Electroencephalographic Changes Induced by a Neurofeedback Training : A Preliminary Study in Primary Insomniac Patients / 수면정신생리

OBJECTIVES: Insomnia is one of the most prevalent sleep disorders. Recent studies suggest that cognitive and physical arousal play an important role in the generation of primary insomnia. Studies have also shown that information processing disorders due to cortical hyperactivity might interfere with normal sleep onset and sleep continuity. Therefore, focusing on central nervous system arousal and normalizing the information process have become current topics of interest. It has been well known that neurofeedback can reduce the brain hyperarousal by modulating patients' brain waves during a sequence of behavior therapy. The purpose of this study was to investigate effects of neurofeedback therapy on electroencephalography (EEG) characteristics in patients with primary insomnia. METHODS: Thirteen subjects who met the criteria for an insomnia diagnosis and 14 control subjects who were matched on sex and age were included. Neurofeedback and sham treatments were performed in a random order for 30 minutes, respectively. EEG spectral power analyses were performed to quantify effects of the neurofeedback therapy on brain wave forms. RESULTS: In patients with primary insomnia, relative spectral theta and sigma power during a therapeutic neurofeedback session were significantly lower than during a sham session (13.9 ± 2.6 vs. 12.2 ± 3.8 and 3.6 ± 0.9 vs. 3.2 ± 1.0 in %, respectively; p < 0.05). There were no statistically significant changes in other EEG spectral bands. CONCLUSION: For the first time in Korea, EEG spectral power in the theta band was found to increase when a neurofeedback session was applied to patients with insomnia. This outcome might provide some insight into new interventions for improving sleep onset. However, the treatment response of insomniacs was not precisely evaluated due to limitations of the current pilot study, which requires follow-up studies with larger samples in the future.

Polysomnographic Characteristics and Prescription Status of Restless Legs Syndrome Patients in Naturalistic Setting / 수면정신생리

OBJECTIVES: The aim of this study is to evaluate the polysomnographic characteristics and prescription status of restless legs syndrome (RLS) patients in naturalistic setting. METHODS: We reviewed medical record of the patients over 18 years olds who (i) satisfied the clinical RLS diagnostic criteria and (ii) had the polysomnography and got treatment related thereto. As a baseline, we evaluated the four diagnostic criteria of the International Restless Legs Syndrome Study Group (IRLSSG) and the International Restless Legs Scale (IRLS) of the subjects. Then the polysomnography and the suggested immobilization test (SIT) were conducted and, after one month of pharmacotherapy using dopamine agonist, the IRLS was evaluated again. RESULTS: A total of 211 subjects participated in this analysis and 94 (44.5%) of them were male and the other 117 (55.5%) were female and the average age of the 211 subjects was 46.9+/-14.2. Out of such 211 subjects, 136 subjects (64.5%) also had the obstructive sleep apnea (OSA), and 53 subjects (25.1%) also had the periodic limb movement disorder (PLMD). 185 subjects (87.7%) out of the 211 subjects had some other sleep disorders except RLS. The results of the polysomnography were as follows : 78.0% of sleep efficiency, 86.8 min of wake after sleep onset, and 3.4% of N3. More specifically, 12.4/h of the average apnea hypopnea index, 14.8/h of the periodic limb movement during sleep (PLMS), 41.2/h of the periodic limb movement during wake during SIT and 21.6/h of total arousal index during sleep. Out of the total subjects, 149 (70.6%) of them took the ropinirole and 47 (22.3%) of them took the pramipexole, and the average dosage of ropinirole was 0.9mg(dosage range 0.125-5 mg) while the average dosage of pramipexole was 0.5 mg (dosage range 0.125-4 mg). The dosage of the ropinirole showed a significant positive correlation with the age (r=0.25, p=0.002) and also with the IRLS (r=0.23, p=0.038). The IRLS at the baseline was 24.9 while the same was decreased down to 13.4 after one month. CONCLUSIONS: Analyzing the result of this study, a majority of clinical RLS subjects demonstrated comorbidity with some other sleep disorder such as the OSA or PLMD. 25.1% of the subjects showed a PLMD, which was less than in previous researches and the average PLMS was not very high as 14.8/h. The dosage of dopamine agonist taken was often a bit more than the amount recommended in Korea. A prospective research using a large scale controlled subjects will be necessary with respect to this topic.

