Treatment of childhood-onset restless legs syndrome and periodic limb movement disorder using intravenous iron sucrose

Objective

An alternative treatment approach is needed for children who cannot tolerate oral iron preparations or when there is a need for rapid replenishment of iron stores. We report on the safety, adverse effects, and efficacy of intravenous iron sucrose in a retrospective sample of children with restless legs syndrome (RLS) or periodic limb movement disorder (PLMD).

Methods

Sixteen children with RLS/PLMD who received intravenous iron sucrose at our institution between 2005 and 2011 were identified. The diagnosis of RLS/PLMD was established after formal sleep consultation and nocturnal polysomnography (PSG). Serum ferritin was assayed in all 16 subjects prior to iron sucrose infusion and in 14 subjects after infusion. The medical records were reviewed for treatment-related details.

Results

The mean age of subjects was 6.6 years (range, 2–16 y; 5/16 girls). The mean periodic limb movement index (PLMI) was 18.2 ± 12.8. Fifteen of the 16 subjects (93.7%) had systemic or neurologic comorbidities. Fourteen of 16 (87.5%) subjects had received prior oral iron supplementation for sleep-related concerns, with the majority of the subjects either having gastrointestinal (GI) side effects or insufficient benefits. Intravenous iron sucrose therefore was provided to these 16 subjects through our outpatient pediatric infusion therapy center. The average dose of intravenous iron sucrose of 3.6 mg/kg was infused over 2 h. The baseline mean serum ferritin was 16.4 ± 6.6 ng/mL. After infusion with intravenous iron sucrose, the mean serum ferritin rose to 45.7 ± 22.4 ng/mL (n = 14; [95% confidence interval, 17.2–41.3]; P < .0001). Parental assessment of response to iron sucrose therapy was conducted on follow-up clinic visits or via telephone calls. There was improved sleep in 62.5% (n = 10) of subjects and no improvement in 12.5% (n = 2) of subjects. No follow-up information was available for 25% (n = 4) of subjects. Minor adverse events occurred in 25% (n = 4) of subjects—two subjects experienced difficulty with peripheral intravenous catheter placement, while two had transient GI symptoms, such as anorexia, nausea, and vomiting. None of the subjects had anaphylaxis.

Conclusions

Intravenous iron sucrose appears to be a relatively effective therapy for patients with childhood-onset RLS/PLMD and iron deficiency who do not tolerate or respond to oral iron supplements. Side effects were transient. The most common adverse events were difficulty with intravenous line placement and GI disturbance. There is a need for systematic prospective studies on the safety and efficacy of intravenous iron sucrose in RLS/PLMD in children.     

A randomized,double‐blind,placebo controlled,multi‐center study of intravenous iron sucrose and placebo in the treatment of restless legs syndrome

Iron deficiency may exacerbate symptoms in the Restless Legs Syndrome (RLS). We investigated the effect of intravenous iron sucrose or placebo on symptoms in patients with RLS and mild to moderate iron deficit. Sixty patients with primary RLS (seven males, age 46 (9) years, S‐ferritin ≤45 μg/L) recruited from a cohort of 231 patients were randomly assigned in a 12‐months double‐blind, multi‐centre study of iron sucrose 1000 mg (n = 29) or saline (n = 31). The primary efficacy variable was the RLS severity scale (IRLS) score at week 11. Median IRLS score decreased from 24 to 7 (week 11) after iron sucrose and from 26 to 17 after placebo (P = 0.123, N.S. for between treatment comparison). The corresponding scores at week 7 were 12 and 20 in the two groups (P = 0.017). Drop out rate because of lack of efficacy at 12 months was 19/31 after placebo and 5/29 patients after iron sucrose (Kaplan–Meier estimate, log rank test P = 0.0006) suggesting an iron induced superior long term RLS symptom control. Iron sucrose was well tolerated. This study showed a lack of superiority of iron sucrose at 11 weeks but found evidence that iron sucrose reduced RLS symptoms both in the acute phase (7 weeks) and during long‐term follow up in patients with variable degree of iron deficiency. Further studies on target patient groups, dosing and dosing intervals are warranted before iron sucrose could be considered for treatment of iron deficient patients with RLS. © 2009 Movement Disorder Society     

