Periodic limb movement disorder.
Q My new partner says that my legs twitch constantly while I'm asleep. Any ideas as to what could be causing this?
A What you are describing sounds like periodic limb movement disorder (PLMD), a condition in which the legs or arms move during sleep. PLMD episodes typically recur every 20 to 40 seconds. The movements can range from slight twitching to more violent jerking of the muscles, and may be very brief or last five seconds or more. Most people with the condition are not aware of the movements, and a bedmate is often the one who notices.
Research suggests that as many as 60 percent of older adults have at least a mild form of PLMD, and it is especially common in elderly women. Some drugs-- including tricyclic and selective serotonin reuptake inhibitor (SSRI) antidepressants--can aggravate PLMD. In some cases, PLMD may be a sign of kidney disease as well as diabetes, anemia, sleep apnea, or another disorder--however, the exact cause for the condition is often unknown.
I recommend you mention the twitching to your primary care doctor, who may refer you for an overnight sleep study to confirm the diagnosis. PLMD treatment is indicated only if the disorder causes problems like excessive daytime fatigue, in which case anti-Parkinson's disease medications may help curb the movements.
Patricia Bloom, MD