Periodic Leg Movements
               and Restless Leg Syndrome

Periodic limb movement disorder (PLMs) and restless legs syndrome (RLS) are known as (nocturnal) "myoclonus",
which describes frequent or involuntary muscle spasms.  

PLMs and RLS are distinct disorders, but often occur simultaneously. 

This section includes information on these sleep disorders - just click on any of the headings below to go to the
relevant section:

What are PLMs
How PLMs are diagnosed
What is RLS?
Indicators of RLS
How is RLS diagnosed
More Information

• Periodic limb movements is a disorder affecting people only during sleep, and usually includes any repetitive, involuntary movement during the night.
• Periodic leg movements are involuntary muscle twitches, which occur repeatedly during sleep, disrupting a person’s sleep pattern and thereby causing daytime sleepiness.
• It is a relatively common, and is estimated to affect up to 10% of the population.
• The condition is characterised by behaviour ranging from shallow, continual movement of the ankle or toes, to wild and strenuous kicking and flailing of the legs and arms. In addition, abdominal, oral, and nasal movement sometimes accompanies PLMs.
• Movement of the legs is more typical than movement of the arms in cases of PLMs.
• Movements typically occur for 0.5 to 10 seconds, in intervals separated by five to 90 seconds.
• The incidence of PLMs increases with age - it is thought to occur in 5% of people age 30 to 50 and in 44% of people over the age of 65.
• PLMs can also be associated with other sleep disorders - up to 12.2% of people suffering from insomnia and 3.5% of people suffering from excessive daytime sleepiness (EDS) may experience PLMs.

How PLMs are Diagnosed

• Often, medical investigation is prompted by the sufferer's sleep partner, who observes the occurrence of PLMs, which usually affect the partner before the sufferer even knows of his or her behaviour.
• The medical diagnosis is made by a sleep technician during an overnight polysomnogram (Sleep Study), which records sleep. This test is often used to assess the cause of excessive daytime sleepiness, such as PLMs and obstructive sleep apnoea (OSA).
• Sleep Services Australia offer convenient Home-Based Sleep Studies to patients suspected of having PLMs - please contact your doctor to ask for a referral.

A common complaint characterised by irritable legs often described as crawling, itching or a "pins and needles" feeling under the skin.

Other symptoms described include cramping, which can be alleviated temporarily by moving your legs.

Approximately 80% of people with RLS also suffer from Periodic Leg Movements, although most people with PLMs do not experience RLS.

Indicators of RLS

• You have a strong urge to move your legs which you may not be able to resist. The need to move is often accompanied by uncomfortable sensations.
• Your symptoms start or become worse when you are resting. The longer you are resting, the greater the chance the symptoms will occur and the more severe they are likely to be.
• Your symptoms get better when you move your legs. The relief can be complete or only partial, but generally starts very soon after starting an activity. Relief persists as long as you continue to move your legs.
• Your symptoms are worse in the evening especially when you are lying down. Activities that bother you at night do not bother you during the day.

How RLS is Diagnosed

• RLS can be difficult to identify because it presents no external secondary symptoms. The diagnosis of RLS is therefore based on the patient's description and personal history. 
• Patients can also complete a RLS Diary (available from Sleep Services Australia), which is completed after waking up, and just before bedtime.  Such a record will offer an overview of the patient's sleep experience, and effects of RLS, such as Excessive Daytime Sleepiness, which can also be measured by completing the Epworth Sleepiness Scale
  (Click Here to access our online ESS Form, or to Click to download a PDf version).
• It is important to distinguish PLMD from other more serious types of nocturnal movement, such as seizure. Nocturnal seizures present problems for patients because they can cause injury and are indicative of disorders that require specialized treatment.
• Also, iron and calcium deficiencies often produce symptoms that mirror RLS, such as leg cramping and tenderness, so please see your General Practitioner if you suffer from these symptoms.

• For further information download our Periodic Leg Movement and Restless Leg Syndrome PDF FactSheet.

To view (pdf) files you will need Adobe Acrobat Reader. Click here for download or more information.

Please Note: The information on this page is intended to be used as a guide only and is not an authoritative statement.
Please consult your family doctor or sleep  physician if you have further questions relating to the information provided here.