Declining incidence of cerebral palsy in South Korea.

Presuming that the incidence of cerebral palsy (CP) in Korea is decreasing due to medical advances, we analyzed the trends and risk factors of CP in changing circumstances. We identified all women who delivered a singleton between 2007 and 2015 using the Korea National Health Insurance (KNHI). Information on pregnancy and birth was obtained by linking the KNHI claims database and data from the national health-screening program for infants and children. The 4-years incidence of CP decreased significantly from 4.77 to 2.52 per 1000 babies during the study period. The multivariate analysis revealed that the risk of developing CP was 29.5 times higher in preterm infants born before 28 weeks of gestational age, 24.5 times higher in infants born between 28 and 34 weeks, and 4.5 times higher in infants born between 34 and 36 weeks, compared to full-term appropriate for age (2.5 ~ 4 kg of body weight) infants. 5.6 times higher in those with birth weight < 2500 g, and 3.8 times higher in pregnancies with polyhydramnios. Additionally, respiratory distress syndrome increased the risk of developing CP by 2.04 times, while necrotizing enterocolitis was associated with a 2.80-fold increased risk of CP. In Korea, the incidence of CP in singleton decreased from 2007 to 2015. We need to continue to focus on developing medical technologies for the early detection of high-risk neonates and minimizing brain damage to reduce the incidence rate of CP effectively.

Gut Bacterial Dysbiosis in Irritable Bowel Syndrome: a Case-Control Study and a Cross-Cohort Analysis Using Publicly Available Data Sets.

Research on the gut microbiota in irritable bowel syndrome (IBS) shows discordant results due to inconsistent study designs or small sample sizes. This study aimed to characterize how gut microbiota in IBS patients differs from that in healthy controls by performing a case-control study and cross- and mega-cohort analysis. Multiple publicly shared data sets were examined by using a unified analytical approach. We performed 16S rRNA gene (V3-4) sequencing and taxonomic profiling of the gut bacterial communities. Fecal samples from children with IBS (n = 19) and age-matched healthy controls (n = 24) were used. Next, we analyzed 10 separate data sets using a unified data-processing and analytical approach. In total, 567 IBS patients and 487 healthy controls were examined. In our data sets, no significant differences existed in stool α-diversity between IBS patients and healthy controls. After combining all the data sets using a unified data-processing method, we found significantly lower α-diversity in IBS patients than in healthy controls. In addition, the relative abundance of 21 bacterial species differed between the IBS patients and healthy participants. Although the causal relationship is uncertain, gut bacterial dysbiosis is associated with IBS. Further functional studies are needed to assess whether the change in gut microorganisms contributes to the development of IBS. IMPORTANCE Research on the gut bacteria in irritable bowel syndrome (IBS) shows discordant results due to inconsistent study designs or small sample sizes. To overcome these issues, we analyzed microbiota of 567 IBS patients and 487 healthy people from 10 shared data sets using a unified method. We demonstrated that gut bacteria are less diverse in IBS patients than in healthy people. In addition, the abundance of 21 bacterial species is different between the two groups. Altered bacterial balance, called dysbiosis, has been reported in several disease states. Although the causal relationship is uncertain, gut bacterial dysbiosis also seems to be associated with IBS.

Gut microbiota affects brain development and behavior.

The gut covers a large surface area of the body and faces various external factors. The brain works in concert with commensal microbes in the gut to efficiently process the enormous amount of chemical signals that enter the gut every day. This review discusses: (1) evidence that gut bacteria can alter brain development and behavior, (2) mechanisms by which gut bacteria communicate with the brain, (3) preclinical and clinical studies demonstrating the impact of gut microbiota on autism spectrum disorder, and (4) variables worth consideration by future research on gut bacteria.

Pre/post-natal exposure to microplastic as a potential risk factor for autism spectrum disorder.

