Number Of Periodic Limb Movements Research Articles

Periodic limb movements in patients with suspected obstructive sleep apnea without comorbid conditions.

Periodic limb movement disorder (PLMD) and obstructive sleep apnea (OSA) are overlapping clinical syndromes with common risk factors. However, current literature has failed to establish a clear pathophysiological link between them. Thus, little is known about periodic limb movements (PLM) in otherwise healthy patients with suspected OSA. We performed a retrospective analysis of 112 patients (age: 44.5 ± 12.0 years, 14.3% female) with suspected OSA who underwent full night polysomnography for the first time. Patients with chronic diseases of any kind, recent infections, malignancies, or daily or regular use of any type of medication were excluded. Group comparisons were made based on the severity of OSA (using the apnea hypopnea index, AHI) or the periodic limb movement index (PLMI). Both, PLMI and the total number of periodic limb movements during sleep (PLMS), showed a significant increase in patients with severe OSA. In addition, AHI and apnea index (AI) were significantly higher in patients with PLMI >15/h, with a similar trend for hypopnea index (HI) (p < 0.001, p < 0.001, and p > 0.05, respectively). PLMI was significantly positive correlated with AHI, AI, and HI (r = 0.392, p < 0.001; r = 0.361, p < 0.001; and r = 0.212, p < 0.05, respectively). Patients with PLMI >15/h were significantly older (p < 0.001). There was no significant association between body mass index (BMI) and PLMI >15/h. We found a significant association between the severity of OSA and PLM in our study population with suspected OSA but without other comorbidities. PLMI and PLMS were significantly increased in patients with severe OSA. Future prospective studies with larger collectives should verify the presented results and should include mechanistic aspects in their evaluation.

Patients with a Higher Number of Periodic Limb Movements Have Higher Nocturnal Blood Pressure.

There is growing evidence that periodic limb movements in sleep (PLMS) may lead to increased blood pressure (BP) values during the night. The aim of this study was to assess if patients with disordered sleep and an increased number of PLMS have higher BP values at night. We analyzed 100 polysomnographic (PSG) recordings of patients with disordered sleep, with the exclusion of sleep-related breathing disorders. Patients also registered beat-to-beat blood pressure during PSG. We compared the BP of patients with an increased number of PLMS (more than 5 PLMS per hour of sleep) during the night (examined group, n = 50) to the BP of patients with a PLMS number within the normal range (up to 5 PLMS per hour of sleep) (control group, n = 50). Patients from the examined group had significantly higher values of systolic BP during the night (119.7 mmHg vs. 113.3 mmHg, p = 0.04), sleep (119.0 mmHg vs. 113.3 mmHg, p = 0.04), and wake (122.5 mmHg vs. 117.2 mmHg, p = 0.04) periods and of diastolic BP during the night (75.5 mmHg vs. 70.6 mmHg, p = 0.04) and wake (77.6 mmHg vs. 71.5 mmHg, p = 0.01) periods. Our results suggest a relationship between the number of PLMS during the night and the values of nocturnal blood pressure. It is possible that their treatment could lower nocturnal BP in patients with sleep disorders, therefore improving their vascular risk profile.

Striatal Dopaminergic Deficit and Sleep in Idiopathic Rapid Eye Movement Behaviour Disorder: An Explorative Study.

IntroductionIdiopathic rapid eye movement (REM) sleep behavior disorder (iRBD) is increasingly recognised as an important precursor disease state of alpha-synucleinopathies. This parasomnia is characterized by a history of recurrent nocturnal dream enactment behaviour, loss of skeletal muscle atonia, and increased phasic muscle activity during REM sleep. Neuroimaging studies of striatal dopamine transporter uptake tracer signaling suggest increasing dopaminergic deficit across the continuum of the alpha-synucleinopathies, with early sleep dysfunction suggestive of early caudate dysfunction. Henceforth, we set out to investigate the relationship between early sleep changes and the striatal dopaminergic availability in iRBD.MethodsTwelve patients with iRBD, who had undergone a video polysomnography and a neuroimaging assessment of striatal dopamine transporter (DaT) uptake tracer signaling, and 22 matched controls who had similarly undergone a video polysomnography were retrospectively identified. Data were statistically analyzed to identify altered sleep parameters and correlate them with striatal dopamine transporter uptake tracer signaling.ResultsThe iRBD patients exhibited an increased number of periodic limb movements during sleep (P=0.001), compared to 22 age-matched healthy subjects. In addition, several significant links were found between regional DaT-uptakes and sleep architecture. Correlational analyses suggested a strong positive association between sleep fragmentation and dopamine deficiency in left caudate (r=−0.630, P=0.028), whilst an increased uptake in the whole striatum was strongly linked to the sleep efficiency, and to a lesser degree to the length of sleep duration.DiscussionTo the best of our knowledge, this is the first demonstration of a close relationship between dopaminergic availability in striatum and the quality of sleep in iRBD. Taken together, our exploratory findings suggest that subtle but functionally significant striatal changes in early stages of iRBD may contribute to the further shaping of sleep architecture.

