Restless Legs Syndrome

Content of This Page

 1- Introduction

2- Causes

3- Symptoms

4- Investigations & Lab Results

5- Complications

6- Treatment

Introduction

Restless Legs Syndrome (RLS), also known as Willis-Ekbom Disease, is a neurological sensorimotor disorder characterized by an unpleasant urge to move the legs, usually accompanied by uncomfortable sensations. These symptoms typically occur or worsen during periods of rest or inactivity, especially in the evening or at night, and are relieved by movement such as walking or stretching.

RLS can significantly affect sleep quality and overall quality of life. It may occur as a primary (idiopathic) condition or secondary to other medical conditions like iron deficiency, pregnancy, or renal failure. The exact cause is not fully understood but is thought to involve dysfunction in the dopaminergic system and iron metabolism in the central nervous system.

 

Causes

1. Primary (Idiopathic) RLS

  • Often familial, suggesting a genetic component

  • Usually begins in middle age or earlier

  • Exact cause unknown but thought to involve:

    • Dysfunction in dopaminergic pathways in the brain

    • Abnormal iron metabolism in the central nervous system

  • No identifiable underlying medical condition

2. Secondary Causes of RLS

RLS may develop as a result of or be associated with other medical conditions or factors:

  • Iron deficiency anemia (most common secondary cause)

  • Chronic kidney disease / End-stage renal disease

  • Pregnancy, especially in the third trimester

  • Peripheral neuropathy

  • Diabetes mellitus

  • Parkinson’s disease

  • Rheumatoid arthritis

  • Certain medications (e.g., antidepressants, antipsychotics, lithium, antihistamines)

  • Vitamin B12 deficiency

3. Triggers / Exacerbating Factors

  • Caffeine, nicotine, and alcohol

  • Sleep deprivation or irregular sleep schedules

  • Stress or anxiety

Symptoms

-Core Symptoms

  • Urge to move the legs, often accompanied by unpleasant sensations described as:

    • Crawling, tingling, itching, burning, or aching

  • Symptoms worsen during periods of rest or inactivity, such as sitting or lying down

  • Symptoms are most severe in the evening or at night, leading to difficulty falling asleep or staying asleep

  • Movement relieves the discomfort temporarily, such as walking, stretching, or shaking the legs

-Additional Features

  • Symptoms may also affect the arms or other body parts (less common)

  • Severity can vary from mild to debilitating

  • Often associated with sleep disturbances and resulting daytime fatigue or irritability

  • Some patients may experience periodic limb movements during sleep (PLMS) — involuntary jerking or twitching of the legs

-Important Points

  • Symptoms typically have a daily pattern, worsening at night

  • The sensations are unpleasant and difficult to describe but are distinct from pain

  • The condition can lead to significant impairment of quality of life if untreated

Investigations & Lab Results

1. Clinical Diagnosis

  • RLS is primarily diagnosed based on patient history and symptom criteria.

  • Diagnostic criteria include:

    • Urge to move the legs usually accompanied by uncomfortable sensations

    • Symptoms worsen during rest and in the evening or night

    • Relief with movement

    • Symptoms not explained by another condition

2. Laboratory Tests

  • Used to identify secondary causes of RLS:

    • Complete blood count (CBC)

      • To check for iron deficiency anemia

    • Serum ferritin

      • Low ferritin (<50 ng/mL) is often associated with RLS even if hemoglobin is normal

    • Serum iron, total iron-binding capacity (TIBC), transferrin saturation

      • To assess iron status in detail

    • Renal function tests

      • To rule out chronic kidney disease

    • Blood glucose and HbA1c

      • To screen for diabetes mellitus

    • Vitamin B12 and folate levels

      • To detect deficiencies that may contribute to symptoms

3. Polysomnography (Sleep Study)

  • Not routinely required but can be useful if diagnosis is uncertain

  • Detects periodic limb movements during sleep (PLMS), which often coexist with RLS

4. Neurophysiological Tests

  • Occasionally used to exclude other neurological disorders, such as peripheral neuropathy

Complications

1. Sleep Disturbances

  • Difficulty falling asleep and frequent awakenings

  • Poor sleep quality and reduced total sleep time

  • Leads to chronic insomnia

2. Daytime Fatigue and Sleepiness

  • Excessive daytime tiredness

  • Impaired concentration and attention

  • Reduced productivity at work or school

3. Mood Disorders

  • Increased risk of depression and anxiety due to chronic sleep deprivation and discomfort

  • Irritability and emotional distress

4. Impaired Quality of Life

  • Social withdrawal and reduced participation in activities

  • Difficulties in relationships due to sleep problems and mood changes

5. Secondary Effects

  • In severe cases, may increase risk of accidents due to daytime sleepiness

  • Possible exacerbation of coexisting medical conditions due to poor rest

Treatment

1. Address Underlying Causes

  • Correct iron deficiency if present (iron supplements)

  • Manage associated conditions such as renal failure, diabetes, or vitamin deficiencies

  • Review and stop medications that may worsen symptoms if possible (e.g., certain antidepressants, antihistamines)

2. Lifestyle Modifications

  • Regular moderate exercise

  • Avoid caffeine, nicotine, and alcohol, especially in the evening

  • Maintain a regular sleep schedule

  • Leg massages, warm baths, or applying heat/cold may provide relief

  • Stress reduction techniques

3. Pharmacological Treatment

First-line Medications:

  • Dopamine agonists (e.g., pramipexole, ropinirole)

    • Effective in reducing symptoms

    • Side effects: nausea, dizziness, impulse control disorders

  • Alpha-2-delta calcium channel ligands (e.g., gabapentin, pregabalin)

    • Useful especially if pain or sensory symptoms are prominent

Alternative or Adjunctive Medications:

  • Iron supplementation if ferritin is low

  • Benzodiazepines (e.g., clonazepam) for sleep improvement, used cautiously

  • Opioids reserved for severe refractory cases

4. Monitoring and Follow-up

  • Regular assessment of symptom control and side effects

  • Adjust treatment as needed for efficacy and tolerability

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