Restless legs syndrome and pregnancy: prevalence,possible pathophysiological mechanisms and treatment

Restless legs syndrome (RLS) is a common sleep disorder that may be associated with pregnancy. Studies have found that the prevalence of RLS among pregnant women ranged from 10 to 34%. Typically, there is complete remission of symptoms soon after parturition; however, in some patients, they may continue postpartum. RLS has been shown to be associated with a number of complications in pregnancy including preeclampsia and increased incidence of Cesarean sections. Although multiple hypotheses have been proposed to explain this association, each individual hypothesis cannot completely explain the whole pathogenesis. Present understanding suggests that a strong family history, low serum iron and ferritin level, and high estrogen level during pregnancy might play important roles. Vitamin D deficiency and calcium metabolism may also play a role. Medical treatment of RLS during pregnancy is difficult and challenging considering the risks to mother and fetus. However, in some cases, the disease may be severe enough to require treatment.     

Hemochromatosis and iron therapy of Restless Legs Syndrome

Restless legs syndrome (RLS) occurs in some persons with iron deficiency, and some persons with RLS benefit from oral iron therapy. Approximately one in 200 persons of northern European ancestry have hemochromatosis attributable to inheritance of two common mutations of the hemochromatosis-associated HFE gene on chromosome 6. We evaluated and treated a 46-year-old man with RLS who was diagnosed as having hemochromatosis after he developed new symptoms associated with taking iron therapy for RLS. He had transferrin saturation 88%, serum ferritin 658 ng/ml, and C282Y homozygosity. Therapeutic phlebotomy of one unit of blood (450-500 ml) weekly (total 24 units) relieved his non-RLS symptoms, caused RLS symptoms to occur more frequently, and was associated with transient fatigue and mild dependent edema. His sister, who also has RLS, was subsequently diagnosed as having hemochromatosis. We conclude that serum transferrin saturation and ferritin levels should be measured before initiation of iron therapy of RLS. Patients with a history of iron deficiency or low serum iron parameters should undergo evaluation for iron deficiency; patients who have histories suggestive of hemochromatosis or iron overload or elevated pre-treatment transferrin saturation or serum ferritin levels should undergo evaluation to determine the cause of these abnormalities before they are treated with iron. In all persons with RLS treated with oral iron, serum iron parameters should be re-measured once or twice yearly during therapy.     

Low body stores of iron and restless legs syndrome: a correctable cause of insomnia in adolescents and teenagers

BACKGROUND: It has been shown that restless legs syndrome (RLS) in adults may be linked to abnormalities in iron stores. Whether reduced iron stores play a role in children is not clear. METHODS: We evaluated the status of iron stores and sleep in three teenagers who presented with severe sleep onset insomnia, subjective sleep latency exceeding 60 min and excessive daytime sleepiness. RESULTS: The three teenagers were found to have RLS and laboratory evaluation confirmed reduced body stores of iron with a low percent iron saturation (mean value 9.7%) and a low serum ferritin level (mean value 17 microg/l). None had marked anemia. The three patients were treated with oral iron for 4-5 months. As a group they had an increase in percent iron saturation (from a mean of 9.7 to 22.7%) and serum ferritin (from a mean of 17 to 27 microg/l) and a marked reduction of the symptoms of RLS, with mean subjective sleep latency decreasing from 143 to 23 min, sleep efficiency increasing from 75.7 to 84.0% and the number of periodic movements per hour of sleep decreasing from 20.5 to 10.5. INTERPRETATION: These findings support the hypothesis that abnormal iron stores or metabolism may result in RLS causing insomnia in teenagers. We recommend evaluation of iron status including serum iron, total iron binding capacity and ferritin levels in teenagers with chronic insomnia of unexplained origin even when anemia is mild or absent.     

