OBJECTIVES: Narcolepsy is characterized by excessive sleepiness, cataplexy, sleep paralysis and hypnagogic hallucination. As there have been few researches on narcolepsy symptomatology in adolescents, we examined gender differences and prevalence of narcolepsy tetrad among students attending high school. METHODS: Total 20, 407 subjects, ages 14-19 years filled out Ullanlinna Narcolepsy Scale (UNS). Subjects whose UNS scores were equal to or more than 14 were interviewed by telephone using semi-structured questionnaire. Variables included questions to evaluate tetrad of narcolepsy. RESULTS: UNS scores were higher in female than male (11.1+/-5.2 vs. 9.6+/-4.5, p< 0.001). Subjects scoring the UNS equal to or more than 14 were 4, 535 (22.2% of all the participants), more frequently observed in female than in male (p< 0.001). Excessive daytime sleepiness, cataplexy-like symptoms, sleep paralysis and hypnagogic hallucination in subjects of UNS > or = 14 were significantly higher in female subjects than male ones. However, no significant gender difference was observed in the frequencies of severe sleep attack and cataplexy-like symptoms. Sleep paralysis was most frequently reported during sleep. There was significant correlation between sleep paralysis and hypnagogic hallucination (r=0.235, p< 0.01). CONCLUSIONS: Our findings were that female adolescents complained more frequently narcolepsy symptoms than male subjects. Female adolescents might be more sensitive than male ones to physical complaints such as sleepiness or muscle weakness.
Adolescent* ; Cataplexy ; Female ; Hallucinations ; Humans ; Male ; Muscle Weakness ; Narcolepsy* ; Prevalence ; Surveys and Questionnaires ; Sleep Paralysis ; Telephone ; United Nations

OBJECTIVES: The objective of this study is to assess cognitive functions and their relationship with sleep symptoms in young narcoleptic patients. METHODS: Eighteen young narcolepsy patients and 18 normal controls (age: 17-35 years old) were recruited. All narcolepsy patients had HLA DQB1 *0602 allele and cataplexy. Several important areas of cognition were assessed by a battery of neuropsychological tests consisting of 13 tests: executive functions (e.g. cognitive set shifting, inhibition, and selective attention) through Wisconsin card sorting test, Trail Making A/B, Stroop test, Ruff test, Digit Symbol, Controlled Oral Word Association and Boston Naming Test; alertness and sustained attention through paced auditory serial addition test; verbal/nonverbal short-term memory and working memory through Digit Span and Spatial Span; visuospatial memory through Rey-Osterrieth complex figure test; verbal learning and memory through California verbal learning test; and fine motor activity through grooved pegboard test. Sleep symptoms in narcolepsy patients were assessed with Epworth sleepiness scale, Ullanlinna narcolepsy scale, multiple sleep latency test, and nocturnal polysomnography. Relationship between cognitive functions and sleep symptoms in narcolepsy patients was also explored. RESULTS: Compared with normal controls, narcolepsy patients showed poor performance in paced auditory serial addition (2.0 s and 2.4 s), digit symbol tests, and spatial span (forward) (t=3.86, p< 0.01; t=-2.47, p=0.02; t=-3.95, p< 0.01; t=-2.22, p=0.03, respectively). There were no significant between-group differences in other neuropsychological tests. In addition, results of neuropsychological test in narcolepsy patients were not correlated with Epworth sleepiness scale score, Ullanlinna narcolepsy scale score and sleep variables in multiple sleep latency test or nocturnal polysomnography. CONCLUSION: The current findings suggest that young narcolepsy patients have impaired attention. In addition, impairment of attention in narcolepsy might not be solely due to sleep symptoms such as excessive daytime sleepiness.
Alleles ; California ; Cataplexy ; Cognition ; Executive Function ; Humans ; Memory ; Memory, Short-Term ; Motor Activity ; Narcolepsy* ; Neuropsychological Tests ; Polysomnography ; Stroop Test ; Trail Making Test ; Verbal Learning ; Wisconsin

OBJECTIVES: The purpose of this study was to assess the difference of subjective daytime sleepiness level between primary insomnia patients and healthy control subjects. We also investigated the relationship between subjective daytime sleepiness level and variables of nocturnal polysomnograghic sleep architecture of insomnia patients. METHOD: Total subjects were 87 patients with primary insomnia diagnosed with polysomnography and 88 normal controls. The daytime sleepiness level in each group was measured by Korean version of Epworth Sleepiness Scale (ESS). The correlations of ESS score and nocturnal polysomnographic variables were calculated in the patient group. RESULTS: Patients with insomnia had the lower ESS scores than the control group. In patients group, the ESS score showed significant negative correlations with total sleep time, sleep efficiency%, and stage 2 sleep time%. The ESS score also showed significant positive correlations with number of awakenings, number of awakenings more than 2 minutes, and wake after sleep onset time. CONCLUSIONS: Insomnia patients showed lower level of subjective daytime sleepiness that may indicate their higher alertness comparing to control subjects. Daytime sleepiness of patients with insomnia was associated with polysomnographic variables including total sleep time, sleep efficiency%, stage 2 sleep time% and disrupted continuity of nocturnal sleep.
Humans ; Polysomnography ; Sleep Initiation and Maintenance Disorders*

