2022 Clinical practice guidelines for central precocious puberty of Korean children and adolescents.

The Committee of Central Precocious Puberty of Korean Pediatrics and Adolescents of the Korean Society of Pediatric Endocrinology has newly developed evidence-based 2022 clinical practice guidelines for central precocious puberty in Korean children and adolescents. These guidelines provide the grade of recommendations, which includes both the strength of recommendations and the level of evidence. In the absence of sufficient evidence, recommendations are based on expert opinion. These guidelines have been revised and supplement the previous guidelines "Clinical Guidelines for Precocious Puberty 2011," and are drawn from a comprehensive review of the latest domestic and international research and the grade of recommendation appropriate to the domestic situation. This review summarizes the newly revised guidelines into 8 key questions and 27 recommendations and consists of 4 sections: screening, diagnosis, treatment, and long-term outcome of central precocious puberty.

Relationship between short stature at 3 years old and height, weight, and body mass index changes for 6 years after birth: a retrospective, nationwide, population-based study of children born 2011-2014 in Korea.

PURPOSE: Height at 3 years of age, when catch-up growth based on birth history is completed, is considered a major prognostic factor for predicting short stature, underweight, and growth faltering. However, too few large-scale studies have followed and analyzed height, weight, and body mass index (BMI) changes in children whose stature was short at 3 years of age. This study followed and compared the growth parameters (height, weight, and BMI) of children with short stature at 3 years of age and children with nonshort stature at 3 years of age for 6 years after birth using nationwide, population-based data. METHODS: We retrospectively analyzed physical measurement data from the National Health Screening Program for Infants and Children for people born in 2011-2014 in Korea and followed to 2020. The data were provided by the National Health Insurance Service's customized data service. Growth parameters were compared using chi-square tests, Student t-tests, analyses of variance, and linear regressions. RESULTS: Among 210,902 enrolled participants, 759 (0.4%) and 210,143 (99.6%) were in the short stature at 3 years group and the nonshort stature at 3 years group, respectively. In both sexes, height, weight, and BMI for 6 years after birth were significantly higher in the nonshort stature at 3 years group than in the short stature at 3 years group (P<0.0001). The BMI rebound was observed later than the standard period in the short stature at 3 years group. CONCLUSION: Early intervention and close follow-up are necessary to prevent persistent short stature and growth faltering in children with short stature at 3 years of age.

Analysis of Critical COVID-19 Cases Among Children in Korea.

BACKGROUND: Coronavirus disease 2019 (COVID-19) is generally asymptomatic or mild in otherwise healthy children, however, severe cases may occur. In this study, we report the clinical characteristics of children classified as critical COVID-19 in Korea to provide further insights into risk factors and management in children. METHODS: This study was a retrospective case series of children < 18 years of age classified as critical COVID-19. Cases were identified by the Korea Disease Control and Prevention Agency surveillance system and medical records were reviewed. Critical COVID-19 was defined as cases with severe illness requiring noninvasive (high flow nasal cannula, continuous positive airway pressure, or bilevel positive airway pressure) or invasive mechanical ventilation, extracorporeal membrane oxygenation (ECMO) or continuous renal replacement therapy (CRRT), between January 20, 2020 and October 7, 2021. RESULTS: Among 39,146 cases diagnosed with COVID-19 in subjects < 18 years of age, eight cases (0.02%) were identified as critical COVID-19. The median age was 13 years (range 10 month-17 years) and male-to-female ratio was 1:1. Three children had underlying diseases; one child has asthma and major depressive disorder, one child had Lennox-Gastaut syndrome and one child had mental retardation and was newly diagnosed with type 2 diabetes mellitus with the diagnosis of COVID-19. Among the eight children, seven were obese (body mass index range [BMI] median 29.3, range 25.9-38.2, weight-for-length > 97% for infant) and one was overweight (BMI 21.3). All patients had fever, six patients had dyspnea or cough and other accompanied symptoms included sore throat, headache, lethargy and myalgia. Radiologic findings showed pneumonia within 1-8 days after symptom onset. Pneumonia progressed in these children for 2-6 days and was improved within 5-32 days after diagnosis. Among the eight critical cases, remdesivir was administered in six cases. Steroids were provided for all cases. Inotropics were administered in one case. Six cases were treated with noninvasive mechanical ventilator and three required mechanical ventilator. One case required ECMO due to acute respiratory distress syndrome. All cases were admitted to the intensive care unit and admission period ranged from 9-39 days. Among all critical COVID-19 cases < 18 years of age, there were no fatal cases. CONCLUSION: To develop appropriate policies for children in the COVID-19 pandemic, it is important to monitor and assess the clinical burden in this population.

