Restless Legs Syndrome: Known Knowns and Known Unknowns (original) (raw)
Related papers
2012
Restless leg syndrome as a condition characterized by uncomfortable and unpleasant sensation in the legs, with an urge to move impairs the sleep and may so negatively affect quality of life and individual functioning of the sufferers. During the night and while asleep, restless legs syndrome which is now turned into periodic limb movements (PLM) can be more frequently seen. This condition is frequently under-diagnosed. They movements may range from a barely visible small extension of the foot or big toe, to classical periodic limb movement with knee and hip bending, to periodic limb movement involving the arms and/or the trunk and so the whole body. In the face-down position, a pelvic component of muscle contractions is sometimes notable in periodic limb movement. PLM can also be smoother or jerkier. A different and very specific situation is the augmentation of restless leg syndrome. Here, the urge to move sometimes becomes overwhelming and very intense or almost violent movements can be observed, often involving the whole trunk with rocking movements. In addition, PLM during the day and night time are present. When observing with a trained eye, there are many opportunities to observe PLM in the public spaces, e.g. in waiting lounges at airports and concert halls. There is a clear division between voluntary and involuntary movements in RLS which can be reported by patients and further evaluated by expert physicians. Today we have a remarkable amount of data coming from the evidence-based medical practice and research with regard to diagnosis, genetics and treatment of RLS. This will be the focus for the present short review.
Restless Legs Syndrome: Current Concepts about Disease Pathophysiology
Tremor and other hyperkinetic movements (New York, N.Y.), 2016
In the past few decades, much has been learned about the pathophysiology of restless legs syndrome (RLS). Investigators have studied neuropathology, imaging, electrophysiology, and genetics of RLS, identifying brain regions and biological systems affected in RLS. This manuscript will review RLS pathophysiology literature, examining the RLS state through consideration of the neuroanatomy, then the biological, organ, and genetic systems. Pubmed (1966 to April 2016) was searched for the term "restless legs syndrome" cross-referenced with "pathophysiology," "pathogenesis," "pathology," or "imaging." English language papers were reviewed. Studies that focused on RLS in relation to another disease were not reviewed. Although there are no gross structural brain abnormalities in RLS, widespread brain areas are activated, including the pre- and post-central gyri, cingulate cortex, thalamus, and cerebellum. Pathologically, the most consistent ...
Dissociation of periodic leg movements from arousals in restless legs syndrome
Annals of Neurology, 2012
The purpose of this study was to characterize the nature of the relation between periodic leg movements during sleep (PLMS) and cortical arousals to contribute to the debate on the clinical significance and treatment of PLMS. Methods: A prospective, placebo-controlled, single-blind, parallel group study was carried out including 46 drugnaive patients with idiopathic restless legs syndrome (RLS). Each patient underwent 2 consecutive full-night polysomnographic studies. The first night was the baseline night. Prior to the second night, 1 group received a single oral dose of 0.25mg pramipexole, whereas a second group received a single oral dose of 0.5mg clonazepam, and the remaining patients received placebo. Sleep stages, cyclic alternating pattern (CAP), and leg movement activity were scored following standard criteria; symptoms of RLS were also assessed. Results: Pramipexole suppressed PLMS without affecting electroencephalographic (EEG) instability (CAP) and arousals (corresponding to CAP A3 and, partially, A2 subtypes), whereas clonazepam did the opposite, reducing non-rapid eye movement sleep EEG instability without effects on PLMS. Both drugs were effective on sensory RLS symptoms. Interpretation: This study demonstrates that a selective pharmacological approach can disconnect PLMS from arousal events, suggesting an indirect relation between each other. These results might weaken the hypothesis of a direct pathological role of PLMS in sleep disruption and can be important for the discussion on the existence of a distinct entity called periodic limb movements disorder. Moreover, the study opens the doors to the possibility of a joint treatment for RLS targeting sensory and motor symptoms, as well as sleep instability.
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...
