Restless Leg Syndrome
- Article Author:
- Abeera Mansur
- Article Author:
- Pablo Castillo
- Article Author:
- Franklyn Rocha Cabrero
- Article Editor:
- Syed Rizwan Bokhari
- Updated:
- 10/23/2020 4:23:35 PM
- For CME on this topic:
- Restless Leg Syndrome CME
- PubMed Link:
- Restless Leg Syndrome
Introduction
Restless legs syndrome, or Willis-Ekbom Disease, is a common, chronic, multifactorial, movement disorder of the limbs in which patients have an irresistible urge to move the legs. This is often associated with abnormal, non-painful sensations that start at rest and are improved by activity. There is a diurnal pattern of worsened symptoms at night. There is sleep disturbance as well as an association with involuntary jerking movements of the legs during sleep known as periodic leg movements of sleep. In the United States, there are more than three million cases per year.
Restless leg syndrome is underdiagnosed and there is a significant delay in diagnosis. The disorder may start in childhood but the diagnosis is often not made until the 3rd decade of life. Restless leg syndrome symptoms are worse at rest and sleep. Today, the condition can be treated with medications.
Etiology
There are two types of Restless Legs Syndrome. Primary Restless Legs Syndrome and Secondary Restless Legs Syndrome.[1]
Secondary Restless Legs Syndrome can occur secondary to some disorders including:
- Iron deficiency
- End-Stage Renal Disease
- Diabetes Mellitus
- Rheumatic disease
- Venous insufficiency
- Peripheral neuropathy
- Folate or magnesium deficiency
- Amyloidosis
- Lumbosacral radiculopathy
- Fibromyalgia
- Celiac disease
- Medications have been known to cause or exacerbate the symptoms of Restless Legs Syndrome. They include antidopaminergic medications (e.g., neuroleptics), Diphenhydramine, Tricyclic antidepressants (TCAs), Selective serotonin reuptake inhibitors (SSRIs).
Restless leg syndrome affects close to 1/3rd of pregnant patients, but luckily the symptoms subside after delivery.
Epidemiology
Between 5% to 15% of the population may have Restless Legs Syndrome. Familial Restless Legs Syndrome tends to occur at ages younger than 45 years. Age can be from childhood to older than 90 years. Women are affected more than men. African Americans are less frequently affected as compared to whites. Eleven percent to 29% of pregnant women are affected. It is threefold more common in pregnant women than in nonpregnant women and has a higher prevalence in the third trimester.[2][3] As many as 25% to 50% of patients with end-stage renal disease have Restless Legs Syndrome with symptoms, particularly during hemodialysis.[4][5]
Pathophysiology
In idiopathic Restless Legs Syndrome, a dysfunction of the dopaminergic system and iron stores in specific regions in the brain diminish. There may be an autosomal dominant inheritance; there have been reports of several large kindreds with different susceptibility loci with Restless Legs Syndrome. This suggests a genetic basis for the disease.
Calcium/phosphate imbalance, anemia, functional iron deficiency, and subclinical peripheral nerve abnormalities may be involved in the pathophysiology of uremic Restless Legs Syndrome.
Vitamin D deficiency and calcium metabolism, pre-eclampsia, a strong family history, low serum iron and ferritin level, high estrogen levels may also play a role in pregnancy.
Polymorphisms in genes including BTBD9 and MEIS1 are associated with Restless Legs Syndrome.
Human neuropathologic and imaging studies have shown decreased iron in different brain regions including substantia nigra and thalamus. These areas also demonstrate a state of relative dopamine excess.[3][6][1]
Restless leg syndrome is extremely common during pregnancy, especially during the third trimester.
History and Physical
Terms that patients use to describe the symptoms include crawling, creeping, pulling, itching, drawing, or stretching, all localized to deep structures rather than the skin. Pain and tingling paresthesia of the type that occurs in painful peripheral neuropathy is usually absent, and there is no sensitivity to the touching of the skin. Symptoms can range from some patients experiencing very mild problems to others having major disruption of sleep and impairments in quality of life.
Symptoms typically worsen towards the end of the day and are maximal at night, when they appear within 15 to 30 minutes of reclining in bed. In severe cases symptoms may occur earlier in the day while the patient is seated, thereby interfering with attending meetings, sitting in a movie theater, and similar activities. In milder cases, patients will fidget, move in bed, and kick or massage their legs for relief. Occasionally, the arms may be affected. Patients with more severe symptoms feel forced to get out of bed and pace the floor to relieve symptoms.
Periodic leg movements of sleep are characterized by involuntary, forceful dorsiflexion of the foot lasting 0.5 to five seconds and occurring every 20 to 40 seconds throughout sleep. There may be limb twitching during sleep. These occur in 80% of patients with Restless Legs Syndrome.
The physical examination is usually normal in patients with Restless Legs Syndrome. It is performed to identify secondary causes.
Essential diagnostic criteria (all must be met):[7]
- There is an uncontrollable urge to move the lower extremities and it may be accompanied by unpleasant and uncomfortable sensations.
- The urge to move the extremities is less during the day but gets progressively worse in the evenings and at night. The symptoms also appear at rest or during periods of sleep and inactivity.