In common with the increase in environmental pollution in the past 10 years, there has also been a recent increase in the prevalence of autism spectrum disorder (ASD). In this regard, we hypothesized that exposure to microplastics is a potential risk factor for ASD. To evaluate the validity of this hypothesis, we initially examined the accumulation of polyethylene (PE) in the brains of mice and then assessed the behavioral effects using mouse models at different life stages, namely, prenatal, post-weaning, puberty, and adult models. Based on typical behavioral assessments of autistic traits in the model mice, we established that ASD-like traits were induced in mice after PE feeding. In addition, we examined the induction of ASD-like traits in response to microplastic exposure using positron emission tomography, magnetic resonance spectroscopy, quantitative real-time polymerase chain reaction, microarray, and microbiome analysis. We believe these findings provide evidence in microplastics as a potential risk factor for ASD.

Hemodynamics of different volumes of red blood cell transfusion in preterm infants.

BACKGROUND: Although many controversies exist regarding the risk of red blood cell (RBC) transfusions, half of preterm infants born at <32 weeks of gestational age receive such transfusions because of anemia of prematurity. Because of the costs and risks associated with multiple transfusions, it has been suggested that a large transfusion volume reduces the number of transfusions. However, there have been persistent concerns that RBC transfusion might lead to volume overload. METHODS: We examined the impacts of large (20 mL/kg) compared to standard volume (15 mL/kg) transfusions on the hemodynamic variables of stable, electively transfused, preterm infants, by serially measuring echocardiographic parameters and plasma B-type natriuretic peptide levels. RESULTS: A total of 39 infants born at <34 weeks of gestation and aged >2 weeks at the time of enrollment were randomly allocated to either a standard volume (15 mL/kg) or a large volume (20 mL/kg) group. Significant reductions in cardiac output and transient increases in plasma B-type natriuretic peptide levels were found after RBC transfusion in both the standard and large volume (20 mL/kg) groups. However, these changes were not significantly different between the two groups. CONCLUSIONS: Large-volume transfusions could be tolerable in stable preterm infants with anemia.

Gut Bacterial Dysbiosis in Children with Intractable Epilepsy.

A few published clinical studies have evaluated the association between gut microbiota in intractable epilepsy, but with inconsistent results. We hypothesized that the factors associated with the gut bacterial composition, such as age and geography, contributed to the discrepancies. Therefore, we used a cohort that was designed to minimize the effects of possible confounding factors and compared the gut microbiota between children with intractable epilepsy and healthy controls. Eight children with intractable epilepsy aged 1 to 7 years and 32 age-matched healthy participants were included. We collected stool samples and questionnaires on their diet and bowel habits at two time points and analyzed the gut microbiota compositions. In the epilepsy group, the amount of Bacteroidetes was lower (Mann-Whitney test, false discovery rate (FDR) < 0.01) and the amount of Actinobacteria was higher (FDR < 0.01) than in the healthy group. The epilepsy subjects were 1.6- to 1.7-fold lower in microbiota richness indices (FDR < 0.01) and harbored a distinct species composition (p < 0.01) compared to the healthy controls. Species biomarkers for intractable epilepsy included the Enterococcus faecium group, Bifidobacterium longum group, and Eggerthella lenta, while the strongest functional biomarker was the ATP-binding cassette (ABC) transporter. Our study identified gut bacterial dysbiosis associated with intractable epilepsy within the cohort that was controlled for the factors that could affect the gut microbiota.

Development of the Korean Developmental Screening Test for Infants and Children (K-DST).

