National Estimates of Narcolepsy in Korea

Background@#and Purpose Epidemiological data on narcolepsy are rare in South Korea.We aimed to provide an overview of the burden of narcolepsy and its temporal trend in South Korea. @*Methods@#Patients with narcolepsy were identified by their registration in the Rare and Intractable Disease (RID) register and the Health Insurance Review and Assessment database.Individuals registered in the RID program with the code V234 were considered as having ‘definite narcolepsy’, while those who claimed health insurance with G47.4 as the primary diagnostic code were considered as having ‘probable narcolepsy’. We estimated the annual prevalence, incidence, and medical costs of narcolepsy between 2010 and 2019. @*Results@#The prevalence of definite narcolepsy was 8.4/100,000 in 2019, peaking at 32.0/100,000 in those aged 15–19 years. The prevalence was higher in males, with a relative risk of 1.72. The prevalence has increased over the past 6 years, with an average annual growth rate (AAGR) of 12.2%. The prevalence of probable narcolepsy was 10.7/100,000 in 2019. The incidence of definite narcolepsy increased up to 1.3/100,000 in 2019 with an AAGR of 7.1%. Annual medical expenditure for definite narcolepsy gradually increased up to 4.1 billion KRW in 2019, with a compound annual growth rate of 11.9%. @*Conclusions@#This study has provided the first nationwide estimates for narcolepsy in South Korea. The prevalence of diagnosed narcolepsy in South Korea was at the low end of the range of narcolepsy prevalence rates reported for other countries. However, the prevalence and incidence have been steadily increasing over the past decade.

Association Between Suggestive Symptom of Restless Legs Syndrome and COVID-19 Vaccination: A Pilot Study

Objectives@#Various sensory symptoms have been recognized after COVID-19 vaccination. Here, we aimed to explore the association between the suggestive symptom of restless legs syndrome (RLSss) and COVID-19 vaccination using an online survey. @*Methods@#We prospectively studied participants who were working in our hospital after at least the first dose of the ChAdOx1 or BNT162b2 mRNA vaccine. The participants were invited via smartphone messages and voluntarily filled out an online questionnaire that included adverse events after vaccination. We considered the participants as having RLSss if they reported that they had three or more symptoms in the restless legs syndrome (RLS) diagnostic criteria. @*Results@#A total of 628 participants (506 female; mean age, 37.7±12.4 years) responded fully to our online survey. 588 participants (93.6%) received the first dose of the ChAdOx1 vaccine (BNT162b2 mRNA vaccine for 40 participants). A total of 44 out of the 628 participants (7.0%) reported that they had RLSss. Myalgia was more common in participants with RLSss than in those without RLSss (97.7% vs. 67.3%, p<0.001). Multivariate testing showed that age (odds ratio, 1.037 per 1 year increase; 95% CI, 1.004–1.071) and the presence of myalgia (odds ratio, 20.479; 95% CI, 4.266–368.206) were associated with the presence of RLSss. @*Conclusions@#This pilot study explored RLSss after COVID-19 vaccination and the results suggested that RLS might be one of the causes of adverse symptoms after COVID-19 vaccination. Further studies are required to confirm the relationship between RLS and COVID-19 vaccination.

Can Fitness Trackers Track Sleep?

Technological advances over the years have led to the widespread use and popularity of consumer wearable devices. Although polysomnography and actigraphy are standard tools for objective evaluation of sleep, common wearable devices that can be used daily can aid with diagnosis and management of sleep disorders. Accelerometer and photoplethysmography sensors are included both in actigraphy and wearable devices; therefore, the wearable device functions as an actigraphy tool to analyze sleep architecture. Easy accessibility, cost-effectiveness, and ease of long-term monitoring serve as advantages of this device; however, scientific validation is warranted to promote the use of the commercial apparatus as a medical device.

