Effects of Continuous Positive Airway Pressure on Sleep State Misperception in Patients With Obstructive Sleep Apnea

Background@#Little is known regarding the effects of continuous positive airway pressure (CPAP) on sleep misperception in obstructive sleep apnea (OSA). @*Methods@#Sleep state perception was measured by subtracting the objective total sleep time from the subjective sleep duration. Sleep underestimation and overestimation were defined as ± 60 minutes sleep perception. Insomnia and depressive symptoms were assessed using questionnaires. Finally, nonparametric statistical analyses were performed. @*Results@#Of the 339 patients with OSA included in the study, 90 (26.5%) and 45 (13.3%) showed sleep underestimation and overestimation, respectively. Overall, a significant underestimation of sleep was noted during CPAP titration comparing to a diagnostic PSG (P < 0.001). OSA patients with insomnia or depressive symptoms did not show any changes in sleep perception between diagnostic and CPAP titration studies, whereas those without insomnia or depressed mood showed significantly underestimated sleep duration during CPAP titration. Patients with OSA and either underestimated or overestimated misperception showed perceptual improvements during CPAP titration regardless of the presence of insomnia or depressive symptoms. However, of 204 patients with normal sleep perception, 138 (67.6%) and 10 (4.9%) had underestimation and overestimation of sleep during CPAP titration. @*Conclusion@#CPAP titration may improve sleep perception with moderate to severe OSA who have sleep misperception. However, CPAP titration may result in sleep misperception especially underestimation of sleep in those who have normal sleep perception.

Sex Differences in Excessive Daytime Sleepiness Among Patients With Obstructive Sleep Apnea

Background@#and Purpose To identify sex differences in daytime sleepiness associated with apnea severity and periodic limb movements during sleep (PLMS) in subjects with obstructive sleep apnea (OSA). @*Methods@#This study used the Epworth Sleepiness Scale (ESS), Beck Depression Inventory (BDI), and Sleep Hygiene Index (SHI) in logistic regression analyses with interaction terms. Severe OSA, excessive daytime sleepiness (EDS), and PLMS were defined as an apnea-hypopnea index of ≥30, an ESS score of ≥11, and a periodic limb movements index of >15, respectively. @*Results@#The 1,624 subjects with OSA (males, 79.1%) comprised 45.3%, 38.2%, and 16.4% with severe OSA, EDS, and PLMS, respectively. Multiple logistic regression without interaction terms showed that sex, severe OSA, and PLMS were not significantly associated with EDS. However, significant interactions were noted between sex and severe OSA and PLMS in EDS in both crude and adjusted models (all p values<0.05). In the adjusted model, severe OSA was associated with EDS in males (p=0.009) but not in females. PLMS were more likely to be associated with EDS in females (p=0.013), whereas PLMS were less likely to be associated with EDS in males (p=0.041). The models were adjusted by the BDI score, SHI, and presence of medical comorbidities. @*Conclusions@#There are significant sex differences in subjective daytime sleepiness in subjects with severe OSA and PLMS. Severe OSA and PLMS may influence daytime sleepiness more in males and females, respectively.

Effects of Appointing a Full-Time Neurointensivist to Run a Closed-Type Neurological Intensive Care Unit

BACKGROUND AND PURPOSE: To investigate whether appointing a full-time neurointensivist to manage a closed-type neurological intensive care unit (NRICU) improves the quality of critical care and patient outcomes. METHODS: This study included patients admitted to the NRICU at a university hospital in Seoul, Korea. Two time periods were defined according to the presence of a neurointensivist in the preexisting open-type NRICU: the before and after periods. Hospital medical records were queried and compared between these two time periods, as were the biannual satisfaction survey results for the families of patients. RESULTS: Of the 15,210 patients in the neurology department, 2,199 were admitted to the NRICU (n=995 and 1,204 during the before and after periods, respectively; p<0.001). The length of stay was shorter during the after than during the before period in both the NRICU (3 vs. 4 days; p<0.001) and the hospital overall (12.5 vs. 14.0 days; p<0.001). Neurological consultations (2,070 vs. 3,097; p<0.001) and intrahospital transfers from general intensive care units to the NRICU (21 vs. 40; p=0.111) increased from the before to after the period. The mean satisfaction scores of the families of the patients also increased, from 78.3 to 89.7. In a Cox proportional hazards model, appointing a neurointensivist did not result in a statistically significant change in 6-month mortality (hazard ratio, 0.82; 95% confidence interval, 0.652–1.031; p=0.089). CONCLUSIONS: Appointing a full-time neurointensivist to manage a closed-type NRICU had beneficial effects on quality indicators and patient outcomes.

