The Five Senses and Beyond: The Encyclopedia of Perception - Jennifer L. Hellier 2017
Restless Legs Syndrome
Restless legs syndrome (RLS), also called Willis-Ekbom disease, is an increasingly common condition characterized by unpleasant sensations and an intense urge to move the legs. The symptoms associated with RLS range from mildly bothersome to unbearably painful and can change in severity from one day to another. Recognition of the disorder has become more frequent in recent years, with a current prevalence of 7—10 percent in the United States. RLS affects people of all ages, but has a higher incidence in the elderly. Additionally, the condition presents in women two times more than in men.
Etiology
RLS is categorized into two different subtypes based on how it originates. Primary RLS is idiopathic, meaning there is no identifiable cause for the disorder. However, clinical observation suggests that primary RLS may have a strong genetic component. More than 40 percent of patients with RLS report a personal family history of the condition, and twin studies have even demonstrated a high likelihood of hereditary contribution. Also, genetic research has found that a significant percentage of people with RLS possess the same defects on certain chromosomes, which appear to be passed down in an autosomal dominant pattern. Primary RLS presents more commonly in the young and slowly develops over time. The other subtype is classified as secondary RLS, which occurs when there is a known nongenetic factor contributing to the disease. Contrastingly, this form presents with a faster onset and more often in older patients.
Several different medical conditions have been implicated in the etiology of secondary RLS. One of the more common causes of worsening symptoms is iron deficiency. Pregnancy is also frequently associated with the disease, possibly due to hormonal changes. Other examples of medical conditions that may contribute to RLS are chronic kidney dysfunction, type 2 diabetes, or neurological issues. Studies have shown that people who have attention deficit disorder, Parkinson’s disease, anxiety, or depression are all at a higher risk of developing symptoms. Deficiencies in many different vitamins, electrolytes, and hormones have also been linked to RLS.
Symptoms
The symptoms of RLS primarily reflect a dysfunction in both the sensory and motor regions of the brain. RLS presents with a spontaneous, uncontrollable urge to move the legs accompanied by uncomfortable sensations. Although occurring most often bilaterally between the ankles and knees, it can present in the arms, trunk, or face. The sensory component of RLS can be difficult to describe but has been expressed by many patients as tingling, itching, creeping, crawling, and burning. Some patients even compare the condition to feeling as though there is an electric current, flowing water, or moving insects under their skin. In severe cases, RLS can manifest as very painful aches and throbs.
The motor component of the disorder involves involuntary movements, described as feeling as if there is trapped energy in the legs. Patients can experience anything from subtle twitching and frequent pacing to full-extension muscle jerks. RLS is a prominent cause of insomnia, making it difficult to both initiate and maintain sleep.
Diagnosis and Management
Diagnosis is based predominantly on clinical symptoms and elimination of other causes, as there are no laboratory markers to determine if a patient has RLS. There are four cardinal criteria that must be met in order to truly diagnose a patient as having RLS: (1) a strong urge for leg movement accompanied by uncomfortable sensations; (2) symptoms that get worse with a lack of activity or while resting; (3) symptoms that get better, at least partially, with physical activity such as walking; and (4) symptoms present more often in the evening or nighttime.
While there is no definite cure for RLS, many therapies have been tried in practice and demonstrate some success with relieving symptoms. As with most medical conditions, the safest option is to begin with a nonpharmaceutical remedy. All patients with RLS report that physical movement can help reduce symptoms. Therefore, it is important to encourage patients to engage in moderate physical exercise, such as walking, for at least a few days per week. Some patients report feeling relief from leg spasms after warm showers or baths. This may be due to the influence of increased temperature, which helps in relaxing the muscles. Likewise, massage therapy and muscle-stretching exercises have been shown to help with pain. Finally, implementing lifestyle changes may help RLS patients alleviate chronic sleep disruption. Performing appropriate sleeping habits, such as going to bed at a reasonable time and avoiding caffeine in the evening, can help improve nighttime symptoms.
The next step in treating patients with RLS is to consider whether there are secondary causes that need to be addressed. Oral iron supplements should be given to people who are deficient, with close monitoring until levels are back to normal range. Other deficient substances that can be effectively normalized through oral supplementation are folate, vitamin B12, and magnesium.
Vidya Pugazhenthi
See also: Attention Deficit Hyperactivity Disorder; Central Nervous System; Thermal Sense; Vibration Sensation
Further Reading
Leschziner, Guy, & Paul Gringras. (2012). Restless legs syndrome. British Medical Journal, 344, e3056.
Medline Plus. (2013). Restless legs. Retrieved from http://www.nlm.nih.gov/medlineplus/restlesslegs.html
Willis-Ekbom Disease Foundation. (2013). About WED/RLS. Retrieved from http://www.rls.org