Sex Differences in Obstructive Sleep Apnea by Bioelectrical Impedance Analysis

Background@#and Purpose Obesity is known of one of the risk factors for obstructive sleep apnea (OSA). Although body mass index (BMI) can be an indicator for obesity, it does not represent the actual body composition of fat or muscle. We hypothesized that bioelectrical impedance analysis (BIA) can help analyze the fat and muscle distributions in males and females with OSA. @*Methods@#This study screened subjects who visited the Department of Neurology, Samsung Medical Center, Seoul, Korea due to sleep disturbances with symptoms suggestive of OSA from December 2017 to December 2019. All subjects underwent overnight type I polysomnography (PSG) and BIA. @*Results@#PSG and BIA were completed in 2,064 OSA patients who had an apnea-hypopnea index (AHI) of ≥5/hour (77.1% males and 22.9% females). The females had remarkably higher fat indicators and lower muscle indicators. The AHI was significant correlated with all BIA parameters in all OSA patients: body fat mass (ρ=0.286, p<0.001), percentage body fat (ρ= 0.130, p<0.001), visceral fat area (VFA) (ρ=0.257, p<0.001), muscle mass (ρ=0.275, p<0.001), and skeletal muscle mass (SMM) (ρ=0.270, p<0.001). The correlations in males were similar to those in all patients, where those in females were not. In females with OSA, all of the BIA fat indicators were correlated with AHI, whereas the muscle indicators were not. Adjusting age and BMI when analyzing the SMM/VFA ratio showed a strong correlation in males with OSA (p= 0.015) but not in females with OSA (p=0.354). @*Conclusions@#This study has revealed that the body composition of fat and muscle has different patterns in OSA patients. The SMM/VFA as measured using BIA is the factor most significantly associated with AHI in males but not in females after adjusting for age and BMI.

Sex Differences in Obstructive Sleep Apnea by Bioelectrical Impedance Analysis

Background@#and Purpose Obesity is known of one of the risk factors for obstructive sleep apnea (OSA). Although body mass index (BMI) can be an indicator for obesity, it does not represent the actual body composition of fat or muscle. We hypothesized that bioelectrical impedance analysis (BIA) can help analyze the fat and muscle distributions in males and females with OSA. @*Methods@#This study screened subjects who visited the Department of Neurology, Samsung Medical Center, Seoul, Korea due to sleep disturbances with symptoms suggestive of OSA from December 2017 to December 2019. All subjects underwent overnight type I polysomnography (PSG) and BIA. @*Results@#PSG and BIA were completed in 2,064 OSA patients who had an apnea-hypopnea index (AHI) of ≥5/hour (77.1% males and 22.9% females). The females had remarkably higher fat indicators and lower muscle indicators. The AHI was significant correlated with all BIA parameters in all OSA patients: body fat mass (ρ=0.286, p<0.001), percentage body fat (ρ= 0.130, p<0.001), visceral fat area (VFA) (ρ=0.257, p<0.001), muscle mass (ρ=0.275, p<0.001), and skeletal muscle mass (SMM) (ρ=0.270, p<0.001). The correlations in males were similar to those in all patients, where those in females were not. In females with OSA, all of the BIA fat indicators were correlated with AHI, whereas the muscle indicators were not. Adjusting age and BMI when analyzing the SMM/VFA ratio showed a strong correlation in males with OSA (p= 0.015) but not in females with OSA (p=0.354). @*Conclusions@#This study has revealed that the body composition of fat and muscle has different patterns in OSA patients. The SMM/VFA as measured using BIA is the factor most significantly associated with AHI in males but not in females after adjusting for age and BMI.

Relapse of Neuromyelitis Optica Spectrum Disorder Presented with Suspected Bacterial Meningomyelitis

Neuromyelitis optica spectrum disorder (NMOSD) is a rare inflammatory demyelinating disease. Anti-aquaporin-4 antibodies serve as a specific biomarker, while other factors including antecedent infection may also play a role in the development of NMOSD. Abnormal cerebrospinal fluid (CSF) findings such as leukocytosis with concentration >50/mm3 are one of the characteristics of NMOSD, but these were not specific for identifying other infective neurological diseases. Here we describe a rare case of NMOSD with CSF findings suggestive of bacterial meningomyelitis.

Insomnia Symptoms and Mood Disturbances in Shift Workers with Different Chronotypes and Working Schedules

14). Depressive mood and anxiety symptom were significantly worse in 3S compare to EOD. The sleep disturbance by ISI score had significant correlations with depressive mood and anxiety symptoms for both EOD and 3S (EOD: rho=0.57, rho=0.57, 3S: rho=0.37, rho=0.33 respectively). Chronotype type in shift workers had no significant correlation with sleep disturbance, depressive mood, nor anxiety symptom. However, after adjustment, the eveningness chronotype have relationship to the depressive mood in shift workers.CONCLUSIONS: Sleep disturbances are more frequent in shift workers than DW. Depressive mood and anxiety symptoms were frequently reported in 3S, then EOD. Different shift schedules cab be a determinant of depressive mood and anxiety symptom.

