Restless leg syndrome (RLS), also known as Willis-Ekbom disease is a type of movement disorder in which a person feels an unpleasant sensation in the legs that is eased by movement. The symptoms can spread to or even begin in arms in some cases. About 10% of the adult population is affected by this disorder.
Causes and Risk Factors of RLS
The exact cause is unknown but the following conditions are often found to be associated with pregnancy, iron deficiency anemia, Parkinson disease (a degenerative disorder of a part of the brain called basal ganglia which causes movement disorder), multiple sclerosis (an autoimmune disease in which antibody attacks neurons of the brain and spinal cord), uremia (high level of urea in the blood due to derangement in the functioning of the kidney) or nerve damage. It has a strong familial tendency. Some drugs known to exacerbate or precipitate RLS are diphenhydramine, prochlorperazine, and antidepressants.Clinical Features of RLS
Patients often describe the sensation as a burning, creepy-crawly feeling or numbness. Some of the common terms used to describe their feelings include tingling, pulling, electric-like, tension, discomfort, and itching. The symptoms are aggravated during the night.About 80% of patients with RLS have periodic leg movement (PLMs) during sleep and occasionally while awake. This periodic leg movement lasts for less than a few seconds and recurs every 5-90 seconds. Restlessness during the night causes poor quality sleep and thus leads to daytime sleepiness. It can severely affect the daily life of some patients.
Diagnosing Restless Leg Syndrome
Diagnosis is made based on clinical features. Your physician will rule out other movement disorders which can mimic RLS like akathisia (feeling of inner restlessness accompanied by mental distress) and side effects of antipsychotic drugs.Polysomnography is done to support the diagnosis, which is basically a sleep study that assesses the brain waves, heart rate, oxygenation status, and breathing of the subject while he is in a sleeping state.
The international restless legs rating scale (IRLS) is a scale to measure the degree of symptoms that a patient is experiencing. This scale also helps physicians to quantify the improvement in clinical features after starting treatment.
Tests to exclude underlying etiology include:
- Ferritin: Ferritin is a blood test to determine the level of iron in your body. It is considered the best measure to assess the total amount of iron in the body. It is decreased in case of iron deficiency anemia.
- Renal function test (RFT): This test determines how well your kidney is functioning. If kidney function is deranged, then urea level rises in blood causing uremia
- Blood glucose level
Managing RLS
Most patients do not require any specific treatment. Patients are often advised to adopt habits to improve sleep hygiene and quality. Some of the behavioral strategies employed include:- Moderate regular exercise
- Reducing caffeine intake
- Mental alerting activities such as doing crossword puzzles at times of boredom
- Withdrawal of possibly predisposing medications
- For symptomatic relief: walking, bicycling, leg massage, and soaking the affected leg
- Avoidance of aggravating factors such as sleep deprivation
If symptoms are intractable, then dopaminergic drugs such as pramipexole, ropinirole, and rotigotine patches are prescribed by physicians. Patients are advised to take these drugs 1-2 hours before bedtime. Levodopa is also an effective drug but the drawback of this medication is that it may worsen restlessness. Since levodopa stays in the body for a short time (eliminated quickly), there is a chance of symptoms rebounding when the effect of the drug wanes.