• Journal of Oral Medicine and Pain
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• v.41 no.2
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• pp.54-60
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• 2016

Purpose: Mandibular advancement devices (MAD) are used effectively and widely for the treatment of obstructive sleep apnea (OSA) and rapid-eye-movement (REM) dependency of the patients can affect the treatment outcome of OSA. The aim of this study was to compare treatment outcomes of MAD between REM-related and not-REM-related OSA patients. Methods: Fifty-six consecutive patients with OSA who received MAD therapy were evaluated using full night polysomnography before and after insertion of the MADs. The patients were divided into REM-related (REM apnea-hypopnea index [AHI] at least two times higher than their non-REM AHI) and not-REM-related (REM AHI less than two times higher than their non-REM AHI) OSA groups. Results: MAD is used for the treatment of OSA effectively. In respect of AHI, MAD therapy were effective both in REM-related OSA and not-REM-related OSA, but MAD therapy was more effective in not-REM-related OSA than REM-related OSA in overall sleep and non-REM sleep. $SpO_2$ saturations were improved after MAD therapy, but were not different between two groups. Epworth sleepiness scale scores were not improved after MAD therapy. Percentage of REM sleep was increased after MAD therapy but was not different between two groups. Conclusions: MAD therapy was more effective in not-REM-related OSA than REM-related OSA and REM dependency can be a predictive factor of treatment outcome of oral appliance for OSA patients.

• Journal of Oral Medicine and Pain
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• v.41 no.4
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• pp.180-187
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• 2016

Purpose: The aims of this study were to evaluate the differences of clinical and polysomnographic features between rapid eye movement (REM)-related obstructive sleep apnea (OSA) and not-REM-related OSA, and to suggest the pathogenesis according to the REM dependency of OSA. Methods: One hundred ninety consecutive patients diagnosed with OSA were evaluated clinical features and performed full night polysomnography. The patients were divided into REM-related (REM apnea-hypopnea index [AHI] at least two times higher than their non-REM AHI) and not-REM-related (a REM AHI less than two times higher than their non-REM AHI) OSA groups and evaluated the differences in age, body mass index (BMI), neck circumference, Ep-worth Sleepiness Scale score, and parameters of polysomnography. Results: REM-related patients were younger and showed higher sleep efficacy, low percentage of light sleep stage (stage 1 sleep), and low rate of positional OSA. Age was significantly associated with REM dependency of OSA and REM AHI were significant correlated with BMI, neck circumference, percentage of sleep in supine position, and percentage time of snoring. Conclusions: Our results showed that REM-related OSA patients showed less severe polysomnographic parameters than not-REM-related patients. However, significant risk factors were differed depending on the REM dependency and OSA severity, and the clinical features correlated with REM AHI and non-REM AHI were also showed differently. We suggest that the occurrence of OSA according to the REM dependency can be based on different mechanisms.

• Sleep Medicine and Psychophysiology
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• v.15 no.1
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• pp.25-32
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• 2008

Objectives: A few studies have compared REM sleep-dependent obstructive sleep apnea syndrome (REM-OSA) with sleep stage non-dependent apnea syndrome (SND-OSA). Despite that REM-OSA might be more common in women than men, no studies have examined the probable characteristics of women patients with obstructive sleep apnea syndrome (OSAS). This study aimed at finding out the characteristics of REM-OSA in women by comparing it with SND-OSA. Methods: Fifty-three subjects diagnosed as OSAS (AHI>5 ; AHI : apnea-hypopnea index) with nocturnal polysomnography at the Center for Sleep and Chronobiology of the Seoul National University Hospital between October 2004 and February 2006 were studied. Of them, 44 subjects with OSAS severity of mild (52 and AHI-NR<15 (AHI-R : AHI during REM sleep, AHI-NR : AHI during non-REM sleep). We compared REM-OSA group with SND-OSA as well as the criteria-determined REM-OSA cases with the visually-determined ones. Results: Among 44 subjects, 28 persons (63.6%) turned out to have REM-OSA by our criteria and 24 persons (54.5%) by visual determination. Statistically significant differences (p<0.05) were found between REM-OSA and SND-OSA groups in AHI, hypopnea index, total sleep time, total wake time, sleep efficiency index, percents of stage 1, 2 and REM sleep, and REM latency. Percent of stage REM sleep (%REM) turned out to have influence on AHI ratio (AHI-R/AHI-NR) (B=0.537, p=0.002). REM-OSA was likely to be diagnosed in milder severity of OSAS (${\chi}^2=13.117$, p<0.001) and those with higher %REM (${\chi}^2=11.325$, p=0.001). There was no significant difference between the criteria-determined and the visually-determined cases of REM-OSA. Conclusion: We suggest that REM-OSA and SND-OSA patients be differentiated in terms of pathophysiology and treatment strategies. Visual determination of REM-OSA might be useful as the screening procedure of REM-OSA. Further studies on women with OSAS and REM-OSA need to be done.

