Periodic Limb Movement Disorder
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.
Periodic Limb Movement Disorder Treatment
Treatment does not cure the disorder but usually relieves symptoms.
Treatment involves medication that either reduces the movements or helps the person sleep through the movements.
Therapy does not cure PLMD but relieves symptoms. Note that many of the medications used to treat PLMD are the same as those used to treat restless legs syndrome.
- Benzodiazepines: These drugs suppress muscle contractions. They are also sedatives and help you sleep through the movements. Clonazepam (Klonopin), in particular, has been shown to reduce the total number of periodic limb movements per hour. It is probably the most widely used drug to treat PLMD.
- Dopaminergic agents: These drugs increased the levels of an important neurotransmitter (brain chemical) called dopamine, which is important in regulating muscle movements. These medications seem to improve the condition in some people but not in others. Widely used examples are a levodopa/carbidopa combination (Sinemet) and pergolide (Permax).
- Anticonvulsant agents: These medications reduce muscle contractions in some people. The most widely used anticonvulsant in PLMD is gabapentin (Neurontin).
- GABA agonists: These agents inhibit release of certain neurotransmitters that stimulate muscle contractions. The result is relaxation of contractions. The most widely used of these agents in PLMD is baclofen (Lioresal).