• Sleep Medicine and Psychophysiology
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• v.13 no.2
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• pp.67-74
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• 2006

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: $22.9{\pm}2.6\;yrs$) 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.

• Sleep Medicine and Psychophysiology
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• v.7 no.2
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• pp.102-108
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• 2000

Objectives: Parkinson's disease (PD) patients may experience fluent mobility upon awakening from a night's sleep, which is called sleep benefit (SB). Although SB is a phenomenon closely associated with sleep, sleep features of PD are not well characterized. The objectives of this study were, first, to investigate if there are any clinical characteristic features between patients with SB and without SB (NSB), and second, to examine if SB patients are associated with any specific sleep variables compared with NSB patients. Methods: Thirty-three PD patients (14 men and 19 women) participated in this study. All subjects were interviewed to examine whether or not they had SB and overnight polysomnography was performed at the sleep center. Various clinical variables were collected through medical record review. Results: The 331 PD patients were divided into 16 SB group (48.5%) and 17 NSB group (51.5%). SB patients were younger (p<0.02), had higher sleep efficiency (p<0.05), and showed shortened sleep latency (p<0.02) as compared with NSB patients. However, no difference was found between SB and NSB with respect to gender, duration or stage of PD, antiparkinsonian medications prescribed, and predominant motor symptoms. SB did not clearly relate to a specific sleep stage and other sleep variables except sleep efficiency and sleep latency. Although primary snoring was more prevalent in SB patients (p<0.05), other sleep disorders were seen with equal frequency in SB and NSB groups. Conclusion: Our results suggest that good sleep efficiency, shortened sleep latency, and age may have an effect on morning motor function (i.e., SB) in Parkinson's disease.

• Sleep Medicine and Psychophysiology
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• v.18 no.1
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• pp.40-44
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• 2011

Narcolepsy is a sleep disorder, which is characterized by excessive daytime sleepiness (EDS) that is typically associated with cataplexy, sleep fragmentation and other REM sleep-related phenomenon such as sleep paralysis and hypnagogic hallucination. Narcoleptic symptoms can be developed from various medical or neurological disorders. A 17-year-old male patient admitted for the evaluation of EDS which started three-month ago. He slept more than 18 hours a day with cataplexy and hypnagogic hallucination. He was obese with body mass index (BMI) of 30.4 kg/$m^2$. After admission he was newly diagnosed to the thyrotoxicosis. T3 391.2 ng/dL (60-181), free T4 4.38 ng/dL (0.89-1.76), TSH <0.01 ${\mu}IU$/mL (0.35-5.5) were measured. His pulse rate ranged 70-90 beats per minute and blood pressure ranged 150/100-120/70 mmHg. Polysomnography revealed many fragmentations in sleep with many positional changes (81 times/h). Sleep onset latency was 33.5 min, sleep efficiency was 47.9%, and REM latency from sleep onset was delayed to 153.6 min. REM sleep percent was increased to 27.1%. Periodic limb movement index was 13.4/h. In the multiple sleep latency test (MSLT), average sleep latency was 0.4 min and there were noted 3 SOREMPs (Sleep Onset REM sleep period) on 5 trials. We couldn't discriminate the obvious sleep-wake pattern in the actigraph and his HLA DQB1 $^*0602$ type was negative. His thyroid function improved following treatment with methimazole and propranolol. Vital sign maintained within normal range. Cataplexy was controlled with venlafaxine 75 mg. Subjective night sleep continuity and PLMS were improved with clonazepam 0.5 mg, but the EDS were partially improved with modafinil 200-400 mg. Thyrotoxicosis might give confounding role when we were evaluating the EDS, though sleep fragmentation was one of the major symptoms of narcolepsy, but enormous amount of it made us think of the influence of thyroid hormone. The loss of sleep-wake cycle, limited improvement of EDS to the stimulant treatmen, and the cataplexy not supported by HLA DQB1 $^*0602$ should be answered further. We still should rule out idiopathic hypersomnia and measuring CSF hypocretin level would be helpful.