Respiratory-Related Leg Movements of Sleep Are Associated With Serotonergic Antidepressants But Not Bupropion.

Respiratory-related leg movements (RRLMs) may contribute to the cardiovascular risk associated with obstructive sleep apnea (OSA). Selective serotonin reuptake inhibitors (SSRIs), but not bupropion, increase periodic leg movements in sleep. This study examines whether patients with OSA using SSRIs have more RRLMs than those taking bupropion or no antidepressant. Patients with an apnea-hypopnea index (AHI) of at least 10 events/h during a full-night diagnostic study or split-night study, who were taking bupropion (n = 32), an SSRI (n = 31), or no antidepressant (n = 31), were selected from a database of prestudy questionnaires. RRLMs were scored according to World Association of Sleep Medicine 2016 standards. Patients using SSRIs had significantly greater overall RRLM% (defined as the percentage of respiratory events associated with a leg movement, including apneas, hypopneas, and respiratory effort-related arousals), RRLM index, and periodic limb movement index relative to patients using bupropion and control patients. The difference between the RRLM% in the SSRI and bupropion groups was limited to patients undergoing split-night studies, and that of the SSRI and control groups was limited to patients undergoing full-night diagnostic studies. The greater number of RRLMs and PLMs in the SSRI group may contribute to treatment-emergent insomnia often seen with SSRI use. Fragmented sleep and elevated autonomic nervous system activation associated with increased RRLMs in patients with OSA taking SSRIs might also limit the tolerability of antidepressant treatment, as well as increase the risk for cardiovascular disease.

Higher nocturnal systolic blood pressure in patients with restless legs syndrome compared with patients with insomnia

BackgroundThere is evidence linking restless legs syndrome (RLS) with increased blood pressure (BP), but the mechanism of this relation remains unclear. Is the BP increased due to some features of RLS or to deterioration of sleep caused by RLS? This study compared values of nocturnal BP in patients with RLS and patients with insomnia. If increased BP in RLS is a consequence of disordered sleep, then it should be similar to increased BP in insomnia. MethodsPolysomnographic recordings of patients admitted to a sleep center with RLS or insomnia were analyzed. Demographic and clinical data, objective sleep parameters, and nocturnal BP were compared. ResultsRecordings of 35 patients with RLS and 33 patients with insomnia were analyzed. The groups did not significantly differ in terms of demographic traits or prevalence of other comorbidities. Patients with RLS had significantly higher systolic BP during the night (122.4 ± 13.8 vs 116.3 ± 13.4; p = 0.03) and during sleep (121.4 ± 13.3 vs 115.7 ± 13.3; p = 0.04). The only significant difference in sleep architecture was an increased number of periodic limb movements in sleep (PLMS) and PLMS with arousal in the RLS group (25.5 ± 24.6 vs 13.9 ± 22.7; p = 0.02 and 4.7 ± 5.4 vs 2.1 ± 3.4; p = 0.01). ConclusionOur results suggest that patients with RLS have higher nocturnal BP than patients with insomnia, and that increased PLMS is related to the increase in BP.

Possible effect of periodic limb movements during sleep on the sleepiness of patients with sleep disordered breathing

We aimed to conduct a cross-sectional study in order to investigate the effect of periodic limb movements during sleep (PLMS) on daytime sleepiness in patients with sleep disordered breathing especially those with obstructive sleep apnea syndrome (OSAS), diagnosed by polysomnography (PSG). Our subjects included 233 male patients who visited our institute during the 25-month period between June 2012 and June 2013. We scored the number of Periodic Limb Movements per hour as the Periodic Limb Movements Index (PLMI) on standard PSG, and considered that periodic limb movements during sleep was present in the patients with PLMI >15/h. Non-PLMS group included those patients with PLMI ≤15/h. To assess the sleepiness of participants, we used Japanese version of the Epworth Sleepiness Scale (JESS) and Japanese version of the Pittsburgh Sleep Quality Index. We compared the sleep parameters and sleepiness indicators between patients with PLMS and age, apnea–hypopnea index (AHI), and body mass index-matched non-PLMS control groups. JESS scores were higher in patients with PLMS than in non-PLMS in both low AHI (<15/h) and high AHI (≥15/h) strata. However, the difference was statistically significant only in high AHI stratum (P = 0.399 and 0.001, respectively). In conclusion, PLMS was associated with increased JESS especially in patients with moderate-to-severe OSAS. Although the magnitude of the difference in those with AHI <15/h was smaller and statistically insignificant in the present study, this issue warrants further investigation by enrolling more patients with AHI <15/h.