Prevalence of Type 2 Diabetes Mellitus among Korean Children, Adolescents, and Adults Younger than 30 Years: Changes from 2002 to 2016.

BACKGROUND: Despite the importance of and social concern regarding prevention of diabetes at younger ages, limited data are available. This study sought to analyze changes in the prevalence of type 2 diabetes mellitus (T2DM) in Koreans younger than 30 years according to sex, age, and level of income. METHODS: The dataset analyzed in this study was derived from health insurance claims recorded in the National Health Insurance Service (NHIS) database. Participants' level of income was categorized as low (quintile 1, <20% of insurance premium) or others (quintile 2-5). RESULTS: In males and females, the prevalence of T2DM per 10,000 people steadily increased from 2.57 in 2002 to 11.41 in 2016, and from 1.96 in 2002 to 8.63 in 2016. The prevalence of T2DM in girls was higher in the age group of 5 to 14 years. Even though the prevalence was higher among those older than 20 years, the increase had started earlier, in the early 2000s, in younger age group. Adolescents aged 10 to 19 years in low-income families showed a remarkable increase in prevalence of T2DM, especially in boys. CONCLUSION: The prevalence of T2DM in young Koreans increased more than 4.4-fold from 2002 to 2016, and the increase started in the early 2000s in younger age groups and in low-income families. This is the first study to examine the trend in prevalence of T2DM in children, adolescents, and young adults in Korea. Future studies and collaborations with social support systems to prevent T2DM at an early age group should be performed.

Impact of the COVID-19 Pandemic on Seasonal Variations in Childhood and Adolescent Growth: Experience of Pediatric Endocrine Clinics.

BACKGROUND: Children experience seasonal variations in growth whereby height increases most in spring and least in autumn, and weight increases least in spring and most in autumn. We hypothesized that activity restriction caused by efforts to contain the spread of coronavirus disease 2019 (COVID-19) would result in increased body mass index (BMI) in children, differing from conventional seasonal growth variations. METHODS: We included 169 children who visited endocrine clinics of three hospitals in Korea at regular intervals under the same conditions for two years. Visit dates were D1 (January, 2019), D2 (July, 2019), D3 (January, 2020) before the COVID-19 outbreak, and D4 (July, 2020) during the pandemic. Differences in the z-score for height (HT), weight (WT), and BMI among time points and between spring seasons (i.e., S1-S3) were compared. RESULTS: There were significant differences in BMIz among time points, which decreased from D1-D2 and increased from D2-D3 and D3-D4. WTz significantly increased from D2-D3 and D3-D4. BMIz values of S1 (spring 2019) and S3 (spring 2020) were -0.05 and 0.16, respectively, showing significant differences. WTz values between S1 and S3 were significantly different (-0.02 vs. 0.13). CONCLUSIONS: In 2019, there were conventional seasonal variations in BMIz, which declined in spring and increased in autumn, while in 2020, BMIz increased even in spring. The COVID-19 pandemic may have affected seasonal variations in the growth of children attending endocrine clinics.

Response to vitamin D replacement in overweight and normal weight children with vitamin D deficiency.

