졸리움의 진단과 치료

신재공 大韓睡眠-精神生理學會 2003 수면·정신생리 Vol.10 No.1

자각몽의 수면의학적 이해와 응용

신재공,Cyn, Jaegong 대한수면의학회 2019 수면·정신생리 Vol.26 No.2

A lucid dream is defined as a dream during which a dreamer is aware that she/he is dreaming. The existence of lucid dream has long been known in the literature, but it hasn't been long before it has received attention in sleep medicine. Although many studies have been conducted since validation of the lucid dream in polysomnography by Steven LaBerge in the 1980s, the neuroscience of lucid dreams is still not fully understood. Here the neuroscientific literature on lucid dreaming, including electroencephalographic, neuroimaging, pharmacological and brain stimulation studies, are reviewed. Also this review gives an overview on how lucid dreams are used in clinical and nonclinical areas, ranging from nightmare therapy to research on consciousness and creative problem solving.

코로나바이러스감염증-19와 수면

신재공 대한수면의학회 2022 수면·정신생리 Vol.29 No.2

"제2형 중증급성호흡기증후군 코로나바이러스(severe acute respiratory syndrome corona virus 2, SARS-CoV-2)에 의하여 유발되어 세계적으로 대유행이 있었던 코로나바이러스감염증-19(corona virus disease 2019, COVID-19)는 아직도 심각한 공중 보건의 문제로 자리잡고 있다. COVID-19는 호흡기뿐만 아니라 여러 부위에 걸쳐 다양한 증상을 유발하며 수면에도 적잖은 영향을 끼친다. COVID-19에 걸린 환자뿐만 아니라 비감염 일반인에서도 불면증과 수면의 질저하가 높은 비율로 관찰되었다. 폐쇄성 수면 무호흡증도 중증 COVID-19 환자의 위험요인으로 간주되고 있다. COVID-19에서 수면장애가 많이 나타나는 원인으로는 바이러스에 의한 중추신경계 손상도 가능성이 높지만, 심리사회적 영향에 의한 것도 상당부분 작용하였을 것으로 보인다. 수면 문제는 감염증상이 끝난 이후에도 상당기간 높은 비율로 지속되었다. 향후에도 COVID-19가 수면에 미치는 영향에 대한 보다 많은 관심과 연구가 필요하다."

수면과 기억

신재공,Cyn, Jae-Gong 대한수면의학회 2005 수면·정신생리 Vol.12 No.1

Study in the field of sleep and memory has greatly expanded recently and the number of publications supporting the association between sleep and memory consolidation is rapidly growing. This study presents evidence related to sleep-dependent memory consolidation, ranging from behavioral task-performing studies to molecular studies, and several arguments against the association. Basic researches show that many genes are upwardly regulated during sleep and patterns of brain activation seen during daytime task training are repeated during subsequent REM sleep. Several electrophysiological studies demonstrate the correlation between spindle density increase following training and subsequent improvement in performing the training task. Overnight improvement or deterioration in task performance correlates with REM or SWS sleep. In the end, a lot of issues remain to be studied and discussed further in the future in spite of supporting evidence now available.

폐경이 폐쇄성 수면무호흡에 미치는 영향

신재공,Cyn, Jae-Gong 대한수면의학회 2010 수면·정신생리 Vol.17 No.1

Obstructive sleep apnea is a common sleep disorder that predominantly affects adult men than women. However, the prevalence in women increases with menopause dramatically. Menopause has long been described as a risk factor for obstructive sleep apnea. Recent large well-designed population studies support that menopause increases the risk for sleep-disordered breathing. The mechanism of that hypothesis is not yet clear. But, the decline in progesterone has been thought to influence the development of obstructive sleep apnea because progesterone is a respiratory stimulant and plays a protective role against sleep apnea. Increased visceral obesity and hypertension as major symptoms of metabolic syndrome are also associated with menopause and place women at increased risk for obstructive sleep apnea and other serious health problem. Hormone replacement therapy has been associated with a lower prevalence of sleep apnea. But, relative risk and benefits of hormone replacement therapy compared with other treatment options will require thorough consideration for each individual woman. Finally, attention should be drawn to the need for obstructive sleep apnea evaluation in perimenopausal and postmenopausal women.