OBJECTIVES: Although many reports have been written on seasonal variations in mood and behavior in foreign countries, few reports have dealt with Korean adolescents, except medical students. The goal of this study was to estimate the frequency of seasonal variations in mood and behavior among Korean high school students. METHODS: A total of 656 high school students living in southeastern Seoul participated in this study. The subjects were investigated with the Korean translated version of the Seasonal Pattern Assessment Questionnaire (SPAQ), and their responses were evaluated for seasonal patterns in mood and behavior change according to Kasper's criteria to make SAD (seasonal affective disorder) or SSAD (subclinical seasonal affective disorder) diagnosis. RESULTS: A total of 565 subjects completed the questionnaire and the responses (M: F=324: 241) were collected and used for analysis. The mean age was 16.73 (SD=0.65) years, and mean global seasonality score 5.88 (SD=4.72). Of the respondents, 413 (73.1%) reported problems related with seasonal changes. Total prevalence rates were 13.6% for SAD, 10.8% for S-SAD. The estimated frequencies were 5.1% for summer SAD, 3.2% for summer S-SAD, 0.5% for winter SAD and 1.1% for winter S-SAD. The prevalence rate of summer SAD or S-SAD was higher than winter SAD or S-SAD. CONCLUSION: The subjects showed a higher prevalence rate of summer type than winter type in SAD or S-SAD. These results were similar to those of other studies carried out in East Asian countries. However, the unpleasant feelings resulting from high temperature and humidity in summer rather than depression may have influenced the results. Therefore, it is necessary to make new SAD criteria of the SPAQ suitable for East Asian countries.
Adolescent ; Asian Continental Ancestry Group ; Depression ; Diagnosis ; Epidemiology ; Humans ; Humidity ; Prevalence ; Surveys and Questionnaires ; Seasonal Affective Disorder ; Seasons* ; Seoul ; Students, Medical

The pathogenesis and mechanism of obstructive sleep apnea (OSA) has been under investigation for over 25 years, but its etiology and mechanism remains elusive. Skeletal (maxillary and/or mandibular hypoplasia or retrodisplacement, inferior displacement of hyoid) and soft tissue (increased volume of soft tissue, adenotonsillar hypertrophy, macroglossia, thickened lateral pharyngeal walls) factors, pharyngeal compliance (increased), pharyngeal muscle factors (impaired strength and endurance of pharyngeal dilators and fixators), sensory factors (impaired mechanoreceptor sensitivity, impaired pharyngeal dilator reflexes), respiratory control system factors (unstable respiratory control) and so on facilitate collapse upper airway. Therefore, OSA may be a heterogeneous disorder, rather than a single disease entity and various pathogenic factors contribute to the OSA varies person to person. As a result, patients may respond to different therapeutic approaches based on the predominant abnormality leading to the sleep disordered breathing.
Compliance ; Humans ; Hypertrophy ; Macroglossia ; Mechanoreceptors ; Pharyngeal Muscles ; Sleep Apnea Syndromes ; Sleep Apnea, Obstructive*

Approximately 1% to 3% of all children have obstructive sleep apnea syndrome (OSAS). OSAS in children can lead to a variety of symptoms and sequalae; impairment of development and quality of life, behavioral and personality disturbance, learning problem, cor pulmonale and hypertension. Diagnosis and treatment of OASA for children are different from those for adults in many respects. Adenotonsillar hypertrophy is major cause of childhood OSAS. Overnight polysomnography in a sleep laboratory is the gold standard for diagnosing childhood OSAS. However, because full polysomnography in children may be difficult to obtain, expensive, and inconvenient, other methods to diagnose OSAS have been investigated. Adenotonsillectomy is the most common surgical treatment of childhood OSAS. But if residual symptoms remained after adenotonsillectomy, it should be considered to additional treatment such as weight control, sleep positional change, and continuous positive airway pressure (CPAP).
Adenoids ; Adult ; Child ; Continuous Positive Airway Pressure ; Diagnosis ; Humans ; Hypertension ; Hypertrophy ; Learning Disorders ; Palatine Tonsil ; Polysomnography ; Pulmonary Heart Disease ; Quality of Life ; Sleep Apnea, Obstructive*

