CLINICAL FEATURES OF RLS
1. Irresistible urge to move legs accompanied by uncomfortable or unpleasant sensations in the legs,
2. The urge to move legs is more during periods of immobility or rest,
3. The urge is partially or completely relieved by movement,
4. The urge to move legs is more in evenings or nights as compared to day time (or is present only during evenings or nights).
These symptoms should occur at least three times per week, and should be present for at least three months, before we can put a label of RLS. Also, these symptoms should cause significant distress or impairment in social, occupational and daily life.
85% of patients with RLS also have periodic leg movements (involuntary forceful dorsiflexion of foot lasting 0.5-5 seconds, occurring every 20-40 seconds throughout sleep) at nights.
Many people suffering from RLS also have sleep disturbance at nights and daytime fatigue.
What age-group patients are affected with RLS?
Symptoms of RLS may start in infancy, however, most patients are diagnosed in their middle ages. There is often a delay of 10-20 years in diagnosis.
RLS is quite common and about 5-15% of population may be affected.
Women are more commonly affected than men, in a ratio of 2:1.
What are the causes of RLS?
Majority of cases of RLS are idiopathic (no obvious cause) due to a disturbance in brain neurotransmitters (dopamine or serotonin). These are also called primary RLS. 25-75% of idiopathic RLS is familial with a genetic component. Familial cases start early (<45 years of age) and progress slowly.
RLS is called secondary RLS, if it is caused due to another disease. There are several such causes:
- Peripheral neuropathy,
- Iron deficiency,
- Folate deficiency,
- Magnesium deficiency,
- Diabetes mellitus,
- Rheumatoid arthritis,
- Renal failure,
- Vitamin B12 deficiency,
- Frequent blood donation,
- Drug-induced (neuroleptics, antidepressants, beta blockers, lithium, alcohol, caffeine).