Correlates of PLMs variability over multiple nights and impact upon RLS diagnosis

ObjectiveNight-to-night variability of periodic leg movements (PLMs) in restless legs syndrome (RLS) was examined to define the range of intra-subject values, impact upon diagnosing RLS, and clinical correlates.MethodsTwenty RLS patients were monitored for 10–15 nights using a validated, tri-axial accelerometer worn on the ankle.ResultsThe mean difference in PLMs index (PLMI) between the lowest and highest night was 25.1/h (range: 3.9–73.8). Inter-subject differences accounted for nearly five times the variance in PLMI relative to between nights within an individual. Based on a single night of recording, PLMI criterion thresholds of 5, 10, and 15/h were exceeded on approximately 70.1%, 51.9% and 34.1% of individual nights among these patients. Based on five randomly sampled nights of recordings, the likelihood that such thresholds were met on at least a single night increased to 91.2%, 80.8% and 62.7%, respectively. Women exhibited greater variability.ConclusionsVariability in PLMs within RLS subjects was substantial, yet individuals’ characteristic PLM level represented a quantitative trait. Variability was unrelated to age or scores on scales of RLS severity, sleepiness, functional status, and mood. A larger number of recording nights increased the likelihood that any criterion was reached.     

Elevated C-reactive protein is associated with severe periodic leg movements of sleep in patients with restless legs syndrome

BackgroundRestless legs syndrome (RLS) is a common sleep disorder in which urges to move the legs are felt during rest, are felt at night, and are improved by leg movement. RLS has been implicated in the development of cardiovascular disease. Periodic leg movements (PLMs) may be a mediator of this relationship. We evaluated systemic inflammation and PLMs in RLS patients to further assess cardiovascular risk.Methods137 RLS patients had PLM measurements taken while unmedicated for RLS. Banked plasma was assayed for high sensitivity C-reactive protein (CRP), interleukin-6 (IL-6), and tumor necrosis factor alpha (TNF-alpha).ResultsMean (SD) PLM index was 19.3 (22.0). PLMs were unrelated to TNF-a and IL-6, but were modestly correlated with log CRP (r(129) = 0.19, p = 0.03). Those patients with at least 45 PLMs/h had an odds ratio of 3.56 (95% CI 1.26–10.03, p = 0.02, df = 1) for having elevated CRP compared to those with fewer than 45 PLMs/h. After adjustment for age, race, gender, diabetes, hypertension, hyperlipidemia, inflammatory disorders, CRP-lowering medications, and body mass index, the OR for those with ?45 PLMs/h was 8.60 (95% CI 1.23 to 60.17, p = 0.03, df = 10).ConclusionsPLMs are associated with increased inflammation, such that those RLS patients with at least 45 PLMs/h had more than triple the odds of elevated CRP than those with fewer PLMs. Further investigation into PLMs and inflammation is warranted.     

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.     

Significant association between systolic and diastolic blood pressure elevations and periodic limb movements in patients with idiopathic restless legs syndrome

ObjectiveA new and unique methodology was developed to evaluate the association between periodic limb movements (PLMs) and nocturnal blood pressure (BP) excursions in patients with restless legs syndrome (RLS).MethodsAll data were collected at baseline of the ENCORE (Effects of Neupro on Cardiovascular Observations in Patients with Restless Legs Syndrome) study, a placebo-controlled polysomnographic study of rotigotine in patients with idiopathic RLS. Continuous beat-by-beat BP and heart rate assessments were performed during a full night of polysomnography. All BP elevations occurring with and without PLMs were systematically identified and analyzed.ResultsPatients (n = 89) had a mean total of 508.9 ± 405.7 PLMs, 788.4 ± 261.9 systolic BP elevations, and 349.7 ± 242.9 diastolic BP elevations during the night. Higher time-adjusted frequencies of systolic BP elevations [mean difference (95% confidence interval, CI): 543.0 (487.2, I); p <0.0001] and diastolic BP elevations (205.8 (169.3, I); p <0.0001) were observed with PLMs than without PLMs. A peak in the frequency of PLM onset coincided with BP elevation onset.ConclusionOur methodology allowed the first evaluation of the total number of nocturnal PLM-associated BP elevations occurring in patients with RLS. Our data clearly indicate an interdependence between BP elevations and PLMs, and they have clinical relevance as BP variability is a potential cardiovascular risk factor.     

