What is the diagnosis and management for a 40-year-old post-menopausal woman with a 1-month history of right lower limb dragging from mid-thigh to calf, nocturnal pain, and deep muscle tenderness on the right side, without pain during day-to-day activities?

Diagnosis: Restless Legs Syndrome (RLS)

This presentation is most consistent with Restless Legs Syndrome (RLS), characterized by nocturnal-only leg discomfort with deep muscle tenderness, absence of daytime symptoms, and unilateral distribution in a postmenopausal woman. 1

Diagnostic Criteria Assessment

The diagnosis of RLS requires meeting four essential criteria, which this patient appears to satisfy 1:

• Urge to move with uncomfortable sensations: The "dragging" sensation and deep muscle tenderness from mid-thigh to calf suggest the characteristic discomfort 1
• Symptoms begin or worsen during rest/inactivity: Pain occurs only at night, never during day-to-day activities, which is pathognomonic for RLS 1
• Relief with movement: The absence of symptoms during daytime work suggests movement provides relief 1
• Circadian pattern: Symptoms exclusively nocturnal, which is the hallmark temporal pattern 1

Critical Differential Diagnoses to Exclude

Peripheral arterial disease (PAD) must be ruled out immediately by checking bilateral lower extremity pulses and performing ankle-brachial index (ABI) 1:

• PAD claudication is exercise-induced and relieved by rest, the opposite pattern of this patient 1
• Vascular claudication would cause symptoms during daytime walking, not exclusively at night 1
• However, deep muscle tenderness could theoretically represent ischemic muscle pain, making pulse examination mandatory 1

Lumbar radiculopathy (L2-L4) should be considered but is less likely 1:

• Radiculopathy typically causes dermatomal sensory loss and may have motor weakness or reflex changes 1
• The unilateral distribution from thigh to calf could suggest nerve root involvement 1
• However, the exclusive nocturnal timing and absence of back pain make this diagnosis unlikely 1

Venous insufficiency is in the differential but less consistent 1:

• Would typically cause daytime symptoms worsened by prolonged standing 1
• The nocturnal-only pattern argues strongly against venous disease 1

Essential Diagnostic Workup

Perform thorough neurologic examination to identify secondary causes 1:

• Assess for peripheral neuropathy or radiculopathy findings 1
• Check bilateral lower extremity pulses to exclude vascular disease 1
• Document muscle strength, reflexes, and sensory examination 1

Obtain serum ferritin level as the only required laboratory test 1:

• Ferritin <50 ng/mL is consistent with RLS and indicates need for iron supplementation 1
• Iron deficiency is strongly associated with secondary RLS, particularly in postmenopausal women 1

Consider additional testing only if examination suggests alternative diagnosis 1:

• ABI if pulses are diminished or absent 1
• Lumbar spine imaging if radicular features are present 1

Management Algorithm

First-Line Pharmacologic Treatment

Initiate dopamine agonist therapy if symptoms are bothersome and affect quality of life 1:

Ropinirole dosing regimen 1:

• Start 0.25 mg orally 1-3 hours before bedtime 1
• Increase to 0.5 mg after 2-3 days 1
• Increase to 1 mg after 7 days 1
• Titrate upward by 0.5 mg weekly increments to maximum 4 mg at week 7 if needed 1

Pramipexole alternative dosing 1:

• Start 0.125 mg orally 2-3 hours before bedtime 1
• Double dose every 4-7 days to maximum 0.5 mg if needed 1

Critical Medication Counseling

Warn about dopamine agonist side effects, particularly important in this 40-year-old patient 1:

• Orthostatic hypotension (check blood pressure sitting and standing) 1
• Nausea (often transient) 1
• Sleepiness and headache 1
• Compulsive behaviors (gambling, shopping, hypersexuality) 1
• Drug interactions with other medications 1

Iron Supplementation

If ferritin <50 ng/mL, initiate iron replacement 1:

• Iron supplementation is indicated as adjunctive or primary therapy 1
• This addresses the underlying pathophysiology of impaired dopamine transport in substantia nigra due to reduced intracellular iron 1

Monitoring for Augmentation

Educate patient about augmentation syndrome, which requires dose adjustment 1:

• Worsening symptoms with earlier onset in the day 1
• Increased intensity of symptoms 1
• Spread of symptoms to other body parts (e.g., from calves to thighs or arms) 1
• Augmentation is less common with ropinirole/pramipexole than with levodopa-carbidopa 1

Common Pitfalls to Avoid

Do not dismiss unilateral presentation as atypical 1:

• While RLS is often bilateral, unilateral presentation occurs and meets diagnostic criteria 1
• The key diagnostic feature is the temporal pattern (nocturnal, rest-induced, movement-relieved), not the distribution 1

Do not overlook vascular disease in postmenopausal women 1:

• Postmenopausal status increases atherosclerotic risk 1
• Always palpate pulses even when RLS seems obvious 1

Do not start levodopa-carbidopa as first-line therapy 1:

• Levodopa has higher rates of augmentation and rebound compared to dopamine agonists 1
• Ropinirole and pramipexole are FDA-approved specifically for RLS 1

Consider menopausal arthralgia as contributing factor 2, 3:

• Arthralgia affects >50% of perimenopausal women and may coexist with RLS 2
• Deep muscle tenderness could represent menopausal musculoskeletal pain 2, 3
• However, the exclusive nocturnal timing still points to RLS as primary diagnosis 1