Productivity Time Lost by Sleep Disturbance among Workers in Korea / 신경정신의학

OBJECTIVES: The daily activities and performance of the working population can be threatened by sleep disturbances, including insomnia. This study evaluated the sleep patterns, sleep problems, daytime sleepiness, and lost productivity time (LPT) resulting from sleep quality and sleep duration issues among workers. METHODS: The Pittsburgh Sleep Quality Index (PSQI), the Epworth Sleepiness Scale (ESS), and the Health and Work Performance Questionnaire (HPQ) were completed by 653 workers in an urban area. Statistical analyses were performed using independent t-tests. RESULTS: The average sleep duration among the subjects was 6 h 37 min. While 19.6% of the subjects complained of poor sleep quality, 53.4% were affected during the day by insomnia. The estimated annual cost of LPT due to presenteeism (Won13,892,545 vs. Won11,840,140 ; p=0.033) and the total annual cost of LPT (Won14,040,968 vs. Won11,961,302 ; p=0.032) were higher in poor sleepers than in good sleepers. Furthermore, workers with a shorter sleep duration had a higher annual LPT due to presenteeism (747.83 vs. 648.57 h ; p=0.046) and a higher total annual LPT (754.48 vs. 657.99 h ; p=0.049) than workers with a longer sleep duration. CONCLUSION: Sleep deprivation among workers caused 1 h 51 min LPT per week. This suggests that sleep disturbance affects workers' performance in an organization, as well as in terms of individual health.

Productivity Time Lost by Sleep Disturbance among Workers in Korea / 신경정신의학

OBJECTIVES: The daily activities and performance of the working population can be threatened by sleep disturbances, including insomnia. This study evaluated the sleep patterns, sleep problems, daytime sleepiness, and lost productivity time (LPT) resulting from sleep quality and sleep duration issues among workers. METHODS: The Pittsburgh Sleep Quality Index (PSQI), the Epworth Sleepiness Scale (ESS), and the Health and Work Performance Questionnaire (HPQ) were completed by 653 workers in an urban area. Statistical analyses were performed using independent t-tests. RESULTS: The average sleep duration among the subjects was 6 h 37 min. While 19.6% of the subjects complained of poor sleep quality, 53.4% were affected during the day by insomnia. The estimated annual cost of LPT due to presenteeism (Won13,892,545 vs. Won11,840,140 ; p=0.033) and the total annual cost of LPT (Won14,040,968 vs. Won11,961,302 ; p=0.032) were higher in poor sleepers than in good sleepers. Furthermore, workers with a shorter sleep duration had a higher annual LPT due to presenteeism (747.83 vs. 648.57 h ; p=0.046) and a higher total annual LPT (754.48 vs. 657.99 h ; p=0.049) than workers with a longer sleep duration. CONCLUSION: Sleep deprivation among workers caused 1 h 51 min LPT per week. This suggests that sleep disturbance affects workers' performance in an organization, as well as in terms of individual health.

Narcolepsy: Clinical Feature, Diagnosis and Treatment / 수면정신생리

Narcolepsy is a central neurologic system disease. It begins early in life with disabling symptoms including excessive daytime sleepiness, cataplexy, sleep paralysis, hypnagogic hallucination and nocturnal sleep fragmentation. Patient with typical symptoms of narcolepsy is diagnosed by objective data from nocturnal polysomnography and multiple sleep latency tests. Narcolepsy is controlled with various medications. Nowadays, modafinil with favorable side effects profiles compared with traditional stimulant is mainly used. Gamma hydroxyl butyrate is effective in cataplexy. Cataplexy is also controlled with antidepressant such as Venlafaxine, SSRI, and TCA. As the knowledge of pathophysiology of narcolepsy expands, new treatment including immunological method, application of hypocretin and histamine systems have been tried.