- The urge to move the lower extremities may partially or completely be relieved by ambulation or stretching the legs. As long as the activity is continued, the symptoms are mild or absent.
- The urge to move the lower extremities ae worse during the evenings and make it impossible to sleep. Thus, the patient is often fatigued during the day.
- The presence of these symptoms must not be attributed to other behavior conditions, such as tardive dyskinesia, leg cramps, muscle spasms or discomfort from the position.
The leg movements are usually involuntary and may involve sudden dorsiflexion motions that may last 1-5 seconds and recur every 30-40 seconds throughout sleep. Positive family history is common in children.
The physical exam is usually normal. However, the patient must be examined to rule out a neurological disorder, radiculopathy or Parkinson's disease.
Evaluation
There are no specific tests except the ones to rule out secondary causes. Blood work is done to rule out other causes as well. Electromyography (EMG) and nerve conduction studies are done if one suspects radiculopathy or neuropathy. Polysomnography is often done to quantify the frequency of leg movements and characterize the pattern of sleep.
Treatment / Management
Avoid caffeine, antidepressants, antipsychotics, dopamine-blocking anti-emetics, and centrally acting antihistamines. Short daily dialysis in renal failure patients, iron replacement, exercise, massage, and heat can all alleviate the symptoms.
Dopamine agonists including pramipexole, ropinirole, rotigotine, and cabergoline have reduced symptoms, improved sleep quality, and quality of life. Pramipexole and ropinirole have adverse effects including gambling addiction and extreme weight gain.
The rotigotine transdermal patch can also be used. It is well tolerated and has a relatively low risk of clinically significant augmentation of restless legs syndrome.
In a large meta-analysis involving 3286 participants, pramipexole was shown to improve the symptoms of patients with primary moderate-to-severe Restless Leg Syndrome and maybe better than ropinirole. In a small study, rotigotine improved periodic limb movements and Restless Leg Syndrome symptoms in the short term among end-stage renal disease (ESRD) patients.
The use of alpha2-delta calcium-channel ligand (Gabapentin or Pregabalin) should be considered for the initial treatment of those patients who have severe sleep disturbance, comorbid insomnia, anxiety, pain, or a previous history of an impulse control disorder (ICD).[8][9][10]
The drugs are effective anywhere from 1-5 years, but they also have adverse effects, which reduce their compliance. today, the first-line treatment is either an alpha2 delta calcium channel ligand or a dopamine receptor agonist. Supplemental iron is recommended for all patients who have low serum ferritin levels.
Restless leg syndrome in pregnancy usually resolves after delivery.
The US FDA approved Relaxis, a vibrating device that can be used during sleep. Studies show that it can improve sleep quality.
Exercise is of benefit in many patients but it is often not realistic in the middle of the night.
Differential Diagnosis
- Tardive dyskinesia
- Akathisia
- Leg cramps
- Vascular disease
- Muscle spasms
- Radiculopathy
Prognosis
In about 70% of patients, the symptoms progress and become moderate to severe. In addition to the legs, some patients may start to experience the same symptoms in the arms. Overall, the symptoms are less severe in the morning and get worse during the evening and night. In some patients, the symptoms are so severe that they are disabling, interrupting sleep and causing day time fatigue. Studies show that restless leg patients are prone to hypertension, headaches, and sleep difficulties. The quality of life for most patients is poor.
Complications
Complications of the disease itself are limited to the quality of life due to disturbed sleep and fatigue. In most patients, the symptoms progress over time and cause significant quality of life issues.
Deterrence and Patient Education
Patients should be educated on the progressive nature of the disease and various nonpharmacological treatment modalities to alleviate symptoms.
Pearls and Other Issues
With prolonged dopamine agonists use, the symptoms may increase in severity despite appropriate treatment. There may be a requirement for an increase in the dose, with earlier onset of symptoms, spreading to unaffected parts, and shorter duration of action of the medication. This is known as Augmentation.
Restless Leg Syndrome may gradually worsen with age. The progression is slower in patients with the idiopathic form of the disease than for those who have an associated medical condition.
Enhancing Healthcare Team Outcomes
The diagnosis and management of restless leg syndrome are complex. The condition can be disabling and is best managed by an interprofessional team that includes a nurse practitioner, neurologist, internist, physical therapist, and the primary care provider.
The primary care provider should emphasize the importance of good sleep hygiene. The patient should be discouraged from consuming alcohol and caffeinated beverages. The physical therapist should educate the patient on types of exercise that can be done while in bed. Since many patients develop anxiety and depression, a mental health nurse should be consulted. The pharmacist should educate the patient on the types of drugs used to treat restless leg syndrome and their potential adverse effects.
While there are many drugs used to treat this disorder, none has been shown to be superior to other classes. Plus, these drugs are not reliable or consistent in their efficacy. Relapses are common. More important, many patients develop adverse reactions to the drug and non-compliance is a major problem in the long run. Overall, the quality of life of patients with RLS is poor.[11]
To prevent the high morbidity of this disorder, close communication between the team members is vital to ensure that the patient is receiving optimal care and support.