LAUSR

We appreciate Dr. Sethi's emphasis on the often overlooked iron treatment of restless legs syndrome (RLS) in the comment on our article.1 The recommendation to treat patients with serum ferritin less than or equal to 75 μg/L was based on the reviewed placebo-controlled study showing significant RLS benefit and ferritin increase with ferrous sulfate 325 mg (65 mg iron) with vitamin C 100 mg dosed twice daily.2 As described in the full-length guideline,1 only oral iron studies where patients had evidence of iron deficiency were considered for the guideline, and oral iron is absorbed only in the context of low iron levels. An additional placebo-controlled study with no serum ferritin limit (average 135 μg/L) showed no benefit on RLS symptoms or ferritin increase,3 likely reflecting limited absorption of iron for ferritin over 75 μg/L and also limitations in precision secondary to sample size. Optimal iron supplementation strategies are still under investigation.4 Clonazepam data are described in the full guideline report supplement,1,5,6 with insufficient evidence to support an evidence-based recommendation. Anecdotal evidence is subject to multiple types of bias and is insufficient to drive recommendations under the 2004 American Academy of Neurology process.