BACKGROUND: Most developmental screening tools in Korea are adopted from foreign tests. To ensure efficient screening of infants and children in Korea, a nationwide screening tool with high reliability and validity is needed. PURPOSE: This study aimed to independently develop, standardize, and validate the Korean Developmental Screening Test for Infants and Children (K-DST) for screening infants and children for neurodevelopmental disorders in Korea. METHODS: The standardization and validation conducted in 2012-2014 of 3,284 subjects (4-71 months of age) resulted in the first edition of the K-DST. The restandardization and revalidation performed in 2015-2016 of 3.06 million attendees of the National Health Screening Program for Infants and Children resulted in the revised K-DST. We analyzed inter-item consistency and test-retest reliability for the reliability analysis. Regarding the validation of K-DST, we examined the construct validity, sensitivity and specificity, receiver operating characteristic curve analysis, and a criterion-related validity analysis. RESULTS: We ultimately selected 8 questions in 6 developmental domains. For most age groups and each domain, internal consistency was 0.73-0.93 and test-retest reliability was 0.77-0.88. The revised K-DST had high discriminatory ability with a sensitivity of 0.833 and specificity of 0.979. The test supported construct validity by distinguishing between normal and neurodevelopmentally delayed groups. The language and cognition domain of the revised K-DST was highly correlated with the K-Bayley Scales of Infant Development-II's Mental Age Quotient (r=0.766, 0.739), while the gross and fine motor domains were highly correlated with Motor Age Quotient (r=0.695, 0.668), respectively. The Verbal Intelligence Quotient of Korean Wechsler Preschool and Primary Scales of Intelligence was highly correlated with the K-DST cognition and language domains (r=0.701, 0.770), as was the performance intelligence quotient with the fine motor domain (r=0.700). CONCLUSION: The K-DST is reliable and valid, suggesting its good potential as an effective screening tool for infants and children with neurodevelopmental disorders in Korea.

Early Prediction of Periventricular Leukomalacia Using Quantitative Texture Analysis of Serial Cranial Ultrasound Scans in Very Preterm Infants.

We compared texture parameters of serial cranial ultrasound (cUS) images of periventricular leukomalacia (PVL) and normal periventricular echogenicity (PVE) in very preterm infants and evaluated the early predictive values of texture analysis (TA) for PVL. Ten individuals with PVL and 10 control individuals with PVE assessed with an initial cUS within 1 wk of birth and follow-up cUS at 2-3 and 4-6 wk of life were included. TA was performed on the region of interest of PVE at the parieto-occipital area on serial cUS. Opposite changes in variance were obtained between the first two cUS sessions in both groups (p = 0.017 in PVL and p = 0.005 in PVE). The variance-to-mean ratio (VMR) between the second and first cUS sessions differed (p = 0.016) and reliably stratified the groups (area under the receiver operating characteristic curve: 0.820, 95% confidence interval: 0.587-1.000, sensitivity: 100%, specificity: 60%). TA of serial cUS helps to predict PVL within 3 wk of life.

Bisphenol A in infant urine and baby-food samples among 9- to 15-month-olds.

Diet is the predominant source of bisphenol A (BPA) intake, but limited data are available on BPA levels in the diet of younger infants. This study investigated BPA levels in baby-food and urine samples collected from young infants (under 2 years old). Samples of homemade baby food (n = 210) and urine (n = 187) were collected at 9, 12, and 15 months after birth from a panel of Korean infants (n = 173). BPA levels in urine and food were measured using HPLC-MS/MS and GC-MS, respectively. BPA was above the limit of detection (LOD) in 85.5-85.7% of the urine samples and 32.5-76.3% of the baby-food samples. The median levels of BPA were 0.45 ng/g wet weight (IQR: not detectable to 5.16 ng/g wet weight) in homemade baby food, 0.93 µg/L (IQR:

Risk of low serum levels of ionized magnesium in children with febrile seizure.

BACKGROUND: Suboptimal intake of magnesium become prevalent due to the modern diet of processed food low in magnesium. Magnesium may modulate seizure activity by antagonizing excitatory calcium influx through the N-methyl-D-aspartate receptor. Although hyponatremia has been reported to be common in febrile seizures, the most common form of seizure, little is known about the status of serum ionized magnesium. We therefore investigated the status of serum ionized magnesium (iMg2+) in children with febrile seizures and compared with controls. METHODS: We included all patients from 1 to 6 years old who had presented with febrile seizure to the pediatric emergency department at the Korea University Guro Hospital from July 2016 to February 2017. The control group comprised patients admitted to the hospital with febrile respiratory tract infections, but with no history of febrile seizure. Clinical data, blood tests, and electroencephalogram (EEG) results were reviewed using the patients' medical records. RESULTS: A total of 133 patients with febrile seizure and 141 control patients were analyzed in the present study. As a result, hypomagnesemia (< 0.50 mmol/L) was more common in patients with febrile seizure than in controls (42.9% vs. 6.9%, p < 0.001) and it was an independent risk factor for febrile seizure (OR, odds ratio = 22.12, 95% CI = 9.23-53.02, P < 0.001). A receiver operating curve analysis revealed that serum iMg2+ levels < 0.51 mmol/L predicted the presence of febrile seizures with a sensitivity of 45.1% and a specificity of 92.6% (AUC, area under the curve = 0.731, 95% confidence interval = 0.671-0.791). When the patients with febrile seizure were divided in terms of a serum iMg2+ concentration of 0.51 mmol/L, there was no difference in clinical features. CONCLUSIONS: Hypomagnesemia was more common and serum iMg2+ level was lower in patients with febrile seizures than in controls. However, further evidence is needed for the causal relationship between low magnesium and febrile convulsions.

