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Periodic Limb Movement Disorder

Periodic Limb Movement Disorder is a neurological disorder that is similar to Restless Legs Syndrome but it occurs during sleep rather than during wakefulness. Periodic Limb Movements usually occur in the legs but may also affect the arms, causing a twitch, jerk or kick about every 10 to 60 seconds and causing you to wake up more often and to sleep less.

Causes of Periodic Limb Movement Disorder

Periodic Limb Movement Disorder is common among people with Parkinson's disease, Narcolepsy and rapid eye movement (REM) behavior disorder. Most people with Restless Legs Syndrome also have Periodic Limb Movement Disorder, but the reverse is not true. There's as Both disorders are more likely in people who:

  • Are female
  • Stop taking certain drugs (including benzodiazepines such as diazepam)
  • Take stimulants (such as caffeine or certain drugs) or certain antidepressants
  • Have iron deficiency
  • Have anemia
  • Are pregnant
  • Have a kidney or liver disorder

Signs and Symptoms of Periodic Limb Movement Disorder

Because a certain number of periodic limb movements occur normally, Periodic Limb Movement Disorder is usually diagnosed with at least 4-5 jerks or kicks per hour of sleep, averaged over the course of the night. The movements usually do not occur continuously throughout sleep, but instead cluster in the first half of the night

It should be noted that periodic limb movements are different from the sudden movement of the entire body, usually accompanied by the sensation of falling, that can occur soon after sleep begins. This movement is normal and usually doesn’t interfere with sleep quality.

Periodic Limb Movement Disorder sufferers may be awakened by leg movements right after they fall asleep and wake up so quickly they are not even aware they were asleep. These people may complain about difficulty falling asleep. Others may experience leg movements accompanied by very brief awakenings throughout the night and report difficulty staying asleep and sleeping very little. Still other sufferers may have only a general complaint of restless or poor sleep.

Some people may not be aware of any nighttime disturbance but experience excessive daytime sleepiness because of the many brief awakenings disturbing their sleep. Children often react to sleepiness by becoming hyperactive, and young people with the disorder may appear hyperactive or inattentive, and may even be diagnosed with ADHD.

Periodic limb movements may cause problems that affect the bed partner rather than the patient. Such complaints may include being kicked at night, bed covers being twisted or thrown off the bed or that limb movements shake the bed.

Risks

Periodic Limb Movement Disorder interrupts the sleep and makes the sufferer feel tired and sleepy during the daytime.

What to Do

If you think you suffer from Periodic Limb Movement Disorder, speak to your physician or one of our sleep specialists, who can help you determine your next steps. Overnight sleep testing is commonly used to diagnose this sleep disorder.  If Periodic Limb Movement Disorder is diagnosed, blood and urine tests may be ordered to check for underlying disorders that can contribute, such as anemia, iron deficiency, and kidney and liver disorders.