Does Rapid Eye Movement Sleep Aggravate Obstructive Sleep Apnea?

OBJECTIVES.: To investigate the apnea-hypopnea index (AHI) according to the sleep stage in more detail after control of posture. METHODS.: Patients who underwent nocturnal polysomnography between December 2007 and July 2018 were retrospectively evaluated. Inclusion criteria were as follows: age >18 years, sleep efficacy >80%, and patients who underwent polysomnography only in the supine position (100% of the time). Patients were classified into different groups according to the methods: the first, rapid eye movement (REM)-dominant group (AHIREM/AHINREM >2), non-rapid eye movement (NREM)-dominant group (AHINREM/AHIREM >2), and non-dominant group; and the second, light sleep group (AHIN1N2>AHISWS) and slow wave sleep (SWS) group (AHISWS>AHIN1N2). RESULTS.: A total of 234 patients (mean age, 47.4±13.9 years) were included in the study. There were 108 patients (46.2%) in the REM-dominant group, 88 (37.6%) in the non-dominant group, and 38 (16.2%) in the NREM-dominant group. The AHI was significantly higher in the NREM-dominant group than in the REM-dominant group (32.9±22.9 events/hr vs. 18.3±9.5 events/hr, respectively). There were improvements in the AHI from stage 1 to SWS in NREM sleep with the highest level in REM sleep. A higher AHISWS than AHIN1N2 was found in 16 of 234 patients (6.8%); however, there were no significant predictors of these unexpected results except AHI. CONCLUSION.: Our results demonstrated the highest AHI during REM sleep stage in total participants after control of posture. However, there were 16.2% of patients showed NREM-dominant pattern (AHINREM/AHIREM >2) and 6.8% of patients showed higher AHISWS than AHIN1N2. Therefore, each group might have a different pathophysiology of obstructive sleep apnea (OSA), and we need to consider this point when we treat the patients with OSA.

Validation of the Uniform Case Definition Criteria for Differentiating Tuberculous Meningitis, Viral Meningitis, and Bacterial Meningitis in Adults / 감염과화학요법

We validated the uniform case definition for differentiating tuberculous meningitis (TBM) from both viral meningitis (VM) and bacterial meningitis (BM) in adults from South Korea, a country with an intermediate TB-burden. ‘Probable’ TBM differentiated ‘definite’ TBM with a sensitivity of 81% and specificity of 98%. ‘Possible TBM’ criteria identified ‘definite’ TBM with a sensitivity of 100% and specificity of 60%. Despite the usefulness of the uniform case definition criteria, there was substantial overlaps among VM, BM, and ‘possible’ TBM, especially in severe cases of VM and indolent cases of BM.

Epilepsy and Driving Regulation in Korea

In Korea, current status of epilepsy and driving are challenging and there are lack of formal legal guidelines about driving in patients with epilepsy. According to the default standards in Korean Road Traffic law, patients with epilepsy are restricted or prohibited from driving except who are conditionally allowed to drive by the Aptitude Judgement Committee (AJC). Though the AJC consist of medical doctors and traffic officials, new regulation and guidelines are required for various type of seizure and characteristics of patients with epilepsy. This review outlines the current applicable legislation about epilepsy and driving in Korea as well as that of the overseas country calling for new laws to establish a consistent assessment.

Tuberculous Meningitis-Mimicking Varicella-Zoster Meningitis / 감염과화학요법

BACKGROUND: Varicella-zoster virus (VZV) is one of the most common etiologies of aseptic meningitis. The severest manifestation of VZV meningitis is occasionally confused with tuberculous meningitis (TBM). Thus, we investigated the clinical manifestations of VZV meningitis as compared with those of TBM. MATERIALS AND METHODS: All adult patients who were diagnosed with VZV meningitis or TBM were enrolled at a tertiary hospital in Seoul, South Korea, during an 8-year period. The clinical characteristics and cerebrospinal fluid (CSF) profile of patients were analyzed. RESULTS: Seventy-nine patients with VZV meningitis and 24 patients with TBM were enrolled in this study. Of the 79 patients with VZV meningitis, 63 (80%) did not received empirical anti-tuberculous therapy (Group 1) and the remaining 16 (20%) received empirical anti-tuberculous therapy (Group 2), compared with 24 patients with TBM (Group 3). Altered mental status, intensive care unit (ICU) admission, neurologic sequelae, CSF protein levels, and CSF adenosine deaminase levels revealed a trend of being higher in Group 3 than Group 2, which was higher than Group 1. However, the CSF/serum glucose ratio was significantly lower in Group 3 than in Group 1 or Group 2. CONCLUSION: About one fifth of VZV meningitis cases presented as severe manifestations, mimicking TBM. The CSF/serum glucose ratio might be useful to differentiate VZV meningitis from TBM until definite diagnostic tests are available. Physicians should keep in mind that a differential diagnosis between severe VZV meningitis and TBM is needed.