The treatment of restless legs syndrome with intravenous iron dextran

BACKGROUND AND PURPOSE: To evaluate the safety and efficacy of a single 1000 mg iron infusion in treating Restless Legs Syndrome (RLS). PATIENTS AND METHODS: A single 1000 mg intravenous (IV) [Am J Med Sci 31 (1999) 213] infusion of iron dextran was evaluated in an open-label study. Primary outcomes of efficacy were symptom severity assessed by global rating scale and periodic leg movements in sleep (PLMS) at 2 weeks post-infusion. Secondary outcomes included total sleep time (TST), hours/day of RLS symptoms, and changes in magnetic resonance imaging (MRI)-determined iron concentrations in the substantia nigra. Primary safety measures were reported adverse events and monthly serum ferritin levels. RESULTS: IV iron therapy significantly improved the mean global RLS symptom severity, TST, hours with RLS symptoms and PLMS, but on an individual basis failed to produce any response in 3 of the 10 subjects who were fully treated. Brian iron concentrations at 2 weeks post-infusion as determined by MRI were increased in the substantia nigra and prefrontal cortex. Serum ferritin levels showed a greater than predicted rapid linear decrease. Side effects were mild, except in one subject who developed an acute allergic reaction. CONCLUSIONS: The results in this study provide valuable information for future studies, but the efficacy and safety of IV iron treatment for RLS remain to be established in double-blind studies. The serum ferritin results suggest that greater than expected iron loss occurs after IV iron loading.     

Risk factors and prevalence rate of restless legs syndrome among pregnant women in Taiwan

BackgroundThe goal of this study was to assess the prevalence and clinical correlates of restless legs syndrome (RLS) among pregnant Taiwanese women.MethodsWe enrolled 461 pregnant women (18–45 years) admitted at Mackay Memorial Hospital for delivery from September 2010 to May 2011. The face-to-face questionnaire used to gather data included assessment of RLS diagnostic criteria, and questions related to RLS.ResultsThe overall prevalence rate of RLS among the study participants was 10.4%; 2.8% were categorized as having chronic RLS. Participants without RLS reported higher folate and iron supplement consumption than those with RLS. Multivariate analysis revealed significant associations of RLS with anemia and peptic ulcer disease. Participants with transient RLS during pregnancy reported more regular coffee consumption before pregnancy, and better sleep latency, duration, and efficiency, than those with chronic RLS. Overall, 81.2% of RLS sufferers reported sleep disturbances.ConclusionsOur study revealed highly prevalent but poorly recognized RLS among Taiwanese pregnant women. The identification of predictors such as medical comorbidities, and protectors such as folate and iron supplements, is warranted for obstetric RLS. In most cases, symptoms began during the second or third trimester and resolved within a week after delivery. Restricted coffee consumption before pregnancy is encouraged, but further evidence is needed to support this recommendation.     

The severity range of restless legs syndrome (RLS) and augmentation in a prospective patient cohort: Association with ferritin levels