The high frequency of periodic limb movements in patients with Lewy body dementia

BackgroundAlthough dementia with Lewy bodies (DLB) is the second most common form of neurodegenerative dementia after Alzheimer's disease (AD), the clinical diagnosis is frequently difficult. Because both REM sleep behavior disorders and Parkinson's disease also have alpha-synucleinopathy similar to DLB, and show an increase in periodic limb movements (PLM), we evaluated the association between DLB and PLM, which may serve as an additional information to differentiate AD and DLB. MethodsOvernight polysomnographic recordings were performed for the inpatients in our hospital who were suspected to have dementia. The quality of sleep, oxygen-desaturation index and periodic limb movements were compared among the patients clinically diagnosed with DLB, AD or as having no dementia. ResultsNine DLB patients, twelve AD patients and ten non-demented patients were enrolled in the study. The number of PLM during sleep per hour of total sleep time (PLMS index) was significantly higher in the DLB patients than the AD patients or the non-demented patients. No significant differences were found between the AD patients and the non-demented patients. To differentiate DLB from AD, a PLMS index of more than 15.0 had a sensitivity of 88.9% and a specificity of 83.3%. ConclusionsThe DLB patients exhibited a higher PLMS index than the AD patients, and this index could be clinically useful for the diagnostic differentiation of DLB from AD.

Assessment of sleep parameters during contingent electrical stimulation in subjects with jaw muscle activity during sleep: a polysomnographic study

There is emerging evidence that feedback techniques based on contingent electrical stimulation (CES) have an inhibitory effect on the electromyogram (EMG) activity of jaw-closing muscles and therefore could be useful in the management of sleep bruxism. This polysomnographic (PSG) study was designed to investigate the effect of CES on PSG parameters in subjects with self-reported bruxism. Fourteen subjects underwent a full PSG investigation in the laboratory for three consecutive nights - one night of adaptation, one night without CES, and one night with CES - in a randomized order. During all sessions the EMG activity was recorded by a portable feedback device from the temporalis muscle. An electrical pulse, which was adjusted to a moderate, but non-painful, intensity, was applied to subjects during the session with CES, if jaw-muscle activity was detected. The total sleep time, the number of micro-arousals per hour of sleep, the time spent in sleep stages 3 and 4 and in rapid eye movement (REM) sleep, and the number of periodic limb movements, were not influenced by CES. The number of EMG episodes per hour of sleep during the nights with and without CES was not significantly different. The present study suggests that CES at non-painful intensities does not cause major arousal responses in any of the sleep parameters assessed in this study.

Polysomnographic Findings are Associated with Cephalometric Measurements in Mouth-Breathing Children

Children with adenotonsillar hypertrophy and those with an abnormal craniofacial morphology are predisposed to having sleep disordered breathing; many of these children are mouth breathers. The aim of this study was to determine whether an association exists between polysomnographic findings and cephalometric measures in mouth-breathing children. Twenty-seven children (15 mouth-breathing children and 12 nose-breathing children [control subjects]), aged 7 to 14 years, took part in the study. Polysomnographic variables included sleep efficiency, sleep latency, apnea-hypopnea index, oxygen saturation, arousal index, number of periodic limb movements in sleep, and snoring. Cephalometric measures included maxilla and mandible position, occlusal and mandibular plane inclination, incisor position, pharyngeal airway space width, and hyoid bone position. As compared with nose-breathing children, mouth breathers were more likely to snore (p < 0.001) and to have an apnea-hypopnea index greater than 1 (p = 0.02). Mouth-breathing children were also more likely to have a retruded mandible, more inclined occlusal and mandibular planes, a smaller airway space, and a smaller superior pharyngeal airway space (p < 0.01). The apnea-hypopnea index increased as the posterior airway space decreased (p = 0.05). Our study showed an association between polysomnographic data and cephalometric measures in mouth-breathing children. Snoring was the most important variable associated with abnormal craniofacial morphology. Orthodontists should send any mouth-breathing child for an evaluation of sleep if they find that the child has a small superior pharyngeal airway space or an increased ANB (the relationship between the maxilla and mandible), NS.PIO (occlusal plane inclination in relationship to the skull base), or NS.GoGn (the mandibular plane inclination in relation to the skull base), indicating that the child has a steeper mandibular plane.

