Restless Leg Syndrome

In our latest You Asked, We Answered blog series; we delve into Restless Leg Syndrome (RLS). This neurologic condition can cause uncomfortable sensations and significant sleep disturbances. Read further to learn what suffers can do to lessen RLS’s symptoms.

Restless Leg Syndrome

Disclaimer: This article is for informational purposes only. Please consult the advice of a health care provider. Do not stop or start any medication based on this article without the guidance of your provider.

Figure 1. Diagnostic criteria for RLS. Patients must have the 4 criteria for diagnosis. The listed supportive features help with further confirmation. Screenshot from https://www.aafp.org/pubs/afp/issues/2008/0715/p235.html [4].

RLS is often accompanied by sleep disturbance and periodic limb movements of sleep (PLMS) – involuntary jerking of the legs during sleep. Periodic limb movement disorder (PLMD) is diagnosed when the patient experiences impaired daytime functioning or significant sleep disturbances associated with PLMS in the absence of RLS [1]. Other conditions that can have overlapping or similar features to RLS must be ruled out (Figure 2).

Figure 2. Conditions that may mimic RLS, which must be ruled out in a workup. Screenshot from https://www.aafp.org/pubs/afp/issues/2008/0715/p235.html [4].

Among the general population, the prevalence of RLS is 5-15% [3] and is more common
in females [4], as well as those of European or North American populations [7]. Approximately
one-third of patients experience symptom severity that requires medical therapy [4]. In most
patients, the cause is unknown (idiopathic RLS [8]), though studies suggest that genetic factors
are responsible for up to 70% of the risk for developing RLS [7]. Ongoing research suggests that
causes may include abnormalities in dopamine and iron function in the central nervous system;
iron is involved in dopamine production. RLS is common in pregnancy, especially in the third
trimester, and typically improves or goes away after giving birth [4]. RLS is also common in
patient with chronic kidney disease (CKD) [5], especially those on dialysis – hypothesized to be
because of the long sedentary periods during treatment, as well as iron deficiency commonly
associated with CKD [6]. A workup for underlying causes may be appropriate.

Figure 3. Treatment of RLS by severity/frequency of symptoms. Screenshot from https://www.aafp.org/pubs/afp/issues/2008/0715/p235.html [4].

The diagnosis of RLS is clinical (meaning it is based on history, physical examination, as
well as ruling out other conditions if appropriate). In suspected RLS cases, a provider will
typically initially take a medical history (including medications, medical conditions, and family
history). Additionally, he/she will perform a physical examination, with a focus on neurologic
systems, including spinal cord and peripheral nerve function [10]. Often, the provider will
recommend testing for iron levels, as well as blood chemistry to rule out CKD and diabetes. A
sleep study is usually not indicated [10]. It is important to search for an underlying etiology, as
that may help guide treatment.

Figure 4. Terms that patients may use to describe their RLS symptoms. It is important for providers to be aware of these descriptors, to help eliminate this language barrier to treatment. Screenshot from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3056753/ [9].

Management of RLS depends on symptom severity and frequency, as well as
patient/provider preference, side effect profile, medical/medication history, among other
considerations (Figure 3). Treatment may involve mediation and/or behavioral strategies. RLS
usually responds well to medication, such as alpha-2-delta voltage-gated calcium channel ligands
(gabapentin, pregabalin), dopaminergic therapy, opioids, and benzodiazepines. Dopamine
agonists are the preferred medication for moderate to severe symptoms [4]. In patients with RLS
whose fasting serum ferritin level is ≤ 75 ng/ml, iron supplementation (either orally or IV,
depending on patient circumstances) is recommended. Symptoms are expected to improve within
6 weeks of IV and within 2-3 months of oral iron therapy. For patients who report mild
symptoms, nonpharmacologic agents may be an appropriate approach for symptom relief.
Behavioral interventions may include: mentally-demanding activities, such as computer work or
crossword puzzles; regular moderate exercise; trial of caffeine and alcohol avoidance. For
symptomatic relief during an episode, activities such as bicycling, walking, and soaking and/or
massaging the affected limbs. Patients may benefit from pneumatic compression devices, which
fill with air and squeeze the legs. Aggravating factors of RLS may include inadequate sleep (deprivation, obstructive sleep apnea, among causes), and medications, such as antidepressants, sedating antihistamines (such as Benadryl and over-the-counter sleep aids), dopamine-blocking anti-emetics (anti-vomiting medication, such as metoclopramide), neuroleptic agents (antipsychotics) [1], and anti-seizure medications [9]. Yoga and acupuncture are low-risk interventions that may provide some relief [1]. Currently, there is a paucity of data regarding effects of lifestyle changes on RLS symptoms [4].

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