ObjectivesThe aim of the study was to prospectively examine all patients with a diagnosis of RLS consulting a sleep disorders clinic and to assess RLS severity and augmentation and their associations, including ferritin levels.MethodsPatients were stratified into patients with RLS as ancillary diagnosis, RLS sufferers without current augmentation and RLS sufferers with current augmentation. Work-up included RLS severity scales and blood biochemical variables including indices of iron metabolism.ResultsIn an 18-month period, 302 patients with RLS (183 women, 119 men; mean age, 59.1 ± 13.7 years) were recruited. RLS was considered idiopathic in 291 patients (96.4%). Most patients (240, 79.5%) were RLS sufferers, whereas the remaining 62 (20.5%) had RLS as ancillary diagnosis. Nineteen out of 162 patients treated with dopaminergic agents (11.7%) had current augmentation. Almost one-third of all patients (31.1%) had ferritin levels <50 μg/l. Patients with an ancillary diagnosis of RLS had higher ferritin levels than RLS sufferers without current augmentation. The lowest ferritin levels were present in RLS sufferers with current augmentation 132.8 ± 98.0 μg/l vs. 100.6 ± 84.5 μg/l vs. 55.8 ± 43.6 μg/l; p = 0.002). Patients with augmentation did not differ from non-augmented patients regarding age, gender, RLS etiology, presence of previous augmentation, or any other documented comorbidity (p > 0.05).ConclusionThe severity spectrum of RLS in this clinical cohort ranged from the ancillary diagnosis of RLS to augmented RLS. There was an inverse correlation between RLS severity and ferritin levels. Patients with current augmentation had the lowest ferritin levels. Our data further strengthen a putative role of low iron stores as a potential aggravator of idiopathic RLS. Moreover, low ferritin might represent a potential biomarker of RLS augmentation under dopaminergic therapy.     

Lower molecular weight intravenous iron dextran for restless legs syndrome

BackgroundVarious techniques used to assess brain iron concentrations have demonstrated the presence of low iron stores in patients with restless legs syndrome (RLS). Previous open-label and randomized studies generally support the value of iron treatment for RLS symptoms. Only one of these studies assessed iron therapy response to changes in brain iron status. The current study was designed to assess the effect of iron therapy on RLS symptoms and on CSF measures of brain iron status.MethodsIdiopathic RLS patients drawn from the Korean population received four weekly intravenous (IV) doses of 250 mg low-molecular weight iron dextran for a total dose of 1 g. One week after the last dose, any subject on RLS medication tapered off the RLS medications. Blood and CSF samples were taken to measure iron parameters at baseline and again, three weeks after the last dose. We have been following their response to the drug for two years after treatment.ResultsTwenty-five patients (age 55.2 ± 9.3, 18 female) enrolled in this study without serious adverse reactions. Seventeen of the 25 patients (68%) showed moderate or complete improvement of all RLS symptoms after treatment based on the Korean-translated versions of the International RLS Severity scale (K-IRLS). Changes in the K-IRLS did not correlate significantly with changes in CSF ferritin. The response to IV iron could not be predicted by patients’ demographics, or by blood or CSF iron baseline characteristics. RLS symptom improvement started between one and six weeks after treatment and the treatment benefits lasted from one month to 22 months. Fourteen patients, (56%) completely stopped all medications, for a mean duration of 31.3 ± 33.1 weeks. These results are comparable to those from a prior study with high molecular weight dextran.ConclusionsIntravenous low-molecular weight iron dextran produced significant improvement of RLS symptoms in a majority of patients without any significant adverse effects. Serious anaphylaxis occurs with high molecular weight, but rarely, if ever, with this low molecular weight dextran. Given apparent comparable efficacy the low molecular weight and not the high molecular weight iron dextran, should be considered for RLS treatment. Although changes in CSF ferritin were seen following therapy, these changes were not related to clinical improvements.     

When gender matters: restless legs syndrome. Report of the "RLS and woman" workshop endorsed by the European RLS Study Group

Sleep is an essential human behavior that shows prominent gender differences. Disturbed sleep, in particular, is much more prevalent in females than males. Restless legs syndrome (RLS) as one cause of disturbed sleep was observed to be somewhat more common among women than men in Ekbom's 1945 seminal series of clinical cases with the disease. He, however, reported this gender difference mainly for those with more severe symptoms. Since then numerous studies have reported that women are affected by RLS about twice as often as males for mild as well as moderate to severe RLS. The present review focuses on RLS in females from the perspectives of both epidemiology and pathophysiology. RLS will generally become worse or might appear for the first time during pregnancy. Parity increases the risk of RLS later in life suggesting that pregnancy is a specific behavioral risk factor for developing RLS. Some evidence suggests that dysfunction in iron metabolism and high estrogen levels might contribute to RLS during pregnancy. But, menopause does not lower the incidence of RLS nor does hormone replacement therapy lead to an increase, suggesting a quite complex uncertain role of hormones in the pathophysiology of RLS. Therefore, further, preferably longitudinal studies are needed to unravel the factors causing RLS in women. These studies should include genetic, clinical and polysomnographic variables, as well as hormonal measures and variables assessing iron metabolism.     

