EEG arousals and awakenings in relation with periodic leg movements during sleep.
It is known that periodic leg movements are frequently accompanied by full awakenings or by signs of EEG arousals. The time relationship of these EEG arousals with leg movements varies from patient to patient. They may precede or follow leg movements or occur simultaneously. It is not clear whether these arousals trigger leg movements or, alternatively, whether both EEG arousals and leg movements are separate expressions of a common pathophysiological mechanism. We investigated the temporal relationship of five EEG arousals, such as alpha activity, K-complexes, spindles, K-alpha, K-spindle activities and awakenings, with leg movements in 10 periodic leg movement patients. These EEG arousals were considered to be associated with leg movements if they occurred 10 s before/after or simultaneously with the onset of right or left tibialis muscle EMG potentials. It was found that 49.19% of EEG arousals occurred before leg movements, 30.61% occurred simultaneously and 23.18% occurred just after leg movements. The number of EEG arousals was significantly higher in the 10 s preceding leg movement than simultaneously or in the 10 s following. Alpha activity was the phenomenon associated most frequently with leg movements, irrespective of its temporal organization and was significantly higher during the 10 s preceding movement. Spindle and K-spindle activities were significantly higher before leg movement, whereas K-complex activity was significantly more frequent during leg movements. The number of awakenings was significantly higher after leg movements than simultaneously. These results indicated that leg movements are not primary, but rather are a phenomenon associated with an underlying arousal disorder. (+info)
Periodic limb movement disorder : a clinical and polysomnographic study.
Periodic limb movement disorder (PLMD) is one of the commonest neurological disorders and causes significant disability, if left untreated. However, it is rarely diagnosed in clinical practice, probably due to lack of awareness and/or lack of necessary diagnostic facilities. Restless leg syndrome (RLS), aging, pregnancy, uraemia, iron deficiency, polyneuropathy are some of the common causes of secondary PLMD. Clinical presentation, polysomnographic findings and management of six patients of PLMD have been discussed in this report. (+info)
Periodic limb movement disorder of sleep in children.
To characterize periodic limb movement disorder (PLMD) in a cohort of prepubertal children we examined sleep-related identifiable differences between children with PLMD and attention-deficit/hyperactivity disorder (ADHD), PLMD alone, and age-matched controls. Children were selected from a chart review of all children referred to a pediatric sleep medicine center and from a community survey of 5-7-year-old-children. Polysomnography (PSG) and parental report data from all children identified as having periodic limb movement index (PLMI) >5 were reviewed and compared with a cohort of age-matched controls. A total of 8.4% of children in the clinic-referred sample, and 11.9% of the children recruited from the community had PLMI >5. Of those, 44.4% were identified as having ADHD. Children with PLMD had significantly lower percentage of rapid eye movement (REM) than control children (P < 0.001). Children in the PLMD/ADHD group had a significantly greater number of arousals associated with PLM (PLMa) than children with PLMD only (P < 0.05). While a relationship between ADHD and PLMD was observed, it was weaker than previous reports (Chervin, R. D. et al. Sleep, 2002; 25: 213; Chervin, R. D. and Archbold, K. H. Sleep, 2001; 24: 313; Picchietti et al. J. Child Neurol., 1999; 13: 588; Picchietti et al. Mov. Disord., 1999; 14: 1000; Picchietti and Walters Sleep, 1999; 22: 297). Children in the PLMD/ADHD group were more likely to have PLMas than were children with PLMD only. We postulate that rather than a direct relationship between ADHD and PLMD, this link may be mediated by the presence of reduced REM sleep and more importantly by the sleep fragmentation associated with PLM-induced arousals. (+info)
Autosomal dominant restless legs syndrome maps on chromosome 14q.
Restless legs syndrome (RLS) is a common neurological disorder characterized by an irresistible desire to move the extremities associated with paraesthesia/dysaesthesia. These symptoms occur predominantly at rest and worsen at night, resulting in nocturnal insomnia and chronic sleep deprivation. In this paper, we show significant evidence of linkage to a new locus for RLS on chromosome 14q13-21 region in a 30-member, three-generation Italian family affected by RLS and periodic leg movements in sleep (PLMS). This is the second RLS locus identified so far and the first consistent with an autosomal dominant inheritance pattern. The new RLS critical region spans 9.1 cM, between markers D14S70 and D14S1068. The maximum two-point log of odds ratio score value, of 3.23 at theta = 0.0, was obtained for marker D14S288. The accurate clinical evaluation of RLS-affected, as well as unaffected, family members allowed for the configuring of RLS as a phenotypic spectrum ranging from PLMS to RLS. Motor component, both while awake and during sleep, was an important aspect of the phenotype in the family analysed. The complementary clinical and genetic studies on multiplex families are likely to be of the utmost importance in unfolding the complete expressivity of RLS phenotype spectrum. (+info)
The effect of cabergoline on sleep, periodic leg movements in sleep, and early morning motor function in patients with Parkinson's disease.
