Frequent occurrence of myoclonus while awake and at rest, body rocking and marching in place in a subpopulation of patients with restless legs syndrome.

While myoclonus awake and at rest, body rocking and marching in place have been occasionally reported to occur in idiopathic restless legs syndrome (RLS), it has not been previously noted that these clinical features occur frequently in a subpopulation of severely affected older RLS patients seeking medical attention for longstanding symptoms that have become progressively worse over the years. We studied 10 unrelated patients from this subpopulation and polysomnographically documented myoclonus while awake and at rest in 8, and intermittent night-time body rocking and marching in place in 6 by history and videotape. Also occurring frequently were the well-known clinical features of floor pacing, paresthesias, sleep disturbances, periodic movements of sleep (PMS), tendency for the signs and symptoms to be worse at night, and a family history suggestive of RLS.