A randomized, double-blind, placebo-controlled trial of intravenous iron sucrose in restless legs syndrome

ObjectiveThe aim of this study was to ascertain whether high-dose intravenous (IV) iron sucrose could improve symptoms and change brain iron concentrations in idiopathic RLS.MethodsThe study was a randomized, parallel-group double-blind study of 1000 mg iron sucrose given IV versus placebo. Primary measures of the clinical status were global rating scale (GRS) and periodic leg movements of sleep (PLMS). Primary measures of brain iron status were CSF ferritin and MRI-determined iron in the substantia nigra.ResultsAt the time of the interim analysis there were 7 placebo and 11 iron-treated subjects. At 2-weeks post-treatment, iron treatment resulted in a small but significant increase in CSF ferritin and a decrease in RLS severity (GRS) but did not change PLMS or MRI iron index. None of the secondary outcomes changed with treatment. There was no single case of clear treatment benefit in any of the patients. This interim analysis revealed an effect size that was too small to allow for adequate power to find significant differences with the planed 36-subject enrollment for either the primary objective outcome of PLMS or any of the secondary outcomes. The study was stopped at this planned break-point given the lack of both adequate power and any indication for clinically significant benefit.ConclusionsHigh-dose IV iron failed to demonstrate the robust changes reported in three prior open-label studies. Differences in iron formulation, dosing regiment, and peripheral iron status may explain some of the discrepancies between this and previous IV iron treatment studies.     

Epilepsy and restless legs syndrome

ObjectiveRestless legs syndrome (RLS) is a common neurological movement disorder occurring in approximately 10% of the general population. The prevalence of moderately severe RLS is 2.7% overall (3.7% for women and 1.7% for men). Epilepsy is also a common neurological disorder with significant associated morbidity and impact on quality of life. We evaluated the severity and frequency of primary RLS in patients with localization-related temporal lobe epilepsy (TLE) and investigated the role of prodromal RLS symptoms as a warning sign and lateralizing indicator.MethodsAll epilepsy patients seen in the outpatient clinic were screened for movement disorders from 2005 to 2015. Ninety-eight consecutive patients with localization-related TLE (50 right TLE and 48 left TLE) who met inclusion criteria were seen in the outpatient clinic. The control group consisted of 50 individuals with no history or immediate family history of epilepsy.Each patient was evaluated with the International Restless Legs Study Group (IRLSSG) questionnaire, NIH RLS diagnostic criteria, ferritin level, and comprehensive sleep screening including polysomnography. Furthermore, patients with obstructive sleep apnea or a definite cause of secondary restless legs syndrome such as low serum ferritin or serum iron levels were also excluded from the study.ResultsThere was a significant association between the type of epilepsy and whether or not patients had RLS χ² (1) = 10.17, p < .01, using the χ² Goodness of Fit Test. Based on the odds ratio, the odds of patients having RLS were 4.60 times higher if they had right temporal epilepsy than if they had left temporal epilepsy, serving as a potential lateralizing indicator. A prodromal sensation of worsening RLS occurred in some patients providing the opportunity to intervene at an earlier stage in this subgroup.SignificanceWe identified frequent moderate to severe RLS in patients with epilepsy. The frequency of RLS was much more common than would typically be seen in patients of similar age. The restlessness was typically described as moderately severe. The RLS symptoms were more common and somewhat more severe in the right TLE group than the left TLE group.     