PURPOSE: It is well known that obesity is related to vitamin D deficiency (VDD). We investigated the response to vitamin D replacement in normal-weight and overweight children. METHODS: This was a prospective study including 62 Korean children with VDD. VDD was defined as a serum 25-hydroxycholecalciferol (25(OH)D) concentration <20 ng/mL. Overweight was defined as a body mass index (BMI)≥the 85th percentile (n=21), and normal weight as a BMI between the 5th and 84th percentiles (n=41). All participants received vitamin D3 supplementation (2,000 IU/day) for 8 weeks. The serum levels of 25(OH)D, PTH and biochemical parameters were measured before and after treatment. RESULTS: The mean age was 10.0±1.4 years in normal-weight children and 10.0±2.1 years in overweight children (P=0.93). After 8 weeks of treatment, 61.9% of normal-weight children and 47.6% of overweight children achieved vitamin D sufficiency (P =0.30). The mean serum 25(OH)D levels after vitamin D replacement were 33.8±7.6 ng/mL and 30.3±6.6 ng/mL in normal-weight and overweight children, respectively (P =0.10). The mean calcium/creatinine ratios after treatment were 0.09±0.07 and 0.08±0.06 in the normal-weight and overweight groups, respectively, and no hypercalciuria was found. In multiple regression analysis, the response to vitamin D replacement was influenced by the BMI (ß=-1.0, P=0.03) and sex (ß=-4.0, P=0.04). CONCLUSION: Eight weeks of vitamin D replacement (2,000 IU/day) is sufficient to overcome vitamin D deficiency in normal-weight and overweight children without any complications.

Morning basal luteinizing hormone, a good screening tool for diagnosing central precocious puberty.

PURPOSE: The standard method used to diagnose central precocious puberty (CPP) is the gonadotropin releasing hormone stimulation test (GnRHST). However, this test is inconvenient for children because it is time-consuming and requires multiple samples. This study aimed to determine the reliability of morning unstimulated luteinizing hormone (mLH) level when screening for CPP, with an emphasis on the influence of diurnal variation. METHODS: This study included 160 girls with signs of early puberty (SMR 2) under 8 years of age. They were classified as CPP or non-CPP based on their standard GnRHST. The auxological, biochemical, and hormonal characteristics of subjects were retrospectively evaluated. The prognostic value of single morning unstimulated gonadotropin level was examined for use in CPP screening. RESULTS: Of 160 patients, 121 (75.6%) presented with CPP, and 39 (24.4%) were determined to be prepubertal. The mLH/mFSH (morning unstimulated follicular stimulating hormone) ratio showed significant differences between the 2 groups (P<0.001). The mLH was correlated with GnRHST variables (r=0.532, P<0.001). The mLH cutoff point when screening for CPP was 0.22 IU/L, which had sensitivity and specificity of 69.4% and 82.1%, respectively. In regression analysis, bone age (BA) (odds ratio [OR], 1.018; 95% confidence interval [CI], 0.967-1.071; P=0.506) and body mass index (BMI) (OR, 0.874; 95% CI, 0.583-1.310; P=0.515) were not significant predictors. The mLH≥0.22 IU/L group (OR, 9.596; 95% CI, 3.853-23.900; P<0.001) was highly suggestive of CPP. CONCLUSION: In this study, single morning unstimulated luteinizing hormone had clinical efficacy for CPP screening, but BA advanced over chronological age and BMI was not useful for CPP screening.

Relationship between the ulnar nerve and the branches of the radial nerve to the medial head of the triceps brachii muscle.

One branch of the radial nerve to the medial head of the triceps brachii muscle (MHN) has been described as accompanying or joining the ulnar nerve. Mostly two MHN branches have been reported, with some reports of one; however, the topographical anatomy is not well documented. We dissected 52 upper limbs from adult cadavers and found one, two, and three MHN branches in 9.6%, 80.8%, and 9.6% of cases, respectively. The MHN accompanying the ulnar nerve was always the superior MHN. The relationship between the ulnar nerve and the MHN was classified into four types according to whether the MHN was enveloped along with the ulnar nerve in the connective tissue sheath and whether it was in contact with the ulnar nerve. It contacted the ulnar nerve in 75.0% of cases and accompanied it over a mean distance of 73.6 mm (range 36-116 mm). In all cases in which the connective tissue sheath enveloped the branch of the MHN and the ulnar nerve, removing the sheath confirmed that the MHN branch originated from the radial nerve. The detailed findings and anatomical measurements of the MHN in this study will help in identifying its branches during surgical procedures. Clin. Anat. 00:1-16, 2018. © 2018 Wiley Periodicals, Inc.

