Diagnostic Criteria for Restless Legs Syndrome
Restless Legs Syndrome is diagnosed when all five essential criteria from the International Restless Legs Syndrome Study Group (IRLSSG) are met, with the critical fifth criterion requiring exclusion of conditions that mimic RLS symptoms. 1
The Five Essential Diagnostic Criteria (All Must Be Present)
1. Urge to Move the Legs
- An urge to move the legs, usually accompanied by or felt to be caused by uncomfortable and unpleasant sensations in the legs
- Note: Sometimes the urge exists without uncomfortable sensations; arms or other body parts may be involved in addition to legs 1
2. Symptoms Triggered by Rest
- The urge to move and any accompanying unpleasant sensations begin or worsen during periods of rest or inactivity, such as lying down or sitting 1
3. Relief with Movement
- The urge to move and accompanying sensations are partially or totally relieved by movement (walking, stretching), at least as long as the activity continues
- In very severe cases, relief by activity may not be noticeable currently but must have been previously present 1
4. Circadian Pattern (Evening/Night Worsening)
- The urge to move and accompanying sensations during rest only occur or are worse in the evening or night than during the day
- In very severe cases, this worsening pattern may not be currently noticeable but must have been previously present 1
5. Exclusion of RLS Mimics (Critical Fifth Criterion)
- The symptoms are not solely accounted for as primary to another medical or behavioral condition 1
Common RLS Mimics That Must Be Excluded
This fifth criterion is essential because without proper differential diagnosis, up to 16% of individuals without RLS can be misclassified as having the condition. 1 The following conditions can superficially meet the first four criteria:
- Leg cramps
- Leg edema and venous stasis
- Positional discomfort
- Muscle aches (myalgia)
- Arthritis
- Habitual foot tapping
- Neuropathy
- Akathisia
- Spasticity
- Nocturnal leg cramps 1
Clinical Significance Specifier
For the diagnosis to be clinically meaningful, symptoms must cause significant distress or impairment in social, occupational, educational, or other important areas of functioning through their impact on:
- Sleep
- Energy/vitality
- Daily activities
- Behavior
- Cognition
- Mood 1
Clinical Course Specifiers
A. Chronic-Persistent RLS
- Symptoms when untreated would occur on average at least twice weekly for the past year 1
B. Intermittent RLS
- Symptoms when untreated would occur on average less than twice weekly for the past year, with at least 5 lifetime events 1
Note: These course criteria do not apply to pediatric cases or special provoked RLS situations (pregnancy, drug-induced) where frequency may be high but limited to the duration of the provocative condition 1
Key Clinical Pitfalls to Avoid
The most common diagnostic error is failing to exclude mimics. A careful clinical history is imperative as there is no objective test to confirm RLS diagnosis. 2 When evaluating patients, probe deeply into:
- The exact quality of sensations (patients with true RLS often describe crawling, creeping, or pulling sensations)
- Specific relief strategies used
- The character of provocative situations
- Timing and pattern of symptoms 3
For children: The description of symptoms should be in the child's own words, as they may have difficulty articulating their experience. 1 Diagnostic instruments validated for adults have not been validated for pediatric populations. 1
Supportive features (not required for diagnosis but strengthen confidence):
- Periodic limb movements during sleep (PLMS)
- Positive response to dopaminergic medication
- Family history of RLS
- Normal neurological examination in idiopathic cases 2