Periodic Limb Movements of Sleep (PLMS) is a sleep disorder characterized by repetitive, involuntary movements of the legs during sleep. These movements typically involve the lower limbs and may include flexing of the ankles, knees, or hips. Episodes often occur every 20 to 40 seconds and can continue for several minutes or even hours throughout the night.

Many people with PLMS are unaware that these movements are occurring. However, the repeated disruptions can interfere with normal sleep patterns, resulting in poor sleep quality and excessive daytime fatigue. PLMS may occur on its own or alongside other sleep disorders, including Restless Leg Syndrome (RLS), sleep apnea, or narcolepsy.

The exact cause of PLMS is not always known, but it has been associated with certain medical conditions, medications, and neurological factors.

Signs & Symptoms

Common signs and symptoms of PLMS include:

• Repetitive jerking, twitching, or flexing movements of the legs during sleep
• Frequent nighttime awakenings or disrupted sleep
• Difficulty staying asleep
• Excessive daytime sleepiness
• Morning fatigue or feeling unrefreshed after sleep
• Bed partner reports of repetitive leg movements during the night
• Difficulty concentrating due to poor sleep quality

Because the movements occur during sleep, many individuals are unaware of the condition until it is identified by a sleep study or reported by a bed partner.

Diagnosis

Diagnosing PLMS begins with a review of your symptoms, sleep habits, and medical history. Your Deborah Heart and Lung Center provider may ask about daytime fatigue, sleep quality, and whether a bed partner has observed unusual movements during sleep.

The most effective way to diagnose PLMS is through an overnight sleep study, known as polysomnography. During the study, sensors monitor brain activity, breathing patterns, heart rate, oxygen levels, and limb movements while you sleep. This testing helps determine the frequency and severity of the movements and can identify other sleep disorders that may be contributing to your symptoms.

Your provider may also evaluate for underlying conditions, medications, or other factors that can be associated with PLMS to help guide treatment recommendations.