Diurnal variation of gonadotropin levels in girls with early stages of puberty.

PURPOSE: Pubertal gonadotropin secretion shows circadian pattern and the luteinizing hormone (LH) levels tend to rise in later stages of puberty in girls. We studied the usefulness of basal LH in the evaluation of central precocious puberty with emphasis on the influence of sampling time. METHODS: Medical records of 334 girls that underwent gonadotropin-releasing hormone stimulation test (GnRHST) were reviewed. Auxological and laboratory data were compared between those with early morning (EM, before 10 AM) and late morning/afternoon (LM/A, after 10 AM) basal samples. RESULTS: Among those in sexual maturity rating (SMR) 2, EM samples showed higher basal LH (P=0.004) compare to LM/A samples, whereas those in SMR 3 showed no difference in LH levels between EM and LM/A samples. Among girls with pubertal response, EM group showed higher basal LH (P=0.031) and follicular stimulating hormone (P=0.008) than LM/A group. The EM basal LH was more closely related with the peak stimulated LH than the LM/A basal LH did (rs=0.871 vs. rs=0.524). The optimal basal LH cutoffs to predict a pubertal response to GnRHST were 0.11 IU/L with a sensitivity of 66.7% and a specificity of 78.7% in EM group, and 0.07 IU/L with a sensitivity of 60.0% and a specificity of 78.9% in LM/A group, respectively. CONCLUSIONS: In girls with early stages of puberty, EM basal LH is a more sensitive screening tool than the LM/A basal LH. Diurnal variation should be considered in evaluating children with precocious puberty.

Morphological Patterns and Variations of the Nasal Septum Components and Their Clinical Implications.

The aim of this study was to clarify the morphological patterns and proportions of the components of the nasal septum. Anatomical examinations were performed on 70 nasal septums of embalmed Korean adult cadavers. The septal deviation was checked before cutting the nasal cavity midsagittally with the aid of a laryngoscope. The shape of each component of the nasal septum was identified, and photographs were taken from a midline sagittal view. A line was drawn on each photograph between the septal components, and then the area of each septal component was measured using software. The mean area proportions of the septal cartilage (SC), the perpendicular plate of the ethmoid bone (PPE), the vomer, and the nasal crest of the maxilla relative to the total area of the nasal septum were 25.6%, 43.0%, 25.8%, and 5.6%, respectively. The morphology of the nasal septum was classified into 3 main patterns according to the proportion of each septal component. The proportions of the SC, the PPE, the vomer, and the nasal crest of the maxilla were similar to the mean values of the present study in 45.7%. The proportions of the SC, the PPE, and the vomer were similar to each other (with a difference of <15%) in 24.3%. The proportion of the PPE exceeded 50% of the total area of the nasal septum in 22.9%. The results reported herein provide detailed anatomical knowledge that can be used as a valuable reference for rhinoplasty procedures.

A cadaveric study on mylohyoid herniation of the sublingual gland.

The purpose of this study was to document the presence of a sublingual gland (SLG) herniating inferiorly through the mylohyoid muscle into the submandibular area. A total of 100 half-heads of 50 adult Korean cadavers were enrolled in this study. The floor of the mouth was dissected from the neck, and mylohyoid muscle patency and position of the sublingual gland were evaluated. Demographic factors of the donor and characteristics of the herniation were evaluated. Herniation was found in 29 (58.0 %) of the 50 cadavers or 42 of the 100 half-heads. Herniation was more frequently observed in females than in males (p = 0.009). However, no laterality was observed. Classifying the location of SLG herniation from the midpoint of the mandible to the hyoid bone into 3 regions, 32 (63 %) of herniations were found in the anterior one-third. No ranula formation was observed. The size and weight of normal glands tended to be larger than those of herniated glands, but no statistical significance was observed. An SLG hernia is a very common condition and is more frequently observed in females. As such, SLG herniation should be considered when a submental neck mass is evaluated.

Intermuscular aponeuroses between the flexor muscles of the forearm and their relationships with the ulnar nerve.

