Periodic Limb Movement Disorder

Periodic limb movement disorder (PLMD) is a sleep disorder characterized by recurrent episodes of frequent limb movements while sleeping. It mostly happens in the lower parts of the body like the toes, ankles, knees and hips. It can also, in some cases, appear in the upper extremities of the body. These movements can lead the patient to wake up, and if so, sleep interruption can be the origin of excessive daytime sleepiness.

PLMD is more common among older adults. It affects only about 2 percent of people less than 30 years of age; but, it may affect up to 40 percent of people age 65 years and older. PLMD affects men and women equally.

The most common symptoms of PLMD include the following:

  • repetitive leg movements in one or both legs and sometimes in the arms, which may involve flexing of the big toe, upward bending of the knee or ankle, or twitching of the hip.
  • restless, unrefreshing sleep.
  • multiple awakenings at night.
  • daytime sleepiness and drowsiness.
  • irritability, behavior problems and decline in performance at school or work due to lack of quality sleep.

What are some of the causes of Periodic Limb Movement Disorder?

Although the exact cause of PLMD isn’t currently known, many researchers believe that PLMD originates in the central nervous system. However, no official link has yet been made.

The following are all thought to contribute or influence PLMD but aren’t necessarily considered a cause:

  • caffeine intake
  • medications like antidepressants anti-nausea drugs, lithium, and anticonvulsants
  • other sleep disorders such as narcolepsy or Restless Leg Syndrome
  • some neuro-developmental disorders
  • iron deficiency anemia
  • metabolic disorders including diabetes and kidney disease.

What are the symptoms of Periodic Limb Movement Disorder?

PLMD movements typically occur every 20 to 40 seconds in batches of 30 minutes or more during the night. They are more common in the legs but may occur in the arms as well. The limb movements typically occur during non-rapid eye movement (non-REM) sleep.

The most common symptoms of PLMD include the following:

  • repetitive leg movements in one or both legs and sometimes in the arms, which may involve flexing of the big toe, upward bending of the knee or ankle, or twitching of the hip.
  • restless, unrefreshing sleep.
  • multiple awakenings at night.
  • daytime sleepiness and drowsiness.
  • irritability, behavior problems, and decline in performance at school or work due to lack of quality sleep.

People with PLMD may also have symptoms of restless leg syndrome (RLS). This may include burning or tingling sensations in the legs when they lie down.

How does Restless Leg Syndrome (RLS) differ from Periodic Limb Movement Disorder?

The main difference between Periodic limb movement disorder (PLMD) and Restless leg syndrome is that RLS symptoms happen while the person is awake and PLMD happens during sleep.

Restless legs syndrome (RLS) causes unpleasant or uncomfortable sensations in the legs and an irresistible urge to move them.  Symptoms commonly occur in the late afternoon or evening hours, and are often most severe at night when a person is resting, such as sitting or lying in bed.  They also may occur when someone is inactive and sitting for extended periods (for example, when taking a trip by plane or watching a movie).  Since symptoms can increase in severity during the night, it could become difficult to fall asleep or return to sleep after waking up.  Moving the legs or walking typically relieves the discomfort but the sensations often recur once the movement stops.

RLS is classified as a sleep disorder since the symptoms are triggered by resting and attempting to sleep, and as a movement disorder, since people are forced to move their legs in order to relieve symptoms.  It is, however, best characterized as a neurological sensory disorder with symptoms that are produced from within the brain itself.

RLS is one of several disorders that can cause exhaustion and daytime sleepiness, which can strongly affect mood, concentration, job and school performance, and personal relationships.  Many people with RLS report they are often unable to concentrate, have impaired memory, or fail to accomplish daily tasks.  Untreated moderate to severe RLS can lead to about a 20 percent decrease in work productivity and can contribute to depression and anxiety.  It also can make traveling difficult.

It is estimated that up to 7-10 percent of the U.S. population may have RLS. RLS occurs in both men and women, although women are more likely to have it than men. It may begin at any age. Many individuals who are severely affected are middle-aged or older, and the symptoms typically become more frequent and last longer with age.

More than 80 percent of people with RLS also experience Periodic limb movement disorder (PLMD).  PLMD is characterized by involuntary leg (and sometimes arm) twitching or jerking movements during sleep that typically occur every 15 to 40 seconds, sometimes throughout the night.  Although many individuals with RLS also develop PLMD, most people with PLMD do not experience RLS.

Fortunately, most cases of RLS can be treated with non-drug therapies and if necessary, medications.

How is Periodic Limb Movement Disorder diagnosed?

Often people first become aware that they may have PLMD when their partner complains of being kicked at night or they may find that their blankets are all over the place in the morning.

PLMD is diagnosed with a polysomnography test, also called a sleep study. This study is done overnight in a laboratory while you sleep.

This test records:

  • brain waves
  • heart rate
  • oxygen levels in your blood
  • eye movements
  • other nerve and muscle functions during sleep
  • blood pressure

We perform this test at San Tan Sleep Solutions. A sleep technologist places sensors on your scalp, temples, chest and legs using medical glue or tape. The wireless sensors transmit to the viewing system and measurements are taken all through the night while you’re asleep.

Your doctor may also get your complete medical history and give you a physical exam to look for other underlying issues that may be disrupting your sleep.

How is Periodic Limb Movement Disorder treated?

If your physician diagnoses you with PMLD, based upon the results of your overnight polysomnography, treatment measures may involve:

  • Avoiding stress and caffeine.
  • Treating underlying conditions like iron deficiency anemia.
  • Prescribing medications.

How do I get started?

Contact San Tan Cardiovascular Center today to make an appointment with one of our healthcare providers.

At this appointment:

  • we will review your medical history, discuss your symptoms and perform a non-invasive, diagnostic test to further determine your medical condition,
  • any pertinent testing that needs to be done beforehand will also be ordered at this time.

Our billing department will then contact your health insurance company to obtain prior authorization.  Upon receiving insurance authorization, the test will be scheduled.