Periodic limb movements and restless legs syndrome in children with a history of prematurity

IntroductionLittle is known about the pediatric population at an increased risk of restless legs syndrome (RLS) and periodic limb movement disorder (PLMD). Polysomnographic data from the Caffeine for Apnea of Prematurity–Sleep (CAPS) study showed a high prevalence of elevated periodic limb movement index (PLMI) in a cohort of ex-preterm children, but the clinical importance of this finding, such as association with RLS, is unknown. We hypothesized that ex-preterm children would have a high prevalence of RLS and PLMD.MethodsEx-preterm children enrolled in CAPS, now aged 5–12 years, completed home polysomnography (PSG) and standardized questionnaires. A diagnosis of RLS or PLMD was established by participants meeting the International Classification of Sleep Disorders, 3rd edition, criteria based on questionnaires and polysomnograms. The clinically available serum ferritin levels were assessed.ResultsIn total, 167 participants underwent polysomnography and completed all questionnaires. The overall prevalence of RLS was 14/167 (8.4%). An additional 13 subjects (7.8%) were found to have PLMD. Of the 26 participants who had PLMI > 5/h, seven (26.9%) had RLS and 13 (50%) had PLMD. The serum ferritin levels were <50 mcg/L (range −38.4) for all eight participants referred for testing.ConclusionsChildren with a history of prematurity have a high prevalence of RLS, particularly those with elevated periodic limb movements. Iron deficiency likely contributes to RLS and PLMD symptoms in this population. Clinicians evaluating ex-preterm children with sleep disturbances should evaluate for RLS and PLMD. Further studies including serum ferritin evaluation are required to confirm these findings.     

Periodic limb movements in sleep: to treat or not to treat?

Background: Approximately 50% of our patients with sleep disturbances have periodic limb movements in sleep (PLMS). We have found that a high PLMS index is not correlated with the severity of symptoms on the Epworth Sleepiness Scale or response to pharmacologic therapy for restless legs syndrome (RLS)/PLMS. We hypothesized that differences in rhythm of contraction, predominance of periodic leg movements (PLMs) in different sleep stages, or PLM interval might distinguish responders from nonresponders.Methods: We analyzed the hypnograms of 20 consecutive patients with PLMS, noting the number of PLMs and the PLM intervals in different sleep stages, the PLMS index, and the percentage of PLMs that led to arousals.Results: We distinguished two groups of patients. The 13 patients in group A had a PLM arousal percentage of 10.9±5% (mean±SD), compared with 41.9±9% for the seven patients in group B. Group B had a lower PLMS index. Group A showed little variance in PLM intervals and experienced more delta sleep.Conclusions: PLMS index was not correlated with arousals. A strict rhythm of contractions was associated with fewer arousals and better quality of sleep. This subgroup may not benefit substantially from specific RLS/PLMS therapy.     

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.     

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.     

Rotigotine transdermal patch in moderate to severe idiopathic restless legs syndrome: A randomized,placebo-controlled polysomnographic study

