Digital polysomnography was developed to overcome the limitations of Rechtschaffen and Kales rule and to compensate the shortcomings of paper polysomnography. It enables easy access to and secure preservation of sleep records, and provides various displays of sleep data to enhance efficiency of visual scoring of sleep records. Rechtschaffen and Kales rule had been criticized for its ambiguity and lack of considerations in spatial information of EEG. As sleep records are acquired and processed in digital mode, they can be analyzed at microscopic and macroscopic levels. Digital analysis of sleep records provides the basis for development of new sleep measures. Sleep staging in digital polysomnography is based on the various analyses of EEG. Sleep apnea, hypopnea and periodic limb movement are detected automatically by digital analysis of respiratory signals and leg EMG. Digital polysomnography plays a complementary role to visual scoring and compensates the limitations of paper polysomnography. Digital polysomnography, including acquisition, processing and analysis of sleep records in digital mode, can be a great help in the development of sleep medicine, enabling the development of new sleep measures and the exchange of sleep records between sleep laboratories.
Brassica ; Electroencephalography ; Extremities ; Leg ; Polysomnography* ; Sleep Apnea Syndromes

INTRODUCTION: Detrended fluctuation analysis (DFA) is used as a way of studying nonlinearity of EEG. In this study, DFA is applied on sleep EEG of normal subjects to look into its nonlinearity in terms of EEG channels and sleep stages. METHOD: Twelve healthy young subjects (age: 23.8+/-2.5 years old, male:female=7:5) have undergone nocturnal polysomnography (nPSG). EEG from nPSG was classified in terms of its channels and sleep stages and was analyzed by DFA. Scaling exponents (SEs) yielded by DFA were compared using linear mixed model analysis. RESULTS: Scaling exponents (SEs) of sleep EEG were distributed around 1 showing long term temporal correlation and self-similarity. SE of C3 channel was bigger than that of O1 channel. As sleep stage progressed from stage 1 to slow wave sleep, SE increased accordingly. SE of stage REM sleep did not show significant difference when compared with that of stage 1 sleep. CONCLUSION: SEs of Normal sleep EEG showed nonlinear characteristic with scale-free fluctuation, long-range temporal correlation, self-similarity and self-organized criticality. SE from DFA differentiated sleep stages and EEG channels. It can be a useful tool in the research with sleep EEG.
Electroencephalography* ; Polysomnography ; Sleep Stages ; Sleep, REM

Adenotonsillar hypertrophy is the leading cause of childhood obstructive sleep apnea. Obstructive sleep apnea syndrome in child-hood, however, can occur from various causes such as obesity or craniofacial abnormalities. Childhood obstructive sleep apnea syndrome can be accompanied by enuresis, parasomnias and behavior problems. For patients with the symptoms of snoring and apnea, obstructive sleep apnea should be suspected and diagnosed properly. In addition, the evaluation of complications and proper treatment are indispensable. When the cause of childhood obstructive sleep apnea is adenotonsillar hypertrophy, symptoms can be improved by surgical methods. If the cause is other than adenotonsillar hypertrophy, such as obesity, it should be treated with other therapeutic modalities, like nasal continuous positive airway pressure (nCPAP), weight reduction and modification of life style. This paper reports a case of nCPAP used to manage severe sleep apnea when it was not resolved after adenoidectomy and tonsillectomy. Differential diagnosis of narcolepsy in a case with excessive daytime sleepiness and reflections on accompanying enuresis and parasomnia were also described.
Adenoidectomy ; Apnea ; Child ; Continuous Positive Airway Pressure ; Craniofacial Abnormalities ; Diagnosis, Differential ; Enuresis ; Humans ; Hypertrophy ; Life Style ; Narcolepsy ; Obesity ; Parasomnias ; Sleep Apnea Syndromes ; Sleep Apnea, Obstructive* ; Snoring ; Tonsillectomy ; Weight Loss

