Andrew says in his blog
that his sleep study showed RLS and PLMS, about 26 kicks per hour in his sleep. He was prescribed one of the dopamine medications (usually used for Parkinson’s Disease)—Requip or Mirapex presumably.
What is restless legs syndrome, and what is periodic limb movements in sleep (RLS and PLMS)? They are not the same, but they are related. Many doctors and patients confuse them. Here are some of the facts about each condition.
RLS
is a diagnosis based on symptoms. RLS cannot be diagnosed from an overnight sleep study. (For the experts reading this, it is true that the suggested immobilization test produces a fairly high sensitivity and specificity.) Some patients with RLS have an almost normal sleep study in fact, but most patients with RLS have PLMS on their sleep study.
RLS is diagnosed when the person has each of the following four symptoms: 1. A hard to describe feeling which includes restlessness, 2. The feeling is worse with inactivity, 3. The feeling is briefly relieved with movement especially walking, and 4. The feeling is worse or present only, in the evening or night.
PLMS is a condition in which the person moves their legs during sleep. The movements can be big or barely noticeable. Sometimes the sleep study, depending on the quality of the video, shows no movement at all. Typical movements are bending up the foot, flexing the knee, and flexing the hip. They are periodic, which means they happen in a rhythm, usually every 20 or 30 seconds during portions of the night, mostly in the beginning.
Most patients with RLS have PLMS, but most patients with PLMS do not have RLS, and usually have nothing. When a person has a sleep complaint such as insomnia or daytime sleepiness, and the sleep study shows only PLMS, then the diagnosis is PLMD (periodic limb movement disorder). This distinction takes into account that most people with PLMS have not symptoms which can be attributed to the PLMS, but if they do, then they have the disorder of PLMD. Many sleep specialist think that true PLMD (without RLS) is rare, although PLMS is quite common.
The dopamine medications improve both the symptoms of RLS and PLMS, even though they are not the same disorder. For many people, it is very reasonable to try a medication for the PLMS and see if sleep or fatigue gets better.
J. Steven Poceta MD
is a licensed practitioner of neurology and sleep disorders who has been engaged by Revolution Health. No information in this blog is intended to diagnose or treat any condition. The opinions expressed here are Dr. Poceta’s own and do not necessarily reflect those of Revolution Health.