Ten-year Nationwide Population-based Survey on the Characteristics of Children with Henoch-SchÓ§nlein Purpura in Korea.

BACKGROUND: Henoch-SchÓ§nlein purpura (HSP) is a common vasculitis of childhood. Though HSP is usually self-limiting, severe complications can occur. The management for this condition has not been established yet. Thus, this nationwide study aimed at investigating epidemiological characteristics of children with HSP in Korea. The patterns of clinical practice with regard to the complications of the condition were also investigated. METHODS: This is a national population-based study that used the National Health Insurance Database. Children below 18 years who were diagnosed with HSP in Korea between 2006 and 2015 were enrolled. Data, such as age, sex, yearly and monthly distribution of HSP, hospitalization, re-hospitalization, comorbidities, and interventions were obtained. The use of steroids was also analyzed. RESULTS: A total of 56,841 children were enrolled. The annual incidence of HSP was 55.9 per 100,000 children. The peak age was 5 years. Spring was the most prevalent season. Sex (male) and young age (< 9 years) were risk factors of hospitalization. Younger children were more likely to be re-hospitalized and suspected with intussusception, arthritis, and nephritis. Only 4 children received laparotomy. In total, 57% were managed with steroids, and mean durations of medication were 4-5 days. Children who were hospitalized and those with comorbidities used steroids more frequently (P < 0.001). CONCLUSION: The annual incidence of HSP is 55.9 per 100,000 children which is higher in Korea than that in other countries. Younger children can have a more severe clinical course. This nationwide survey provides valuable information to understand HSP in children and to inspire further research on HSP.

Exposure to lead and mercury through breastfeeding during the first month of life: A CHECK cohort study.

Mercury and lead are naturally occurring toxicants and are responsible for various health issues including neurobehavioral and developmental disorders. Because of crucial synchronized developmental processes occurring at the early stage of life, infancy and childhood are considered as among the most susceptible windows to the exposure to these metals. Breastmilk is often the only source of nutrition during the first months of life. As breastmilk can be contaminated with these metals, breastfeeding may serve as a significant route of heavy metal exposure among infants. In order to understand current levels of exposure to mercury and lead through breastfeeding, and their associated risks, a total of 157 lactating mothers were recruited from Children's Health and Environmental Chemicals of Korea (CHECK) cohort, and breastmilk samples were collected at 15 and 30days after delivery (n=207). Mercury was detected from 100% of breastmilk with a median concentration of 0.59µg/L, and lead was detected in 77% of the samples with a median at 4.71µg/L. Higher concentrations of lead were found in the 30- day breastmilk than in the 15-day. Up to 45% of the breastmilk samples exceeded the normal range of the breastmilk lead suggested by WHO. Based on Monte Carlo simulation, about 71% of 15days old infants and 56% of 30days old infants were estimated at risk due to lead exposure through breastfeeding. Considering vulnerability of infants and well-known neurological toxicity of these metals, further studies to identify major exposure sources that contribute the lead concentration in breastmilk and health implication of early life stage exposure to lead among the breastfed infants are warranted.

Need for Lumbar Puncture in Children Younger Than 12 Months Presenting With Simple Febrile Seizure.