INTRODUCTION: Excessive daytime sleepiness and cataplexy are key features of narcolepsy. Modafinil is psychostimulant used in the treatment of narcolepsy. In this study, we evaluated effects of modafinil on nocturnal sleep structure and sleep latency in multiple sleep latency test and clinical features. METHODS: Twelve narcoleptic patients (7 male, age: 22.9 +/- 2.6 yrs) were participated in the study. All of them had done nocturnal polysomnography (nPSG), multiple sleep latency test (MSLT), clinical symptoms scales and have repeated same procedure after taking 200 mg of modafinil. We have done linear mixed model analysis to describe effects of group, medication and nap time on these measures. RESULTS: Modafinil did not affect clinical scales except PSQI which had been reduced after medication. In this study, Modafinil reduced total sleep time, sleep efficiency and increased wake after sleep onset and percent of arousal during sleep in nocturnal polysomnography and prolonged mean sleep latency in multiple sleep latency tests in both group. DISCUSSION: Modafinil has stimulant effect of central nervous system but its effect on night sleep is less than other psychostimulants such as methylphenidate. We ascertained that modafinil affected total sleep time, sleep efficiency and percent of wake during sleep but did not effect on sleep structure. Modafinil was effective in the management of day time sleepiness. Modafinil can enhance alertness of control group without day time sleepiness.
Arousal ; Cataplexy ; Central Nervous System ; Humans ; Male ; Methylphenidate ; Narcolepsy* ; Polysomnography ; Weights and Measures

The quantitative sudomotor axon reflex testing (QSART) is a classic test of routine postganglionic sudomotor function. We investigated sudomotor function by QSART after summer (July 2012) and winter (January 2013) seasonal acclimation (SA) in the Republic of Korea. QSART with acetylcholine (ACh) iontophoresis were performed to determine directly activated (DIR) and axon reflex-mediated (AXR1, 2) sweating rate. Onset time of axon reflex, activated sweat gland density (ASGD), activated sweat gland output (ASGO), tympanic and skin temperatures (T(ty), T(sk)), basal metabolic rate (BMR), and evaporative loss volume changes were measured. Tympanic and mean body temperature (T(b); calculated from T(ty), T(sk)) were significantly lower after summer-SA than that of winter-SA. Sweat onset time was delayed during winter-SA compared to that after summer-SA. BMR, AXR(1), AXR(2), and DIR sweat rates, ASGD and ASGO, and evaporative loss volume were significantly diminished after winter-SA relative to after summer-SA. In conclusion, changes in sweating activity measured by QSART confirmed the involvement of the peripheral nervous system in variation of sudomotor activity in seasonal acclimation.
Acclimatization* ; Acetylcholine ; Axons ; Basal Metabolism ; Body Temperature ; Humans* ; Iontophoresis ; Peripheral Nervous System ; Reflex ; Republic of Korea ; Seasons* ; Skin Temperature ; Sweat ; Sweat Glands ; Sweating

OBJECTIVE: To assess the reliability of triple marker screening test in midtrimester pregnancy for fetal Down syndrome. METHODS: From October 1, 1996 to May 31, 1998 at Nowon Eulji Hospital, 3700 Pregnant women underwent serum tiple marker screening for Down syndrome during 15-20weeks of gestational age. The results of serum triple marker screenig tests for Down syndrome and the outcomes of pregnancies were retrospectively assesed. RESULTS: Sixty seven of 3700 cases(1.81%) were positive in screening test, and 3633(98.18%) cases were negative. Among 67 cases of positive screening test, 1 case(1.49%) was diagnosed as Down syndrome. Among 3633 cases of negative screening test, 4 cases(0.1%) were diagnosed as chromosomal abnormalies postnatally. Two of these 4 cases of chromosomal abnormalies were Down syndrome. CONCLUSION: With this results, sensitivity of triple marker screeing test for Down syndrome is very low as 33.3%. In order to increase the sensitivity, some compensatory adjustment is required in triple marker screening test.
Down Syndrome* ; Equidae ; Female ; Gestational Age ; Humans ; Mass Screening* ; Pregnancy ; Pregnancy Outcome ; Pregnancy Trimester, Second* ; Pregnant Women ; Retrospective Studies

PURPOSE: To evaluate the clinical features of high myopic eyes with cataracts implanted with negative power intraocular lenses (IOLs) at the time of cataract surgery. METHODS: A retrospective chart review was conducted of 18 eyes of 14 patients who underwent cataract surgery with negative power IOLs and 10 eyes in 9 patients with low power IOLs. We investigated axial length, IOL power, preoperative and postoperative best-corrected visual acuity (BCVA) and preoperative and postoperative spherical equivalent (SE) refractive errors. RESULTS: Mean BCVA showed significant improvement in both groups. We measured postoperative SE refraction and the difference between the mean intended and the mean achieved SE refractive errors in the negative power group (17 eyes) was +1.59 ± 1.34 D and +0.31 ± 0.50 D in the low power group. CONCLUSIONS: BCVA was significantly improved in the majority of eyes, although they had myopic macular degeneration or posterior staphyloma. However, the mean achieved postoperative SE refraction was more hyperopic than the predicted postoperative SE error. Additionally, hyperopic refractive error was greater in the negative power group than the low power group. Therefore, we recommend that postoperative hyperopic refractive error should be considered when performing cataract surgery in high myopic patients.
Cataract Extraction* ; Cataract* ; Humans ; Lens Implantation, Intraocular* ; Lenses, Intraocular* ; Macular Degeneration ; Myopia* ; Refractive Errors ; Retrospective Studies ; Visual Acuity