Clinical Efficacy of Individual Cognitive Behavioral Therapy for Patients with Primary or Secondary Insomnia / 수면정신생리

OBJECTIVES: This study aimed to evaluate the clinical efficacy of individual cognitive behavioral therapy (CBT) for Patients with Primary or Secondary Insomnia. METHODS: Participants were recruited from a primary care sleep clinic from January 2008 to June 2009. The study sample included 64 outpatients with primary insomnia (n=30) and secondary insomnia (n=34) according to the criteria of DSM-IV. Participants completed sleep diaries, Dysfunctional Beliefs and Attitudes about Sleep Scale-16 (DBAS), State-Trait Anxiety Inventory (STAI) before CBT and shortly after completion of CBT. CBT was provided in 7 weekly, 40-50-minute individual therapy sessions. RESULTS: Both groups of patients with primary and secondary insomnia showed significant improvement in the DBAS and sleep parameters including sleep onset latency, total sleep time, and sleep efficiency. Repeated-measures ANOVA of the DBAS and sleep parameters showed no significant group-by-time interactions between patients with primary and secondary insomnia, suggesting the efficacy of CBT for patients with secondary insomnia was equivalent to that of CBT for patients with primary insomnia. CONCLUSION: This study suggests that CBT is effective for the management of primary and secondary insomnia in a primary care setting.

Detrended Fluctuation Analysis of Sleep Electroencephalogram between Obstructive Sleep Apnea Syndrome and Normal Children / 수면정신생리

Unlike the case of adult obstructive sleep apnea syndrome (OSAS), there was no consistent finding on the changes of sleep architecture in childhood OSAS. Further understanding of the sleep electroencephalogram (EEG) should be needed. Non-linear analysis of EEG is particularly useful in giving us a new perspective and in understanding the brain system. The objective of the current study is to compare the sleep architecture and the scaling exponent (alpha) from detrended fluctuation analysis (DFA) on sleep EEG between OSAS and normal children. Fifteen normal children (8 boys/7 girls, 6.0+/-2.2 years old) and twelve OSAS children (10 boys/2 girls, 6.4+/-3.4 years old) were studied with polysomnography (PSG). Sleep-related variables and OSAS severity indices were obtained. Scaling exponent of DFA were calculated from the EEG channels (C3/A2, C4/A1, O1/A2, and O2/A1), and compared between normal and OSAS children. No difference in sleep architecture was found between OSAS and normal controls except stage 1 sleep (%) and REM sleep latency (min). Stage 1 sleep (%) was significantly higher and REM latency was longer in OSAS group (9.3+/-4.3%, 181.5+/-59.9 min) than in controls (5.6+/-2.8%, 133.5+/-42.0 min). Scaling exponent (alpha) showed that sleep EEG of OSAS children also followed the 'longrange temporal correlation' characteristics. Value of alpha increased as sleep stages increased from stage 1 to stage 4. Value of alpha from C3/A2, C4/A1, O1/A2, O2/A1 were significantly lower in OSAS than in control (1.36+/-0.05 vs. 1.41+/-0.04, 1.37+/-0.04 vs. 1.41+/-0.04, 1.37+/-0.05 vs. 1.41+/-0.05, and 1.36+/-0.07 vs. 1.41+/-0.05, p<0.05). Higher stage 1 sleep (%) in OSAS children was consistent finding with OSAS adults. Lower 'alpha' in OSAS children suggests decrease of self-organized criticality or the decreased piling-up energy of brain system during sleep in OSAS children.