Epidemiology and clinical findings of restless legs syndrome
Sleep Medicine, 2004
Restless legs syndrome (RLS) is a sensory-motor disorder characterized by discomfort of and urge to move the legs, primarily during rest or inactivity, partial or total relief with movement, with presence or worsening exclusively in the evening. It is a relatively common but frequently unrecognized disorder, with a prevalence ranging from 2.5 to 15% of the general population, increasing with age and with a female preponderance. The diagnosis is clinical but polysomnography is useful to determine its profound impact on sleep (difficulties in sleep onset, maintaining sleep during the night, and sleep fragmentation) and for the evidence of periodic legs movements during sleep and wake. RLS is generally idiopathic, with familial association in 40 -60% of the cases, but may also be symptomatic of such associated conditions (secondary forms) as peripheral neuropathies, uremia, iron deficiency (with or without anemia), diabetes, Parkinson's disease and pregnancy. Response to dopaminergic drugs indicates that dopamine receptors are implicated, and although much progress has been made in diagnosis and treatment in the last decade, more is needed for complete elucidation of the etiology and pathophysiology of RLS. q
Toward a better definition of the restless legs syndrome
Movement Disorders, 1995
A large International Restless Legs Syndrome (RLS) Study Group has been formed. As its first task, the group has taken upon itself the role of definig the clinical features of the RLS. As minimal criteria for diagnosis, the group proposes the following four features: (a) desire to move the extremities, often associated with paresthesias/dysesthesias; (b) motor restlessness; (c) worsening of symptoms at rest with at least temporary relief by activity, and (d) worsening of symptoms in the evening or night. Other features commonly seen in RLS include sleep disturbance, periodic limb movements in sleep and similar involuntary movements while awake, a normal neurological examination in the idiopathic from, a tendency for the symptoms to be worse in middle to older age, and, in some cases, a family history suggestive of an autosomal dominant mode of inheritance.
Circadian rhythm of periodic limb movements and sensory symptoms of restless legs syndrome
Movement Disorders, 1999
The symptoms of restless legs syndrome (RLS) worsen while patients are sitting or lying and also worsen at night. The current study was designed to determine if the periodic limb movements (PLMs) and sensory symptoms of RLS are modulated by an independent circadian factor. We recorded sleeping and waking PLMs and waking sensory symptoms in eight volunteers with RLS for 3 successive nights and days, starting with a polysomnographic recording of 2 nights, followed by a third night of sleep deprivation and the day after sleep deprivation. This study showed that both the PLMs and sensory symptoms were worst at night with a maximum for both between midnight and 1:00 AM and a minimum between 9:00 and 11:00 AM. Sleep and drowsiness had a tendency to worsen PLMs and sensory symptoms after the night of sleep deprivation. Circadian temperature curves were normal in all four patients with adequate data collection. The highest PLM counts occurred on the falling phase of the circadian temperature curve whereas the lowest PLM counts occurred on the rising phase of the curve. We conclude that the PLM and sensory symptoms in RLS are influenced by a circadian rhythm, and that the ''worsening at night'' criterion of the RLS Definition Criteria is, at least in part, distinct from the ''worsening while lying or sitting'' criterion. Key Words: Restless legs syndrome (RLS)-Circadian rhythm-Periodic limb movements (PLM)-Sleep disorders.
Pathophysiological concepts of restless legs syndrome
Movement Disorders, 2007
Pathophysiological concepts of restless legs syndrome (RLS) are based mainly on neuroimaging and on neurophysiological data. Furthermore treatment effects contribute essentially to the present understanding of the disease, unless the genetic progress expected in the near future will clarify substantially open issues. The concept agreed on assumes a dysfunction of the dopaminergic system, possibly on the level of striatal and/or spinal dopamine receptors, and the A11 neuron group localized in the hypothalamus as an integrated part of the system. These neurons modulate spinal excitability, alterations of which in turn affect sensory processing predominantly of leg afferents in brain stem structures. Neurophysiologically excitability alterations can be measured by a variety of methods such as determination of pain thresholds, H-reflex testing, and quantitative sensory testing.
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/...