Pregnancy as a risk factor for restless legs syndrome

Pregnant women have at least two or three times higher risk of experiencing restless legs syndrome (RLS) than the general population. These data come from few epidemiological studies finding an 11-27% prevalence of RLS during pregnancy. Women affected by pre-existing RLS often complain of worsening symptoms during pregnancy. This is usually a benign form of RLS, with the highest degree of severity in the third trimester and a tendency to disappear around delivery. The causes of the association between RLS and pregnancy are unknown. The most debated hypotheses are: metabolic alterations, with particular regard to iron and folate deficiency; hormonal influences related to the increase of prolactin, progesterone and estrogens during late pregnancy; and the changing motor habits and psychological state of pregnant women. The importance of folate and iron supplementation during pregnancy in preventing RLS is unclear. RLS in pregnant women is frequently unrecognized; they are often worried about the symptoms and do not receive an adequate explanation by doctors.     

Open-label study of the efficacy and safety of intravenous ferric carboxymaltose in pregnant women with restless legs syndrome

ObjectiveThe objective of this study was to test the efficacy and safety of intravenous ferric carboxymaltose (FCM) in pregnant women with restless legs syndrome (RLS) and iron deficiency or anemia. The open-label pilot study (exploratory) was performed at the University Hospital of Zürich and the Neurocenter of Southern Switzerland (Lugano).Patient and MethodsNineteen women in the third trimester of pregnancy with moderate-to-severe RLS and serum ferritin levels <35 µg/l or hemoglobin (Hb) < 11.0 g/dl were included in the study. RLS was graded according to the International Restless Legs Syndrome (IRLS) Study Group rating scale. All participants had a score of ≥20 or had RLS ≥3 times/week. Based on the Hb levels, 500 or 700 mg of FCM was administered over 20 min. The primary end point was a ≥ 50% reduction in the mean IRLS score one week after FCM infusion. The secondary end points included periodic limb movements (PLMs; assessed using nocturnal foot actigraphy), sleep quality (assessed using the Pittsburgh Sleep Quality Index), and safety.ResultsThe IRLS score decreased from 23 ± 7 (baseline) to 13 ± 7 (P <0.01), whereas the PLM index decreased from 35 ± 26 (baseline) to 25 ± 20 (P <0.001). Significant improvement in sleep quality was also reported (P <0.029), and treatment was well tolerated. Three serious adverse events were reported, but they were considered unrelated to treatment.ConclusionsThese data provide promising evidence on the safety and efficacy of FCM for moderate-to-severe RLS in pregnant women with iron deficiency or anemia. Therefore, a future placebo-controlled study is warranted.     

Outcomes of long-term iron supplementation in pediatric restless legs syndrome/periodic limb movement disorder (RLS/PLMD)

ObjectivesRestless legs syndrome (RLS) and periodic limb movement disorder (PLMD) are thought to center around a genetically mediated sensitivity to iron insufficiency. Previous studies have shown the effectiveness of short-term iron therapy in children with low iron storage. Little is known, however, about long-term iron treatment in children with RLS and PLMD. Therefore, we performed this study to assess the long-term effect of iron therapy in children with RLS and PLMD.MethodsA retrospective chart review was performed for children who met the following criteria: A) diagnosed as having either RLS or PLMD, B) started on iron supplementation, C) followed up for >2 years in a sleep clinic. Baseline values for iron, ferritin, and periodic limb movement of sleep index (PLMS index) were defined in the three months leading up to the initiation of iron therapy. Values were also computed for follow-up periods of 3–6 months, 1–2 years, and >2 years. Serum iron and ferritin levels and PLMS index were compared between baseline and all subsequent follow-ups.ResultsIn total, 105 patients met inclusion criteria, of whom 64 were diagnosed with PLMD alone, seven with RLS alone, and 35 with both RLS and PLMD. The average age was 10.2 ± 5.3 years. Compared to the baseline (27.4 ± 12.1 ng/ml), the average ferritin values at 3–6 months (45.62 ± 21.2 ng/ml, p < 0.001, n = 34), 1–2 years (52.0 ± 48.3 ng/ml, p <0.001, n = 63), and >2 years (54.7 ± 40.5 ng/ml, p <0.001, n = 67) were all significantly increased. Inversely, compared to baseline (21 ± 27.0/h, n = 66), PLMS index values at 3–6 months (7.5 ± 9.5/h p < 0.05, n = 11), 1–2 years (6.9 ± 8.9/h, p <0.001, n = 29), and >2 years (10 ± 14.5/h, p <0.001, n = 31) were all significantly decreased. No significant change in serum iron levels was noted at any time point.ConclusionWhile retrospective in nature, this study demonstrates a sustained improvement in PLMS index and maintenance of adequate ferritin levels >2 years after iron therapy initiation in our RLS/PLMD cohort with a long-term follow-up. Iron therapy appears to lead to long-lasting improvements in children with RLS/PLMD.     

