Restless legs syndrome

It is a sleep disorder, present in 5-10% of the population, characterized by a feeling of discomfort in the legs and an uncontrollable and urgent urge to move them. It often occurs at the end of the day, with greater intensity in resting positions or long periods of immobility which often hinders sleep and rest, and leads to impaired daytime functioning.

The underlying cause is currently unknown. A genetic component has been described as more relevant especially in cases of early onset of symptoms. Research also suggests a disorder in the functioning of dopamine, a neurotransmitter involved in the regulation of movement, or its imbalance against serotonin. Additionally, in part of the cases it also seems to be associated with other simultaneous pathologies:

  • Iron deficiency probably related to alteration at the level of movement control by dopamine which requires iron for its correct functioning.
  • End-stage renal failure and hemodialysis, which can be associated with iron deficiency or anemia, as well as other biochemical abnormalities that can trigger or worsen restless legs syndrome.
  • Deficient blood circulation in the legs or muscle disorders.
  • Vitamin or mineral deficiencies.
  • Alcohol, nicotine and caffeine consumption.
  • Pregnancy, especially in the last trimester, although in most cases they disappear a few weeks after delivery.
  • Neuropathy (nerve damage) affecting the feet or hands.
  • Lack of sleep and other disturbances such as apnea may aggravate or trigger symptoms.
  • Certain drugs that may aggravate symptoms such as those used to prevent nausea, antipsychotics, antidepressants that increase serotonin, or cold or allergy drugs containing antihistamines.

Symptoms

It can be triggered at any age, but is most common in the fourth decade of life. The main symptom is the need to move the legs. It usually occurs on both sides of the body and less frequently, these sensations occur in the arms and rarely the chest or head. The sensations in the extremities are relieved by movement such as stretching, shaking the legs or walking. Symptoms often vary in intensity, even from day to day and from person to person. Sometimes they even disappear for periods of time, only to reappear later, although symptoms generally tend to become more severe over time.

It may be accompanied by nocturnal leg spasms at night. This may be associated with periodic limb movement disorder during sleep, which often occurs simultaneously.

The sensations, which occur are difficult to define, and are usually described as tingling, tingling, pulling, throbbing, aching, itching or electrical charge.

Prevention

There are no specific measures available to prevent restless legs syndrome, however, lifestyle changes may help alleviate the symptoms of restless legs syndrome:

  • Establish good sleep hygiene by establishing a regular daily schedule of at least 7 hours in a cool, quiet, comfortable environment. Avoid large meals before bedtime, and allow at least 2 hours after dinner.
  • Moderate and regular physical exercise can alleviate symptoms. However, intense exercise or exercise close to sleeping hours may intensify them.
  • Avoid or reduce the amount of caffeine daily, both in the form of coffee or tea and other foods such as chocolate or cola.
  • Stop smoking and reduce alcohol consumption.
  • Relaxing the musculature with baths and warm water massages.
  • The use of cold or heat, or alternating between them in the form of compresses, can reduce the sensations in the extremities.
  • Reduce stress as much as possible. Try meditation, yoga, soft music or other options.
  • Address possible causes that may be contributing to restless legs syndrome, such as iron deficiency, use of related drugs, kidney function abnormalities, etc.

Number of observed variants

13.5 million variants

Number of risk loci analyzed in the study

24 loci

Bibliography

Jiménez-Jiménez FJ et al. Genetics of restless legs syndrome: An update. Sleep Med Rev. 2018 Jun; 39:108-121.

National Health Services [April 2022]

Nationa Institute of Health. National Institute of Neurological Disorders and Stroke [April 2022]

Sleep Research Institute [April 2022]

Mayo Clinic [April 2022]

Didriksen M et al. Large genome-wide association study identifies three novel risk variants for restless legs syndrome. Communications Biology. 2020 Nov;3(1):703.

The DNA test you were looking for