OBJECTIVES: Recently, conflicting results have been reported regarding the necessity of routine lumbar puncture in children less than 12 months of age with simple febrile seizure. The aims of this study were to evaluate the results of lumbar puncture in children younger than 60 months of age with febrile seizure and to reassess the need for lumbar puncture in children younger than 12 months with simple febrile seizure. METHODS: A retrospective chart review was performed in patients younger than 60 months who presented with febrile seizure and underwent lumbar puncture from January 2005 to January 2015. RESULTS: A total of 1249 patients presenting with febrile seizure were admitted. Of these, 816 met inclusion criteria for presenting with simple febrile seizure. Lumbar puncture was performed in 75 patients (9.2%; age, mean ± SD, 12.05 ± 9.13 months; male/female, 31/44), who were reviewed. Sixty-six (88.0%) of 75 patients were younger than 12 months. Five patients (6.7%) showed pleocytosis in cerebrospinal fluid, and 4 of them were younger than 1 year of age. Three patients (4.0%) had bacterial meningitis and were 4, 8, and 12 months. Streptococcus pneumoniae (2 patients) and Klebsiella pneumoniae (1 patient) were isolated in cerebrospinal fluid. Nobody had neurologic signs suggesting bacterial meningitis, and all of them completed scheduled immunizations and were up-to-date. CONCLUSION: Lumbar puncture should be considered in every child younger than 12 months of age with a simple febrile seizure owing to lack of abnormal neurologic sign even if immunization is up-to-date.

Association between maternal exposure to major phthalates, heavy metals, and persistent organic pollutants, and the neurodevelopmental performances of their children at 1 to 2years of age- CHECK cohort study.

Exposure of the developing fetus and infants to toxic substances can cause serious lifelong health consequences. Several chemicals have been associated with adverse neurodevelopmental disorders in the early life stages of humans. However, most epidemiological studies have focused on a limited number of chemicals, and hence may exclude important chemicals from consideration or result in conclusions built on associations by chance. In the present study, we investigated the chemical exposure profile of the women, and associated these with the early neurodevelopmental performance of their offspring at 13-24months of age. The chemicals assessed include four phthalates, bisphenol A, three heavy metals, 19 polychlorinated biphenyls (PCBs), 19 organochlorine pesticides, and 19 polybrominated diphenyl ethers, which were measured from urine, whole blood, serum, and/or breastmilk of the pregnant or lactating women. For neurodevelopmental performance, the Bayley Scales of Infant Development-II (BSID-II), Social Maturity Scale (SMS), and Child Behavior Checklist (CBCL) were measured from a total of 140 toddlers. Among the measured chemicals, monoethyl phthalate (MEP) in maternal urine was significantly associated with early mental, psychomotor, and social development. In addition, breast milk di-ethylhexyl phthalate (DEHP) metabolite and blood lead concentrations were inversely associated with mental and psychomotor development indices, respectively. Maternal blood PCB153, heavy metals, and urinary MEP levels were also higher among the children with behavioral problems, as indicated by the CBCL range. Taken together, maternal exposure to several EDCs such as PCBs and DEHP was associated with adverse neurodevelopmental performances among the children aged 1-2years. Confirmation of these association in larger populations, as well as longer-term consequences of such exposure warrant further investigation.

Bisphenol A distribution in serum, urine, placenta, breast milk, and umbilical cord serum in a birth panel of mother-neonate pairs.

Bisphenol A (BPA) exposure during the perinatal and postnatal periods increases the susceptibility to disease over the life cycle. However, information on the BPA delivered to fetuses or infants via the placenta and breastfeeding is limited. We determined the BPA exposure levels in various bodily fluids and tissues of pregnant women and described fetus and infant exposures to BPA based on associations and BPA ratios in mother-neonate paired samples. Maternal serum, urine, placenta, breast milk, cord serum, and neonatal urine samples were collected from 318 mother-neonate pairs at six university hospitals in Korea. BPA levels were detected using liquid chromatography tandem mass spectrometry. The ratios of the BPA levels in the other sample types to the levels in maternal serum were calculated. BPA was detected in 79.5-100% of the maternal and fetal samples. The median BPA concentration in the samples decreased in the order of neonatal urine (4.75ng/mL), maternal urine (2.86ng/mL), cord serum (1.71ng/mL), maternal serum (1.56ng/mL), breast milk (0.74ng/mL), and the placenta (0.53ng/g). We estimated the ratios of BPA levels in the other sample types to those in maternal serum. The median (95th percentile) cord serum-to-maternal serum ratio was 1.12 (15.2) for 160 mother-fetal pairs, in which BPA was detected in both samples. The placenta-, maternal urine-, neonatal urine-, and breast milk-to-maternal serum ratios were 0.28 (5.31), 1.79 (29.9), 1.98 (28.2), and 0.51 (10.5), respectively. In addition, the median (95th percentile) cord serum-to-placenta ratio was 4.03 (45.8), and the neonatal urine-to-cord serum ratio was 1.95 (25.6). The 95th percentile values were 14-20-fold greater than the medians. Urine contained the highest BPA concentrations, followed by serum, breast milk, and the placenta. The variations of BPA ratio show individual differences in the amounts of BPA delivered from mother to fetus.