ObjectiveTo assess the efficacy of rotigotine transdermal patch in subjects with moderate to severe idiopathic restless legs syndrome (RLS) and periodic limb movement (PLM) in sleep in a double-blind, randomized, placebo-controlled, multicenter study (NCT00275236).MethodsSixty-seven (46 rotigotine, 21 placebo) subjects applied rotigotine (maximum 3 mg/24 h) or placebo patches once-daily during a 4-week maintenance period; efficacy evaluations used polysomnographic measures and clinician/patient ratings.ResultsMean PLM index (PLMI; PLM/h time in bed) decreased more with rotigotine (50.9/h to 8.1/h) than with placebo (37.4/h to 27.1/h; adjusted treatment ratio 4.25 (95% CI [2.48, 7.28], p < 0.0001). PLM during sleep with arousal index (PLMSAI; 8.57/h to 2.47/h under rotigotine, 6.5/h to 4.95/h under placebo; adjusted treatment difference: ?3.12 (95% CI [?5.36, ?0.88], p = 0.0072) also improved more under rotigotine. At end of maintenance, 39% of rotigotine subjects had PLMI levels <5/h and 26% showed no RLS symptoms (IRLS = 0), whereas no placebo subject met these criteria. Common drug-related adverse events for rotigotine and placebo included nausea (21.7%/4.8%), headache (17.4%/14.3%), application site reactions (17.4%/4.8%), and somnolence (10.9%/9.5%); most were mild to moderate in intensity.ConclusionsRotigotine transdermal patch was efficacious and well tolerated in the short-term treatment of RLS motor symptoms and associated sleep disturbances.     

Polysomnographic findings in restless legs syndrome (RLS) patients with severe augmentation

Background and objectivesAugmentation can occur frequently in restless legs syndrome (RLS) patients treated with dopaminergic agents. Video-polysomnographic (PSG) data from augmented RLS patients are scant. The aim of this study was to evaluate PSG findings in augmented RLS patients and compare them with those of non-augmented RLS patients.Patients and methodsValid PSG data were analyzed from 99 augmented and 84 non-augmented RLS inpatients who underwent one night PSG.ResultsBoth patient groups showed a high subjective burden of RLS symptoms. The mean scores on the International RLS Study Group Rating Scale (IRLS) were significantly higher in the group with augmentation than in the group without. The periodic leg movement index (PLMI) was increased in both groups, mostly on account of the PLM in wakefulness (PLMW). Both groups presented a reduced sleep efficiency and an increased sleep latency. The levodopa equivalent dose (LED) was significantly higher in the augmented group.ConclusionsOur study confirms that RLS patients with augmentation have disturbed sleep due to high amount of leg movements and fragmented sleep. Overall, however, polysomnographic characteristics were not different between insufficiently treated RLS and severely augmented RLS patients, implying that augmentation could represent a severe form of RLS and not a different phenomenon.     

Evidence-based and consensus clinical practice guidelines for the iron treatment of restless legs syndrome/Willis-Ekbom disease in adults and children: an IRLSSG task force report

BackgroundBrain iron deficiency has been implicated in the pathophysiology of RLS, and current RLS treatment guidelines recommend iron treatment when peripheral iron levels are low. In order to assess the evidence on the oral and intravenous (IV) iron treatment of RLS and periodic limb movement disorder (PLMD) in adults and children, the International Restless Legs Syndrome Study Group (IRLSSG) formed a task force to review these studies and provide evidence-based and consensus guidelines for the iron treatment of RLS in adults, and RLS and PLMD in children.MethodsA literature search was performed to identify papers appearing in MEDLINE from its inception to July 2016. The following inclusion criteria were used: human research on the treatment of RLS or periodic limb movements (PLM) with iron, sample size of at least five, and published in English. Two task force members independently evaluated each paper and classified the quality of evidence provided.ResultsA total of 299 papers were identified, of these 31 papers met the inclusion criteria. Four studies in adults were given a Class I rating (one for IV iron sucrose, and three for IV ferric carboxymaltose); only Class IV studies have evaluated iron treatment in children. Ferric carboxymaltose (1000 mg) is effective for treating moderate to severe RLS in those with serum ferritin <300 μg/l and could be used as first-line treatment for RLS in adults. Oral iron (65 mg elemental iron) is possibly effective for treating RLS in those with serum ferritin ≤75 μg/l. There is insufficient evidence to make conclusions on the efficacy of oral iron or IV iron in children.ConclusionsConsensus recommendations based on clinical practice are presented, including when to use oral iron or IV iron, and recommendations on repeated iron treatments. New iron treatment algorithms, based on evidence and consensus opinion have been developed.     

Periodic leg movements in RLS patients as compared to controls: Are there differences beyond the PLM index?