A Nationwide Survey of Shift Schedules for Sleep Technicians in Korea

OBJECTIVES: It is a paradox that sleep technicians are at risk of shift work sleep disorder to help diagnose other people's sleep disorder. Until now, there have been no guidelines for scheduling shifts for sleep technicians. The purpose of this study was to survey the current shift schedule of sleep technicians. METHODS: We performed a nationwide survey of work schedules for sleep laboratories. We sent email questionnaires to sleep technicians working in university-affiliated hospitals. Information regarding starting time and duration of shift, duty on-duty off pattern for the past month, and rotation and number of sleep technicians in the sleep labs were collected. RESULTS: We received responses from 29 sleep labs. Among the 25 labs which had designated sleep technicians, three labs had night shift schedules mixed with day work on a weekly basis and the remaining 22 labs had night only shift schedule. In cases of night only shift schedules, 11 labs alternated from night shift to day shift works or vice versa every 3 months to 3 years, while the remaining 11 labs had fixed schedules without daytime rotation. Number of night shift was four or less per week, with shift durations of 9–19 hours. CONCLUSIONS: The current policies regarding scheduling shifts varied vastly depending on individual sleep labs. We found that some labs had shift schedules with long work time, quick returns, or permanent night shifts, which are generally not recommended. Further studies are needed to develop consensus guidelines for scheduling shift of sleep technicians.

Systemic White Blood Cell Count as a Biomarker Associated with Severity of Chronic Obstructive Lung Disease / 결핵및호흡기질환

BACKGROUND: Chronic obstructive pulmonary disease (COPD), is a chronic inflammatory disorder. We evaluated whether white blood cell (WBC) count, is associated with the severity of COPD, independent of other inflammatory conditions, such as metabolic syndrome. METHODS: The WBC counts were compared between 1227 COPD patients and 8679 non-COPD adults older than 40. The relationships between the WBC count, lung function, and symptoms score in COPD patients, were determined, using general linear regression analyses. RESULTS: The WBC count was negatively associated with forced vital capacity (FVC, L), FVC (% predicted), forced expiry volume in one second (FEV₁, L), and FEV₁ (% predicted) in COPD patients. Additionally, the WBC count was independently associated with the quality of life measure, by EQ5D-index score. However, this relationship between WBC count, and disease severity, was not significant in current smokers, because of the confounding effect of smoking, on the WBC count. CONCLUSION: The WBC count is associated with current smoking status and COPD severity, and a risk factor for poor lung function, and quality of life, especially in non-currently smoking COPD patients. The WBC count can be used, as an easily measurable COPD biomarker.

Management of Alcohol Withdrawal Syndrome and Alcohol Withdrawal Seizure

Alcohol withdrawal syndrome (AWS) is a common condition occurring after intentional or unintentional abrupt cessation of alcohol in an alcohol-dependent individual. AWS represents a major problem in our society and alcohol withdrawal seizure is the major cause of seizures encountered by neurology residents in the emergency department. Patients with AWS present with mild symptoms of tremulousness and agitation or more severe symptoms including withdrawal seizures and delirium tremens. Particularly, severe AWS can produce significant rates of the morbidity (complications) and mortality. When diagnosed and managed insufficiently, the morbidity and mortality rates increase. Nevertheless, patients with AWS may be neglected and are often marginalized and the teaching about AWS to neurology residents is usually minimal. Also, attending neurologists are often poorly informed on the topic. Although there is insufficient consensus about the optimal investigation and management, the purpose of this review is to serve as a summary of the appropriate identification and management of this important condition in a neurological setting.

