Periodic limb movements

Measurement of muscle activity, usually measured by electrodes placed on the skin. The EMG is used in sleep research to aid in the discrimination of sleep stages, and also as part of diagnosis of sleep disorders such as periodic limb movements and restless legs syndrome. 

Restless-Legs Syndrome and Periodic Limb Movements of Sleep (PLMS)... 

PLMS periodic limb movements of sleep Force of the Standards of Practice Committee of the American... 

Similar to RLS, periodic limb movements in sleep (PLMS) is a sleep disorder in which people move their limbs (particularly the legs) during sleep. In PLMS, a person involuntarily twitches their legs every 20 to 40 seconds while sleeping. The difference between PLMS and RLS is that PLMS patients do not always feel the crawling uncomfortable sensations that make them want to move their legs. The limb movements in PLMS often occur during sleep while the person is completely unaware of them. However, occasionally PLMS can cause the person to... 

Periodic limb movements in sleep (PLMS)—A sleep disorder in which people move their limbs (particularly the legs) during sleep. 

Insomnia secondary to a general medical condition, especially with pain- or sleep-disordered breathing Circadian rhythm disturbance Periodic limb movement disorder Restless legs syndrome... 

Sleep disorders are common, and are generally underdiagnosed. The two major complaints related to sleep are insomnia ( I can t sleep ) and excessive daytime sleepiness (EDS, I can t stay awake ). EDS is a relatively nonspecific symptom. It can be the end result of any factor that causes sleep disruption, and it can be caused by primary or intrinsic sleep disorders. Insomnia of any cause can result in sleep deprivation and subsequent EDS. The most common cause of EDS in the general population is self-imposed sleep deprivation, or insufficient sleep syndrome. By contrast, the most common causes of EDS seen in a sleep center are primary (intrinsic) disorders of EDS. The American Academy of Sleep Medicine (AASM, formerly the American Sleep Disorders Association) classification of sleep disorders includes over 80 diagnoses that are associated with EDS, but the majority of patients evaluated at sleep centers have sleep apnea, narcolepsy, idiopathic hypersomnia, or periodic limb movements of sleep. 

Sleepiness is a primary symptom of narcolepsy, often preceding the onset of the other well-known symptoms of the disease, namely cataplexy, sleep paralysis, and hypnagogic hallucinations (44). Evaluation of the MSLT of narcoleptic patients has demonstrated a short sleep latency (<5 min) and multiple sleep-onset REM periods (SOREMPs). The more specific finding in the MSLT of narcoleptic patients is more than 2 SOREMPs, shown to reach a specificity of 99% by Amira et al. (45), which further increased to 99.2% if 3 SOREMPs were recorded (46). On the other hand, more than one SOREMP can occur in nonnarcoleptic patients, such as those with sleep apnea, sleep deprivation, depression, periodic limb movements, circadian rhythm disruption, or withdrawal from REM-suppressing medications (5,47). Thus, the findings of the MSLT, which is always performed for suspected narcoleptic patients, must be interpreted in view of the clinical history and nocturnal PSG. 

Periodic limb movement disorder (PLMD), originally described by Symonds as nocturnal myoclonus (11), was questioned as being an epileptic equivalent. Lugaresi et al. (12) demonstrated that it was not epileptic in nature and found a close association between it and restless legs syndrome. Guilleminault et al. (13) showed that it may be associated with insomnia, nocturnal sleep disruption, and daytime fatigue. Further studies have shown that periodic limb movements can vary greatly in severity. 

Trenkwalder C, Hening WA, Walters AS, Campbell SS, Rahman K, Chokroverty S. Circadian rhythm of periodic limb movements and sensory symptoms of restless legs syndrome. Movement Disord 1999 14 102-110. 

American Academy of Sleep Medicine (AASM) Report Standard of Practice Committee of the AASM Practice parameters for the treatment of restless leg syndrome and periodic limb movement disorder. Sleep 1999 22 961-968. 

Further sleep disturbance in FM may be related to increased incidence of periodic limb movements in sleep, restless legs syndrome, or the presence of comorbid depression. Consequently, given that a number of factors contribute to the sleep disturbance in FM, it would appear prudent to undertake a multifactorial approach to best understand sleep complaints and daytime symptoms of FM patients. Consistent with this notion, the interaction between psychological variables, such as cognitive appraisals of pain and sleep, as well as emotional reactions ought to be more carefully examined to best understand this complex syndrome. 

Significant periods of movement are also evident during REM sleep periods, when REM sleep behavior disorder is present (117,138). These include vocalizations, increased muscle tone, and complex muscle movements. During NREM sleep, increased incidence of periodic limb movements is also evident in up to one third of Parkinson s patients (139). Muscle activity is often present in limbs that also express tremor during waking periods. 

Montplaisir J, Nicolas A, Godbout R, Walters A. Restless legs syndrome and periodic limb movement disorders. In Kryger NH, Roth T, and Dement WC, eds. Principles and Practice of Sleep Medicine. Philadelphia WB Saunders, 2000 742-752. 

Moreover, there is evidence for increased rates of ADHD symptoms in clinical populations of children with sleep disorders, including children with the obstructive sleep apnea syndrome (OSAS), periodic limb movements of sleep (PLMS), narcolepsy, and sleep-wake schedule disorders. Studies indicate that treating the primary sleep disorder can produce significant improvement in ADHD symptoms (103). 

Of the 88 sleep disorders listed in the International Classification of Sleep Disorders (12), the better-known and more prevalent disorders are the obstructive sleep apnea syndrome, insomnia, restless legs syndrome/periodic limb movement disorder, and narcolepsy (see also Chap. 5).These sleep disorders are common, and are known to interfere with the quality of sleep this chapter addresses the socioeconomic impact of these disorders. 

Periodic limb movement is characterized by periodic episodes of repetitive and highly stereotyped limb movements that occur during sleep (12). It is reported to affect up to 34% of patients over age 60 years, and 1-15% of patients with insomnia. Movements are associated with partial awakening or arousals. Patients with isolated periodic limb movements in sleep (PLMS) without RLS may be asymptomatic. 

Ohayon MM, Roth T. Prevalence of restless legs syndrome and periodic limb movement disorder in the general population. J Psychosom Res 2002 53 547-554. 

The effective management of insomnia begins with recognition and adequate assessment. Family doctors and other health care providers should routinely enquire about sleep habits as a component of overall health assessment. Identification and treatment of primary psychiatric disorders, medical conditions, circadian disorders, or specific physiological sleep disorders, such as sleep apnea and periodic limb movement disorder, are essential steps in the management of insomnia [8],... 

Sleep disturbances in restless legs syndrome (RLS) and periodic limb movements (PLM)... 

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