ObjectiveTo characterize periodic leg movements (PLM) and their association with sleep disturbances in drug-free patients with restless legs syndrome (RLS) and healthy subjects without sleep complaints.MethodsPolysomnographic recordings of 95 patients with idiopathic RLS and 31 age-matched controls were compared, and correlation analysis between sleep efficiency and PLM variables was performed. All patients and controls were free of medication for 10 days prior to polysomnography.ResultsPLM measures revealed a significantly longer mean duration of single PLM during wakefulness and non rapid eye movement (NREM) sleep in RLS patients as compared to controls. PLM indices were higher in RLS patients than in controls during all sleep stages, but not during wakefulness and slow wave sleep. A significantly higher number of PLM sequences was found in RLS patients than in controls. In RLS patients decreased sleep efficiency was associated with a higher number and a shorter duration of PLM sequences.ConclusionsThe mean duration of single PLM might be an appropriate parameter to discriminate between healthy subjects with PLM and patients with RLS. High numbers of PLM sequences of short duration might be an indicator for the decreased sleep quality in RLS patients.     

Periodic limb movements in sleep: Prevalence and associated sleepiness in the Wisconsin Sleep Cohort

Objectives

Periodic limb movements in sleep (PLMS) are thought to be prevalent in elderly populations, but their impact on quality of life remains unclear. We examined the prevalence of PLMS, impact of age on prevalence, and association between PLMS and sleepiness.

Periodic leg movements in narcolepsy patients: impact on sleep architecture

INTRODUCTION: We assessed the effect of periodic leg movements (PLMs) on sleep architecture in narcolepsy patients by comparing sleep patterns in narcoleptics of comparable age with and without PLMs. METHODS: Patients diagnosed with narcolepsy between January 1999 and December 2005 were divided into those with PLM index >or= 5/hr and <5/hr. Each patient underwent polysomnographic recording followed by a multiple sleep latency test (MSLT). RESULTS: There were 47 patients, of mean age 28.9 +/- 1.8 years, 31 (66%) with PLM index >or= 5/hr and 16 (34%) with PLM index <5/hr. Arousal index, PLM arousals and total number of arousals were all significantly higher in narcoleptics with PLM index >or= 5/hr than in those with PLM index <5/hr. Significant correlations were found between PLM index and arousal index, stage shifts, Stage 1 and average sleep latency on MSLT. CONCLUSIONS: Our findings demonstrated that narcolepsy patients with PLMs have a higher arousal index and increased PLM arousals compared with narcolepsy patients without PLMs. The contribution of the above to the perceived sleep quality and daytime sleepiness is not clear.     

Circadian rhythm of restless legs syndrome: relationship with biological markers

Recently, it was suggested that the intensity of restless legs syndrome (RLS) symptoms may be modulated by a circadian factor. The objective of this study was to evaluate, during a 28-hour modified constant routine, the nycthemeral or circadian variations in subjective leg discomfort and periodic leg movements (PLMs) and to parallel these changes with those of subjective vigilance, core body temperature, and salivary melatonin. Seven patients with primary RLS and seven healthy subjects matched for sex and age entered this study. Although the symptoms were more severe in patients than in controls, a significant circadian variation in leg discomfort and PLM (p < 0.01) was found for both groups. In both groups, the profiles of leg discomfort and PLM were significantly correlated with those of subjective vigilance, core body temperature, and salivary melatonin. However, among these variables, the changes in melatonin secretion were the only ones that preceded the increase in sensory and motor symptoms in RLS patients. This result and those of others studies showing that melatonin exerts an inhibitory effect on central dopamine secretion suggest that melatonin might be implicated in the worsening of RLS symptoms in the evening and during the night.     

