Diagnosis: Restless Legs Syndrome (RLS)
This patient meets all five essential diagnostic criteria for Restless Legs Syndrome and should be diagnosed with RLS. 1
Diagnostic Confirmation
Your patient's presentation satisfies the mandatory criteria established by the International Restless Legs Syndrome Study Group:
- Criterion 1 (Urge to move): She reports a "desperate need to move her leg" 1
- Criterion 2 (Worsens with rest): Symptoms occur after sitting for more than 30 minutes and when lying down 1
- Criterion 3 (Relief with movement): Symptoms improve when she starts to move or gets distracted 1
- Criterion 4 (Circadian pattern): Symptoms are mostly in the evening when she lays down, not during the day 1
- Criterion 5 (Exclusion of mimics): Physical exam shows no pitting edema, venous varicosities, or neuropathy, effectively ruling out common RLS mimics like venous stasis, peripheral neuropathy, and arthritis 1
The absence of vascular pathology and neuropathy on examination is particularly important, as these are the most common conditions that superficially mimic RLS but represent distinct pathologies requiring different management. 1
Immediate Diagnostic Workup
Check serum ferritin immediately - this is the single most important laboratory test for RLS management. 1
- Ferritin levels <50 ng/mL are consistent with RLS diagnosis and indicate need for iron supplementation 1
- Iron deficiency impairs dopamine transport in the substantia nigra, which plays a critical role in RLS pathophysiology 1, 2
- Some experts recommend checking both ferritin and transferrin saturation 3
Review all current medications to identify potential exacerbating agents:
- Tricyclic antidepressants, SSRIs, lithium, and dopamine antagonists (antipsychotics) can worsen RLS 1
- If she's taking any of these, consider alternatives 2
Treatment Algorithm
First-Line Management
If ferritin <50 ng/mL (or even <75 ng/mL per some guidelines): Start iron supplementation 1, 2
- This addresses a reversible secondary cause and may resolve symptoms entirely 2
- Correction of iron deficiency improves RLS symptoms 2
For pharmacologic symptom control, dopamine agonists are first-line therapy:
The American Geriatrics Society recommends dopamine receptor agonists over levodopa-carbidopa because they cause less rebound and symptom augmentation. 1
Ropinirole: Start 0.25 mg orally 1-3 hours before bedtime, increase to 0.5 mg after 2-3 days, then to 1 mg after 7 days. Titrate upward by weekly 0.5 mg increments to maximum 4 mg at week 7 if needed 1
Pramipexole: Start 0.125 mg orally 2-3 hours before bedtime. Double the dose every 4-7 days to maximum dose as needed 1
Important side effects to monitor: nausea, orthostatic hypotension, sleepiness, headache, and compulsive behaviors. 1 In older patients, particular attention should be paid to drug interactions and orthostasis risk. 1
Second-Line Options
If dopamine agonists are contraindicated or not tolerated:
Critical Pitfalls to Avoid
Do not confuse RLS with nocturnal leg cramps: Leg cramps cause painful, involuntary muscle contractions with tightening sensation, relieved specifically by stretching the affected muscle, not general movement. 4 Your patient has dysesthesias and urge to move, not cramping pain. 4
Watch for augmentation: This is paradoxical worsening of symptoms with dopaminergic treatment, characterized by more intense symptoms, earlier occurrence, and symptom spread to arms or other body regions. 3, 5 This is why dopamine agonists are preferred over levodopa-carbidopa. 1
The positive leg raise test mentioned in your exam is not part of RLS diagnosis - the physical examination is typically unremarkable in primary RLS. 1 This finding may be incidental or suggest a concurrent musculoskeletal issue.
Polysomnography is not needed for diagnosis - RLS is diagnosed by history alone in the majority of cases. 1