PURPOSE: In the present study, a case of double fovea artifact on spectral-domain optical coherence tomography (SD-OCT) was reported. CASE SUMMARY: A nine-year-old male presented with blurred vision of both eyes. His best corrected visual acuity (BCVA) was 20/20 in both eyes, and complete ophthalmologic evaluation including fundus examination and fundus photography revealed no abnormality in both eyes. He underwent SD-OCT imaging with the Cirrus HD-OCT. The Macular Cube 512 × 128 protocol of his right eye revealed an unusual pseudo-duplication of the fovea in the vertical meridian. The same protocol in his left eye also rendered a pseudo-duplication of two foveas in the vertical and horizontal meridians on the retinal thickness map. Re-examination with the same OCT system and protocol was performed two weeks later after the patient received counseling on fixation during the examination, and it revealed normal contour of the fovea in both eyes. CONCLUSIONS: Double fovea artifact seen in SD-OCT is a rare artifact that can possibly lead to misdiagnosis and inappropriate clinical treatment. Since the artifact was resolved with better fixation of the patient, repeating the scan with better patient compliance is necessary when such an artifact is encountered.
Artifacts* ; Counseling ; Diagnostic Errors ; Humans ; Male ; Meridians ; Patient Compliance ; Photography ; Retinaldehyde ; Tomography, Optical Coherence* ; Visual Acuity

PURPOSE: To compare the clinical effectiveness of 1% Prednisolone acetate ophthalmic solution and 0.1% Bromfenac sodium hydrate ophthalmic solution on prevention of cystoid macular edema after cataract surgery. METHODS: A retrospective chart review of 349 patients who received phacoemulsification with intraocular lens implantation in Severance Hospital from July 2013 to January 2016 was performed. In these patients, 192 eyes received 1% Prednisolone acetate ophthalmic solution, and 157 eyes were treated with topical 0.1% Bromfenac sodium hydrate ophthalmic solution. The incidence and severity of cystoid macular edema (CME) were evaluated by retinal foveal thickness on optical coherence tomography for patients who showed best corrected visual acuity (BCVA) less than 0.5 (log MAR ≥ 0.3). RESULTS: There was no significant difference between the two groups in age (p = 0.708), sex (p = 0.977), or the side of operated eye (p = 0.443). The two groups showed BCVA 0.04 ± 0.09 (Steroid group) and 0.03 ± 0.07 (nonsteroidal anti-inflammatory drug [NSAID] group) at 1 month after the surgery and the difference was not significant (p = 0.947). One eye in the topical steroid group had cystoid macular edema, and 3 eyes in the steroid group showed elevated intraocular pressure (IOP) over 30 mm Hg. There were no IOP elevations or macular edema in the NSAID group. CONCLUSIONS: The results showed that 0.1% Bromfenac sodium hydrate ophthalmic solution had a similar effect to 1% Prednisolone acetate ophthalmic solution on preventing CME after cataract surgery. This indicates that topical NSAID can be considered along with topical steroids in order to prevent CME after cataract surgery.
Cataract* ; Humans ; Incidence ; Intraocular Pressure ; Lens Implantation, Intraocular ; Macular Edema* ; Phacoemulsification ; Prednisolone* ; Retinaldehyde ; Retrospective Studies ; Sodium ; Steroids ; Tomography, Optical Coherence ; Treatment Outcome ; Visual Acuity

The Beckwith-Wiedemann syndrome, which included congenital anomalies such as macroglossia, exomphalos, postnatal somatic gigantism, have a substantially increased risk for the development of tumor. We report a case of testicular yolk sac tumor associated with Beckwith-Wiedemann syndrome, a previously unreported association. Pathologic examination showed Schiller-Duval body with evidence of testicular yolk sac tumor. This finding appears to represent a previously unreported association between Beckwith-Wiedemann syndrome and testicular yolk sac tumor.
Beckwith-Wiedemann Syndrome* ; Endodermal Sinus Tumor* ; Gigantism ; Hernia, Umbilical ; Macroglossia ; Testis ; Yolk Sac*