Restless legs syndrome in Friedreich ataxia: A polysomnographic study

Friedreich ataxia (FA) is the most common type of hereditary ataxia. Frataxin deficiency due to a GAA expansion in the first intron of chromosome 9 results in intramitochondrial iron accumulation. On the basis of the patients' complaints about sleep disturbance and pathophysiological considerations, we systematically assessed sleep history and polysomnography in FA. We included 16 consecutive FA patients (11 men, 5 women; mean age, 35.4 ± 11.1 years) with a mean disease duration of 16.5 ± 7.0 years. All patients underwent a standardized protocol including a detailed sleep history and polysomnographic recordings. Eight out of 16 patients were diagnosed with restless legs syndrome (RLS). In seven patients, RLS onset was after the onset of FA. Interestingly, FA patients with RLS had significantly lower serum ferritin levels than FA patients without RLS (76.3 ± 56.0 μg/L vs. 176.3 ± 100.7 μg/L; P = 0.043 after correction for sex and age). Moreover, periodic leg movements in wakefulness (PLMW) indices were significantly higher in FA patients with RLS than FA patients without RLS (FA with RLS, 118.1 ± 50.7; FA without RLS, 65.6 ± 44.2; P = 0.028). There was an inverse correlation between serum ferritin levels and PLMW indices obtained in all FA patients (rho ?0.538, P = 0.039). RLS is common in FA. Its frequency in this primarily spinal ataxia appears consistent with the concept of dysfunctional spinal sensorimotor integration in the pathophysiology of RLS. The finding that RLS is more frequent in the context of lower serum ferritin levels in FA is interesting, but requires further investigation in larger patient samples. © 2009 Movement Disorder Society.     

Periodic leg movements during sleep in children scheduled for adenotonsillectomy: frequency,persistence, and impact

ObjectiveThe aim of this study was to assess the frequency and potential clinical impact of periodic leg movements during sleep (PLMS), with or without arousals, as recorded incidentally from children before and after adenotonsillectomy (AT).MethodsChildren scheduled for AT for any clinical indications who participated in the Washtenaw County Adenotonsillectomy Cohort II were studied at enrollment and again 6 months thereafter. Assessments included laboratory-based polysomnography, a Multiple Sleep Latency Test (MSLT), parent-completed behavioral rating scales, neuropsychological testing, and psychiatric evaluation.ResultsParticipants included 144 children (81 boys) aged 3–12 years. Children generally showed mild to moderate obstructive sleep apnea (median respiratory disturbance index 4.5 (Q1 = 2.0, Q3 = 9.5)) at baseline, and 15 subjects (10%) had at least five periodic leg movements per hour of sleep (PLMI ≥ 5). After surgery, 21 (15%) of n = 137 subjects who had follow-up studies showed PLMI ≥ 5 (p = 0.0067). Improvements were noted after surgery in the respiratory disturbance index; insomnia symptoms; sleepiness symptoms; mean sleep latencies; hyperactive behavior; memory, learning, attention, and executive functioning on NEPSY assessments; and frequency of attention-deficit/hyperactivity disorder (DSM-IV criteria). However, PLMI ≥ 5 failed to show associations with worse morbidity in these domains at baseline or follow-up. New appearance of PLMI ≥ 5 after surgery failed to predict worsening of these morbidities (all p > 0.05), with only one exception (NEPSY) where the magnitude of association was nonetheless negligible. Similar findings emerged for periodic leg movements with arousals (PLMAI ≥ 1).ConclusionPLMS, with and without arousals, become more common after AT in children. However, results in this setting did not suggest substantial clinical impact.     

A prospective study of Willis–Ekbom disease/restless legs syndrome during and after pregnancy

