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

Using a T(2)* gradient echo magnetic resonance imaging (MRI) sequence, regional T(2) signal intensity (SI) values, a surrogate marker for T(2) 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 T(2) relaxation times on T(2)-weighted MRI. We used regional T(2)* SI to estimate regional T(2)-values. A T(2)-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 T(2) 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.