미세각성이 없는 수면중 주기성 사지운동증 뇌파의 스펙트럼 분석

신재공,서완석,오정수,정도언,Cyn, Jae-Gong,Seo, Wan-Seok,Oh, Jung-Su,Jeong, Do-Un 대한수면의학회 2003 수면·정신생리 Vol.10 No.2

Objectives: Periodic leg movements in sleep (PLMS) might be subdivided based upon whether or not they are associated with visible EEG microarousals (MA). MA is considered to be responsible for nonrestorative sleep and daytime fatigue. The American Sleep Disorders Association's (ASDA) scoring rules for MA based on visual analysis of the EEG changes suggest that MA should last more than 3 seconds. However, it has been suggested that visual analysis may not detect some changes in EEG activity. This study is aimed at measuring changes in EEG spectra during PLMS without MA in order to better understand the arousing response of PLMS. Methods: Ten drug-free patients (three men and seven women) diagnosed with PLMS by polysomnography were studied. Spectral analysis of the EEG was performed in each patient on 30 episodes of PLMS without MA, chosen randomly across the night in stage 2 non-REM sleep. We applied stricter criteria for MA compared to ASDA, by defining it as a return to alpha and theta frequency lasting at least 1 second. Results: The mean PLMS index was $16.7{\pm}10.0$. The mean PLMS duration was $1.3{\pm}0.7$ seconds. Comparison of 4-second EEG activity both before and after the onset of PLMS without MA using independent t-test showed that the movements were associated with significant increase of relative activity in the delta band (p=0.000) and significant decrease of activity in the alpha (p=0.01) and sigma (p=0.000) bands. No significant decrease in the theta (p=0.05), beta (p=0.129), or gamma (p=0.062) bands was found. Conclusion: PLMS without MA was found to be associated with EEG change characterized by increase in the delta frequency band. This finding seems to be compatible with the hypothesis of an integrative hierarchy of arousal responses of Sforza's. Considering that the subjects had lower PLMS index and shorter PLMS duration than those of the previous study, it is suggested that an even less severe form of PLMS without MA could induce neurophysiologic change, which may potentially be of clinical significance. 배 경:뇌파 미세각성은 수면 회복감을 저하시키고 주간 피로감을 초래하는 것으로 알려져 있다. 수면중 주기성 사지운동증은 뇌파기록의 육안판독 소견에 나타나는 미세각성 유무에 따라 두 종류로 나뉘어진다. 미국 수면장애협회에서 제시한 기준은 수면중 주기성 사지운동 이후에 뇌파의 변화가 3초 이상 지속되는 경우를 미세각성으로 판정하고 있다. 그러나 육안판독 만으로는 뇌파 활동의 일부 미세한 변화를 찾아내기 어렵다는 주장도 제기되고 있다. 그러므로 본 연구의 목적은 미세각성이 없는 수면중 주기성 사지 운동의 뇌파변화를 스펙트럼 분석방법을 이용하여 세밀하게 측정하여 수면중 주기성 사지운동증에서 나타나는 각성 반응을 보다 자세히 이해하는데 있다. 방 법:야간 수면다원검사로 수면중 주기성 사지운동증 진단을 받은 환자 10명을 대상으로 하였다. 각각의 피험자에서 2단계 비렘수면에서 발생한 주기성 사지운동 중에서 뇌파의 미세각성이 없는 삽화 30개를 무작위로 선택하여 스펙트럼 분석을 실시하였다. 본 연구에서는 알파파나 세타파로 뇌파변화가 최소 1초 이상 나타날 경우라도 미세각성으로 간주하여 대상군에서 제외함으로써 때문에 최소 3초 이상을 미세각성으로 삼는 미국수면장애학회의 기준보다 엄격한 기준을 적용하였다. 사지운동이 시작된 시각을 기준으로 시작 전 4초 구간과 시작 후 4초 구간의 두 군으로 나누고 해당 뇌파를 각각 스펙트럼 분석하였고 독립 스튜던트 t 검증을 사용하여 두 군을 비교하였다. 결 과:수면중 주기성 사지운동증 지수의 평균은 $16.7{\pm}10.0$회였고 수면중 주기성 사지운동증 지속시간의 평균은 $1.3{\pm}0.7$초였다. 독립 스튜던트 t 검증의 결과 델타파(p=0.000) 영역의 비교활동도가 사지운동후에 유의하게 증가하였고, 알파파(p=0.01) 영역과 시그마파(p=0.000) 영역은 유의하게 감소하였다. 세타파(p=0.05), 베타파(p=0.129), 그리고 감마파(p=0.062) 영역이 감소하였으나 유의할 만한 수준은 아니었다. 결 론:델타파 영역이 증가를 보인 결과는 각성반응이 단계적인 순서로 일어난다는 이론과 합치되는 소견이다. 본 연구의 대상환자가 이전의 유사한 연구의 대상환자에 비하여 평균 지속시간이 더 짧다는 점과 평균 지수가 낮다는 점을 고려한다면, 경한 형태의 수면중 주기성 사지운동증에서도 신경생리학적인 변화가 유발된다고 결론을 내릴 수 있다.

