Restless Legs Syndrome Linked To Inefficient Use Of Iron In BrainSymptoms Include Prickly Sensations< August 20, 2003 >A new study reported in the medical journal Neurology shows that symptoms of restless legs syndrome (RLS) may result from inefficient processing of iron in certain brain cells. The findings provide a possible explanation for this disorder and may lead to new ways of treating the disease. The study, conducted in brain tissue during autopsy exams, was led by Dr. James R. Connor of Penn State University College of Medicine. It was funded in part by the National Institute of Neurological Disorders and Stroke (NINDS). The study provides no evidence of lost or damaged cells in the RLS brains. Instead, the researchers found that receptors which help cells absorb iron are abnormally regulated in cells that produce the nerve-signaling chemical dopamine. Symptoms Often Keep People Awake at NightRLS affects more than 12 million people in the US. The National Sleep Foundation states that recent research shows RLS affects about 10 percent of adults in North America and Europe with rates increasing with age. Lower prevalence has been found in India, Japan, and Singapore, indicating that racial or ethnic factors may be associated with RLS. RLS causes unpleasant sensations often described by people as burning, creeping, tugging, or like insects crawling inside the legs. Lying down and trying to relax makes the symptoms worse. As a result, most people with RLS have difficulty falling asleep and staying asleep, which leads to exhaustion and daytime fatigue. According to the National Center on Sleep Disorders Research, "Restless legs syndrome is a common, under diagnosed, and treatable condition." A number of studies have linked RLS to deficiencies of dopamine and iron. Medications that affect dopamine levels, such as the drug levodopa, relieve symptoms of the disease in some people. Injections of large doses of iron also sometimes relieve symptoms, even in people who do not have an iron deficiency. However, it has never been clear exactly what causes the symptoms of this disease. In the new study, the researchers found no evidence of brain damage. However, the amount of iron in brain cells from a region called the substantia nigra was extremely low, and there were very few receptors for transferrin, a protein that binds to iron and transports it into cells. Levels of several other proteins linked to iron storage and transport were also low. The lack of iron in the cells may cause them to malfunction, leading to the symptoms of RLS, Dr. Connor says. "This may explain why treatment strategies tend to work. In RLS, we just need to tweak the system to improve cell function, rather than replacing lost cells," he says. Seek Medical Advice on TreatmentThe results do not mean that people with RLS have an iron deficiency, Dr. Connor says. Instead, the iron in their bodies is not being delivered to specific brain cells in an effective way. The findings help to confirm that RLS is a neurological problem and not a psychological disorder, as some people have suggested, he adds. People should not start taking iron supplements without a physician's advice, Dr. Connor cautions. Most studies that have found a benefit from iron supplementation have used very large doses of iron, administered intravenously. Taking too much iron can lead to problems such as dizziness, headaches, low blood pressure, coma, and even death. Studies have suggested that high levels of iron also can increase the risk of Alzheimer's and Parkinson's disease, Dr. Connor adds. The researchers are now focusing on studies to determine precisely how iron transport is altered in people with RLS, why the transferrin receptors are decreased, and how the iron deficit affects cells. In the future, Dr. Connor hopes to study how iron supplementation works in people with RLS. He also hopes to find medications or medical techniques that can specifically target the problem with iron uptake in the brain. Always consult your physician for more information. |
For more information on health and wellness, please visit health information modules on this Web site. What Is Restless Legs Syndrome?According to the National Institute of Neurological Disorders and Stroke (NINDS) of the National Institutes of Health (NIH), restless legs syndrome is a movement disorder characterized by uncomfortable sensations in the legs, which are worse during periods of inactivity or rest or while sitting or lying down. Symptoms of RLS vary from person to person. Individuals affected by the disorder sometimes describe the sensations as pulling, drawing, crawling, wormy, boring, tingling, pins and needles, prickly, and sometimes painful sensations that are usually accompanied by an overwhelming urge to move the legs. Sudden muscle jerks may also occur. Movement provides temporary relief from the discomfort. In rare cases, the arms may also be affected. Symptoms may interfere with sleep onset (sleep onset insomnia). NINDS states that restless legs syndrome is related to periodic limb movement disorder (PLMD), another more common motor disorder which causes involuntary leg twitching during sleep. According to the Restless Legs Syndrome Foundation, RLS is diagnosed by reviewing a person's medical history. After ruling out other medical conditions as the cause of the symptoms, a physician can make the diagnosis of RLS by listening to your description of the sensations. No lab test exists that can confirm a diagnosis of RLS. However, a thorough physical examination, including the results of necessary lab tests, can reveal temporary disorders, such as iron deficiency, that may be associated with RLS. Some people (including those with periodic limb movements of sleep and without the abnormal sensations of RLS) will require an overnight sleep studies to determine other causes of their sleep disturbance. Treatment for restless legs syndrome addresses symptoms. Massage and application of cold compresses may provide temporary relief. Physicians may suggest a variety of medications to treat RLS. Generally, physicians select from dopaminergics, benzodiazepines (central nervous system depressants), opoids, and anticonvulsants. However, many of these medications have side effects, NINDS warns. Always consult your physician for more information. Online Resources(Our Organization is not responsible for the content of Internet sites.) Centers for Disease Control and Prevention (CDC) National Center on Sleep Disorders Research National Institutes of Health (NIH) National Institute of Neurological Disorders and Stroke (NINDS) |
