Restless Legs Syndrome

Diagnosis

Essential Criteria

The International RLS Study Group developed, published, and updated the four essential diagnostic criteria for RLS (Table 1)119; all four of these essential criteria must have been met at some time throughout the course of the patient's condition.

Table 1

Essential Diagnostic Criteria

An urge to move the legs is present, usually accompanied or caused by uncomfortable and unpleasant sensations in the legs.

Sometimes the urge to move is present without the uncomfortable sensations, and sometimes the arms or other body parts are involved in addition to the legs.

The urge to move or unpleasant sensations begin or worsen during periods of rest or inactivity such as lying or sitting.

The urge to move or unpleasant sensations are partially or totally relieved by movement, such as walking or stretching, at least as long as the activity continues.

The urge to move or unpleasant sensations are worse in the evening or night than during the day or only occur in the evening or night.

When symptoms are severe, the worsening at night may not be noticeable but must have been previously present.

Modified from Allen RP, Picchietti D, Hening WA, Trenkwalder C, Walters AS, Montplaisir J. Restless legs syndrome: diagnostic criteria, special considerations, and epidemiology. A report from the restless legs syndrome diagnosis and epidemiology workshop at the National Institutes of Health. Sleep Med 2003;4(2):101-119.

The first criterion requires that the patient has an urge to move the legs, usually accompanied or caused by uncomfortable and unpleasant sensations in the legs. Some patients, however, are unable to delineate a specific sensation and only relate an overwhelming urge to move the limbs. Typically, these sensations occur in the legs; however, they may also occur in the arms12, 120-122and, very rarely, the trunk or face.123

Criterion two relates to the role of quiescence in increasing the sensations and urge to move. This criterion is supported by findings from the Suggested Immobilization Test (SIT), which verify that patients with RLS, as compared with controls, experience more discomfort and have more periodic limb movements during this one-hour testing period.124-130

Criterion three requires that the urge to move or unpleasant sensations be partially or totally relieved by movement, with support, again, from the SIT.124-130 Patients employ a variety of techniques to relieve the sensations and urge to move. These techniques range from simply stretching or rubbing the leg, to pounding the leg and performing deep knee bends, to executing convoluted contortions. The critical factor in this criterion is that the relief is experienced almost as soon as the patient begins the movement and persists as long as the patient continues performing the sensation-relieving movement.

Intrinsic circadian factors define criterion four, with a worsening of symptoms during the evening and night relative to daytime levels; however, patients with severe RLS may not exhibit a diurnal variation in symptoms. Research studies have shown that increased symptoms, both sensory and limb movement, occur on the falling phase of core body temperature.131-135