Normal regional brain iron concentration in restless legs syndrome measured by MRI

Abstract

Susanne Knake1, Johannes T Heverhagen2, Katja Menzler1, Boris Keil2, Wolfgang H Oertel1, Karin Stiasny-Kolster11Department of Neurology, Center of Nervous Diseases, 2Department of Radiology, Philipps University, Marburg, GermanyAbstract: Using a T2* gradient echo magnetic resonance imaging (MRI) sequence, regional T2 signal intensity (SI) values, a surrogate marker for T2 values, were determined in 12 regions of interest (substantia nigra, pallidum, caudate head, thalamus, occipital white matter, and frontal white matter bilaterally) and in two reference regions (cerebrospinal fluid and bone) in 12 patients suffering from moderate to severe idiopathic restless legs syndrome (RLS; mean age 58.5 ± 8.7 years) for 12.1 ± 9.1 years and in 12 healthy control subjects (mean age 56.8 ± 10.6 years). Iron deposits shorten T2 relaxation times on T2-weighted MRI. We used regional T2* SI to estimate regional T2-values. A T2-change ratio was calculated for each region of interest relative to the reference regions. We did not find significant differences in any of the investigated brain regions. In addition, serum measures involved in iron metabolism did not correlate with T2 SI values. We could not replicate earlier findings describing reduced regional brain iron concentrations in patients with RLS. Our results do not support the view of substantially impaired regional brain iron in RLS.Keywords: restless legs syndrome, pathophysiology, iron, MRI, substantia nigra