Restless Legs Syndrome

A 33-year-old woman is diagnosed as having restless legs syndrome. What is the most relevant blood
test to perform?
A. ESR
B. Ferritin
C. Blood glucose
D. Urea and electrolytes
E. Liver function tests

Answer:
B. Ferritin
( a low serum ferritin is most likely to be a cause of secondary restless legs syndrome)

Discussion: Restless legs syndrome (RLS) is a syndrome of spontaneous, continuous lower limb movements that may be associated with paraesthesia. It is extremely common, affecting between 2-10% of the general population.
Males and females are equally affected and a family history may be present.

Clinical features :
1. Uncontrollable urge to move legs (akathisia). Symptoms initially occur at night but as condition progresses may occur during the day. Symptoms are worse at rest
2.Paraesthesias e.g. 'crawling' or 'throbbing' sensations
3.Movements during sleep may be noted by the partner - periodic limb movements of sleeps (PLMS)

Causes and associations 

• there is a positive family history in 50% of patients with idiopathic RLS 
• iron deficiency anaemia 
• uraemia 
• diabetes mellitus 
• pregnancy 

Diagnosis: The diagnosis is clinical although blood tests to exclude iron deficiency anaemia may be appropriate

Management :
Simple  Non Pharmacological measures: walking, stretching, massaging affected limbs
Pharmacological treatment:
1. Treat any iron deficiency
2. Dopamine agonists are first-line treatment (e.g. Pramipexole, ropinirole)
3. Benzodiazepines
4. Gabapentin