Periodic Limb Movement Disorder (PLMD)

Periodic Limb Movement Disorder Overview

Periodic limb movement disorder affects people only during sleep.

Periodic Limb Movement Disorder (PLMD), formerly known as nocturnal myoclonus, is a condition in which a person's legs or arms twitch or move involuntarily and periodically during sleep.

The condition is characterized by behavior ranging from shallow, continual movement of the ankle or toes, to wild and strenuous kicking and flailing of the legs and arms.

Furthermore, abdominal, oral, and nasal movement sometimes accompanies PLMD. Movement of the legs is more typical than movement of the arms in cases of Periodic limb movement disorder .

The limb movements typically occur 20 to 30 seconds apart, 5 or more times an hour, on and off throughout the night during periods of non-REM sleep. The affected individual is usually unaware of the repetitive motion or the accompanying brief awakenings that disrupt sleep.

People who have Periodic limb movement disorder usually complain of difficulty in falling asleep, staying asleep, or staying awake during the day. Thus, Periodic limb movement disorder can cause poor sleep, which may lead to sleep maintenance insomnia and/or excessive daytime sleepiness.

They may also note restless sleep, hot or cold feet, or hair wearing off their legs. Bed partners often report being kicked, fighting for bed covers, or being awakened by the movements. The incidence of Periodic limb movement disorder increases with age.

It is estimated to occur in 5% of people age 30 to 50 and in 44% of people over the age of 65. As many as 12.2% of patients, suffering from insomnia and 3.5% of patients suffering from excessive daytime sleepiness may experience Periodic limb movement disorder.