What are the diagnostic criteria and treatment options for restless leg syndrome?

Restless Leg Syndrome Diagnosis and Treatment

Restless Leg Syndrome (RLS) is diagnosed based on five essential criteria established by the International Restless Legs Syndrome Study Group, and first-line treatment includes dopamine agonists such as ropinirole or alpha2-delta calcium channel ligands, with iron supplementation when indicated. 1

Diagnostic Criteria for RLS

All five of the following essential criteria must be met for diagnosis:

1. An urge to move the legs, usually accompanied by uncomfortable and unpleasant sensations in the legs
2. The urge to move and accompanying sensations begin or worsen during periods of rest or inactivity
3. The urge to move and accompanying sensations are partially or totally relieved by movement (walking, stretching) as long as the activity continues
4. The urge to move and accompanying sensations are worse in the evening or night compared to daytime
5. The symptoms are not solely accounted for by another medical or behavioral condition (RLS mimics)

Clinical Significance Specifier

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

Clinical Course Specifiers

• Chronic-persistent RLS: Symptoms occur at least twice weekly for the past year when untreated
• Intermittent RLS: Symptoms occur less than twice weekly for the past year, with at least 5 lifetime events

Differential Diagnosis - RLS Mimics

It's critical to rule out conditions that can mimic RLS 1:

• Leg cramps
• Venous stasis
• Leg edema
• Arthritis
• Positional discomfort
• Habitual foot tapping
• Myalgia
• Neuropathy

Diagnostic Approach

1. Clinical interview focusing on the five essential criteria

2. Evaluate for secondary causes:

   • Iron deficiency (check serum ferritin)
   • Pregnancy
   • Renal failure
   • Neuropathy
   • Essential tremor
   • Genetic ataxias

3. Consider sleep study if periodic limb movements during sleep are suspected (present in most RLS patients but not required for diagnosis)

Treatment Options

First-Line Treatments

1. Dopamine Agonists 2:

   • Ropinirole: Start at 0.25 mg once daily 1-3 hours before bedtime, titrate based on response over 7 weeks to maximum 4 mg daily
   • Clinical trials showed significant improvement in RLS symptoms with ropinirole compared to placebo as measured by the International RLS Rating Scale (IRLS)

2. Alpha2-Delta Calcium Channel Ligands 3:

   • Gabapentin
   • Pregabalin
   • Gabapentin enacarbil

3. Iron Supplementation 3:

   • For patients with low or low-normal serum ferritin
   • Can be oral or IV depending on severity and response

Second-Line Treatments

1. Opioids 4:

   • Used when first-line treatments fail or are contraindicated

2. Benzodiazepines 4:

   • Generally considered third-line due to side effect profile

Treatment Considerations and Pitfalls

Augmentation

A major pitfall with dopaminergic treatment is augmentation - paradoxical worsening of symptoms with long-term use 3:

• Characterized by earlier symptom onset
• Increased symptom severity
• Anatomic spread of symptoms

Management of augmentation:

1. Add an alpha2-delta ligand or opioid
2. Once adequate symptom control is achieved, very slowly taper the dopamine agonist

Secondary RLS

Always treat underlying conditions 5:

• Iron supplementation for iron deficiency
• Address medications that may worsen RLS (antidepressants, antihistamines)
• Treat comorbid sleep disorders like OSA

Monitoring and Follow-up

1. Assess treatment response using validated tools:

   • International RLS Rating Scale (IRLS)
   • Clinical Global Impression-Global Improvement (CGI-I)

2. Monitor for side effects:

   • Nausea (40% with ropinirole vs 8% with placebo) 2
   • Somnolence (12% with ropinirole vs 6% with placebo) 2
   • Dizziness (11% with ropinirole vs 5% with placebo) 2

3. Watch for augmentation with dopaminergic agents

4. Reassess iron status periodically in patients with initial iron deficiency

By following these diagnostic criteria and treatment approaches, most patients with RLS can achieve significant symptom relief and improved quality of life.