Restless Leg Syndrome
What causes restless leg syndrome? All the information about this sleep disorder.
Symptoms and Causes
Restless Leg Syndrome, or Willis-Ekbom Disease, is a sensory-motor neurological disorder characterized by an unpleasant and discomforting sensation in the legs when they are at rest, accompanied by an overwhelming urge to move them, which temporarily reduces or eliminates the discomfort. It primarily occurs at night, in bed, interfering negatively with rest, although it can also happen while awake, while sitting or lying down.
Symptoms
Restless Leg Syndrome manifests with the following symptoms:
- Discomfort in the legs after a period of rest: tingling, prickling, pulsating sensation, tugging, or cramping.
- Relief with movement: standing up, stretching, or walking alleviates the discomfort.
- Involuntary leg movements during sleep: jerking or kicking.
Symptoms do not always appear daily; periods without symptoms can occur, only for them to reappear later.
Causes
The exact cause of restless leg syndrome is not known, although it has been linked to the presence of:
- Imbalances in certain neurotransmitters of the central nervous system, such as dopamine and glutamate, responsible for controlling muscle movement and mood, respectively.
- Low iron levels in the brain, due to improper distribution of this mineral in the blood, have also been associated with the syndrome, as it plays a crucial role in dopamine production.
- Hereditary component, and it has been linked to specific genetic variations on chromosome 6 of the BTBD9 gene.
Risk Factors
The likelihood of developing restless leg syndrome increases under these conditions:
- Age: it is more common after the age of 50.
- Sex: more frequent in women.
- Family history.
- Use of stimulants, such as alcohol, nicotine, and caffeine.
- Peripheral nerve injuries.
- Spinal cord injuries.
- Diabetes: causes damage to peripheral nerves.
- Kidney disease: causes iron deficiency.
- Parkinson's disease: this disease damages the dopaminergic system, and its treatment includes dopamine agonists.
- Pregnancy: hormonal changes may produce restless leg syndrome symptoms, which can disappear after childbirth.
Complications
The complications of restless leg syndrome stem from the associated difficulty in falling asleep or staying asleep. Lack of sleep can affect the individual's quality of life, causing daytime drowsiness, fatigue, lack of concentration, irritability, and even depression.
Prevention
Restless leg syndrome cannot be prevented. However, steps can be taken to decrease the frequency of episodes or reduce symptoms:
- Avoiding the use of stimulants.
- Maintaining regular sleep patterns.
- Massaging the legs or taking a warm bath.
- Applying heat or cold to the legs, or alternating between them.
- Using a vibrating pad or a bandage that presses on the feet, specially designed for this syndrome.
- Performing aerobic exercises and leg stretches.
Which doctor treats restless leg syndrome?
Restless leg syndrome is evaluated and treated by neurologists and neurophysiologists specialized in sleep medicine.
Diagnosis
The diagnosis of restless leg syndrome is primarily clinical, based on the combination of four fundamental symptoms:
- Unpleasant sensation in the legs with an overwhelming need to move them.
- Onset or worsening of symptoms at rest, lying down, or sitting.
- Improvement of symptoms with leg movement.
- Appearance of symptoms during the evening or night.
After confirming the symptoms, additional tests may be conducted:
- Blood tests, to measure iron levels and rule out other diseases that may cause similar symptoms.
- Electromyography: using electrodes placed on the muscle, the electrical signals of muscles at rest and in motion are measured. This test is performed to rule out the presence of polyneuropathy, a disorder that presents similar symptoms in its early stages. In restless leg syndrome, the electromyography values are normal.
- Polysomnography: a sleep study in which electrodes placed on the patient measure their bodily functions while sleeping. This test helps confirm or rule out the presence of other sleep disorders, such as sleep apnea.
Treatment
Treatment focuses on alleviating symptoms and improving the patient’s rest, as restless leg syndrome has no cure. If preventive measures are insufficient to relieve symptoms, different medications are prescribed:
- Iron supplements, if iron deficiency is the cause of the disorder.
- Anticonvulsants: reduce sensory disturbances and nerve pain.
- Dopaminergic agents: increase dopamine in the brain. They should not be administered in high doses or long-term, as they can worsen symptoms.
- Opioids: for severe cases that do not respond to the previous treatments.
- Sedatives or muscle relaxants: may be taken to alleviate anxiety, muscle spasms, and insomnia.
