesis that regional brain iron deficiency plays a role in the pathophysiology of late-onset RLS.
authors.affiliation: Department of Neurology, Dongsan Medical Center, Keimyung University School of Medicine, Daegu, Korea.
authors.forename: Hye-Jin
authors.initials: HJ
authors.lastname: Moon
authors.affiliation: Department of Molecular Medicine, Kyungpook National University Hospital, Daegu, Korea.
authors.forename: Yongmin
authors.initials: Y
authors.lastname: Chang
authors.affiliation: Department of Neurology, Dongsan Medical Center, Keimyung University School of Medicine, Daegu, Korea.
authors.forename: Yeong Seon
authors.initials: YS
authors.lastname: Lee
authors.affiliation: Department of Medical & Biological Engineering, Kyungpook National University Hospital, Daegu, Korea.
authors.forename: Hee Jin
authors.initials: HJ
authors.lastname: Song
authors.affiliation: Department of Radiology, Dongsan Medical Center, Keimyung University School of Medicine, Daegu, Korea.
authors.forename: Hyuk Won
authors.initials: HW
authors.lastname: Chang
authors.affiliation: Department of Biomedical Engineering, Dongsan Medical Center, Keimyung University School of Medicine, Daegu, Korea.
authors.forename: Jeonghun
authors.initials: J
authors.lastname: Ku
authors.affiliation: Department of Neurology, Dongsan Medical Center, Keimyung University School of Medicine, Daegu, Korea.
authors.forename: Yong Won
authors.initials: YW
authors.lastname: Cho
keywords: T2 relaxometry; iron; red nucleus; restless legs syndrome; substantia nigra