Usefulness of the Korean Developmental Screening Test for infants and children for the evaluation of developmental delay in Korean infants and children: a single-center study.

PURPOSE: To evaluate the usefulness of the Korean Developmental Screening Test (K-DST) for infants and children for developmental delay assessment. METHODS: This study was based on retrospective studies of the results of the K-DST, Preschool Receptive-Expressive Language Scale (PRES), Sequenced Language Scale for Infants (SELSI), Childhood Autism Rating Scale (CARS), Modified Checklist for Autism in Toddlers (M-CHAT), electroencephalography, magnetic resonance imaging, and extensive tests conducted in 209 of 1,403 patients, of whom 758 underwent the K-DST at the Korea University Guro Hospital between January 2015 and December 2016 and 645 were referred from local clinics between January 2015 and June 2016. RESULTS: Based on the K-DST results, the male children significantly more frequently required further or follow-up examination than the female children in most test sections, except for gross motor. The male children had notably lower mean scores than the female children. The PRES/SELSI results showed that when more further or follow-up evaluations were required in the K-DST communication section, significantly more problems in language delay or disorder emerged. When further or follow-up evaluation was required in the cognitive section in the CARS/M-CHAT, the possibility of autism increased significantly. A child tended to score low in the CARS test and show autism when further or follow-up evaluation was recommended in the K-DST. CONCLUSION: This study demonstrated the usefulness of the K-DST as a screening test early in the development of infants and children in Korea. Data of normal control groups should be examined to determine the accuracy of this investigation.

Usefulness of intraoperative insular electrocorticography in modified functional hemispherectomy.

BACKGROUND: The insular cortex is not routinely removed in modified functional hemispherectomy due to the risk of injury to the main arteries and to deep structures. Our study evaluates the safety and usefulness of applying intraoperative electrocorticography (ECoG) on the insular during the hemispherectomy. METHODS: We included all patients who underwent insular ECoG during a modified functional hemispherectomy from 2012 to 2015. After the surgery, the decision for further resection of the insular cortex was made based on the presence of electrographic seizures on ECoG. RESULTS: The study included 19 patients (age, 6.4 ± 4.7 years, mean ± standard deviation). Electrographic seizures were identified in 5 patients (26.3%). Sixteen of the 19 patients (84.2%) became seizure-free with a follow-up duration of 3.1 ± 0.6 years and no vascular complication occurred. CONCLUSIONS: Intraoperative insular ECoG monitoring can be performed safely while providing a tailored approach for insular resection during modified hemispherectomy.

Urinary phthalate metabolites over the first 15months of life and risk assessment - CHECK cohort study.

Phthalates are important group of endocrine disruptors. Infants and young children are susceptible to phthalate exposure. However, information on the phthalate exposure during the early stages of life is very limited. This study was conducted to understand the temporal trend of exposure to major phthalates among infants of Korea during the first 15months after birth, and to estimate associated risks. A total of 286 urine samples were collected from 171 children at 3, 9, 12, or 15months of age, with 77 children sampled for two or more times. Four phthalates, i.e., di(2-ethylhexyl) phthalate (DEHP), di-isobutyl phthalate (DiBP), di-n-butyl phthalate (DnBP), and diethyl phthalate (DEP) were chosen, and their major metabolites were analyzed in the urine. The DEHP metabolites were detected in 100% of the urine samples at relatively higher levels compared to those reported in other countries. The levels of mono-ethyl phthalate (MEP) were generally lower. Urinary concentrations of most phthalate metabolites, especially DEHP metabolites, increased as children grew older. Intra-class correlation coefficients (ICCs) calculated for DEHP metabolites over time were high (0.7-0.8), suggesting persistence of consistent exposure sources during this sensitive period of life. Hazard quotient (HQ) and hazard index (HI) were calculated from daily intake estimates divided by recommended toxicity thresholds. Among the study population, 4, 16, and 26% of the children showed HI >1 at 9, 12, and 15months of age, respectively. DEHP exposure explained most of the risk estimates. Considering vulnerability of young children to endocrine disruption, efforts to identify sources of exposure and to develop appropriate mitigation options are warranted.

