-what-is-periodic-limb-move : Symptoms, Causes, Treatment & Prevention

Periodic limb movement disorder (PLMD) is a condition characterized by twitching, flexing, and jerking movements of the legs and arms during sleep. It’s sometimes referred to as periodic leg movement during sleep (PLMS). The movements typically occur every 20 to 40 seconds and may last for minutes or hours throughout the night.

People with PLMD don’t know their limbs are moving. They’re unable to control or stop the movements. They often wake up tired and irritable.

What causes 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 RLS
• neurodevelopmental disorders like attention deficit hyperactivity disorder and Williams syndrome
• spinal cord injury
• iron deficiency anemia
• metabolic disorders including diabetes and kidney disease

PLMD is more common among older adults. According to the Sleep Health Foundation, 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.

What are the symptoms of periodic limb movement disorder?

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 RLS. This may include burning or tingling sensations in the legs when they lie down. Not everyone with PLMD has RLS, but according to the American Sleep Association, about 80 percent of people with RLS also have PLMD.

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

How is periodic limb movement disorder treated?

Treatment for PLMD will depend on the results of the sleep study and other diagnostic tests as well as the severity of your disorder. It may also depend on whether you have another sleep disorder, such as RLS.

Avoiding caffeine and reducing stress

You might not need treatment at all if your PLMD is moderate and doesn’t disturb you or your partner too much. In this case, cutting down on caffeine, alcohol, and smoking can help. Caffeine isn’t just found in coffee. It’s also in sodas, teas, chocolates, energy drinks, and some medications, such as Excedrin.

Yoga, meditation, and other relaxation exercises may also help reduce symptoms. As well, massages or a hot bath prior to sleep can help tame symptoms at night.

Treating the underlying condition

If you’re diagnosed with iron deficiency or another medical condition, treatment is aimed at the underlying condition. Your doctor may want to monitor your iron levels over time and prescribe an iron supplement or recommend a diet high in iron-rich foods.

Taking medications

For severe cases of PLMD, medications that regulate muscle movements may be prescribed as a last resort. These include:

• dopamine agonists, which are commonly prescribed to control tremors in people with Parkinson’s disease
• benzodiazepines such as clonazepam (Klonopin)
• anticonvulsants such as gabapentin (Neurontin, Gralise, Horizant)