Nasal obstruction may cause or aggravate sleep disordered breathing but exact pathogenesis is not clear. The possible mechanism could be combination of alteration in upper airway aerodynaimcs, loss of nasal reflex or sensation, effect of mouth opening, and a genetic predisposition. Anatomical narrowing of nasal airway cause more rapid airflow and induce more negative inspiratory air pressure. So, it increases collapsibility of pharyngeal airway. Loss of nasal sensation to airflow block nasal reflex. Mouth opening decreases the activity of pharyngeal airway dilator muscles and narrowing the pharyngeal airway may occur. The treatment of nasal obstruction should be done according to the cause. The causes of nasal obstruction are various from problems of external nasal opening to nasopharynx. Relief of nasal obstruction may not cure sleep disordered breathing always. In some mild obstructive sleep apnea patients, treatment of nasal obstruction only may cure sleep disordered breathing. In some severe sleep apnea patients, treatment of nasal obstruction may increase compliance of continous nasal positive airway pressure.
Air Pressure ; Compliance ; Genetic Predisposition to Disease ; Humans ; Mouth ; Muscles ; Nasal Obstruction* ; Nasopharynx ; Reflex ; Sensation ; Sleep Apnea Syndromes* ; Sleep Apnea, Obstructive

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.
Cytokines ; Immune System ; Interleukin-1 ; Physiology ; Sleep Apnea, Obstructive ; Sleep Wake Disorders ; Tumor Necrosis Factor-alpha

OBJECTIVES: The sensitivity and accuracy of thermistor airflow signal has been debated. The purposes of this study were to compare apnea-hypopnea index(AHI) detected from a conventional thermistor signal and a nasal pressure transducer of airflow(NPT), to evaluate the value of NPT for the diagnosis of upper airway resistance syndrome (UARS), and to measure airway pressure fluctuations which produced respiratory arousals in UARS by naso-oro-esophageal manometer catheter. The subjects were 30 patients with obstructive sleep apnea syndrome [mild(540), 10), and 6 UARS patients. Airway resistance arousal in this study was defined as arousals which were not associated with apnea or hypopnea of thermistor signal, but showed significant decrease of nasal airflow pressure just before arousal and a prompt recovery of nasal airflow pressure after arousal, The airway pressure fluctuations were measured during 260 airway resistance arousals observed in 10 patients with OSAS, 2 with UARS. RESULTS: Mean AHIs of patients with OSAS were 33.4 by thermistor and 48.4 by NPT. The AHIs of mild, moderate and severe OSAS group were 10.2, 32.1, 65.4 respectively by thermistor and 23.1, 45.9, 76.4 by NPT. The mean AHI of patients with UARS was 3.2 by tehrmistor and 108 by NPT. The mean AHI of patients with nonspecific arousals was 2.7 by thermistor and 4.4 by NPT. The mean airway pressure changes during resiratory arousals of different groups were 8.7 cmH2O in mild OSAS, 11.4 cmH2O in moderate OSAS, 24.7 cmH2O in severs OSAS and 6.6 cmH2O in UARS. CONCLUSION: The nasal pressure transducer of airflow was more sensitive and accurate for assessing respiratory disturbances of patients with OSAS and was extremely helpful for the diagnosis of UARS without esophageal pressure monitoring. From the results, we would like to propose carefully the NPT diagnostic criteria for sleep disordered breathing as follows : NPT-AHI 5-15->UARS, 15-35->mild OSAS, 35-55->moderate OSAS and >55 ->severe OSAS.
Airway Resistance* ; Apnea ; Arousal ; Catheters ; Diagnosis ; Humans ; Sleep Apnea Syndromes ; Sleep Apnea, Obstructive* ; Transducers, Pressure

We report a case of obstructive sleep apnea syndrome, which occurred primarily during the REM sleep stage. A 55-year-old female patient who complained of chronic insomnia on the initial visit turned out to have obstructive sleep apnea syndrome of a mild degree (respiratory disturbance index (RDI) of 13.8/hour, %time spent below 90% of SaO2=5.0%) on nocturnal polysomnography. Interestingly, apnea episodes and desaturations mainly occurred during REM sleep stage. And RDI and destaturations during REM sleep stage were found to be severe enough to classify as a severe degree of obstructive sleep apnea syndrome. These findings suggest that severe obstructive sleep apnea syndrome might be masked under the symptom of chronic insomnia and that apneas can be predominantly localized within REM sleep epochs. In terms of treatment, "REM sleep-dependent" apneas may call for different methods of treatment, especially REM sleep-specific pharmacological intervention.
Apnea ; Female ; Humans ; Masks ; Middle Aged ; Polysomnography ; Sleep Apnea, Obstructive* ; Sleep Initiation and Maintenance Disorders ; Sleep, REM