• Journal of Information Processing Systems
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• v.2 no.1
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• pp.39-43
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• 2006

In this paper, we proposed TASL-MAC, a medium-access control (MAC) protocol for wireless sensor networks. In wireless sensor networks, sensor nodes are usually deployed in a special environment, are assigned with long-term work, and are supported by a limited battery. As such, reducing the energy consumption becomes the primary concern with regard to wireless sensor networks. At the same time, reducing the latency in multi-hop data transmission is also very important. In the existing research, sensor nodes are expected to be switched to the sleep mode in order to reduce energy consumption. However, the existing proposals tended to assign the sensors with a fixed Sleep/Listening schedule, which causes unnecessary idle listening problems and conspicuous transmission latency due to the diversity of the traffic-load in the network. TASL-MAC is designed to dynamically adjust the duty listening time based on traffic load. This protocol enables the node with a proper data transfer rate to satisfy the application's requirements. Meanwhile, it can lead to much greater power efficiency by prolonging the nodes' sleeping time when the traffic. We evaluate our implementation of TASL-MAC in NS-2. The evaluation result indicates that our proposal could explicitly reduce packet delivery latency, and that it could also significantly prolong the lifetime of the entire network when traffic is low.

• Korean Journal of Pharmacognosy
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• v.44 no.3
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• pp.281-285
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• 2013

Ethanol extract of Gastrodia elata fermented with Lactobacillus brevis was highly effective on the duration of pentobarbital hypnosis in mice. Pretreatment of mice with ethanol extract of the fermented Gastrodia elata (200 mg/kg, p.o.) prolonged markedly the duration of pentobarbital sleeping time and reduced the sleep latency. The mechanism of the extract of the fermented Gastrodia elata was investigated to inhibit the binding of $^3H$-Flumazenil, a selective benzodiazepine receptor antagonist, to benzodiazepine receptor of mice cortices. $IC_{50}$ value from displacement of $^3H$-Flumazenil binding was 62 ${\mu}g/mL$ at the treatment of the fermented Gastrodia elata. Therefore, these finding, such as increase of sleeping time and reduction of sleep latency, was examined by elevated concentration of GABA and parishin C, which were increased by Lactobacillus brevis.

• Annals of Clinical Neurophysiology
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• v.17 no.1
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• pp.17-23
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• 2015

Background: Sleep-related disturbances and sleep disorders are common in Parkinson's disease (PD) and have a great impact on daily life of PD patients. This study was done to find the sleep characteristics and sleep disturbing factors in PD patients according to disease severity through clinical interview and polysomnographic (PSG) study. Methods: Fifty patients with PD (22 males, age $60.6{\pm}6.4$, Hoehn and Yahr (HY) stage $2.7{\pm}1.0$) were recruited and thoroughly interviewed about their sleep. PSG was performed on the patients taking routine antiparkinsonian medications. Patients were grouped into mild and moderate/severe group according to HY stage, and the results were compared between each group. Results: Ninety-four percent of total patients had one or more sleep-related disturbances based on the interview or PSG. On interview, the moderate/severe group complained more insomnia and REM sleep behavior disorder (RBD) than mild group. In PSG findings, the moderate/severe group showed lower sleep efficiency, longer sleep latency, REM sleep latency, waking time after sleep onset, and higher prevalence of RBD. Conclusions: In this study, most patients with PD had sleep disturbances. Clinical interview and PSG findings revealed deterioration of sleep quality along the disease severity. Our results suggest that sleep disturbances in PD patients are prevalent and warrant clinical attention, especially to the patients with advanced disease.

• Sleep Medicine and Psychophysiology
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• v.20 no.1
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• pp.22-30
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• 2013

Objectives: Sleep problems has been consistently reported as a suicidal risk factor in adults and, recently, also in adolescents. In this study, dividing study subjects by the previous suicidal behaviors (suicidal vs non-suicidal), we compared the group differences of suicidal risk factors, and examined the possibility of sleep as a suicidal risk factor. Methods: Study subjects were 561 (271 boys and 290 girls) from a community sample of high school students. Suicidal Risk Behavior Checklist, Center for Epidemiological Study-Depression (CES-D), Symptom Checklist-90-Revision (SCL-90-R) Anxiety and Aggression subscale, Pittsburg Sleep Quality Index (PSQI) were done. Results: Forty six students (8.1%) reported previous actual self-harm behavior as a suicidal attempt, 181 students (32.4%) reported having suicidal thought only. Three hundred thirty four students (59.5%) reported no previous suicidal behavior (thought and attempt, both). Suicidal behavior group showed higher score on risk behaviors such as school violence, substance use and internet addiction. CES-D, SCL-90-R, PSQI showed significant group difference. Logistic regression analysis showed suicidal risk were significantly associated with depression, stress in suicidal risk factors and sleep latency, daytime dysfunction in PSQI. Analysis of variance (ANOVA) shows the most prolonged sleep latency and increased index of all PSQI components except sleep efficiency in suicidal attempt group. Conclusions: Sleep Problems had a strong association with the suicidal risk behavior in adolescents. Sleep problems, especially, prolonged sleep latency, daytime dysfunction might be important markers for suicidal behavior. Screening for sleep problems in adolescents are encouraged for the parents, school teachers, and related medical physicians.

