Periodic Leg Movements During Sleep - PLMS

PLMS/PLMD

 

  PLMS (Periodic Leg Movement during Sleep) consists of involuntary movements of the legs, while asleep. People who suffer from PLMS can be unaware of their limb movements, as they do not always wake from them. PLMS is related to PLMD or Periodic Leg Movement Disorder. These movements happen during the night, at regular intervals before one enters REM sleep. Sufferers often complain of the inability to fall asleep or to remain asleep in association with PLMS. Men and women are equally affected by PLMS; children may develop it as well. This disorder is most common in people over the age of 65, although one may develop it at any age.

 

Symptoms…

  People who suffer from PLMS often complain of difficulty falling asleep or staying asleep due to the limb movements they experience. Chronic disruption of sleep can lead to daytime sleepiness, irritability or general changes in mood.  The characteristic movements associated with PLMS usually occur in the legs, but less commonly can occur in the arms as well. These rhythmic movements usually consist of involuntary extension of the big toe and then progress to an upward bending of the knee, ankle or hip.  The symptomatic limb movements will usually persist over a certain interval, lasting from a few minutes up to several hours. Within these events, the leg movements will occur about 5 – 90 seconds apart and last from .5 seconds to 10 seconds. Sufferers of PLMS may also experience some of the same symptoms of RLS like burning, tingling sensations or general discomfort in their legs when they lay down to rest. Not everyone who has PLMS has RLS; however, about 80% of people who suffer from RLS also suffer from PLMS.

  Often ones bed partner will be more aware of the movements than the sufferer is. Many times when one suffers from PLMS, they may not fully awaken from the movements, although it does disrupt their sleep. Additionally, one may find they frequently wake up just as they are falling asleep and not know what work them, as the leg movements usually last only a few seconds. These movements will often occur in the first stage of your sleep cycle, before REM sleep. REM sleep is the “dream cycle” of sleep; it is also the episode in which one obtains their most restful sleep. Constant disruptions of the sleep cycle can keep one from attaining REM sleep, leaving a person unrested in the morning.  During the REM sleep cycle a persons voluntary muscles are paralyzed, which keeps one from acting out their dreams. It is possible that because of this paralysis, PLMS can only occur before or after REM sleep.  

 

Causes…

  While there is no known exact cause of PLMS, researchers are working to find the cause and new treatment options. Currently scientists think that the central nervous system and PLMS could be related, but no studies have proven links between central nervous system abnormalities or disorders and PLMS.

  Many underlying medical conditions that cause RLS (restless leg syndrome) may cause PLMS as well. Research shows that anemia, iron deficiency, CNS problems, and kidney disorders may cause RLS and may cause symptoms of PLMS as well. A hereditary link has been seen in people suffering from RLS, the same may be true for people suffering from PLMS. While these conditions can be associated, they are not found to cause one and other, they are only seen as being generally related.

  PLMS by it’s self is not a medically serious condition it can make life unpleasant. Many people who suffer from PLMS often complain of daytime sleepiness, fatigue or feeling unrested when they awake. These symptoms alone can make day-to-day life difficult. If one is unaware of their symptoms, and they are severe enough, PLMS can be a cause of chronic insomnia. PLMS, like RLS, can also be an indicator of more serious underlying medical conditions like diabetes, kidney disease or anemia.

 

Diagnosing/Treatment…

  If a person thinks they suffer from PLMS or experiences RLS symptoms like burning or general discomfort in their lower legs, one may want to see a health care professional. A medical provider may want to review your medical history and request a current physical. The medical provider may also ask ones bed partner some questions about their sleep habits; often when people suffer from PLMS the movements will wake their bed partner as well.

 

  A medical professional may recommend that a person have a sleep study done to monitor ones movement during sleep. Sleep studies are typically done in a hospital or a sleep center. For the sleep study one will typically spend a night in a private room near the sleep technicians, so they are able to monitor a persons sleep experiences and physical information. A sleep study may also ascertain weather or not a persons’ PLMS is related to other sleep conditions like RLS, sleep apnea or other breathing problems. PLMS is only diagnosed as a disorder when the symptoms cannot be explained by another condition like RLS. A medical provider may also determine it would be best for one to see a sleep specialist or refer you to a sleep center for further testing and diagnosis

  If your symptoms are very frequent or severe, your medical provider may prescribe medications. The medications most frequently prescribed are dopamine agonists or benzodiazepines. Dopamine agonists are commonly prescribed for Parkinson’s disease to control the associated tremors. Benzodiazepines are a class of anticonvulsants, commonly prescribed for seizure disorders. Both of the types of medications work by suppressing abnormal central nervous system activity. Successful management of PLMS has been found with each of the classes of medication.

  Many people who suffer from mild or moderate PLMS can successfully manage their condition with out medication. People often report that relaxation exercises like yoga or meditation can help reduce their symptoms. Some times a hot bath or messaging ones legs before going to sleep will help with the movements as well.

  Reviewed September, 2007

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