Parental Symptom Report and Periodic Limb Movements of Sleep in Children

To examine the prevalence of raised periodic limb movements of sleep (PLMS) index in children referred for polysomnography (PSG) and whether parental report of symptoms correlates with objective measurement during PSG. Records of children undergoing PSG from January 2006 to July 2006 were retrospectively reviewed. At their initial sleep clinic visit, parents had been asked whether their child was restless or moved their legs excessively during sleep. Their response to these questions was compared to the child's PLMS index (number of periodic limb movements per hour) during a full PSG. PLMS were scored according to internationally accepted criteria. Data were examined for 101 children (60 male) with mean age 6.5 years (range 1.2 to 17.6 years). Excessive leg movements were reported by parents in 50% and restlessness in 73%. A raised PLMS index (defined as > or = 5 per hour) was noted in 10 cases (prevalence 10%). Asking parents about whether their child kicks their legs excessively in sleep had sensitivity 50%, specificity 51%, positive predictive value (PPV) 10%, negative predictive value (NPV) 90% and positive likelihood ratio (LR+) 1.02 when compared to objective analysis. Asking parents about whether their child is restless in sleep had sensitivity 70%, specificity 26%, PPV 9%, NPV 89% and LR+ 0.95. Asking parents about their child's symptoms is not an accurate predictor of raised PLMS index. We recommend that leg electromyography be used in all pediatric sleep studies to record PLMS.

Some Children with Growing Pains May Actually Have Restless Legs Syndrome

Growing pains may be an important clue to the diagnosis of childhood restless legs syndrome (RLS). However, there are no previous studies to determine whether a subpopulation of children with growing pains meet the diagnostic criteria for RLS. The purpose of this study is to determine if some children with growing pains meet diagnostic criteria for RLS and to compare the polysomnographic characteristics of these children to controls. DESIGN/PARTICIPANTS/MEASUREMENTS: Eleven children from a pediatric neurology clinic with an emphasis on attention-deficit/hyperactivity disorder (ADHD) and with a diagnosis of growing pains were referred. They were interviewed with the parent to determine if their symptoms of growing pains met criteria for definite RLS. Those who met clinical criteria for RLS underwent polysomnography, and the results of their polysomnographic studies were compared to those of a control group (10 children, mean age 9.7 years). Academic medical center. Ten (mean age 10.4 years) of the 11 children with growing pains met clinical criteria for RLS. In 4 of 8 families of these 10 children, 1 parent had RLS. Six of the 10 children had ADHD. There were no differences in the polysomnographic findings between the growing-pain and control groups, and none of the children with RLS had what is considered to be a clinically significant number of periodic limb movements of sleep. There were no differences in the polysomnographic findings between the "growing-pain ADHD" and "growing-pain non-ADHD" subgroups. The growing pains were severe enough for the patients and family to ask for treatment in 4 cases, and carbidopa/levodopa was utilized. Some children diagnosed with growing pains meet diagnostic criteria for RLS, and a family history of RLS is common in these children. In some cases symptoms are severe enough to warrant treatment.

Successful Treatment of the Idiopathic Restless Legs Syndrome in a Randomized Double-Blind Trial of Oxycodone Versus Placebo

In a double-blind randomized crossover trial, oxycodone or placebo was given in divided night-time doses to 11 patients with idiopathic restless legs syndrome (RLS) for 2 weeks prior to appropriate polysomnographic studies. Under double-blinded conditions, patients were asked to do daily ratings of their leg sensations, motor restlessness and daytime alertness on a 1-4 scale for the 2 weeks prior to the polysomnographic studies and for the nights of the polysomnographic studies as well. Leg sensations (p < 0.009), motor restlessness (p < 0.006) and daytime alertness (p < 0.03) were significantly improved on oxycodone as compared to baseline or placebo. Patients were studied polysomnographically under double-blinded conditions for 2 nights in each phase of the protocol. On an average dose of 15.9 mg oxycodone (equivalent to approximately three 5-mg tablets of commercial preparation), there was a statistically significant reduction in the number of periodic limb movements in sleep [(PLMS)/hour sleep (p < 0.004)] and in the number of arousals/hour sleep (p < 0.009) on drugs as compared to baseline or placebo. A statistically significant improvement was also noted in sleep efficiency (p < 0.006) and 10 of the 11 patients preferred oxycodone over placebo. We conclude that oxycodone is an effective treatment for RLS and PLMS.