Sleep-Related Breathing Disorders in the Elderly: Clinical Feature, Diagnosis and Treatments

Sleep-related breathing disorder in the elderly is common but not diagnosed and treated properly. Sleep apnea in the elderly differs from that in young adults and does not show overt sign of it such as snoring and excessive daytime sleepiness. Co morbidities of elderly patients make it difficult to diagnosis and treatment of sleep apnea. Untreated sleep-related breathing disorders can cause cardiovascular disease, cognitive impairment and dementia. Sleep-related breathing disorder is diagnosed with thorough history taking and polysomnography. Continuous positive airway pressure (CPAP) is treatment of choice for sleep apnea in elderly. When patient failed to adapt in CPAP, oral appliance or surgical approach can be considered.

Correlation between the Severity of Obstructive Sleep Apnea and Heart Rate Variability Indices

The risk of cardiovascular disease is known to be increased in obstructive sleep apnea syndrome (OSAS). Its mechanism can be explained by the observation that the sympathetic tone increases due to repetitive apneas accompanied by hypoxias and arousals during sleep. Heart rate variability (HRV) representing cardiac autonomic function is mediated by respiratory sinus arrhythmia, baroreflexrelated fluctuation, and thermoregulation-related fluctuation. We evaluated the heart rate variability of OSAS patients during night to assess their relationship with the severity of the symptoms. We studied overnight polysomnographies of 59 male untreated OSAS patients with moderate to severe symptoms (mean age 45.4+/- 11.7 yr, apnea-hypopnea index [AHI]=43.2+/-23.4 events per hour, and AHI >15). Moderate (mean age 47.1+/-9.4 yr, AHI=15-30, n=22) and severe (mean age 44.5 +/-12.9 yr, AHI >30, n=37) OSAS patients were compared for the indices derived from time and frequency domain analysis of HRV, AHI, oxygen desaturation event index (ODI), arousal index (ArI), and sleep parameters. As a result, the severe OSAS group showed higher mean powers of total frequency (TF) (p=0.012), very low frequency (VLF) (p= 0.038), and low frequency (LF) (p=0.002) than the moderate OSAS group. The LF/HF ratio (p=0.005) was higher in the severe group compared to that of the moderate group. On the time domain analysis, the HRV triangular index (p=0.026) of severe OSAS group was significantly higher. AHI was correlated best with the LF/HF ratio (r(p)=0.610, p<0.001) of all the HRV indices. According to the results, the frequency domain indices tended to reveal the difference between the groups better than time domain indices. Especially the LF/HF ratio was thought to be the most useful parameter to estimate the degree of AHI in OSAS patients.

Discrimination between obstructive sleep apnea syndrome and primary snoring in children : comparison of clinical parameters and behavioral disturbance / 소아과

PURPOSE: To determine whether primary snoring could be distinguished from obstructive sleep apnea syndrome (OSAS) by clinical evaluation and symptom scores. METHODS: 56 snoring and 20 asymptomatic subjects were recruited and polysomnography was used to confirm that there were 39 OSAS, 17 primary snoring, and 20 control subjects. We evaluated the size of the childrens adenoids and tonsils. Parents completed sleep disordered breathing scale (SDBS) and obstructive sleep apnea 18 (OSA-18) questionnaires for use as symptom scores, as well as an attention deficit hyperactivity disorder rating scale-IV (ADHD RS-IV). RESULTS: There were no differences between primary snoring and OSAS in terms of tonsil and adenoid size, SDBS (9.4+/-4.6 vs 10.8+/-4.5), and OSA-18 score (61.1+/-25.1 vs 71.2+/-8.4). The patients with OSAS (15.8+/-7.9) and PS (22.2+/-9.4) had a higher ADHD RS-IV score than the control subjects (2.9+/-3.3). There was no difference in the ADHD RS-IV scores of patients with primary snoring and OSAS. CONCLUSION: We confirmed that clinical evaluation could not distinguish OSAS and primary snoring. In addition, our study suggests that primary snoring as well as OSAS is associated with attention deficit hyperactivity disorder.