ObjectivesWillis–Ekbom disease/restless legs syndrome (WED/RLS) is the most common sleep-related movement disorder in pregnancy. We designed a prospective longitudinal study to investigate the correlates of WED/RLS during and after pregnancy.DesignA total of 138 pregnant women with WED/RLS and a control group of 251 age-matched pregnant women were enrolled prospectively. A questionnaire was administered during a face-to-face interview at first evaluation during pregnancy and three months after delivery.ResultsAmong all women in the first trimester, 15.6% were diagnosed with WED/RLS, whereas 32.8% of those in the second trimester and 38.8% of those in the third trimester were diagnosed with WED/RLS (p = 0.032). In regression analysis, later gestational age [p < 0.001; odds ratio (OR) 1.054] and previous history of WED/RLS (p = 0.001; OR 2.795) were positively correlated with the presence of WED/RLS, while ferritin levels (p = 0.001; OR 0.956) were negatively correlated with the presence of WED/RLS. Ferritin levels were also negatively correlated with the International RLS Study Group severity index (p = 0.041). Forty-eight patients (34.8%) experienced WED/RLS symptomatology after delivery. The ferritin levels were lower, and the mean number of pregnancies was higher, in women with residual WED/RLS (p = 0.008).ConclusionOur survey showed that WED/RLS was more common in the second and third trimesters. Emergence of WED/RLS during the second trimester was strongly associated with residual WED/RLS. Lower ferritin levels were associated with both WED/RLS in pregnancy and residual WED/RLS after delivery. A higher number of pregnancies were also associated with a greater likelihood of having residual WED/RLS after delivery.     

PLM detection by actigraphy compared to polysomnography: a validation and comparison of two actigraphs

ObjectiveTo compare periodic leg movement (PLM) counts obtained with polysomnography (PSG) to those obtained from actigraphy with two devices (Actiwatch and PAM-RL).MethodsTwenty-four patients underwent full night actigraphy with Actiwatch from both legs and simultaneous PSG. Out of these patients, 10 had additional actigraphy with PAM-RL. Bilateral and unilateral PLM indices (PLMI) for both actigraphs were calculated for time in bed and compared to polysomnographic PLMI. Additionally, a comparison between the two different actigraphs was performed.ResultsPLMI obtained with Actiwatch were significantly lower than those obtained with PSG (21.2 ± 25.6/h versus 34.4 ± 30.7/h; p < 0.001), whereas the PLMI from PAM-RL were significantly higher than in PSG (63.6 ± 39.3/h versus 37.0 ± 33.5/h; p = 0.009). In direct comparison, Actiwatch gave significantly lower PLMI than the PAM-RL (p = 0.005). The correlations between Actiwatch and PSG (rho = 0.835, p < 0.001), PAM-RL and PSG (rho = 0.939, p < 0.001), and Actiwatch and PAM-RL (rho = 0.915, p < 0.001) were significant. Unilateral actigraphy compared to standard PSG gave less consistent findings. When comparing different settings of the PAM-RL, manual threshold setting resulted in PLMI that were no longer different from PSG (p = 0.074), in contrast to the default threshold setting.ConclusionsThe Actiwatch underestimated and the PAM-RL overestimated PLMI compared to PSG. Whereas PLMI obtained with two actigraphs and PSG were highly correlated, they differed in mean values. Therefore, PSG, actigraphy and also the different actigraphs cannot be interchanged in longitudinal studies, and actigraphy should not be used for diagnostic decision making based on PLM indices. The best approximation to PSG PLMI was achieved by using manual threshold setting with the PAM-RL.     

Periodic limb movement in a community population detected by a new actigraphy technique

BACKGROUND: Periodic limb movements (PLMs) have been studied in both community and sleep clinic populations using polysomnography. An alternative detection method is actigraphy. Our aims were to determine the frequency of PLMs, measured by actigraphy in a community sample, and to assess the relationships of PLMs with age, gender, and reported sleep-related symptoms. METHODS: Volunteers had bilateral foot actigraphy (Cambridge Neurotechnology) at home and completed sleep questionnaires. Actigraphy was scored for PLMs per hour in bed (PLMI) and statistical analysis performed to assess possible associations. RESULTS: PLMI (mean of two nights) ranged from 0 to 60.3 and 37% of the sample had a PLMI> or =5. Men had significantly higher PLMIs than females (P=0.003) but PLMI was not correlated with age. There was a modest but significant correlation between subjectively reported restless leg severity and PLMI (r=0.238; P=0.003), but none with reported sleepiness. CONCLUSIONS: This actigraphy technique is a practical and reliable tool for community studies. A large proportion of this community sample, particularly men, had PLMs. PLMI was not correlated with age or Epworth Sleepiness Score.