Periodic Limb Movement Disorders Diagnosis

Periodic limb movement disorders can be observed by the sleep partners.

Periodic limb movement disorders often affect the partner before the patient knows of his or her behavior.

Leg movements are recorded during sleep. This is called the Periodic Limb Movement index.

If this index is greater than or equal to five, i.e., leg movements occurred at least five times an hour, then the diagnosis of Periodic limb movement disorders is made.

In other cases, the Periodic limb movement disorders diagnosis is made on an overnight polysomnogram (test that records sleep and the bioelectrical signals coming from the body during sleep).

This test is often used to assess the cause of daytime sleepiness or recurrent awakenings from sleep. Blood work may be done in order to test iron status, folic acid, vitamin B12, thyroid function, and magnesium levels.

Periodic limb movement disorders Diagnosis Exams and Tests:

In most people with Periodic limb movement disorders, poor sleep and daytime sleepiness are the most bothersome symptoms. Many people do not link their sleep problem with leg movements.

Depending on how you describe your symptoms of Periodic limb movement disorders, your health care provider may ask you many very 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 Periodic limb movement disorders.

However, certain tests can identify underlying medical causes such as anemia, other deficiencies, and metabolic disorders that could cause Periodic limb movement disorders.

• A urine sample may be collected to check for traces of drugs that can cause sleep problems. 
• 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 Periodic limb movement disorders.

Polysomnography (sleep lab testing) is the only way to confirm that you have Periodic limb movement disorders. 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 Periodic limb movement disorders.