It may involve kicking, twitching, or extension of the legs.
Importantly, restless legs syndrome (RLS) symptoms are noted during wakefulness while PLMS occur during sleep.
The movements associated with PLMS often consist of flexion or extension at the ankle.
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In some cases, this may also occur at the knee.
It may occur on one side or alternate back and forth between the left and right sides.
It tends to increase with age and often, but does not always, accompanies restless legs symptoms.
Diagnosis
The gold standard for diagnosis of PLMS is asleep studycalled apolysomnogram.
As part of this study, superficial electrodes are placed on the legs and sometimes even the arms.
These are able to detect any muscle contraction or movements.
If the movements are associated with arousals or awakenings from sleep, they may be more significant.
They also may be deemed important if they become disruptive to the bed partner.
If the movements cannot be explained by another disorder, PLMS may be the likely diagnosis.
Prescription medications can be effective in treating PLMS.Many of the drugs used to treat RLS are also helpful.
These may include benzodiazepines (often clonazepam), Mirapex (generic name pramipexole), and ropinirole.
After a diagnostic study, the cause can be properly identified and the appropriate treatment may be pursued.
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Cleveland Clinic.Periodic limb movements of sleep (PLMS).
Sleep Foundation.Periodic limb movement disorder.
2004 Sep;24(3):249-59. doi:10.1055/s-2004-835066
