Leg movements during wakefulness in restless legs syndrome: Time structure and relationships with periodic leg movements during sleep
ABSTRACT Approximately one third of patients with restless legs syndrome (RLS) also show periodic leg movements (PLM) during relaxed wake fulness (PLMW). In contrast with the large amount of data published on periodic leg movements during sleep (PLMS), PLMW have received less attention from the scientific community. The objective of this study was to evaluate the correlations/differences of time-structure and response to a dopamine-agonist between PLMW and PLMS in patients with RLS.
Ninety idiopathic RLS patients and 28 controls were recruited. Subjects underwent clinical and neurophysiological evaluation, hematological screening, and one or two consecutive full-night polysomnographic studies. A subset of patients received 0.25mg of pramipexole or placebo before the second recording. Polysomnographic recordings were scored and LM activity was analyzed during sleep and during the epochs of wakefulness occurring during the first recording hour.
RLS patients had higher LM activity during wakefulness than controls, but with a similar periodicity. Even if correlated, the ability of the PLMW index to predict the PLMS index decreased with increasing LM activity. Intermovement intervals during wakefulness showed one peak only at approximately 4s, gradually decreasing with increasing interval in both patients and controls. The effect of pramipexole was very limited and involved the small periodic portion of LM activity during wakefulness.
PLMW index and PLMS index were correlated; however, the magnitude of this correlation was not sufficient to suggest that PLMW can be good predictors of PLMS. Short-interval LM activity during wakefulness and sleep might be linked to the severity of sleep disruption in RLS patients and the differences between their features obtained during wakefulness or sleep might be relevant for the diagnosis of sleep disturbances in RLS.
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ABSTRACT: Background In 2003, following a workshop at the National Institutes of Health, the International Restless Legs Syndrome Study Group (IRLSSG) developed updated diagnostic criteria for restless legs syndrome/Willis–Ekbom disease (RLS/WED). These criteria were integral to major advances in research, notably in epidemiology, biology, and treatment of RLS/WED. However, extensive review of accumulating literature based on the 2003 NIH/IRLSSG criteria led to efforts to improve the diagnostic criteria further. Methods The Clinical Standards Workshop, sponsored by the WED Foundation and IRLSSG in 2008, started a four-year process for updating the diagnostic criteria. That process included a rigorous review of research advances and input from clinical experts across multiple disciplines. After broad consensus was attained, the criteria were formally approved by the IRLSSG executive committee and membership. Results Major changes are: (i) addition of a fifth essential criterion, differential diagnosis, to improve specificity by requiring that RLS/WED symptoms not be confused with similar symptoms from other conditions; (ii) addition of a specifier to delineate clinically significant RLS/WED; (iii) addition of course specifiers to classify RLS/WED as chronic–persistent or intermittent; and (iv) merging of the pediatric with the adult diagnostic criteria. Also discussed are supportive features and clinical aspects that are important in the diagnostic evaluation. Conclusions The IRLSSG consensus criteria for RLS/WED represent an international, interdisciplinary, and collaborative effort intended to improve clinical practice and promote further research.Sleep Medicine 08/2014; 15(8). DOI:10.1016/j.sleep.2014.03.025 · 3.10 Impact Factor
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ABSTRACT: Objectives To evaluate the specific time structure of periodic leg movements during sleep (PLMS) in untreated Parkinson disease (PD) patients by means of an advanced analysis; and to evaluate the effects of treatment on this activity, in a cross-sectional comparison and in a prospective follow-up study, in a subgroup of previously untreated patients. Methods Forty-four consecutive PD patients were enrolled in the study; 19 had not yet started any drug therapy for PD (PDnother); 10 out of these patients were re-evaluated after an average time lag of 19.6 months from baseline. The remaining 25 patients (PDther) were taking l-dopa and/or dopamine agonists. Eighteen age-matched normal controls were also included. All subjects underwent a polysomnographic recording and the time structure of their sleep leg movement activity was analyzed by means of the periodicity index and other advanced measures. Results Both PD groups tended to show increased PLMS and decreased isolated limb movement activity with respect to controls. PLMS index >15/h was found in 26.3% of PDnother patients, 24.0% of PDther subjects, and in 16.7% of controls; none of the three PDnother patients who had PLMS index >15/h at baseline sustained this level at follow-up, nor did the other seven patients. The intermovement interval distribution showed a clear peak at 10–40 s in the PDnother group; a suppression of this peak was observed after the introduction of dopaminergic treatment in the subgroup of 10 PDnother patients. Both groups of PD patients showed a progressively decreasing number of PLMS through the night; an almost complete abolition of PLMS was seen in the first 2 h of sleep after the introduction of dopaminergic drug therapy. Conclusion Our data do not seem to support the hypothesis that PLMS are particularly frequent in PD but seem to indicate an interaction between PD pathophysiology and genetic predisposition for PLMS, producing a slightly increased number of patients with this sleep motor phenomenon, when compared to controls.Sleep Medicine 07/2014; 15(7). DOI:10.1016/j.sleep.2014.03.011 · 3.10 Impact Factor
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ABSTRACT: Study Objectives: To validate the Multiple Suggested Immobilization Test (m-SIT), a symptom-provocation test measuring restless legs syndrome (RLS) severity multiple times a day while the patient is awake and resting under controlled conditions. The m-SIT was designed to overcome some limitations in measuring RLS severity with rating scales. Design: Patients completed two m-SITs on 2 consecutive days while on 24-h dopaminergic medication. After treatment discontinuation, they completed one more m-SIT 3 days later. Controls performed only one m-SIT. Setting: Sleep laboratory. Participants: Nineteen patients with RLS and 10 healthy controls. Interventions: The original m-SIT consisted of seven modified 60-min SITs performed every 2 h between noon and midnight. During each SIT, the subject reclined quietly but could move his or her legs without restriction to alleviate symptoms. Every 10 min, periodic leg movements during wakefulness (PLMW) were evaluated and the m-SIT Disturbance Scale (m-SIT-DS; range 0-10) was completed. Measurements and Results: The m-SIT, composed of 6: 00PM, 8:00PM, 10:00PM, and 12:00PM SITs, discriminated patients from controls (mean m-SIT-DS: 2.68 +/- 2.35 versus 0.08 +/- 0.26; mean PLMW/h, P = 0.0001) and between treatment groups (on medication versus taken off medication; mean m-SIT-DS, P = 0.0001; mean PLMW/h, P < 0.01). It proved reliable on retest and covariated well with the International Restless Legs Scale (IRLS) and scales measuring daytime symptoms (Spearman rho > 0.4). Conclusions: The m-SIT is a valid and reliable test to evaluate RLS severity and treatment response, and could be useful in the future to confirm diagnosis and identify daytime symptoms. Although it was primarily designed for clinical trials, it might be useful in clinical settings because it provides a standardized testing condition to measure RLS symptoms.Sleep 07/2013; 36(7):1101-1109. DOI:10.5665/sleep.2820 · 5.06 Impact Factor