Sleep-related movement disorders.

Restless legs syndrome – this disorder is characterized by a nearly irresistible urge to move the legs while awake. Sometimes an uncomfortable tingling or sensation is also present. Relief can usually be obtained immediately by walking or moving the legs. This can be a cause of insomnia.

Periodic limb movement disorder – this disorder occurs while asleep and is characterized by periodic, repetitive, highly stereotyped movements generally of the legs although the arms may also be affected. The individual may be unaware of these movements unless a bed partner complains about kicking or restlessness.

Sleep related leg cramps – these painful leg cramps are usually in the calf or small muscles of the foot and occur while asleep or awake. They generally start abruptly and may last for a few seconds or several minutes. A cramp of this type is often called a “charley horse."

Sleep related bruxism – this is commonly called teeth grinding. Individuals with this disorder often grind the teeth or clench the teeth during sleep. This disorder can contribute to temporomandibular joint problems, wearing down of the teeth or disturbances to sleep quality.