• Food Science of Animal Resources
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• v.37 no.5
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• pp.646-653
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• 2017

Alcalase hydrolysis of liquid egg white was used to produce 5-hydroxytryptophan (HTP) under various conditions and investigate the sleep-potentiating activity of liquid egg white hydrolysate (LEH) on pentobarbital-induced sleep. Alcalase hydrolysis yielded the highest content of 5-HTP ($13.50{\mu}g/mL$), while neutrase hydrolysis showed the lowest 5-HTP content ($5.23{\mu}g/mL$). The liquid egg white to water ratio (1:1) was optimal for the production of 5-HTP with high amino-nitrogen (A-N) content and degree of hydrolysis. The 5-HTP, amino-nitrogen, and degree of hydrolysis increased until 24 h of hydrolysis and slightly increased thereafter during hydrolysis with 2% and 5% enzyme addition. 5-HTP administration at doses of 6 and 9 mg/kg significantly increased sleep duration and decreased sleep latency time compared to that in the control (p<0.05). LEH (150 mg/mouse), which was equivalent to 5-HTP at 6 mg/kg, significantly decreased sleep latency time and increased sleep duration time compared to that in the control (p<0.05). Oral administration of LEH showed sleep-potentiating effects because of 5-HTP. The sleep-potentiating activity of LEH may have occurred through 5-HTP in our pentobarbital-induced sleep model. LEH may be a valuable alternative to sleep enhancement and may be used as a sleep-potentiating agent.

• Journal of Korean Neurosurgical Society
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• v.61 no.5
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• pp.600-607
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• 2018

Objective : It has been reported in recent studies that 50-80% of patients with cervical disc hernia have concomitant sleep disorders. The aim of this study was to evaluate the quality of sleep before and after surgical treatment in patients with cervical disc hernia and to assess the effects on treatment. Methods : The study included 32 patients performed discectomy and fusion with an intervertebral cage through the right anterior cervical approach. Oswestry Disability Index (ODI), Visual Analog Scale (VAS) and Pittsburgh Sleep Quality Index (PSQI) were applied to all patients preoperatively and at one month postoperatively. Results : The postoperative PSQI total points and all the PSQI subscale points, the ODI and VAS scores were significantly reduced compared to the preoperative values. A positive correlation was determined between the preoperative ODI points and the PSQI total points and sleep duration, sleep latency and daytime functional loss subscale points. A positive correlation was also found between preoperative ODI points and VAS points. A positive correlation was determined between the preoperative VAS points and and the PSQI total points and sleep duration, and sleep latency subscale points. A negative correlation was determined between the postoperative ODI and the daytime functional loss subscale points. Conclusion : The results of the study showed that in patients with cervical disc hernia, sleep quality and daytime functionality were negatively affected by severity of pain that limited daily activities. Bringing the pain under control with surgical treatment was observed to increase sleep quality. It can be concluded that when planning treatment for these patients, it should be taken into consideration that there could be a sleep disorder in addition to the complaints and symptoms such as pain, hypoestesia and loss of strength.

• Sleep Medicine and Psychophysiology
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• v.2 no.1
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• pp.44-54
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• 1995

It is very difficult to evaluate sleep disorders by simple history taking, because which covers very comprehensive areas such as psychobiosocial fields. Although polysomnography is used for the method of final diagnosis, systemic history taking and sleep question-aires are still critically important especially in evaluation of insomnia. Proper informations through sleep questionnaires can provide very precise data for effective treatment as well as exact diagnosis. Sleep questionnaires consist of largely four kinds of questionnaires, which are screening questionnaire of sleep disorders, sleep diary and questionnaire of sleep hygine, diagnostic questionnaire for specific sleep disorder and questionnaire of special symptoms of sleep disorders including insomnia, daytime sleepiness, cognitive function, mental symptom and personality, parasomnia, physical illness and sexual function. However, for more conclusive diagnosis especially in excessive daytime sleepiness nocturnal polysomnography and multiple sleep latency test should be performed.