Periodic Limb Movement Disorder

Periodic limb movement disorder (PLMD), also called nocturnal myoclonus, is when repetitive limb movements occur while you are sleeping. According to the American Academy of Sleep Medicine, PLMD occurs in up to 34 percent of people in the United States who are over 60 years old, although the condition can occur in people of all ages. Treatment is aimed at reducing involuntary movement during sleep.

Symptoms

• PLMD occurs most often during the first stage of sleep before you are sleeping soundly. During this time, the legs, hips, feet and knees may jerk involuntarily. Some people also experience movement in their arms and hands. Particularly strong movements may wake you and may disrupt the sleep of anyone who shares a bed with you. Bedmates may also suffer accidental injury depending on the severity of your movements. Movements usually last no longer than 10 seconds and may occur in groups. According to the Sleep Channel, there may be 5 to 90 seconds between each movement.

PLMD and Restless Leg Syndrome

• PLMD is sometimes confused with restless leg syndrome (RLS). RLS happens when you are awake and is characterized by an intense need to move your legs. A tingling, burning sensation may also be present in the legs. According to the American Sleep Association, approximately 80 percent of people who have RLS also have PLMD.

Risk Factors

• Certain conditions may increase your chances of developing PLMD. These conditions may include diabetes, low iron levels, chronic lung disease, kidney failure, leukemia, fibromyalgia, peripheral nerve damage, spinal cord injury, vitamin B-12 deficiency, rheumatoid arthritis, narcolepsy, Parkinson's disease and amyotrophic lateral sclerosis (Lou Gehrig's disease). Taking lithium, anti-nausea medications or certain antidepressants can cause PLMD, as can withdrawal from barbiturates, anti-convulsants and tranquilizers containing benzodiazepine.

Effects

• Involuntary movements that wake you multiple times during the night can result in sleep deprivation for both you and anyone who sleeps with you. Being constantly tired can make you feel depressed or in a bad mood and can decrease your attention span.

Diagnosis

• If you suffer from the symptoms of PLMD, your doctor may ask that you keep a sleep diary for several weeks. The sleep diary will provide your doctor with valuable information on the time and duration of your symptoms and any factors that might be contributing to your problem. A sleep study, or polysomnogram, may be needed to diagnose PLMD. During a sleep study, electrodes are attached to your chin, scalp and eyes. Monitors are also attached to the chest. As you sleep, readings of your brain waves, eye movements, heart and breathing rates, heart rhythm, blood pressure and saturation and muscle activity are recorded. The sleep study technician also observes you while you sleep and looks for signs of PLMD.

Treatment

• Reducing caffeine intake, particularly in the evening, can help alleviate the symptoms of PLMD. Learning yoga or relaxation techniques may also be helpful. If the problem is severe, your doctor may recommend medication. Anti-convulsants normally used to treat seizure disorders can be helpful in treating the involuntary movements associated with PLMD. Dopamine agonist medications usually used to treat Parkinson's disease can reduce PLMD symptoms by suppressing abnormal activity in the central nervous system.