Differences of EEG and Sleep Structure in Pediatric Sleep Apnea and Controls / 수면정신생리

INTRODUCTION: In this study, we compared sleep structure, EEG characteristic of pediatric obstructive sleep apnea (OSA) and normal controls which were matched in sex and age. METHODS: Fifteen children (male:female=4:11) who complained snoring and were suspected to have sleep apnea and their age and sex matched normal controls (male:female=5:10) have been done nocturnal polysomnography (NPSG). Sleep parameters, sleep apnea variables and relative spectral components of EEG from NPSG have been compared between both groups. RESULTS: Pediatric OSA group were distinguished from normal controls in terms of apnea index, respiratory disturbance index and nadir of oxyhemoglobulin desaturation. Pediatric OSA group showed increased percent of sleep stage 1, decreased rapid eye movement sleep percent and increased delta power in O1 EEG channel. However other sleep parameters and spectral powers were not different between two groups. CONCLUSION: In pediatric OSA group, sleep structure parameter disruption may be not prominent as the previous studies for adult OSA group because of including mild OSA data in diagnostic criteria. In addition, EEG changes might not be distinct due to low arousal index compared to adult OSA patients. We can observe general characteristics and particularity of pediatric OSA through this study.

A Case of Child with Obstructive Sleep Apnea Syndrome Recurred after Adenotonsillectomy / 수면정신생리

The most common cause of obstructive sleep apnea syndrome (OSAS) in childhood is adenotonsillar hypertrophy. Adenotonsillectomy improves the symptoms quite well in most cases. However, some patients could experience the OSAS again after adenotonsillectomy, who might have several risk factors such as incomplete operation, misdiagnosis, combined anatomical malformation, sinusitis or chronic allergic rhinitis, obesity, initial severe OSAS, and early onset OSAS. We report a case of 11-year-old obese boy who presented with snoring for several years. He was obese with body mass index (BMI) of 26.3 kg/m2 and also found to have fatty liver by ultrasonogram. Initial polysomnography (PSG) showed that he met the criteria of severe OSAS with the apnea-hypopnea index (AHI) of 70.5. He underwent adenotonsillectomy and symptoms improved immediately. Four months later symptoms were relieved with AHI of 0, but 1 year after the adenotonsillectomy he started to complain snoring again and the subsequent PSG results showed that OSAS has relapsed with AHI of 43. Paranasal sinus X-ray and physical examination showed sinusitis and re-growth of adenoid. Obesity was proved not to be a contributing factor because his BMI decreased to normal range (23.1 kg/m2) after diet control and regular exercise. Also, liver transaminase was normalized and fatty liver was disappeared on follow-up abdominal ultrasonogram. After treatment of sinusitis, symptoms were relieved with decreased AHI (8.5). This case suggests that simple adenotonsillectomy might not be the end of OSAS treatment in childhood. Patients who had adenotonsillectomy should be followed by subsequent PSG if symptoms recur. It is also important to be aware of risk factors in the recurrent OSAS for the proper intervention according to the cause.

A case of restless legs syndrome in a child presenting with growing pains / 소아과

Restless legs syndrome (RLS) is a common neurological sleep disorder in adults characterized by the following diagnostic criteria: an urge to move that is usually associated with unpleasant sensations and symptoms that are worse at rest, relieved by movement, and most severe at night. The definite diagnosis of RLS in children is stricter and consists of self-description of leg discomfort or the presence of 2 of 3 supportive criteria combined with 4 essential criteria for diagnosis in adults. RLS in childhood has often been misdiagnosed as growing pains or a part of normal development. As a result, physicians have often missed the chance for proper management. We diagnosed a case of RLS in a 5-year-old boy presenting with growing pains, whose mother was found to have had RLS since childhood. We confirmed RLS by using a polysomnograph, in which the indices of periodic limb movement syndrome (PLMS) and periodic limb movement during wakefulness (PLMW) were recorded to be compatible with RLS criteria. The patient's ferritin level was low normal, and his symptoms improved after taking iron supplements.