• Sleep Medicine and Psychophysiology
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• v.11 no.1
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• pp.10-16
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• 2004

Sleep is associated with definite changes in respiratory function in normal human beings. During sleep, there is loss of voluntary control of breathing and a decrease in the usual ventilatory response to both low oxygen and high carbon dioxide levels. Especially, rapid eye movement (REM) sleep is a distinct neurophysiological state associated with significant changes in breathing pattern and ventilatory control as compared with both wakefulness and non-rapid eye movement (NREM) sleep. REM sleep is characterized by erratic, shallow breathing with irregularities both in amplitude and frequency owing to marked reduction in intercostal and upper airway muscle activity. These blunted ventilatory responses during sleep are clinically important. They permit marked hypoxemia that occurs during REM sleep in patients with lung or chest wall disease. In addition, sleep-disordered breathing (SDB) is more frequent and longer and hypoventilation is more pronounced during REM sleep. Although apneic episodes are most frequent and severe during REM sleep, most adults spend less than 20 to 25% of total sleep time in REM sleep. It is, therefore, possible for patients to have frequent apneas and hypopneas during REM sleep and still have a normal apnea-hypopnea index if the event-rich REM periods are diluted by event-poor periods of NREM sleep. In this review, we address respiratory physiology according to sleep stage, and the clinical implications of SDB and hypoventilation aggravated during REM sleep.

• Proceedings of the Korean Institute of Interior Design Conference
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• 2006.11a
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• pp.115-120
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• 2006

This study concentrates on a new idea that is formulated as a creative space recognition in contemporary architecture and painting. It is stimulated from Deleuze's philosophy, which is expressed with the philosophical instrument, "Non-Representation". After discussing the concept of non-representation used in Deleuze's philosophy, case example in contemporary architecture are analysed to comparatively Investigate the relationship between the architectures by Rem Koolhaas and painting by Francis Bacon. Therefore, he founds expressions of "diagram" and "movement" in painting of F. Bacon. Diagram meansit is a power that is comprised of various points of wiew with the kind experiences that one has in life. Movement that were extracted form the Instrument in space recognition of Deleuze's panting theory were of topology, insertion of geometry, reiteration of layers, transparency and translucency, reflection effect.

• Sleep Medicine and Psychophysiology
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• v.15 no.2
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• pp.77-81
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• 2008

Introduction: REM sleep which shows characteristic muscle atonia and increased resistance of upper respiratory track is known to be vulnerable to sleep apnea. Previous studies reported that REM sleep-dependent (or related) obstructive sleep apnea syndrome (REM-dependent OSA) could be one of sleep disordered breathing. The present study aimed to investigate clinical findings and polysomnographic variables of REM-dependent OSA. Methods: Fifty-six patients diagnosed with mild to moderate obstructive sleep apnea by overnight polysomnography (5$53.7{\pm}16.7$ years, 42 males). REM-dependent OSA was defined as AHI-REM/AHI-NREM ratio>2. We compared clinical and polysomnographic findings between REM-dependent OSA and No REM-dependent OSA patients. Results: Among 56 patients, 37.5% (n=21, average age of $52.3{\pm}19.7$ years, 14 males) met the REM-dependent OSA criteria. There were no significant differences in age, sex and body mass index between two groups. After controlling for age, sex, body mass index and periodic leg movements index, REM-dependent OSA patients showed significantly lower AHI, lower number of oxygen desaturation events and higher stage 2 sleep proportion compared to No REM-dependent OSA patients (p=0.010, p=0.006, p=0.031, respectively). After controlling for age, sex, body mass index and periodic legs movements index, AHI-REM was positively correlated with the number of oxygen desaturation events in REM-dependent OSA group (p=0.002). Conclusion: Current results suggested that 37.5% of patients with mild to moderate severity of obstructive sleep apnea could be classified into REM-dependent OSA. REM-dependent OSA was more common in mild severity of OSA, equally prevalent in both sexes and accompanied with sleep architecture changes, i.e. increased proportion of stage 2. In addition, apneic events during REM sleep in REM-dependent OSA were related to oxygen desaturation.