Effect of socio-economic status on sleep.

AIM: Sufficient sleep is an important factor in physical and mental health. Sleep duration can be affected by socio-economic status (SES). This study aimed to examine the association between sleep duration and SES in Korean adolescents. METHODS: This study was conducted with 1608 adolescents aged 12-18 years, based on data from the 2010 to 2012 Korean National Health and Nutrition Examination Survey (KNHANES). Sleep duration was self-reported in hours and three SES indicators were used: household income, basic livelihood security programmes and type of health insurance. Confounding factors in this study were age, mental health and physical activity. RESULTS: Participants' average age was 15.6 ± 0.05 years and average sleep duration was 7.04 ± 0.05 h. There was a strong association between sleep duration and household income (P < 0.05) rather than other socio-economic indicators. In addition, it showed that sleep duration was significantly associated with age, body mass index (P < 0.05) and low mood is associated with short sleep and long sleep (>9 h/night). We found similar results in both genders, that is, that the highest income group had shorter sleep duration than the lowest income group. CONCLUSIONS: This study shows that the SES, particularly household income, is an important factor in short sleep duration in Korean adolescents. Our findings suggest that, in future investigations of the adolescent's sleep problem, attention should be paid to household income.

Impact of intraoperative 3-T MRI with diffusion tensor imaging on hemispherectomy.

OBJECTIVE Hemispherectomy can produce remarkable seizure control of medically intractable hemispheric epilepsy in children, but some patients continue to have seizures after surgery. A frequent cause of treatment failure is incomplete surgical disconnection of the abnormal hemisphere. This study explores whether intraoperative 3-T MRI with diffusion tensor imaging (DTI) during hemispherectomy can identify areas of incomplete disconnection and allow complete disconnection during a single surgery. METHODS The charts of 32 patients with epilepsy who underwent hemispherectomy between January 2012 and July 2014 at the Florida Hospital for Children were reviewed. Patients were grouped as having had curative or palliative hemispherectomy. To assess the completeness of disconnection when the surgeon considered the operation completed, intraoperative 3-T MRI-DTI was performed. If incomplete disconnection was identified, additional surgery was performed until MRI-DTI sequences confirmed satisfactory disconnection. Seizure outcome data were collected via medical records at last follow-up. RESULTS Of 32 patients who underwent hemispherectomy, 23 had curative hemispherectomy and 9 had palliative hemispherectomy. In 11 of 32 surgeries, the first intraoperative MRI-DTI sequences suggested incomplete disconnection and additional surgery followed by repeat MRI-DTI was performed. Complete disconnection was accomplished in 30 of 32 patients (93.8%). Two of 32 disconnections (6.3%) were incomplete on postoperative imaging. Cross-sectional results showed that 21 of 23 patients (91.3%) who had curative hemispherectomy remained free of seizures (International League Against Epilepsy Class 1) at a median follow-up of 1.7 years (range 0.4-2.9 years). The longitudinal seizure freedom after curative hemispherectomy was 95.2% (SE 0.05) at 6 months, 90.5% (SE 0.06) at 1 year, and 90.5% (SE 0.05) at 2 years. CONCLUSIONS Intraoperative 3-T MRI-DTI sequences can identify incomplete disconnection during hemispherectomy and allow higher rates of complete disconnection in a single surgery. Higher rates of complete disconnection seem to achieve better seizure-free outcome following modified functional hemispherectomy.