Periodic Limb Movements of Sleep and Restless Legs Syndrome

What are periodic limb movements of sleep?

Periodic movements of the arms and legs may cause brief awakenings during sleep, leaving a person feeling fatigued in the morning, even though they do not recall any problems during the night. A bed partner may view the arm or leg movements as “restlessness,” however in some cases they may be so subtle that they go unnoticed.

What are the physical effects of periodic limb movements of sleep?

As with any sleep disorder, the physical effects of sleep loss go much farther than fatigue. Sleep deprivation has been shown to worsen inflammation and decrease the effectiveness of certain immune processes.

Who is at risk for periodic limb movements of sleep?

Periodic Limb Movements of Sleep (PLMS) has been estimated to occur in 3-5% of the total population, but this is likely to be an underestimate. It is much more common with advancing age, occurring in up to a third of people over the age of 60 years, and it is very common in people with neurological diseases. It commonly occurs with degenerative disc disease of the spine, spinal stenosis, diabetes, and iron deficiency, just to name a few causative medical disorders. Some people inherit the disorder, and still others may only have symptoms when they are treated with certain types of medication. When a person has PLMS and assorted daytime symptoms of limb discomfort, such as odd sensations or the persistent need to stretch, a diagnosis of Restless Legs Syndrome (RLS) may be made.

How is periodic limb movements of sleep diagnosed?

The diagnosis of PLMS and RLS relies heavily on a person’s symptom history and medical evaluation, but it can only be clearly diagnosed and differentiated from other sleep disorders by a sleep study (polysomnogram, or PSG). The PSG may occasionally be repeated to help determine whether treatment is proceeding effectively in complicated cases.  

How is periodic limb movements of sleep treated?

Treatment of PLMS should include elimination of anything that might be aggravating the symptoms and treatment of medical conditions that might be causing or worsening them. Some medications can significantly reduce PLMS without causing further sleep disturbance, while still other medications are used for sedative effects, but they don’t really help the underlying condition. The daytime symptoms of RLS may require different medications in place of (or in addition to) the nighttime treatment.  It is reasonable for a person to expect the treatments of PLMS and RLS to require adjustment over time, as the causative medical conditions, the natural course of symptoms, and response to medications may change.