Sleep Walking (Restless Leg Syndrome, RLS) (Cont'd)

Restless legs movement is associated with unexplained feelings of tingling and twitching beneath the skin, usually between the thighs and ankles, or feelings of crawling, creeping, and pulling skin are often reported by people suffering from the syndrome. These sensations cause discomfort, making sleeping almost impossible, and creates an irresistible urge to move the legs. These symptoms are worse when the victim is at rest, and the sensations are typically lessened by voluntary movement of the affected extremity. The symptoms are also worse in the evening and at night, especially true when the individual lies down. Movements in the toes, feet or legs are seen when the inflicted person sits down or lies down in the evening. This restlessness is seen as fidgetiness or nervousness. About 80% of people that have restless legs movement also have periodic limbs movement of sleep (PLMS). PLMS, or known also as nocturnal myoclonus, is characterised by the recurrent episodes of limb movement that recur at intervals of 15 to 40 seconds during Non-REM sleep (see What is Sleep?). It usually involve the legs, where they may consist of extension of the great toe associated with flexion at the ankle, knee, and hip. As the arms are also involved, it is called periodic limbs movement rather than periodic legs movement. When the movement is severe, it can disrupt sleep.
Polysomnographic study demonstrates the existence of PLMS in 70% to 90% of patients with RLS. It is estimated that no more than 30% of patients with PLMS will also have RLS. PLMS may occur at any age, but their prevalence increases markedly in later life, until more than 30% of all individuals over age 65 may have a significant number of PLMS. Individuals inflicted with RLS have difficulty sleeping as lying down or relaxation activates the symptoms. In addition to that, the individual also has difficulty in maintaining their sleep. This may be greatly due to PLMS, which can arouse and awaken the victim. The cause and cure of the two syndromes are unknown as yet.