Development of Spinal Epidural Abscess during Treatment of Pneumococcal Meningitis / 대한내과학회지

There have been a few reports of pneumococcal meningitis complicated by spinal epidural abscess. A 58-year-old female with Streptococcus pneumoniae meningitis underwent a recurrent pleocytosis without apparent clinical deterioration after appropriate antibiotic treatment. Subsequently, she developed a spinal epidural abscess. Spinal epidural abscess is a rare complication of pneumococcal meningitis, and subclinical deterioration of neutrophil-dominant pleocytosis may precede development of a spinal epidural abscess in individuals with bacterial meningitis.

The Utility of Three Screening Questionnaires for Obstructive Sleep Apnea in a Sleep Clinic Setting

PURPOSE: The aim of this study was to determine the diagnostic value of three screening questionnaires in identifying Korean patients at high risk for obstructive sleep apnea (OSA) in a sleep clinic setting in Korea. MATERIALS AND METHODS: Data were collected from 592 adult patients with suspected OSA who visited a sleep center. All patients completed the Sleep Apnea of Sleep Disorder Questionnaire (SA-SDQ), the Berlin questionnaire, and the STOP-Bang questionnaire. Estimated OSA risk was compared to a diagnosis of OSA. The sensitivity, specificity, positive predictive value, and negative predictive value were calculated for each questionnaire. RESULTS: The prevalence of OSA was 83.6% using an apnea-hypopnea index (AHI) > or =5/h and 58.4% for an AHI > or =15/h. The STOP-Bang questionnaire had a high sensitivity (97% for AHI > or =5/h, 98% for AHI > or =15/h), but the specificity was low (19% and 11%, respectively). In contrast, the sensitivity of the SA-SDQ was not high enough (68% for AHI > or =5/h, 74% for AHI > or =15/h) to be useful in a clinical setting, whereas the specificity was relatively good (66% and 61%, respectively). The sensitivity and specificity values of the Berlin questionnaire fell between those of the STOP-Bang questionnaire and the SA-SDQ. CONCLUSION: The STOP-Bang questionnaire may be useful for screening OSA in a sleep clinic setting, but its specificity is lower than the acceptable level for this purpose. A new screening questionnaire with a high sensitivity and acceptable specificity is therefore needed in a sleep clinic setting.

Seizure Frequencies and Number of Anti-epileptic Drugs as Risk Factors for Sudden Unexpected Death in Epilepsy

The purpose of this study was to investigate the association between clinical variables and sudden unexpected death in epilepsy (SUDEP) and identify risk factors for SUDEP. SUDEP is one of the most frequent causes of death in patients with epilepsy. Previous studies have reported possible risk factors associated with SUDEP, but there need to be elucidated yet. The cases were 26 patients with SUDEP and three control patients were included for each case, matched for age, sex, and date of initial clinical visit. All demographic and clinical characteristics, including age, sex, disease duration, classification of epilepsy, age at seizure onset, kind and number of antiepileptic drugs, were compared between cases and controls. Seizure frequency was higher in SUDEP cases than in controls (P=0.035). Univariate analysis using conditional logistic regression showed that higher seizure frequency (odds ratio [OR]=3.1, P=0.021) and the number of antiepileptic drugs (AEDs) (OR=2.0, P=0.009) were significantly associated with SUDEP. Only the number of AEDs remained significant in multivariate analysis (OR=1.8, P=0.026). Frequent seizures and multi-drug therapy were associated with SUDEP. This may suggest that the severity of epilepsy is associated with SUDEP, regardless of the type of AED used.