Long Term Follow-Up Results of Adenotonsillectomy on Pediatric Obstructive Sleep Apnea / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Adenotonsillecotmy is the most commonly recommended for pediatiric obstructive sleep apnea (OSA). The clinical improvement after surgery had been suggested on previous studies, which looked at only very short time follow-up. We aimed to study long-term changes in polysomnography (PSG) after adenotonsillectomy for OSA in children. SUBJECTS AND METHOD: Nine children (age range 3 to 13) who had macroscopic adenotonsillar hypertrophy and a respiratory disturbance index (RDI) greater than 1 on preoperative PSG were enrolled in this study and underwent adenotonsillectomy. All children underwent preoperative and postoperative PSG at 3 months and 12 months after surgery. In addition, the caregivers for each child were asked to check attention deficit hyperactivity disorder rating scale-IV (ADHD RS-IV) before, 3 months and 12 months after surgery. Scores from preoperative and postoperative PSG and ADHD RS-IV were compared using the paired sample t-test. RESULTS: Mean of RDI and apnea index improved significantly in postoperative 3 months and 12 months (p<0.05). About 67% (6 of 9) patients had RDI lesser than 1 in postoperative 3 months. However, 12 months later, 44% (4 of 9) children had RDI lesser than 1. ADHD RS-IV score showed significant improvement in postoperative 3 months and 12 months (p<0.05). CONCLUSION: This study suggests that adenotonsillectomy is effective in the treatment of childhood OSA. And the effects of adenotonsillecotmy on pediatric OSA are maintained at least 12 months.

Effect of Adenotonsillectomy on Pediatric Obstructive Sleep Apnea / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Adenotonsillar hypertrophy is the leading cause for obstructive sleep apnea (OSA) in children. However, clinical improvement after adenotonsillectomy has not been confirmed objectively in Korean children. We evaluated the effects of adenotonsillectomy on polysomnography (PSG) in children with OSA. SUBJECTS AND METHOD: Fifteen children (age range 3 to 13) who had macroscopic adenotonsillar hypertrophy and a respiratory disturbance index (RDI) greater than 1 on preoperative PSG were enrolled in this study and underwent adenotonsillectomy. All children underwent preoperative and postoperative PSG at 10 weeks after adenotonsillectomy. In addition, the care-givers of each child were asked to check the deficit hyperactivity disorder rating scale-IV (ADHD RS-IV) before and 8 weeks after surgery. Scores from the preoperative and postoperative PSG and ADHD RS-IV were compared using the paired samples t-test. RESULTS: The improvements in RDI, apneahypoapnea index, apnea index, arousal index, lowest O2 saturation and snoring time on postoperative PSG were significant (p<0.05). About 67% (10 of 15) patients were successfully treated with surgery, but 33% (5 of 15) children had RDI greater than 1 after surgery. ADHD RS-IV score showed significant improvement (p<0.05). CONCLUSION: This study suggests that adenotonsillectomy is effective in the treatment of childhood OSA, but dose not have perfect results. The presence of residual OSA after surgery in a large number of patients is a significant probability that deserves more studies and intervention.

Detrended Fluctuation Analysis on Sleep EEG of Healthy Subjects / 수면정신생리

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.

The effects of modafinil on clinical features and sleep structure of narcolepsy patients and healthy controls / 수면정신생리

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.