• Proceedings of the Korea Society of Design Studies Conference
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• 2004.05a
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• pp.126-127
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• 2004

• Natural Product Sciences
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• v.15 no.4
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• pp.213-221
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• 2009

Longanae Arillus (the rind of fruits of Dimocarpus longan) has been consumed for the treatment of insomnia and anxiety in Asia. To provide further scientific basis to traditional uses of this fruit on insomnia, we evaluated the effects of methanol extract of Longanae Arillus (MELA) on the alteration of sleep architecture and electroencephalogram (EEG) power spectra in acutely and chronically restraint-stressed rats. Following postsurgical recovery, Polygraphic signs of sleep-wake activities were recorded for 24 h after MELA administration in rats. Rats in the acute stress and chronic stress were administered with MELA for 10 days. On the $8^{th},\;9^{th}\;and\;10^{th}$ day of MELA administration, the rats were stressed for 3 h once per day. On the $10^{th}$ day and 1 h after MELA administration, the rats were stressed once for 22 h in the chronic stress group. Acute and chronic stress induced alternations in cortex EEG recordings during non-rapid eye movement (NREM), rapid eye movement (REM) sleep and wakefulness. MELA shortened the total and REM sleep and increased the wakefulness in night time recording without changing daytime recordings. Chronic stress increased wakefulness and REM sleep, decreased total and NREM sleep in the daytime recording, and increased REM and decreased NREM sleep without changing total sleep and wakefulness in night time recording. These findings suggest that MELA ameliorated the alterations in REM and NREM sleep of acutely and chronically stressed rats via modulation of cortical ${\alpha}-$, ${\theta}-$ and ${\delta}-$ wave activity.

• Sleep Medicine and Psychophysiology
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• v.13 no.1
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• pp.5-10
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• 2006

Alcohol has extensive effects on sleep and daytime sleepiness. Alcohol has a sleep inducing effect and the effect of increased non-REM sleep and suppressed REM sleep during the first half portion of night sleep, but alcohol induces the effect of decreased non-REM sleep and increased light sleep and frequent awakenings and REM rebound during the second half portion of night sleep. Alcohol provokes chronobiological change such as the changes of amplitude or the phase shifts of hormones or core body temperature. The sleep disruption resulting from alcohol drinking may lead to daytime fatigue and sleepiness. The elderly are at particular in the increased risk of alcohol-related sleep disorders because they achieve higher levels of alcohol in the blood and brain than do younger adults after consuming an equivalent dose. Bedtime alcohol consumption among older adults may lead to unsteadiness if walking is attempted during the night, with increased risk of falls and injuries. Continued alcohol use for sleep induction often induces aggravation of insomnia, alcoholism or sleep related breathing disorders such as obstructive sleep apnea. Alcohol should not be used as substitution of sleep pill because of the dependence and tolerance for sleep inducing effect, and the sleep disruption produced by alcohol withdrawal.

• Journal of Oral Medicine and Pain
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• v.42 no.1
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• pp.1-7
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• 2017

Purpose: The aims of this study were to evaluate the clinical characteristics and polysomnographic results of patients visited the Seoul National University Dental Hospital (SNUDH) and to suggest guidelines for the management of sleep disordered-breathing patients in a dental clinic. Methods: Five hundred sixty-two patients who visited the Snoring and Sleep Apnea Clinic of SNUDH were evaluated for clinical characteristics including associated comorbidities, age, gender, body mass index (BMI), neck circumference, and daytime sleepiness and among them 217 patients were performed nocturnal polysomnography for evaluating respiratory disturbance index, apnea-hypopnea index (AHI), oxygen saturation levels, and sleep stages. The associations among clinical characteristics, sleep parameters, and positional and rapid eye movement (REM) dependencies of the patients were analyzed. Results: The most common co-morbidities of the patients were cardiovascular (30.2%), endocrine (10.8%), and respiratory diseases (7.9%). Age (${\beta}=0.394$), total AHI (${\beta}=0.223$), and lowest $O_2$ saturation levels (${\beta}=0.205$) were significantly associated with the number of co-morbidities in patients with obstructive sleep apnea (OSA). Mean $O_2$ saturation was not significantly associated with number of co-morbidities. Non-positional OSA patients had higher BMI, longer neck circumferences, more severe AHI values, and lower mean and lowest $O_2$ saturation levels compared to positional OSA patients. Not-REM-related patients were older and had more severe AHI values compared to REM-related patients. Not-REM-related patients have longer duration of stage I sleep and shorter stage II, III, and REM sleep than REM-related patients. There were no significant differences in each sleep stage between positional and non-positional patients. Neck circumference, positional dependency, REM dependency, and percentage of supine position were significantly associated with severity of OSA. Conclusions: Age, total AHI, and lowest $O_2$ saturation level were significantly associated with the number of co-morbidities in patients with OSA. Neck circumference, positional dependency, REM dependency, and percentage of supine position were significantly associated with severity of OSA.