• The Journal of the Korean dental association
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• v.48 no.3
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• pp.178-183
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• 2010

Obstructive Sleep Apnea(OSA) is a form of sleep disordered breathing(SDB) characterized by the occurrence of episodes of complete or partial upper airway obstruction during sleep that is often quantified as the apnea-hyponea index(AHI). It is increasingly being recognized that OSA is a public health hazard and there is increasing evidence that it is associated with an increase in morbidity. Early recognition and diagnosis of this condition may lead to earlier treatments (eg, CPAP, Oral appliances) with reduction of the risk of metabolic disease, cardiovascular diseases, such as hypertension, ischemic heart disease, arrhythmias and pulmonary hypertension.

• Sleep Medicine and Psychophysiology
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• v.7 no.2
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• pp.115-119
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• 2000

Objectives Summary: A 20-year-old man was presented with a history of difficult waking for 10 years. He suffered from morning headache, chronic fatigue and mild daytime sleepiness but had no history of irresistible sleep attack, cataplexy, hypnagogic hallucination or sleep paralysis. Methods: Night polysomnography (PSG), multiple sleep latency test (MSLT) and HLA-typing were carried out. Results: The PSG showed short sleep latency (4.0 min) and REM latency (2.5 min), increased arousal index (15.7/hour), periodic limb movements during sleep (PLMS index=8.1/hr) with movement arousal index 2.1/hr and normal sleep efficiency (97.5%). The MSLT revealed normal sleep latency (15 min 21 sec) and 4 times sleep-onset REM (SOREM). HLA-typing showed DQ6- positive, that corresponded at the genomic level to the subregion DQB1*0601, which was different from the usual locus in narcolepsy patients (DQB1*0602 and DQA1*0102). Conclusion: Differential diagnosis should be made with circadian rhythm disorder and other causes of primary waking disorder. The possibility of a variant type of narcolepsy could be suggested with an unusual clinical manifestation and a new genetic marker.

• Sleep Medicine and Psychophysiology
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• v.28 no.2
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• pp.70-77
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• 2021

Objectives: Our study aims to investigate the clinical and polysomnographic variables associated with subjective sleep perception. Methods: Among the patients who underwent nocturnal polysomnography (PSG) at the Center for Sleep and Chronobiology of Seoul National University Hospital from May 2018 to July 2019, 109 diagnosed with insomnia disorder based on DSM-5 were recruited for the study, and their medical records were retrospectively analyzed. Self-report questionnaires about clinical characteristics including Pittsburgh sleep quality index (PSQI), Beck depression inventory (BDI), and Epworth sleepiness scale (ESS) were completed. Subjective sleep quality was measured using variables of subjective total sleep time (subjective TST), subjective sleep onset latency (subjective SOL), subjective number of awakenings, morning feeling after awakening, and sleep discrepancy (subjective TST-objective TST) the morning after PSG. Pearson and Spearman correlation analyses were used to determine the factors associated with subjective sleep perception. Results: In patients with insomnia, subjective TST was negatively correlated with Wake After Sleep Onset (WASO) (p = 0.001) and N1 sleep (p = 0.039) parameters on polysomnography. Also, it was negatively correlated with PSQI (p < 0.001) and BDI (p = 0.014) scores. Sleep discrepancy was negatively correlated with PSQI score (p = 0.018). Morning feeling was negatively correlated with PSQI (p = 0.019) and BDI (p < 0.001) scores. Conclusion: Our results demonstrated that subjective sleep perception is associated with PSG variables (WASO and N1 sleep) and with PSQI and BDI scores. In clinical practice, it is helpful to assess and manage insomnia patients in consideration of objective sleep variables, subjective sleep quality, and depressed mood, which can influence subjective sleep perception.

• Journal of Oral Medicine and Pain
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• v.39 no.1
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• pp.10-14
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• 2014