A Case of Cerebral Salt Wasting Syndrome in Neuromyelitis Optica Spectrum Disorder

Neuromyelitis optica spectrum disorder (NMOSD) may present with area postrema syndrome, which is characterized by intractable vomiting and hiccups. Hyponatremia is common in NMOSD and is mostly associated with the syndrome of inappropriate antidiuretic hormone secretion (SIADH). In contrast to SIADH, cerebral salt wasting syndrome (CSWS) causes hyponatremia, which is associated with severe natriuresis and extracellular volume depletion in patients with cerebral disease. To our knowledge, hyponatremia associated with CSWS has not been reported in a patient with NMOSD. Here, we describe a NMOSD presenting with hyponatremia, which may be caused by CSWS following area postrema syndrome.

Subjective Sleep Disturbances of Factory Workers in Relation to Shift Work Schedule and Chronotype

OBJECTIVES: Shift work in Korea is most prevalent in automobile system manufacturing industries. The subjective sleep complaints and individual chronotypes of shift worker was evaluated. METHODS: A cross-sectional study was conducted among single automobile system manufacturing industries in Korea. All participants completed questionnaires about the work schedule, duration of sustained employment and various division of work. And sleep questionnaires including: Epworth Sleepiness Scale, Insomnia Severity Index, Hospital Anxiety and Depression Scale, and Morningness-Eveningness Questionnaire. RESULTS: This study enrolled 208 participants [shift workers (SWs)=142, day workers (DWs)=66]. Insomnia symptoms were significantly worse in the SW group (p<0.001). Excessive daytime sleepiness was not significantly different between groups. The evening chronotype in DWs was related to both excessive daytime sleepiness (EDS) (p=0.008) and insomnia (p=0.034). On the other hand, chronotypes in SWs were not significantly different in terms of EDS and insomnia. CONCLUSIONS: Insomnia symptoms were significant in SWs compare to DWs. In DWs the evening types were sleepier and had more insomnia symptoms than other chronotypes. The sleep symptoms are prevalent in automobile industries workers, and in part it is related to work schedule and individual chronotype.

Diagnostic Confusion of Nocturnal Paroxysmal Motor Activity

It is a significant challenge for the clinician to make distinction between nocturnal epilepsy form non-epileptic sleep disorders. Although in some patients, diagnosis is easy to achieve but sometimes not. At times even with help of polysomnogram and electroencephalogram, diagnostic confusion remains. We present two cases of nocturnal paroaxysmal events, which still need elucidate diagnosis.

Fatal Rhino-Orbital-Cerebral Mucormycosis Complicated with Thrombosis and Rupture of Mycotic Aneurysm in Distal Internal Carotid Artery

Mucormycosis is a rare opportunistic infection caused by fungi of the order Mucorales that typically occurs in patients with diabetes or immunocompromised state. Rhino-orbital-cerebral mucormycosis is the most common type, often has a life-threatening outcome. Mucormycosis has specific vascular tropism complicating mucorthrombosis or mycotic aneurysm. We report a diabetic patient presenting with ophthalmoplegia, orbital necrosis, and contralateral hemiparesis, who suddenly progressed to coma and died of subarachnoid hemorrhage due to the rupture of mycotic aneurysm in distal internal carotid artery.

Fatal Rhino-Orbital-Cerebral Mucormycosis Complicated with Thrombosis and Rupture of Mycotic Aneurysm in Distal Internal Carotid Artery

Mucormycosis is a rare opportunistic infection caused by fungi of the order Mucorales that typically occurs in patients with diabetes or immunocompromised state. Rhino-orbital-cerebral mucormycosis is the most common type, often has a life-threatening outcome. Mucormycosis has specific vascular tropism complicating mucorthrombosis or mycotic aneurysm. We report a diabetic patient presenting with ophthalmoplegia, orbital necrosis, and contralateral hemiparesis, who suddenly progressed to coma and died of subarachnoid hemorrhage due to the rupture of mycotic aneurysm in distal internal carotid artery.

Vertebrobasilar Insufficiency Caused by Lateral Head Tilting

Vertebrobasilar insufficiency (VBI) in rotatory vertebral artery occlusion syndrome can be caused by voluntary head turning in the yaw plane. We report a case of VBI for head tilting in the roll plane. Transcranial Doppler on left head tilting resulted in decreased blood flow in both vertebral arteries. A CT angiogram revealed that the stenotic left vertebral artery was very close to an enlarged thyroid gland, suggesting mechanical compression of the vertebral artery during head tilt.