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Periodic Limb Movement Disorder

Periodic Limb Movement Disorder Symptoms

The most common symptoms noted by people with PLMD are not leg movements but poor sleep and daytime sleepiness. Many people with PLMD are unaware of their leg movements unless their bed partner tells them.

Leg movements involve one or both limbs.

  • Typically the knee, ankle, and big toe joints all bend as part of the movements.
  • The movements vary from slight to strenuous and wild kicking and thrashing.
  • The movements last about 2 seconds (and thus are much slower than the leg jerks of myoclonus).
  • The movements are rhythmic and repetitive and occur every 20-40 seconds.

Exams and Tests

In most people with PLMD, poor sleep and daytime sleepiness are the most bothersome symptoms. Many people do not link their sleep problem with leg movements. Sleep disturbance has many different causes. Depending on how you describe your symptoms, your health care provider may ask you many detailed questions. These questions concern your medical problems now and in the past, family medical problems, medications you take, your work and travel history, and your habits and lifestyle. A detailed physical examination will look for signs of an underlying cause for your sleep problem.

There is no lab test or imaging study that can prove that you have PLMD. However, certain tests can identify underlying medical causes such as anemia, other deficiencies, and metabolic disorders that could cause PLMD.

  • You may have blood drawn to check your blood cell counts and hemoglobin, basic organ functions, chemistry, and thyroid hormone levels. You also may be checked for certain infections that could cause secondary PLMD.
  • A urine sample may be collected to check for traces of drugs that can cause sleep problems.

Polysomnography (sleep lab testing) is the only way to confirm that you have PLMD. As you sleep in the lab, your leg movements can be documented.

At any time during your evaluation, your health care provider may refer you to a neurologist (a specialist in disorders of the nervous system). This specialist can help rule out other neurological problems and confirm the diagnosis of PLMD.

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