표적 기억 재활성화로 수면 중 기억 강화 증진 시키기

신재공 대한수면의학회 2017 수면·정신생리 Vol.24 No.2

Targeted memory reactivation (TMR) is a method whereby cues associated with previous learning are used to externally reactivate aspects of this learning. Research findings demonstrate that TMR can be a useful tool to enhance memory consolidation during sleep in both animals and humans, especially in the declarative/spatial domain. Neurocognitive processing during sleep with covert cueing via auditory or olfactory stimulation can benefit memory storage. These beneficial effects on memory consolidation during sleep are associated with the activation of memory-related brain areas. The purpose of the present review is to provide a short overview of the findings of studies that adopted the TMR method of sleep-dependent memory consolidation and to suggest the potential applications of TMR in variable areas. TMR은 이전 학습 과제와 연관되었던 단서 자극을 사용하여 현재 학습의 재활성화를 유도하는 절차적 방법을 일컫는다. 여러 동물 및 인간 연구들에서 TMR이 수면 중 기억강화를 증진하는 유용한 방법이라는 것이 증명되었고 특히서술 기억 영역에 일관된 결과를 보인다. 청각 혹은 후각 단서 자극을 은밀히 제시하는 방법을 적용한 수면 중 신경인지 처리 과정을 통하여 기억 강화의 증진을 도모할 수 있었다. 이러한 증진 효과는 기억 강화와 관련된 뇌 부위의 활성과 연관되어있다. 이 종설을 통하여 TMR을 적용한 수면 중기억 강화 연구들의 현황을 살펴보았고 다양한 분야에서의발전 가능성을 엿볼 수 있었다.

주기성 사지운동증의 개관

신재공,Cyn, Jae-Gong 대한수면의학회 2008 수면·정신생리 Vol.15 No.1

Periodic leg movements during sleep (PLMS) are best described as repetitive stereotypical movements of the lower extremities characterized by dorsiflexion of the ankle, dorsiflexion of the toes and a partial flexion of the knee and sometimes the hip. The prevalence of PLMS is about 5-11% in adults and is predicted much higher than previously surveyed. They are also frequently found in various sleep disorders, several disorders not primarily affecting sleep, and patients taking psychiatric medications. Although they are rarely found in children, they are common findings in children referred to a pediatric sleep laboratory. The pathophysiology is strongly associated with decline of central dopaminergic function and closely related to arousal system during sleep. Benzodiazepines, levodopa, dopamine agonists and opioids are generally recommended for treatment but more controlled studies on the effectiveness are needed.

수면과 시토카인

신재공,Cyn, Jae-Gong 대한수면의학회 2005 수면·정신생리 Vol.12 No.2

Cytokines are the main regulatory molecules of not only immune system but also sleep system. Research on the role of cytokines on sleep has greatly been expanding since the first report of sleep-promoting effects of interleukin-1, the first cytokine molecule. Interleukin-1 and tumor necrosis factor are most widely studied among various cytokines. Studies over about twenty years demonstrate that most cytokines promote sleep but several cytokines inhibit sleep. Slow wave sleep is the main part that cytokines have effects on. Besides normal sleep physiology, cytokines have more major roles on pathophysiology of various sleep disorders. Obstructive sleep apnea is the representative sleep disorder that shows how deeply cytokines are involved in their pathophysiologic mechanisms of sleep disorders. Though there are many controversial issues on this topic, more mysterious part of normal sleep physiology and sleep disorders will be revealed in near future through thorough studies on sleep and cytokine.

불면증에서 순환교대파형의 의미

신재공,Cyn, Jae-Gong 대한수면의학회 2010 수면·정신생리 Vol.17 No.2

The cyclic alternating pattern (CAP) is a periodic EEG activity in NREM sleep, characterized by sequences of transient electrocortical events that are distinct from background EEG activities. A CAP cycle consists of two periodic EEG features, phase A and subsequent phase B whose durations are 2-60 s. At least two consecutive CAP cycles are required to define a CAP sequence. The CAP phase A is a phasic EEG event, such as delta bursts, vertex sharp transients, K-complex sequences, polyphasic bursts, K-alpha, intermittent alpha, and arousals. Phase B is repetitive periods of background EEG activity. The absence of CAP more than 60 seconds or an isolated phase A is classified as non-CAP. Phase A activities can be classified into three subtypes (A1, A2, and A3), based on the amounts of high-voltage slow waves (EEG synchrony) and low-amplitude fast rhythms (EEG desynchrony). CAP rate, the percentage of CAP durations in NREM sleep is considered to be a physiologic marker of the NREM sleep instability. In insomnia, the frequent discrepancy between self-reports and polysomnographic findings could be attributed to subtle abnormalities in the sleep tracing, which are overlooked by the conventional scoring methods. The conventional scoring scheme has superiority in analysis of macrostructure of sleep but shows limited power in finding arousals and transient EEG events that are major component of microstructure of sleep. But, it has recently been found that a significant correlation exists between CAP rate and the subjective estimates of the sleep quality in insomniacs and sleep-improving treatments often reduce the amount of CAP. Thus, the extension of conventional sleep measures with the new CAP variables, which appear to be the more sensitive to sleep disturbance, may improve our knowledge on the diagnosis and management of insomnia.