Purpose: The aim of this study is to evaluate the difference between gustatory functions in a sleep disordered breathing (SDB) group and a control group. The pathogenesis of SDB has not been fully understood. Though the precise contributions of neuromuscular and anatomical factors on SDB pathogenesis are still debated, we hypothesized that the gustatory dysfunction could be predisposed to SDB. Methods: All patients were diagnosed as SDB by polysomnography (PSG). On the basis of PSG results, patients were divided into 3 groups: snoring, mixed, and obstructive sleep apnea (OSA). The control group comprised healthy volunteers who were the same age as those of the SDB group and whose breathing was verified as normal using a portable sleep monitor device. The patient group and the control group were evaluated for gustatory functions with an electrogustometry (EGM). The electrical taste thresholds were measured in the anterior, midlateral, and posterior sides of the tongue and soft palatal regions, both sides. To find out the difference in EGM scores, statistical analysis was performed using the Kruskal-wallis and Mann-Whitney U test with 95% confidence interval and p<0.05 significance level. Results: The patients with SDB had higher EGM scores than the control group at all spots tested, except for the right midlateral of the tongue, and there was a statistical significance in the comparison between the control group and the divided SDB groups, respectively. Among the divided SDB groups, the snoring group had the most significant differences in the number of the measured spots, but there was no difference among the snoring, mixed, and OSA groups. Conclusions: These results may suggest that neurologic alterations with sleep disordered breathing could be associated with gustatory dysfunction. In the future, further systemic studies will be needed to confirm this study.

• Annals of Clinical Neurophysiology
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• v.1 no.1
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• pp.1-9
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• 1999

Since Hans Berger reported the first paper on the human electroencephalogram in 1920s, huge technological advance have made it possible to use a number of electrophysiological approaches to neurological diagnosis in clinical neurology. In majority of the neurology training hospitals they have facilities of electroencephalography(EEG), electromyography(EMG), evoked potentials(EP), polysomnography(PSG), electronystagmography(ENG) and, transcranial doppler(TCD) ete. Clinicials and electrophysiologists should understand the technologic characteristics and general applications of each electrophysiological studies to get useful informations with using them in clinics. It is generally agreed that items of these tests are selected under the clinical examination, the tests are performed by the experts, and the test results are interpretated under the clinical background. Otherwise these tests are sometimes useless and lead clinicians to misunderstand the lesion site, the nature of disease, or the disease course. In this sense the clinical utility of neurophysiological tests could be summerized in the followings. First, the abnormal functioning of the nervous system and its environments can be demonstrated when the history and neurological examinations are equivocal. Second, the presence of clinically unsuspected malfunction in the nervous system can be revealed by those tests. Finally the objective changes can be monitored over time in the patient's status. Also intraoperative monitoring technique becomes one of the important procedures when the major operations in the posterior fossa or in the spinal cord are performed. In 1996, the Korean Society for Clinical Neurophysiology(KSCN) was founded with the hope that it will provide the members with the comfortable place for discussing their clinical and academic experience, exchanging new informations, and learning new techniques of the neurophysiological tests. The KSCN could collaborate with the International Federation of Clinical Neurophysiology(IFCN) to improve the level of the clinical neurophysiologic field in Korea as will as in Asian region.1 In this paper the clinical neurophysiological tests which are commonly used in clinical neurology and which will be delt with and educated by the KSCN in the future will be discussed briefly in order of EEG, EMG, EP, PSG, TCD, ENG, and Intraoperative monitoring.

• Journal of IKEEE
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• v.23 no.4
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• pp.1273-1279
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• 2019

Though sleep polysomnography (PSG) is considered as a golden rule for medical diagnosis of sleep disorder, it is essential to find alternative diagnosis methods due to its cost and time constraints. Recently, as the popularity of wearable health devices, there are many research trials to replace conventional actigraphy to consumer grade devices. However, these devices are very limited in their use due to the accessibility of the data and algorithms. In this paper, we showed the predictive model for sleep stages classified by American Academy of Sleep Medicine (AASM) standard and we proposed the estimation of sleep cycle by comparing sensor data and power spectrums of δ wave and θ wave. The sleep stage prediction for 31 subjects showed an accuracy of 85.26%. Also, we showed the possibility that proposed algorithm can find the sleep cycle of REM sleep and NREM sleep.

• Korean Journal of Clinical Laboratory Science
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• v.40 no.2
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• pp.129-134
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• 2008