INTRODUCTION: The aim of this study was to clarify the morphological characteristics of the intermuscular aponeurosis between the flexor carpi ulnaris (FCU) and flexor digitorum superficialis (FDS; IMAS), and that between the FCU and flexor digitorum profundus (FDP; IMAP), and their topographic relationships with the ulnar nerve. MATERIALS AND METHODS: Fifty limbs of 38 adult cadavers were studied. RESULTS: The IMAS extended along the deep surface of the FCU adjoining the FDS, having the appearance of a ladder, giving off "steps" that decreased in width from superficial to deep around the middle of the forearm. Its proximal part divided into two bands connected by a thin membrane, and was attached to the medial epicondyle and the tubercle (the most medial prominent part of the coronoid process of the ulna), respectively. The IMAP extended deep between the FCU and FDP from the antebrachial fascia, and its distal end was located on the posterior border of the FCU. The IMAP became broader toward its proximal part, and its proximal end was attached anterior and posterior to the tubercle and the olecranon, respectively. The ulnar nerve passed posterior to the medial epicondyle and then medial to the tubercle, and was crossed by the deep border of the IMAS at 58.3 ± 14.1 mm below the medial epicondyle. CONCLUSION: The deep border of the IMAS and aberrant tendinous structure passing across the ulnar nerve, or the parts of the IMAS and IMAP passing posterior to the ulnar nerve are potential causes of ulnar nerve compression.

Waist-to-Height Ratio as an Index for Cardiometabolic Risk in Adolescents: Results from the 1998-2008 KNHANES.

PURPOSE: To describe the relationship between the waist-to-height ratio (WHtR) and cardiometabolic risk factors (CMRFs) and to evaluate the validity of WHtR in identifying adolescents with metabolic syndrome. MATERIALS AND METHODS: We analyzed data from a pooled population of 4068 adolescents aged 10-19 years from the Korean National Health and Nutrition Examination Surveys conducted between 1998 and 2008. Overweight individuals were defined by body mass index (BMI) ≥85th percentile. Those with at least 2 CMRFs among hypertension, hyperglycemia, hypertriglyceridemia, and decreased high-density lipoprotein cholesterol (HDL-C) were classified as having multiple CMRFs. RESULTS: WHtR was significantly related to systolic blood pressure, HDL-C, and triglycerides in both non-overweight and overweight adolescents (all p<0.01). Among overweight adolescents, the area under the curve (AUC) for WHtR in identifying multiple CMRFs was significantly greater than that for BMI (p=0.014). Metabolic syndrome was more common in overweight adolescents with a WHtR of ≥0.5 than in those with a WHtR of <0.5 (p<0.001). In non-overweight adolescents, the prevalences of multiple CMRFs (p=0.001) and metabolic syndrome (p<0.001) were higher in those with a WHtR of ≥0.5 than in those with a WHtR of <0.5. Among those without central obesity, the prevalence of multiple CMRFs was higher in those with a WHtR of ≥0.5 than in those with a WHtR of <0.5 (p=0.021). CONCLUSION: WHtR is a simple and valid index for identifying adolescents with increased cardiometabolic risk and is related to CMRFs even in non-overweight adolescents. In adolescents already screened via BMI and waist circumference (WC), WHtR seems to be of additional help in discriminating those at higher cardiometabolic risk.

The enigmatic subcostal muscle: Anatomical study with application to spine and chest pain syndromes and avoidance of confusion on imaging.

The aim of this study was to revisit the morphological characteristics of the subcostal muscle and to obtain its morphometric data. One hundred and two sides of the thorax from 51 adult cadavers were used. The total number of subcostal muscles in the 102 specimens was 559. The subcostal muscle commonly comprised an aponeurosis at its superior and inferior attachments. This muscle had a thin band-like shape in 64.2% cases, while in the other 35.8% either its superior or inferior attachment was wider. It was classified into the following four types on the basis of its inferior attachment: in Types I and II it extended to two (79.3%) and three (12.0%) lower ribs, respectively; in Type III it joined adjacent muscles such as the psoas major (2.2%) or quadratus lumborum (0.7%); and in Type IV it was attached to the transverse process (0.4%) or body (3.9%) of the 12th thoracic vertebra and the body of the 1st lumbar vertebra (1.4%). The subcostal muscle was found at the deepest layer of the intercostal space, and mainly presented in the upper and lower parts of the thorax. Its width and height were 18.2 ± 10.9 mm (mean ± SD) and 56.0 ± 13.3 mm, respectively. The distances from the midsagittal line to the superior and inferior attachments of the subcostal muscle were 77.1 ± 13.0 mm and 48.9 ± 13.5 mm, respectively. The results of this study will help to advance current understanding of the subcostal muscle.