To investigate the effect of the dopamine D2 and D1 receptor agonist cabergoline on sleep, periodic leg movements (PLMs) in sleep, and early morning motor performance in patients with Parkinson's disease (PD). It was hypothesized that cabergoline had long-lasting beneficial effects on sleep and PLMs in sleep in patients with PD, after a single evening intake. A total of 15 patients with idiopathic PD underwent two nights of polysomnography and motor tests (UPDRS, tapping test) before and after 6-8 weeks of treatment with cabergoline (dosage: 3-6 mg/day). Additionally, patients completed a subjective sleep visual analog scale (VAS) before and during cabergoline treatment. Compared to baseline values, treatment with cabergoline did not change sleep efficiency or the amount of stage 1 and stage 2 sleep. The number of awakenings (22.4+/-10.1 vs 32.5+/-13.3, p<0.05) and stage shifts (119+/-42 vs 148+/-46, p<0.05) were increased during treatment with cabergoline, and PLMs in sleep were reduced (PLM index 34.9+/-44.9 vs 6.7+/-4.2 per hour, p<0.05). Cabergoline significantly improved early morning motor function, and in spite of increased phase shifts and awakenings, patients felt significantly more refreshed in the morning during cabergoline therapy. Cabergoline slightly fragmented sleep, without altering its total amount. The functional significance of this finding is uncertain. The subjective quality of sleep improved, and periodic limb movements in sleep decreased. (+info)
Periodic leg movements during sleep in Japanese community-dwelling adults based on the assessments of their bed partners.
BACKGROUND: There is little known about epidemiologic evidence on periodic leg movements during sleep (PLMS) for the Japanese. The present study was a cross-sectional epidemiologic study to estimate the prevalence of PLMS and examine the associated factors of PLMS in Japanese community-dwelling adults. METHODS: The subjects were 884 with bed partners or bedroom mates of 1,889 Japanese adults aged 20 years and over randomly selected from the general population. The case ascertainment of PLMS was based on the assessments of their bed partners or bedroom mates using the Pittsburgh Sleep Quality Index. Multiple logistic regression analyses were used for investigating the associated factors. RESULTS: The age-adjusted prevalences (95% confidence interval) were 5.8% (4.7-6.8%) and 1.3% (0.8-1.9%) for 1 to 2-times, and 3-times or greater of PLMS per week during the preceding month, respectively. Those with PLMS were more likely to experience difficulty in initiating sleep, snore during sleep, be depressed, and suffer from peptic ulcer. Sex, age, difficulty in maintaining sleep, excessive daytime sleepiness, medication use to aid sleep, and any psychoactive substances (tobacco, alcohol, and caffeine) were not identified as significant associated factors of PLMS. CONCLUSIONS: The results suggest that the prevalence of PLMS in Japanese community-dwelling adults is not so high as those reported from Western countries, and that PLMS is correlated with some sleep and health disturbances. (+info)
Activity patterns of leg muscles in periodic limb movement disorder.
The movements of leg muscles in reference to periodic limb movement disorder (PLMD) have only been described in global terms. The sequences of contracting muscles that cause the PLMs are said to be stereotypical. There is, however, doubt about this fixed sequencing in PLMD. Our goal was to define the sequence of muscle movements in PLMs and then analyse their patterns. We recorded with surface EMG all movements of the muscles said to be involved in PLMs (extensor digitorum brevis, EDB; tibialis anterior, TA; biceps femoris, BF; tensor fasciae latae; TFL) as well as the quadriceps (Q) and soleus (S) muscles in 12 patients with restless legs syndrome combined with PLMD. Accompanying polysomnography provided the sleep parameters. In total, 469 movements were analysed. In only 12% was there the appearance of the classic movement (EDB-TA-BF-TFL) or its direct variants. The most frequent sequences were characterised by contraction of only the TA, TA-EDB only, or TA-EDB followed by all other combinations (32%). The pattern EDB only, EDB-TA, or EDB-TA followed by contraction of one or more other muscles, was seen in 18%. All other combinations appeared in much smaller numbers or only once. Eight patients had specific patterns. Three consistently started with the same muscle. One patient always contracted all six muscles. Six patients never contracted more than three muscles. The number of muscles contracted correlated positively with the appearance of arousal from sleep. The interval between onset of contractions within the PLMs varied randomly in a range of 0-1 s. Within PLMs many variations of muscle movements were documented. Patterns were recognisable, individually determined, and related to arousal from sleep. (+info)
Interrater reliability between scorers from eight European sleep laboratories in subjects with different sleep disorders.
Interrater variability of sleep stage scorings is a well-known phenomenon. The SIESTA project offered the opportunity to analyse interrater reliability (IRR) between experienced scorers from eight European sleep laboratories within a large sample of patients with different (sleep) disorders: depression, general anxiety disorder with and without non-organic insomnia, Parkinson's disease, period limb movements in sleep and sleep apnoea. The results were based on 196 recordings from 98 patients (73 males: 52.3 +/- 12.1 years and 25 females: 49.5 +/- 11.9 years) for which two independent expert scorings from two different laboratories were available. Cohen's kappa was used to evaluate the IRR on the basis of epochs and intraclass correlation was used to analyse the agreement on quantitative sleep parameters. The overall level of agreement when five different stages were distinguished was kappa = 0.6816 (76.8%), which in terms of kappa reflects a 'substantial' agreement (Landis and Koch, 1977). For different groups of patients kappa values varied from 0.6138 (Parkinson's disease) to 0.8176 (generalized anxiety disorder). With regard to (sleep) stages, the IRR was highest for rapid eye movement (REM), followed by Wake, slow-wave sleep (SWS), non-rapid eye movement 2 (NREM2) and NREM1. The results of regression analysis showed that age and sex only had a statistically significant effect on kappa when the (sleep) stages are considered separately. For NREM2 and SWS a statistically significant decrease of IRR with age has been observed and the IRR for SWS was lower for males than for females. These variations of IRR most probably reflect changes of the sleep electroencephalography (EEG) with age and gender. (+info)