Comparison of Actigraphic Performance between ActiWatch (r) and SleepWatch (r) : Focused on Sleep Parameters Utilizing Nocturnal Polysomnography as the Standard / 수면정신생리

OBJECTIVES: We attempted to compare the performance of 2 commercially available actigraphies with focus on sleep parameters, using polysomnography as standard comparison tool. METHODS: Fourteen normal volunteers (5 males and 9 females, mean age of 28+/-4.6 years) participated in this study. All the participants went through one night of polysomnography, simultaneously wearing 2 different kinds of actigraphies on each wrist. Polysomnographic and actigraphic data were stored, downloaded, and processed according to standard protocols and then statistically compared. RESULTS: Both ActiWatch (r) and SleepWatch (r) tended to overestimate the total sleep time, compared to the polysomnography. Sleep-Watch (r) tended to underestimate the sleep latency. The two actigraphs and the polysomnograph did not show significant difference of sleep efficiency, when compared with one another. In addition, all of the sleep parameters from the instruments showed linear correlations except in SleepWatch (r) 's sleep latency. The sleep parameters from the two actigraphs did not show much noteworthy difference, and linear relationships were found between the sleep parameters from the two actigraphs. There was no significant distinction in the results of the two different actigraphs. CONCLUSION: The results of two actigraphies can be used interchangeably since the sleep parameters of the two different actigraphies do not show significant differences statistically. Overall, it is not legitimate to use actigraphy as a substitute for polysomnography. However, since sleep parameters except sleep latency show linear correlations, actigraphy might possibly be used to follow up patients after polysomnography.

Supplemental Value of the Wrist-Worn Actigraphy in Diagnosing the Obstructive Sleep Apnea Syndrome / 수면정신생리

OBJECTIVES: Obstructive sleep apnea syndrome (OSAS) has drawn increasing attention as medical community has become to be aware of its co-morbidities and complications, especially cardiovascular complications and excessive daytime sleepiness with accident proneness. As of now, polysomnography is the standard tool to diagnose sleep apnea and estimate the treatment validity. However, its being rather expensive and inconvenient, alternate diagnostic tools have been proposed including wrist actigraphy. So far, actigraphies have been adopted usefully to field-survey sleep apnea prevalence. In this study, we attempted in a sleep laboratory setting to assess the supplemental value of actigraphy in diagnosing OSAS. METHODS: This study was done at the Division of Sleep Studies, the Seoul National University Hospital. Thirty-seven clinically suspected cases of OSAS underwent the one-night polysomnography, simultaneously wearing an actigraphy on non-dominant wrist. We analyzed the data of 27 polysomnographically-proven OSAS patients (male: female 20: 7; age 47.6+/-12.9 years old; age range 23 to 72 years) with no other sleep disorders. We calculated RDI (respiratory disturbance index) from the polysomnography data and FI (fragmentation index) from the actigraphy data. Pearson correlation was calculated in order to compare FI with RDI and to evaluate the supplemental diagnostic value of the actigraphy. RESULTS: Mean total sleep time on polysomnography was 401.4+/-57.8 min (range of 274.0 to 514.1 min). Mean RDI was 21.7+/-20.4 /hour. Mean FI was 21.9+/-13.0 / hour. RDI and FI showed significant correlation (r=0.55, p< 0.01). CONCLUSIONS: Wrist actigraphy in OSAS patients generates a comparable outcome to polysomnography, in measuring the nocturnal sleep fragmentation. The actigraphy could be used supplementally in inpatients, outpatients, and field survey subjects, if polysomnography is unavailable or impossible. In follow-ups related with nasal CPAP (continuous positive airway pressure), upper airway surgery, and oral appliance in OSAS patients, the actigraphy might play a more dominant role in the future.

Actigraphic Evaluation of Treatment Responses in Periodic Limb Movements in Sleep Patient: Case Study / 수면정신생리

Periodic limb movements in sleep (PLMS) have been diagnosed easily by nocturnal polysomnography (NPSG) and treated effectively with dopamine receptor agonist, benzodiazepine and opioid. However, few reports have objectively assessed the treatment responses. We treated a PLMS patient with clonazepam and pramipexole, and evaluated their efficacy with actigraphy. Clonazepam improved sleep quality without reducing frequency of limb movements, and pramipexole reduced frequency of limb movements without improving sleep quality, results which are consistent with previous study findings. Actigraphy proved useful in evaluation of treatment response of PLMS.