Sleep Apnea And Restless Legs Syndromeperiodic Limb Movement Disorder Restless Legs Syndrome

RLS is a sensorimotor disorder, classified as a sleep-related movement disorder due to its close association with periodic limb movements in sleep (PLMS) (30). The diagnosis of RLS is subdivided into essential criteria, and supportive and associated features of RLS (84). The four essential criteria in adults are: an urge to move the legs usually accompanied or caused by uncomfortable and unpleasant sensations in the legs; the urge to move or unpleasant sensations begin or worsen during periods of rest or inactivity such as lying or sitting; the urge to move or unpleasant sensations are partially or totally relieved by movement, such as walking or stretching; and the urge to move or unpleasant sensations are worse in the evenings or night than during the day or only occur in the evening or night. The supportive clinical features of RLS include positive family history, presence of periodic limb movements during wake-fulness (PLMW) or sleep (PLMS) and a positive response to dopaminergic therapy. The associated features of RLS include a variable clinical course, but typically chronic and often progressive, normal physical examination in idiopathic/familial forms, and sleep disturbance, a common complaint in more affected patients.

Effect of Restless Legs Syndrome on Sleep

Both the RLS sensory symptoms and PLMW occur at the transition between waking and sleep, disturbing sleep onset or the return to sleep. PLMS occur in at least 80% of patients with RLS. The PLMS of patients with RLS are frequently associated with arousal from sleep, which can then lead to long periods of wakefulness and cause sleep disruption. In a study of 133 patients with RLS, most of the patients (84.7%) frequently experienced difficulty falling asleep at night because of RLS, and 86% reported that symptoms woke them up frequently during the night. Several patients (46.2% of men and 22.2% of women) also reported excessive daytime fatigue or somnolence, probably as a consequence of disrupted nocturnal sleep (85).

PLMS are defined as repetitive and stereotyped limb movements in sleep typically characterized by rhythmic extensions of the big toe and dorsiflexion of the ankle with occasional flexion of knee and hip. The quantification of PLMS is routinely obtained by recording bilateral surface electromyographic (EMG) of the tibialis anterior muscles. It is defined as a brief increase in EMG amplitude lasting 0.5 seconds to 5 seconds and repeating every 4 seconds to 90 seconds in a sequence of at least four movements (86). PLMW are recorded similarly except the maximum duration is increased to 10 seconds. Occurrence of PLMS at a rate of five or more per hour of sleep and/or PLMW greater than 15 per hour of waking during the entire night sleep period support a diagnosis of RLS. Recording and scoring of PLMS must be an integral part of PSG evaluations to prevent misinterpretation of movements following EEG arousals from respiratory events (87). There are major controversies with regard to the functional significance of PLMS, and several authors have concluded that PLMS have little impact on nocturnal sleep or daytime vigilance. Recently, more attention has been paid to other signs of physiologic activation associated with PLMS. Regardless of the presence of EEG arousals, almost all PLMS are associated with a tachycardia (decreased R-R intervals for

5-10 beats) associated with a rise of blood pressure followed by a bradycardia and relative fall of blood pressure (88,89). Further, it has been shown that arousals often precede rather than follow the movements (90) and they are still present after suppression of leg movements with L-dopa, suggesting that leg movements are not a cause of the arousals but rather a phenomenon associated with an underlying disorder. These data show that EEG arousals are probably not the only parameter of activation to consider in the evaluation of sleep disruption secondary to PLMS (91). Although the functional significance of PLMS has been a matter of dispute their quantification is often used in sleep laboratory diagnostic procedures for RLS (92) and for monitoring treatment.

Sleep Apnea

Sleep Apnea

Have You Been Told Over And Over Again That You Snore A Lot, But You Choose To Ignore It? Have you been experiencing lack of sleep at night and find yourself waking up in the wee hours of the morning to find yourself gasping for air?

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