Sleep-related leg cramps are also known as or subsume Charley horse and Nocturnal leg cramps. -ed.
Sleep-related leg cramps are a sleep-related movement disorder whereby painful contractions of the calf muscles arise at sleep onset and during sleep and awaken the patient, interrupting sleep. Sleep-related leg cramps may be associated with muscle cramps during wakefulness and are encountered at all ages, but they are especially prevalent among the elderly. They result from a variety of pathologies, metabolic muscle and nerve disorders, electrolyte disturbances, vascular disease, and toxic and drug side effects. Sleep-related leg cramps may sometimes mimic and need to be differentiated from the manifestations of restless legs syndrome.