Restless Leg Syndrome (RLS) may occur in children. Symptoms are typically uncomfortable feelings or sensations in the legs occurring at bedtime that may be difficult for children to describe. These symptoms disrupt sleep and produce symptoms of sleep deprivation. Limb movements during sleep are detected by polysomnography (sleep study) and support the diagnosis. Limb movements on polysomnography with daytime symptoms of sleep deprivation but without sensory symptoms at bedtime may represent another clinical entity called Periodic Limb Movement Disorder.