1. The syndrome is divided into two categories: primary and symptomatic
(1) Primary restless legs syndrome
The cause of this type is unknown, and a few patients have a family history.
(2) Symptomatic restless legs syndrome
RLS is also secondary to other diseases, commonly due to the following causes: uremia, iron deficiency anemia, folic acid deficiency, pregnancy, rheumatoid arthritis, Parkinson’s disease, multifocal neuropathy, metabolic diseases and drugs.
2.Clinical manifestations
The clinical features are a spontaneous, unbearably painful abnormal sensation occurring in the lower extremities. It is most common in the gastrocnemius muscle, and can occasionally occur in the thighs or upper extremities, usually symmetrically. Patients often complain of a tearing, creeping, tingling, burning, painful or itchy sensation deep in the lower extremities. Patients have an urgent and intense feeling of needing to move and this leads to hyperactivity. Symptoms occur at rest and can be partially or completely relieved by activity. Normally, symptoms become intense at night while lying in bed and peak after midnight, forcing patients to kick their legs, move their joints or massage their legs, often describing “not having a comfortable place to put their legs.” In severe cases, the patient has to get up and walk constantly to get relief. As a corollary, most patients experience periodic movements of sleep (PMS), a stereotyped, repetitive flexion of the legs that occurs during REM sleep and wakes the patient. As a result of nocturnal sleep disorder, the patient suffers from severe daytime sleepiness and reduced work capacity.
3.Diagnosis and differential diagnosis
Diagnostic criteria: The International Restless Legs Syndrome Study Group (IRLSSG) has developed a minimum diagnostic criteria consisting of four symptoms.
(1) Leg movement triggered by leg discomfort: indescribable discomfort in the limbs leads to a strong desire to move the limbs, mainly the lower limbs. These abnormal sensations often occur deep in the limb rather than on the surface, such as the skin.
(2) Motor symptoms:The patient is unable to sleep, and continuous movement of the limbs can partially or completely relieve the symptoms. The main manifestations are walking back and forth, constantly shaking or flexing and extending the lower limbs, or grinding and turning in bed.
(3) Symptoms are aggravated at rest and can be temporarily relieved by activity.
(4) The symptoms are aggravated at night, with a peak between 23:00 and 4:00 am.
4.Treatment
(1) General treatment.
(1) Remove the causative factors: Patients with RLS should pay attention to sleep hygiene as well as regular work and rest. Use less coffee and coffee-containing beverages, quit smoking, drink less alcohol or take a hot bath before bedtime. Excessive daytime sleep should be avoided to reduce the resulting sleep disorders. In addition, excessive physical exercise during the day may also exacerbate the symptoms of RLS.
(2) Discontinue medications that can induce restless legs syndrome: e.g., dopamine receptor blockers; sedatives; antidepressants; antihistamines, etc.
(2) Pharmacological treatment.
When patients complain of severe motor symptoms and/or sleep disturbances or fatigue in RLS, they should be treated with appropriate medications. In general, treatments are symptomatic and only provide temporary relief. Because symptoms of RLS may resolve spontaneously, physicians may consider medication tapering or leave therapy when appropriate. For the pharmacological treatment of primary RLS, dopaminergic medications are preferred. For mild to moderate symptoms, levodopa is preferred, starting with small doses, such as 50 mg to 100 mg. Depending on the patient’s needs, doses of 100 mg to 400 mg may be taken throughout the night, up to one hour before bedtime. A commonly used preparation is a combination of levodopa and a dopa decarboxylase inhibitor, such as methyldopa. If the patient’s symptoms progress into the daytime or the first half of the night, the amount of levodopa should not be increased and a switch to a dopamine agonist may be considered. For severe RLS, dopamine agonists such as pramipexole and ropinirole may be preferred.
Anticonvulsants such as carbamazepine, sodium valproate, or gabapentin are used as second-line drugs and can be chosen when the above drugs are ineffective or the side effects are not tolerated. For secondary RLS, the first step is to treat the primary disease. As the cause of the disease is eliminated, the symptoms of RLS will disappear. For example, renal transplantation in uremic patients, iron therapy in patients with iron deficiency anemia, folic acid supplementation in patients with folic acid deficiency, etc.