Zuckerkandl's tubercle of the thyroid gland: Its location in the anatomical position, and comparative morphology of the same specimens before and after fixation.

The aim of this study was to elucidate the definition of the borders and surface of the thyroid lobe in the anatomical position, and to compare the morphology of Zuckerkandl's tubercle (ZT) in the fresh and fixed states. One hundred thyroid lobes from 50 fresh Korean cadavers were used. The lateral border of the thyroid lobe could be defined as the most lateral margin of its anterior aspect when in the anatomical position. The posteromedial border was the margin that projected toward the trachea or tracheoesophageal groove. The lateral and posteromedial borders, and the posterior surface between these borders, could be identified in most of the fixed cadavers. The posterolateral border could only be identified in the thyroid lobe if there was compression by the internal carotid artery in cross-sectioned specimens and CT images. The ZT was identifiable in 85% of both fresh and fixed specimens. It was identified mainly at the posteromedial border of the thyroid lobe when in the anatomical position, and extended to the tracheoesophageal groove or esophagus. In the fresh state, the ZT projected as a rounded cone with a usually semicircular base, but its shape was very variable in the fixed state. In the present study, the ZT was found at the posteromedial border or posterior surface of the thyroid lobe in both the fresh and fixed states, contrary to most previous reports. The location of the ZT should be established in the anatomical position to avoid confusion.

A new morphological classification for the fibularis quartus muscle.

PURPOSE: The fibularis quartus muscle (FQ) is an accessory fibular muscle that can be found in humans, reportedly in up to 22%. The aim of this study was to classify morphological patterns of the FQ and its anatomical variations. METHODS: Eighty lower limbs of 40 formalin-fixed adult Korean cadavers were used in this study. RESULTS: The FQ was present in 13 of 80 specimens (16.3%). In two specimens, each specimen had two FQs with different origins and insertion sites. Thus, 15 cases of FQ were found in 13 specimens. The FQ originated from the fibularis brevis muscle (FB) in 12 cases (15%). In these cases, the FQ arose either as a muscle or as a tendon. The muscle fibers of the FQ merged into a tendon (8 of 12 cases) that inserted variously into (1) the tendon of the FB (three cases, 3.8%), (2) the lateral surface of calcaneus (two cases, 2.5%), (3) the inferior peroneal retinaculum (two cases, 2.5%), or (4) the dorsal surface of the base of fifth metatarsal bone (one case, 1.3%). The FQ arose as a tendon from the FB in 4 of 12 cases. In three of the four cases, the FQ inserted into the lateral surface of calcaneus. The FQ arose from structures other than the FB (three cases, 3.8%). CONCLUSION: The present study has demonstrated a new classification for the FQ and its anatomical variations, and provided detailed data for its accurate identification of a muscle and relevant surgical procedures.

Distribution of the internal branch of the human accessory nerve.

It was recently reported that the internal branch of the accessory nerve not only comprises the cranial root but also various combinations of the cranial root, spinal root, and the vagal component of the vagus nerve. The aim of this study was to demonstrate the anatomical distribution of each component of the internal branch of the human accessory nerve. Ten half-heads and necks of adult cadavers were used. The internal branch of the accessory nerve had three courses: the pharyngeal branch, the descending branch to the thorax, and the recurrent laryngeal nerve. The pharyngeal branch of the internal branch originated mainly from the vagus nerve, rather than from the cranial root of the accessory nerve. All of the components of the internal branch descended to the thorax along the vagus nerve. The recurrent laryngeal nerve comprised the internal branch and the vagus nerve in all specimens, and it was separated into bundles originating from the internal branch and vagus nerve. Both bundles gave off branches to the trachea and esophagus. The laryngeal distribution of the internal branch and vagus nerve was confirmed in the posterior cricoarytenoid, lateral cricoarytenoid, and thyroarytenoid muscles. These three laryngeal muscles were innervated by the cranial root and/or vagus nerve, but the distribution pattern was different in each specimen. Although the vagus nerve and cranial root are morphologically distinct nerves in the cranial cavity, they can be regarded functionally as the same nerve based on their distribution in the laryngeal muscles.