The First Reported Case of West Nile Encephalitis in Korea

West Nile encephalitis was first identified in 1937, but until now, it was never diagnosed in Korea. A 58-yr-old Korean man was admitted with headache and cognitive dysfunction. The patient had been on a business trip in Guinea. Cerebrospinal fluid (CSF) showed pleocytosis. The patient complained of both leg weakness,and arachnoiditis and myelitis were observed on lumbar magnetic resonance imaging (MRI). A specific neutralizing antibody for West Nile virus was positive in serum. After a treatment with interferon-alpha 3mu, follow up CSF findings recovered completely after 3 months later. The first case of West Nile encephalitis in Korea was imported from Guinea, and was cured successfully.

The First Reported Case of West Nile Encephalitis in Korea

West Nile encephalitis was first identified in 1937, but until now, it was never diagnosed in Korea. A 58-yr-old Korean man was admitted with headache and cognitive dysfunction. The patient had been on a business trip in Guinea. Cerebrospinal fluid (CSF) showed pleocytosis. The patient complained of both leg weakness,and arachnoiditis and myelitis were observed on lumbar magnetic resonance imaging (MRI). A specific neutralizing antibody for West Nile virus was positive in serum. After a treatment with interferon-alpha 3mu, follow up CSF findings recovered completely after 3 months later. The first case of West Nile encephalitis in Korea was imported from Guinea, and was cured successfully.

Paraneoplastic Extralimbic Encephalitis Presenting with Partial Motor Clonic Seizure in a Patient with Invasive Thymoma

Paraneoplastic encephalitis presenting with partial clonic seizure is rare. We report a 57-year-old man with clonic seizure in his left arm. He had past medical history of recurrent thymoma and thymomectomy. Magnetic resonance imaging showed multiple brain lesions, but none of them were congruent with the partial seizure. His symptoms and brain lesions resolved after steroid therapy. This is the first reported case extralimbic encephalitis presenting as partial seizure with invasive thymoma in Korea.

Paraneoplastic Extralimbic Encephalitis Presenting with Partial Motor Clonic Seizure in a Patient with Invasive Thymoma

Paraneoplastic encephalitis presenting with partial clonic seizure is rare. We report a 57-year-old man with clonic seizure in his left arm. He had past medical history of recurrent thymoma and thymomectomy. Magnetic resonance imaging showed multiple brain lesions, but none of them were congruent with the partial seizure. His symptoms and brain lesions resolved after steroid therapy. This is the first reported case extralimbic encephalitis presenting as partial seizure with invasive thymoma in Korea.

Idiopathic REM Sleep Behavior Disorder in Young Adults and Quantitative Analysis of Polysomnography

Rapid eye movement sleep behavior disorder (RBD) is a sleep disorder characterized by loss of muscle atonia during REM sleep associated with dream enactment, which usually start at the age of older than 50. RBD in elders are known to be developing symptoms of neurodegenerative disorders in the course of disease. However, the pathophysiology and prognosis of "early-onset" idiopathic RBD is unclear. Several existing standard value about REM sleep without atonia (RSWA) of RBD patients was established with "late-onset" RBD for those diagnosed at age 50 and greater, RSWA metrics in "early-onset" RBD patients diagnosed prior to age 50 years have not been previously described. Therefore, we report here two patients who were diagnosed as "early-onset" idiopathic RBD, and performed quantitative RSWA scoring. We suggested that "early-onset" idiopathic RBD has different etiologies the various characteristics of RSWA than adults with RBD.

Kinetics of T-cell-based assays on cerebrospinal fluid and peripheral blood mononuclear cells in patients with tuberculous meningitis

BACKGROUND/AIMS: The goal of this study was to monitor tuberculosis (TB)-specific T-cell responses in cerebrospinal fluid-mononuclear cells (CSF-MCs) and peripheral blood mononuclear cells (PBMCs) in patients with tuberculous meningitis (TBM) over the course of anti-TB therapy. METHODS: Adult patients (> or = 16 years) with TBM admitted to Asan Medical Center, Seoul, South Korea, were prospectively enrolled between April 2008 and April 2011. Serial blood or CSF samples were collected over the course of the anti-TB therapy, and analyzed using an enzyme-linked immunosorbent spot (ELISPOT) assay. RESULTS: Serial ELISPOT assays were performed on PBMCs from 17 patients (seven definite, four probable, and six possible TBM) and CSF-MC from nine patients (all definite TBM). The median number of interferon-gamma (IFN-gamma)-producing T-cells steadily increased during the first 6 months after commencement of anti-TB therapy in PBMCs. Serial CSF-MC ELISPOT assays revealed significant variability in immune responses during the first 6 weeks of anti-TB therapy, though early increases in CSF-MC ELISPOT results were associated with treatment failure or paradoxical response. CONCLUSIONS: Serial analysis of PBMCs by ELISPOT during the course of treatment was ineffective for predicting clinical response. However, increases in TB-specific IFN-gamma-producing T-cells in CSF-MC during the early phase of anti-TB therapy may be predictive of clinical failure.

