Restless Legs Syndrome

Definitions

• Spontaneous, continuous leg movements
• Associated with unpleasant paresthesias
• Periodic Leg Movements of Sleep (PLMS)
• Associated condition of involuntary jerking leg movements
• Nocturnal leg cramps
• A separate disorder of frequent cramps

Epidemiology

• Probably affects ~2.7% of the population
• Increases with age
• Family history is a risk factor
• Some putative genes identified
• Onset often occurs in teenage years

Pathogenesis

• Primary
• Likely genetic basis
• Secondary (~40%)
• Iron deficiency
• ESRD (20-40% of dialysis patients)
• DM
• MS
• PD
• Pregnancy
• Drugs – TCA, SSRI, lithium, dopamine agonists
• Others

Clinical manifestations

• Occur at rest and relieved by movement
• Discomfort that occurs in the legs and is relieved by movement
• Worse at night
• Usually bilateral
• Arms can also be affected
• Periodic limb movements of sleep
• Jerking leg movements that occur in many patients
• Pt’s usually unaware, however can awaken pt in some cases
• Periodic limb movement disorder – is the term used if daytime fatigue accompanies PLMS

Diagnosis

• Clinical features (there are diagnostic criteria)
• Urge to move legs (associated with uncomfortable and unpleasant sensations)
• Sensations worse during rest or inactivity
• Sensations relieved by movement
• Sensations worse during night or evening
• Supportive evidence
• Positive family history
• Response to dopaminergic drugs
• PLMS
• Sleep studies may be used
• DDx: Akathisia

Treatment

• Correction of secondary causes
• Leg stretching prior to sleep may help
• Avoid potential aggravating substances
• Caffeine, nicotine, alcohol
• Dopamine agonists
• Pramipexole and ropinirole
• First line agents
• Small dose 2 hours before bed
• Levodopa
• Small dose at night proven useful in some trials
• Benzodiazepines
• May help
• Little in the way of RCTs
• Opioids
• Benefit in non-randomized trials
• Gabapentin
• Effective, usually reserved for more severe cases

Prognosis