People with RLS complain of an irresistible urge to move their legs while at rest. A person with RLS will experience a vague, uncomfortable feeling while at rest, only relieved by moving the legs. The symptoms of RLS may be present all day long, making it difficult for an individual to sit motionless. Or they may be present only in the late evening. Late evening symptoms can lead to sleep onset insomnia, which tends to compound the effects of RLS. Pregnancy, uremia, and post-surgery conditions have also been known to increase the incidence of RLS.
Restless leg syndrome is estimated to affect 5% of the population. Approximately 80% of people with RLS have PLMD, though most people with PLMD do not experience RLS.
Symptoms of RLS
Many who experience RLS may also experience generalized anxiety that results from the incessant need to change the positioning of their legs. Moving the legs temporarily relieves the discomfort.
The intensity of RLS can vary significantly throughout the day. Many people have no symptoms at all until nighttime, when they attempt to sleep. The discomfort in the legs and the need to move them prevents them from sleeping. Other patients have severe symptoms all day long, which may affect work, travel, or the ability to concentrate.
There are many conditions that have been associated with PLMD and RLS, including:
- Chronic kidney failure
- Myelopathies (conditions of the spinal cord)
- Peripheral neuropathies
- Amyloidosis (metabolic disorder of organs and tissues)
- Diabetes mellitus
- Anemia and related hemoglobin deficiencies
- Iron deficiency
- Vitamin B12 deficiency
- Uremia (kidney-related toxicity)
- Chronic lung disease
- Rheumatoid arthritis
- Fibromyalgia (chronic fatigue syndrome)
- Certain medications may also induce RLS and PLMD, including lithium and tricyclic antidepressants.
- Withdrawal from other medications, including anticonvulsants, benzodiazepines, and barbiturates may also induce RLS and PLMD.
Generally, there are three classes of drugs that are used to treat RLS. These are benzodiazepines, Parkinson drugs, and narcotics. Medical treatment of RLS often significantly reduces or eliminates the symptoms of this disorder, though not always. There is no cure for RLS, and medical treatment must be continued to provide potential relief.
Clonazepam is the most commonly employed benzodiazepine treatment. It is effective in many cases, but not all, and it usually causes drowsiness or sedation. Sometimes, clonazepam allows the patient a better, more restful night’s sleep without affecting the occurrence of limb movement.
The drugs used to treat Parkinson’s disease are also very effective against RLS. These include, L-dopa/carbidopa, bromocriptine (which suppresses the excretion of prolactin), pergolide, and selegiline. If either benzodiazepines or Parkinson’s medications do not relieve symptoms, then narcotics, such as codeine, oxycodone, methadone, and propoxyphene are sometimes employed.
The causes of RLS are unknown. The vast majority of RLS cases occur independently of other disease processes. It is certain that these conditions often cause insomnia, and some research shows that they might also be caused by other sleep disturbances.