Restless Leg Syndrome (RLS) and Periodic Limb Movement Disorder (PLMD) are believed to be related to some degree.  RLS affects at least 5% of the population, primarily adults.  The incidence of PLMD is probably 30% in individuals greater than 65 years of age, although the disorder can occur in infancy as well.

    PLMD, unlike RLS, is not usually recognized by the sufferer.  Essentially, it does not occur until the individual is asleep.  PLMD involves slight movements of the legs that may be noticed by a bed partner.  Although this disorder seems relatively benign, each time the leg moves, a partial awakening occurs that is not typically recognized by the victim.  With leg movements occurring hundreds of times nightly, the victim's sleep is severely fragmented, resulting in daytime sleepiness.  PLMD tends to worsen after exercise and with certain medications. especially antidepressants.

    In some individuals, the leg movements will bring the individual to a complete awakening during sleep; although, once awakened, the victim will not be able to identify the leg movement as the actual cause.

    The diagnosis of this disorder is trickier than RLS, since PLMD patients are unaware of the leg movements.  The sufferer may notice a disheveled bed in the mornings.  Typically, insight is provided by a family member who reports the patient "kicks" during sleep.  A medication trial is often attempted in patients who seem to  sleep solidly through the night, but continue to have the sensation of poor sleep and daytime sleepiness.  An overnight stay in a sleep laboratory may be necessary to make the diagnosis.

    Medical treatment for PLMD is usually successful, but the disorder is life-long.  As with RLS, further information regarding this disorder can be obtained by contacting:

RLS Foundation, Inc.

304 Glenwood Avenue

Raleigh, NC 27603-1455

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