We thank Dr Machtey for sharing his extensive experience with a disorder that often goes unrecognized and untreated. His observations on the lack of ethnic variability in the study of RLS and its prevalence are particularly interesting, as little has been published on this topic.
We must take issue, however, with his statement, "Actually, no difference from the night restlessness can be found, with only one exception: during the day, patients pay no attention to it, while at night it awakens them." In RLS patients, the circadian rhythm of motor restlessness, sensory symptoms, and periodic limb movements has been documented to be independent of activity.1- 3 Because there is no reliable biologic marker for RLS as yet, we must rely on a careful clinical evaluation to make the diagnosis, and the presence of circadian variability is requisite for the diagnosis of this disorder.4- 5 One is in danger of misdiagnosing neuropathy or other movement disorders similar to RLS if this feature is discounted. Furthermore, RLS is a sleep disorder because it is worse at night.