Sleep Medicine

Periodic leg movement syndrome is a condition that can be characterized by rhythmic, often-violent leg movements, during sleep, that the person suffering from this condition is rarely aware of. Most patients that suffer from this disorder complain of excessive daytime drowsiness and unrefreshing sleep.

Movements occur periodically throughout the night and can fluctuate in severity from one night to the next. They tend to cluster in episodes that last anywhere from a few minutes to several hours. These movements are very different from normal spasms, called hypnic myoclonia, that we often experience initially while trying to fall asleep.

What Causes Periodic Leg Movement Syndrome?

The causes of periodic leg movement syndrome are unknown; however, recent research has shown that people with a variety of medical problems, including Parkinson's disease and narcolepsy, may have frequent periodic leg movements in sleep. Also, periodic leg movement syndrome may be induced by medications—most notably, antidepressants.

What are the Symptoms of Periodic Leg Movement Syndrome?

Symptoms are usually leg movements with the extension of the big toe in combination with a partial flexing of the ankle, knee or hip. It can often cause a brief partial or full awakening resulting in fragmented sleep. Patients are frequently unaware of these movements.

How is Periodic Leg Movement Syndrome Diagnosed?

A sleep partner may observe the occurrence of periodic leg movements, which often affects the partner before the patient knows of his or her behavior. In other cases, the diagnosis is made on an overnight polysomnogram, which is a test that records sleep and the bioelectrical signals coming from the body during sleep. This test is often used to assess the cause of daytime sleepiness or recurrent awakenings from sleep. Blood work may be done in order to test iron status, folic acid, vitamin B12, thyroid function and magnesium levels.

How is Periodic Leg Movement Syndrome Treated?

Generally, there are several classes of drugs that are used to treat this condition. These include Parkinson's disease drugs, anticonvulsant medications, benzodiazepines and narcotics. Current treatment recommendations consider the anti-Parkinson's medications as a first line of defense. Medical treatment often significantly reduces or eliminates the symptoms of these disorders.

There is no cure and medical treatment must be continued to provide relief.

Are There Substances That Should Be Avoided?

The use of caffeine often intensifies periodic leg movement syndrome symptoms. Caffeine-containing products such as chocolate, coffee, tea and soft drinks should be avoided. Also many antidepressants can worsen the condition.