Prevalence and clinical characteristics of patients with restless legs syndrome with painful symptoms

BackgroundThe complaint of pain has largely been ignored in the diagnostic criteria for restless legs syndrome (RLS). The purpose of this study was to investigate the prevalence of painful symptoms in RLS, and to compare sleep-related characteristics between the patients who experienced the painful symptoms and those who did not.MethodsThe patients with RLS were retrospectively screened from July 2011 to December 2013 at a tertiary-care sleep center. For classifying those with pain and those without pain, more than three specialists separately observed the patients' reports and complaints of symptoms, and the final decision was made through consensus. The demographics and clinical characteristics, including sleep, psychiatric-related scales, and polysomnographic data were reviewed for the study.ResultsOne hundred and sixty patients with RLS were selected, and 23.8% of them reported painful symptoms of RLS. Patients with RLS who experienced painful sensations were found to have lower ferritin levels, more severe RLS symptoms, anxiety and depressive symptoms, and a lower quality of life. The polysomnography data found that patients with RLS who experienced painful sensations had a longer latency to sleep onset and a lower periodic limb movement index (PLMI) (p <0.05).ConclusionsPatients who experienced painful sensations had more severe RLS symptoms and a trend toward lower PLMI during sleep. According to these results, an inference can be made that painful sensations may be one important point in determining the severity of RLS.     

Is preeclampsia associated with restless legs syndrome?

ObjectiveRestless legs syndrome (RLS) is a common neurologic disorder. Secondary RLS includes pregnancy and iron deficiency. Prevalence of RLS in pregnancy ranges from 11% to 27%. We aimed to assess the frequency and characteristics of RLS in pregnancy in a Peruvian population and to evaluate the possible pregnancy or delivery complications due to RLS.MethodsWe assessed 218 consecutive expectant mothers at the inpatient clinic of the Hospital San Bartolome in Lima, Peru. Assessment was performed by using the standard diagnostic criteria for RLS and by using a clinical and diagnostic interview. Questionnaires for RLS severity, idiopathic RLS (IRLS), and excessive daytime sleepiness (EDS) according to the Epworth sleepiness scale (ESS) were used. Blood examination was performed for hemoglobin and hematocrit. For comparison, RLS patients were matched for age and body mass index (BMI) with pregnant women without RLS.ResultsOut of 218 patients, 40 (18.4%) fulfilled diagnostic criteria for RLS. In RLS patients, prophylactic iron supplementation therapy during pregnancy was less frequently taken (P = .02). Pregnant women with RLS had a higher ESS score than pregnant controls (10.6 +/− 3.1 vs 7.6. +/− 3.6; P < .001). Preeclampsia was more frequent in RLS (7/40 vs 1/39; P = .03).ConclusionsIn our study, RLS was frequent in pregnant Peruvian women, especially in those without prophylactic iron supplementation. RLS patients described more EDS. Preeclampsia was more common in RLS. Our study is the first study to indicate a possible association between RLS and preeclampsia.     