Obstructive sleep apnea syndrome (OSAS) is occurred by apnea by the obstruction of upper trachea while sleeping, followed by repetitive drop on arterial oxygen saturation ($SpO_2$). Therefore, the present study was focused on relation between $SpO_2$ of while having difficulty in breathing and clinical characteristics of OSAS while sleeping. The study took place at Ewha women university Mokdong hospital with 149 subjects (male 121, female 28) who were examined for polysomnography (PSG) from May 2007 to February 2008. All subjects were adhered to electrodes and sensors to measure electroencephalogram (EEG), electrooculogram (EOG), chin & leg electromyogram (EMG), airflow at nasal and oral cavities, breathing movement of chest and abdominal snoring sound and $SpO_2$. Lowest $SpO_2$ in male was meaningfully low with higher body mass index (BMI), louder snoring sound and thick neck circumference (p<0.01). While mean $SpO_2$ based on the degree of AHI did not show significant difference, lowest $SpO_2$ was significantly low with high AHI (p<0.001). Also, lowest $SpO_2$ was closely correlated with BMI (r=-00.343, p<0.001), snoring sound (r=0.177, p<0.05), apnea index (r=-0.589, p<0.001), hypopnea index (r=-0.336, p<0.001) and apnea-hypopnea index (r=-0.664, p<0.001). $SpO_2$ was closely related to clinical characteristics of OSAS, like male, BMI, snoring sound and neck circumference. Also, polysomnography accompanied by recent development of sleep study is considered as critical test to diagnose OSAS, decide the severity of illness, and evaluate the treatment plan.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.42 no.3 s.303
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• pp.47-52
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• 2005

Obstructive Sleep Apnea (OSA) is a representative symptom of sleep disorder caused by the obstruction of upper airway. Because OSA causes not only excessive daytime sleepiness and fatigue, hypertension and arrhythmia but also cardiac arrest and sudden death during sleep in the severe case, it is very important to detect the occurrence and the frequency of OSA. OSA is usually diagnosed through the laboratory-based Polysomnography (PSG) which is uncomfortable and expensive. Therefore researches to improve the disadvantages of PSG are needed and studies for the detection of OSA using only one or two parameters are being made as alternatives to PSG. In this paper, we developed an algorithm for the detection of OSA based on Heart Rate Variability (HRV). The proposed method is applied to the ECG data sets provided from PhysioNet which consist of learning set and training set. We extracted features for the detection of OSA such as average and standard deviation of 1 minute R-R interval, power spectrum of R-R interval and S-peak amplitude from data sets. These features are applied to the input of neural network. As a result, we obtained sensitivity of $89.66\%$ and specificity of $95.25\%$. It shows that the features suggested in this study are useful to detect OSA.

• Korean Journal of Clinical Laboratory Science
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• v.51 no.1
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• pp.119-123
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• 2019

Obstructive sleep apnea (OSA) is a sleep disorder with no breathing symptoms due to repetitive upper airway resistance. OSA is a disease that can have significant effects on the cerebral cardiovascular system. Active treatment is needed to prevent these complications. The use of continuous positive airway pressure (CPAP), the standard therapy of OSA, has comparative therapeutic effects. On the other hand, there is no comparison report of the polysomnography (PSG) results before and after CPAP therapy without using a mask. This paper reports a patient who was diagnosed as OSA and used CPAP every night for more than 2 years. The patient showed a decrease in the apnea-hypopnea index from 64.7/h to 12.9/h. In addition, other sleep-related indicators improved significantly. The daily use of CPAP as a treatment for OSA for more than 2 years may improve the PSG results. Constant follow up of PSG will be needed to adjust the appropriate CPAP pressure to patients because there might be a change in the Apnea-Hypopnea Index and other sleep-related indicators for constant CPAP users for at least 2 years.

• Journal of Rhinology
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• v.25 no.2
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• pp.69-74
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• 2018

Background and Objectives: Sleep disturbances and excessive daytime sleepiness (EDS) are the major symptoms of obstructive sleep apnea (OSA). This study aimed to investigate clinical implications of insomnia and EDS in patients with OSA using the Pittsburgh Sleep Quality Index (PSQI) and Epworth Sleepiness Scale (ESS). Materials and Method: We evaluated 131 subjects with suspected OSA who were undergoing polysomnography (PSG) and performing the PSQI and ESS surveys. OSA was diagnosed when the apnea-hypopnea index was five or more. EDS was defined when ESS score was 11 points or higher. Detailed history and questionnaire were used to categorize insomnia. We compared clinical variables and PSG results in subgroups with or without insomnia and EDS. Results: There were no significant differences of PSQI and ESS score between controls and OSA. OSA with insomnia had significantly increased total score (p<0.001) and decreased total sleep time (p=0.001) and sleep efficiency (p=0.001) on the PSQI compared to those without insomnia. OSA with EDS showed significantly increased PSQI score (p=0.022) and decreased total sleep time (p=0.018) on PSG compared to those without EDS. Neither PSQI nor ESS score had a correlation with respiratory variables such as AHI and oxygen saturation. Total sleep time had a significant effect on both insomnia and EDS in patients with OSA. Conclusion: Decreased total sleep time had important effects on subjective symptoms of OSA and comorbid insomnia. Therefore, restoration of decreased sleep time is important in the management of OSA.