Recurrent Anti-GQ1b Antibody Syndrome

Anti-GQ1 antibody is found in patients with Miller-Fisher syndrome (MFS), atypical MFS, and Bickerstaff's brainstem encephalitis (BBE). These conditions are various manifestations of post-infectious autoimmune disorders, and anti-GQ1b antibodies play a core pathogenic role. So they are referred as the 'anti-GQ1b antibody syndrome'. We report two cases of recurrent anti-GQ1b antibody syndrome.

Japanese Encephalitis Associated with Flaccid Quadriplegia

Japanese encephalitis is the one of the leading causes of viral encephalitis in Asia. We report on a 56-year-old man with Japanese encephalitis with an unusual manifestation of flaccid quadriplegia. Brain MRI revealed bilateral lesions in the thalamus, midbrain, and medial temporal lobe. Cervical MRI revealed lesion in the bilateral anterior spinal cord. Electromyography revealed active denervation in all four limbs and paraspinal muscles, suggesting a diffuse anterior-horn cell lesion. We report a patient with Japanese encephalitis accompanied by flaccid quadriplegia.

Downbeat Nystagmus Associated With Brainstem Compression by Vertebral Artery

Rarely, downbeat nystagmus can occur due to compression of the lower brainstem by the ectatic vertebral artery and be resolved by microvascular decompression. We present a case of a 67-year-old man with downbeat nystagmus associated with brainstem compression by ectatic vertebral artery. He presented with oscillopsia and vertigo. When he turned his head upward, his symptoms were aggravated and a gait disturbance occurred. Magnetic resonance imaging and computed tomographic angiography demonstrated compression of the medulla oblongata by the left ectatic vertebral artery and other medical causes of downbeat nystagmus were ruled out. Retromastoid craniotomy was performed and after lifting the vertebral artery off the medulla, a trough-shaped indentation in the lower brainstem was identified. The ectatic vertebral artery was repositioned and a Teflon was inserted between the brainstem and the ectatic vertebral artery. Postoperatively, downbeat nystagmus had disappeared.

Intracranial Ictal EEG Patterns Predicting the Surgical Outcome and the Yield of Intracranial Electrodes in Patients with Temporal Lobectomy

BACKGROUND: Analysis of intracranial ictal patterns may help to predict surgical outcomes. We investigated intracranial EEG patterns to correlate with surgical outcomes and compared the yield of 'subdural electrodes alone (SE)' versus 'combined depth and subdural electrodes (CDSE)' for ictal lateralization in temporal lobe epilepsy (TLE). METHODS: We reviewed a total of 95 seizures recorded by bilateral temporal depth and subdural electrodes in 25 TLE patients who underwent surgery. We classified surgical outcomes as 'seizure-free' or 'not-seizure-free'. Each seizure was analyzed based on the presence or absence of peri-ictal discharges, ictal distribution, waveform patterns, onset frequency and involved number of electrodes, and interhemispheric propagation time (IHPT). The accuracy of lateralizing seizure foci by CDSE was compared to that by SE. RESULTS: 20 patients (80.0%) were 'seizure-free' and 5 (20.0%) were 'not-seizure-free'. The presence of peri-ictal discharges (p<0.001), distribution of depth only or depth and medial electrodes (p<0.001) and higher onset frequency (p=0.021) were associated with 'seizure-free' outcomes. Ictal onset pattern with fast spike trains was common in 'seizure-free', whereas pattern with rhythmic activity was common in 'not-seizure-free' (p=0.005). SE correctly lateralized in 18 of 20 patients, and incorrectly lateralized in the remaining 2 patients, but CDSE correctly lateralized in all 20 patients. CONCLUSIONS: Some intracranial ictal patterns were significantly correlated with good surgical outcomes. These findings suggest that the analysis of ictal EEG patterns help to predict surgical outcomes. CDSE is more accurate for the lateralization of seizure foci compared to SE.