Celiac disease as a possible cause for low serum ferritin in patients with restless legs syndrome

ObjectiveTo describe celiac disease (CD) as a possible cause for low serum ferritin in patients with restless legs syndrome (RLS).BackgroundLow iron stores have been found to be a risk factor for RLS with serum ferritin levels less than 45–50 ng/mL associated with increased severity of RLS. It has become routine clinical practice to test serum ferritin in the initial assessment of RLS. CD is a common genetic disorder that can cause iron deficiency.MethodsConsecutive case series of four patients with RLS and serum ferritin below 25 ng/mL, who had positive screening tests for celiac disease.ResultsWe report four patients who had serum ferritin <12 ng/mL and positive screening tests for CD. All had CD confirmed by duodenal biopsy and response to a gluten-free diet. RLS symptoms improved in all four, with two able to discontinue RLS medication and two responding without medication.ConclusionsIn patients with RLS and low serum ferritin who do not have an obvious cause for iron deficiency, we suggest looking for CD by simple, inexpensive serologic testing. Diagnosis and treatment of CD is likely to improve the outcome for RLS, as well as identify individuals who are at risk for the significant long-term complications of CD.     

Exploring the relationship between Parkinson disease and restless legs syndrome

BACKGROUND: Restless legs syndrome (RLS) and Parkinson disease (PD) are common neurological conditions that respond to dopaminergic therapy. To our knowledge, the relationship between the two has not been thoroughly explored. METHODS: We consecutively queried 303 patients with PD seen in our clinic for the presence of RLS symptoms, and evaluated their condition with the Epworth Sleepiness Scale and other demographic and sleep measures. We then looked for predictors of RLS in these patients with PD. We also compared a larger group of patients with PD/RLS with a group of patients with RLS alone. RESULTS: Of 303 patients with PD, 63 (20.8%) had symptoms of RLS. Neither PD patient demographics nor PD treatments could reliably predict the development of RLS symptoms; however, lower serum ferritin levels were associated with RLS symptoms in our patients with PD (P =.01). In 54 (68%) of the 79 total patients with PD/RLS (including additional patients with PD/RLS seen in the clinic) with reliable age-at-onset data, the PD symptoms preceded the RLS symptoms (chi(2) test, P<.001). Compared with patients with idiopathic RLS (N = 146), patients with PD/RLS (N = 109) were older at RLS onset (P<.001), were less likely to have a family history of RLS (P<.001), and had lower serum ferritin levels (P =.01). CONCLUSIONS: Symptoms of RLS are common in patients with PD; however, except in patients with a family history of RLS, they seem to reflect a secondary phenomenon, perhaps in relation with lower ferritin levels. There is no evidence that RLS symptoms early in life predispose to the subsequent development of PD.     

Development of restless legs syndrome after dopaminergic treatment in a patient with periodic leg movements in sleep

Periodic leg movements in sleep (PLMS) unrelated to restless legs syndrome (RLS) are a polysomnographic finding with a controversial clinical value. We describe a patient with isolated periodic leg movements in sleep (without any awake or sleep complaints), who developed severe diurnal RLS symptoms a few months after starting dopaminergic treatment, a phenomenon mimicking augmentation. The diurnal RLS symptoms disappeared after withdrawal of the dopaminergic drugs. Serum ferritin levels were relatively low (31-61 mcg/l; normal: 30-400 mcg/l). Since low levels of ferritin have been implicated in the genesis of RLS, and augmentation is a phenomenon associated with RLS, our findings here suggest that asymptomatic PLMS may have pathogenic mechanisms similar to RLS. Isolated PLMS and RLS could be, at least in some cases, different clinical forms of the same disorder. The conjunction of dopaminergic treatment with low ferritin levels may expose a patient with isolated PLMS to the development of RLS. Discontinuation of dopaminergic drugs in patients with isolated PLMS who develop RLS during the course of the treatment would be a reasonable recommendation.