Rare communication between the musculocutaneous and median nerves in the forearm: its clinical significance.

Morphologic classifications of communication between musculocutaneous and median nerves are not based on the distribution and the function of the communicating branch. The authors report a rare case of such a communication with passage of the median nerve through the pronator teres muscle and discuss its clinical significance. The musculocutaneous nerve was divided into a lateral branch that continued to the lateral antebrachial cutaneous nerve and a medial branch that joined the median nerve in the forearm. The authors separated the nerve bundles and noted that the communicating branch derived from the sixth to seventh cervical nerves and supplied nerve fibers to the pronator teres muscle and the proper palmar digital nerve of the thumb. In addition, the median nerve penetrated the humeral head of the pronator teres muscle. Isolated musculocutaneous neuropathy with such a communication may cause unexpected symptoms such as sensory deficit in the palm and muscular weakness of the forearm and the thumb.

Vitamin D deficiency in Korean children: prevalence, risk factors, and the relationship with parathyroid hormone levels.

PURPOSE: This study was performed to investigate the relationship between serum vitamin D and parathyroid hormone (PTH) levels as well as to describe the prevalence and the risk factors of vitamin D deficiency (VDD) in Korean children. METHODS: Participants were 1,212 children aged 4 to 15 years, who visited Bundang CHA Medical Center (located at 37°N) between March 2012 and February 2013. Overweight was defined as body mass index≥85th percentile. Participants were divided into 4 age groups and 2 seasonal groups. VDD was defined by serum 25-hydroxyvitamin D (25OHD) <20 ng/mL. RESULTS: The level of 25OHD was significantly lower in overweight group than in normal weight group (17.1±5.1 ng/mL vs. 19.1±6.1 ng/mL, P<0.001). Winter-spring season (odds ratio [OR], 4.46; 95% confidence interval [CI], 3.45-5.77), older age group (OR, 1.60; 95% CI, 1.36-1.88), and overweight (OR, 2.21; 95% CI, 1.62-3.01) were independently related with VDD. The PTH levels were significantly higher in VDD group compared to vitamin D insufficiency and sufficiency group (P<0.001). In normal weight children, 25OHD (ß=-0.007, P<0.001) and ionized calcium (ß=-0.594, P=0.007) were independently related with PTH, however, these associations were not significant in overweight children. CONCLUSION: VDD is very common in Korean children and its prevalence increases in winter-spring season, in overweight children and in older age groups. Further investigation on the vitamin D and PTH metabolism according to adiposity is required.

Morphological characteristics of the cranial root of the accessory nerve.

There has been the controversy surrounding the cranial root (CR) of the accessory nerve. This study was performed to clarify the morphological characteristics of the CR in the cranial cavity. Fifty sides of 25 adult cadaver heads were used. The accessory nerve was easily distinguished from the vagus nerve by the dura mater in the jugular foramen in 80% of 50 specimens. The trunk of the accessory nerve from the spinal cord penetrated the dura mater at various distances before entering the jugular foramen. In 20% of the specimens there was no dural boundary. In these cases, the uppermost cranial rootlet of the accessory nerve could be identified by removing the dura mater around the jugular foramen where it joined to the trunk of the accessory nerve at the superior vagal ganglion. The cranial rootlet was formed by union of two to four short filaments emerging from the medulla oblongata (66%) and emerged single, without filament (34%), and usually joined the trunk of the accessory nerve directly before the jugular foramen. The mean number of rootlets of the CR was 4.9 (range 2-9) above the cervicomedullary junction. The CR of the accessory nerve was composed of two to nine rootlets, which were formed by the union of two to four short filaments and joined the spinal root of the accessory nerve. The CR is morphologically distinct from the vagus nerve, confirming its existence.