Familial restless legs with periodic movements in sleep: electrophysiologic, biochemical, and pharmacologic study.

Restless legs syndrome was present in nine members of a family over a span of five generations. In three subjects, the diagnosis was confirmed by all-night sleep recordings and concomitant EMG. Two of these three subjects also had periodic movements in sleep. The frequency of leg movements decreased from wakefulness to stages 1 and 2 non-REM sleep. There was an increase of free dopamine and homovanillic acid in CSF of the propositus. Clonazepam effectively controlled restless legs in the propositus and his mother.