Variability of periodic leg movements in various sleep disorders: implications for clinical and pathophysiologic studies (original) (raw)

Restless Legs Syndrome and Periodic Leg Movements in Sleep: The Primary Role of Dopaminergic Mechanism

European Neurology, 1991

Restless legs syndrome is a frequent neurological disorder with potentially serious and highly distressing treatment complications. The role and potential implications of periodic leg movements during sleep range from being a genetic risk marker for restless legs syndrome to being a cardiovascular risk factor. The diagnosis of restless legs syndrome in patients with daytime movement disorders is challenging and restless legs syndrome needs to be differentiated from other sleep-related movement disorders. This article provides an update on the diagnosis of restless legs syndrome as an independent disorder and the role of periodic leg movements and reviews the association of restless legs syndrome with Parkinson's disease and other movement disorders. V

Different periodicity and time structure of leg movements during sleep in narcolepsy/cataplexy and restless legs syndrome

Sleep, 2006

To analyze periodic leg movements (PLM) during sleep in patients with narcolepsy and compare the results with those obtained in normal controls and subjects with restless legs syndrome (RLS). We recruited 40 HLA DQB1*0602-positive patients with narcolepsy/cataplexy, 22 with RLS, and 22 controls. The time structure of their polysomnographically recorded LMs was analyzed by means of an approach particularly able to consider their periodicity. Nineteen patients with narcolepsy had a PLM index greater than 15. The distribution of inter-LM intervals was clearly bimodal in RLS and narcoleptics, with 1 peak at 2 to 4 seconds and another at around 22 to 26 seconds; in the range 22 to 40 seconds, patients with RLS had values significantly higher than patients with narcolepsy. All periodicity parameters were significantly lower in the narcolepsy group. Finally, the distribution of the number of PLM per hour of sleep was bell shaped in normal controls and patients with narcolepsy, whereas pati...

Defining the boundaries of the response of sleep leg movements to a single dose of dopamine agonist

Sleep, 2008

To define which leg movements (LM) associated with restless legs syndrome (RLS) respond to dopamine-agonist treatment and verify if they fall within current diagnostic criteria for periodic LM during sleep (PLMS). Single-blind placebo-controlled study. Sleep laboratory. 43 consecutive untreated patients with idiopathic restless legs syndrome. Patients underwent clinical and neurophysiological evaluation, hematological screening, and 2 consecutive full-night polysomnographic studies. Before the second polysomnographic study, all patients were randomized to receive 0.25 mg of pramipexole or placebo. LM parameters such as duration, amplitude, interval, and periodicity were analyzed. Compared to placebo, pramipexole significantly (P < 0.01) reduced PLMS while increasing sleep efficiency. Specifically we observed a significant (P < 0.01) reduction in LM ranging 2-4 s in duration and with intermovement interval of 6-46 s and a significant decrease in the periodicity of motor events....

Different sleep characteristics in restless legs syndrome and periodic limb movement disorder

2003

Objective: Periodic limb movements in sleep (PLMS) may or may not be associated with restless legs syndrome (RLS). The number of PLMS is commonly used to assess the clinical severity and sleep quality of patients with RLS. It is still unclear whether the sleep disorder of periodic limb movement disorder (PLMD) is different from the sleep disorder in RLS. Methods: We compared the polysomnograms (PSGs) of 27 prospectively recruited RLS patients and 26 retrospectively recruited age-and sex-matched PLMD patients without RLS symptoms. Results: The PLM index and the index of arousal-associated PLMS (PLMAI) were significantly higher in PLMD, whereas the index of EEG arousals not associated with any sleep-related event was significantly higher in RLS. In PLMD patients, the PLMI correlated negatively with the percentage of PLMS associated with an arousal, whereas this correlation was positive in RLS patients. Further, RLS patients spent significantly more time in wake-after-sleep onset, had more rapid eye movement sleep (REM) and less sleep stage I. Conclusions: We conclude that the sleep disorder in RLS differs from that in PLMD. Spontaneous, not PLM associated EEG arousals should be included in the assessment of the sleep structure of patients with RLS, particularly in studies concerned with drug-efficacy. q

A Polysomnographic and Cluster Analysis of Periodic Limb Movements in Sleep of Restless Legs Syndrome Patients with Psychiatric Conditions

Psychiatry International, 2021

Only survey studies have linked specific individual psychiatric disorders such as anxiety, depression and schizophrenia to Restless Legs Syndrome (RLS), Periodic Limb Movements in Sleep (PLMS) or both. We therefore aim to polysomnographically characterize sleep in a sample of physician-based, newly diagnosed cases of RLS with various ICD-10 psychiatric diagnoses. Retrospective analysis of data from a convenience sample of psychiatric patients (n = 43) per standard clinical sleep disorder cut-offs was conducted. Next, a cluster analysis was performed on the sleep data, taking into account the psychiatric diagnosis, comorbid non-psychiatric somatic problems and medication. We found that 37.2% of our sample showed clinically significant PLMS ≥ 15 and 76.5% exhibited an apnea hypopnea index (AHI) ≥ 5. Sleep structure was unaltered apart from the PLMS-related parameters. Two clusters were statistically identified: Cluster 1 primarily representing recurrent major depressive issues and Clu...

Leg movements during wakefulness in restless legs syndrome: Time structure and relationships with periodic leg movements during sleep

2012

Background and objective: 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. Methods: 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 0.25 mg 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. Results: 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 4 s, 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. Conclusions: 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.

An Evidence-based Analysis of the Association between Periodic Leg Movements during Sleep and Arousals in Restless Legs Syndrome

Sleep, 2015

To analyze statistically the association between periodic leg movements during sleep (PLMS) and arousals, in order to eventually support or challenge the current scoring rules and to further understand their reciprocal influence. Sleep research center. Twenty untreated consecutive patients with restless legs syndrome (RLS) (13 women and 7 males, mean age 60.9 y). In each recording, we selected all PLMS/ arousal pairs that met the following inclusion criteria: (a) PLMS event that was separated from another PLMS event (preceding or following) by at least 10 s of EMG inactivity; (b) arousal event separated from another arousal event (preceding or following) by at least 10 s of stable EEG baseline activity; (c) PLMS/ arousal pairs were then selected among events identified according to the previous two criteria, when PLMS and arousal were separated (offset-to-onset) by no more than 10 s, regardless of which was first. Measurements and Results: We selected a mean of 46.1 (SD 25.55) PLMS/...

New approaches to the study of periodic leg movements during sleep in restless legs syndrome

Sleep, 2006

To describe a new approach for the analysis of quantity, type, and periodicity of the leg motor activity during sleep in patients with restless legs syndrome (RLS) and periodic leg movements (PLM). The following parameters were taken into account for LM: duration, amplitude, area under the curve, sleep stage, side, interval, and bilaterality. The analysis of inter-LM intervals was carried out by drawing their distribution graphs. A new index evaluated their periodicity and was validated by means of a Markovian analysis. The differences in inter-LM intervals, LM duration, and area under the curve between normal controls and patients and between the 3 patient subgroups identified on the basis of their periodicity were statistically analyzed. N/A. Sixty-five patients with RLS and periodic LM and 22 young healthy controls. The RLS patients' inter-LM interval distribution graph showed a wide peak with a maximum located at around 15 to 30 seconds and extending from 10 to 90 seconds, n...