1.Incidental White Matter Lesions in Pediatric Headache: Prevalence and Longitudinal Magnetic Resonance Imaging Findings
Young Hwan KIM ; Dong Won LEE ; Kye Hyang LEE
Annals of Child Neurology 2026;34(2):144-150
Purpose:
Brain magnetic resonance imaging (MRI) is commonly performed to exclude secondary causes of pediatric headache. Incidental findings are detected in approximately one-fifth of scans, and nonspecific white matter lesions (WMLs) have been reported in 0.7% to 47% of pediatric patients with headache. However, the natural history of these lesions remains unclear. This study aimed to determine the prevalence and radiologic course of WMLs in pediatric patients with headache.
Methods:
We retrospectively reviewed the clinical and MRI data of pediatric patients who underwent brain MRI for headache at a single tertiary-care center between September 2006 and July 2023. Patients with neurological or systemic conditions known to cause WMLs were excluded. MRI findings and clinical characteristics were analyzed descriptively.
Results:
Among the 515 enrolled patients (mean age, 10.7 years), abnormal MRI findings were observed in 126 (24.5%), including nonspecific WMLs in eight (1.6%). Most lesions were supratentorial (seven of eight), with a mean maximum diameter of 10.0 mm (range, 4.3 to 24.9). Follow-up MRI was available for three patients; two demonstrated interval increases in lesion extent on repeat imaging. During the same period, headache frequency or severity also increased, but no new neurological deficits were documented.
Conclusion
Nonspecific WMLs were rare in pediatric patients with headache. In a small subset with limited follow-up, interval radiologic changes were observed without neurological deterioration. Larger prospective studies are needed to clarify the natural history and clinical significance of WMLs in pediatric headache.
2.Clinical Features of Febrile Seizures Associated with Exanthem Subitum: A Single-Center Retrospective Study
Young Hwan KIM ; Kye Hyang LEE
Annals of Child Neurology 2026;34(2):120-125
Purpose:
Exanthem subitum (ES), most commonly caused by human herpesvirus 6B (HHV-6B), is a prevalent febrile illness in infants and toddlers. Previous studies have suggested a possible association between HHV-6B infection and an increased risk of complex febrile seizures (CFS). Given that CFS may prompt additional diagnostic procedures to rule out serious neurological disorders, we compared the clinical characteristics and management of patients with and without ES.
Methods:
We retrospectively reviewed the medical records of 141 children younger than two years of age who experienced their first febrile seizure between March 2013 and August 2024 at a tertiary medical center. We collected demographic, clinical, and laboratory data and compared clinical profiles between children diagnosed with ES and those without ES.
Results:
Twenty-eight children (19.9%) were clinically diagnosed with ES. Although the frequency of CFS did not significantly differ between the ES and non-ES groups (42.9% vs. 28.3%, P=0.172), children with ES were more likely to undergo lumbar puncture (42.9% vs. 11.5%, P<0.001) and receive empiric intravenous antibiotics for suspected central nervous system infection (39.3% vs. 10.6%, P<0.001).
Conclusion
Despite the typically benign and self-limiting nature of ES, febrile seizures occurring in the context of ES appear to be associated with more aggressive diagnostic and therapeutic interventions. The development of rapid, noninvasive diagnostic assays for HHV-6B may help reduce unnecessary procedures and promote more judicious management.
3.Molecular Epidemiology of Extended-spectrum β-Lactamase-producing Escherichia coli in South Korea: A Korean Global Antimicrobial Resistance Surveillance System Report
Dokyun KIM ; SungYoung LEE ; Jun Sung HONG ; Min Hyuk CHOI ; Hyun Soo KIM ; Young Ree KIM ; Young Ah KIM ; Young UH ; Kyeong Seob SHIN ; Jeong Hwan SHIN ; Jeong Su PARK ; Kyoung Un PARK ; Soo Hyun KIM ; Jong Hee SHIN ; Jungsik YU ; Seok Hoon JEONG
Annals of Laboratory Medicine 2026;46(1):72-82
Background:
Extended-spectrum β-lactamase (ESBL)-producing Escherichia coli is among the most important multidrug-resistant pathogens causing bloodstream infections (BSIs).Cefotaximase (CTX-M) enzymes are the most common and highly diverse ESBL family in E.coli. CTX-M-15 in group CTX-M-1 and CTX-M-14 in group CTX-M-9 are the most extensively disseminated enzymes. Multidrug-resistant E. coli strains complicate empirical therapy and increase healthcare burden globally and in Korea. We investigated the molecular epidemiology, sequence types (STs), and ESBL genotypes of E. coli bloodstream isolates in Korea and identified clinical risk factors for cefotaxime resistance.
Methods:
We collected all non-duplicated isolates of E. coli and related clinical information from patients with BSIs at eight sentinel hospitals in the Korean Global Antimicrobial Resistance Surveillance System (Kor-GLASS) collection network during 2017–2021. Duplicate isolates were removed to ensure representativeness of the data. Antimicrobial susceptibility was tested using disk diffusion tests, and multilocus sequence typing and betalactamase genotyping were performed.
Results:
Among 9,232 E. coli blood isolates, resistance rates to cefotaxime and ceftazidime were 36.4% and 11.4%, respectively. Among the clinical factors, age > 65 yrs (adjusted odds ratio [aOR], 1.36), hospital-origin infection (aOR, 2.55), and admission type (intensive care unit [ICU] vs. general ward; aOR, 1.34) were significant cefotaxime resistance risk factors. ST131 was the most prevalent among cefotaxime-resistant E. coli (64.8%, 2,180/3,363), followed by ST1193 (5.3%, N = 177), and ST69 (5.1%, N = 170).ST131, ST648, ST405, and ST410 cefotaxime-resistant E. coli isolates frequently harbored blaCTX-M-15, whereas ST1193 and ST68 showed a high proportion of blaCTX-M-27 carriers, and most ST457 and ST5150 isolates carried blaCTX-M-55.
Conclusions
Continuous monitoring of ESBL-producing E. coli is required to prevent further dissemination, guide empirical therapy, inform infection control policies, and ensure early detection of multidrug-resistant clones with the potential for widespread transmission.
4.Performance Evaluation of the 2020 European Society of Cardiology 0-hour/1-hour Algorithm Using High-sensitivity Cardiac Troponin I for Non-ST-segment Elevation Acute Coronary Syndrome and Mortality Assessment Based on 1-year Real-world Data
Changhee HA ; Yeon Jae LEE ; Jong Do SEO ; Hanah KIM ; Hee-Won MOON ; Mina HUR ; Young Hwan LEE ; Sang O PARK ; Kyeong Ryong LEE ; Hyun-Joong KIM ; Yeo-Min YUN
Annals of Laboratory Medicine 2026;46(1):52-61
Background:
The 2020 European Society of Cardiology (ESC) 0-hr/1-hr algorithm using high-sensitivity cardiac troponin I (hs-cTnI) for non-ST-segment elevation acute coronary syndrome (NSTE-ACS) aims at early diagnosis and shorter emergency department (ED) stays. While this algorithm has been well-established in controlled studies, real-world implementation remains challenging. We evaluated the algorithm’s clinical performance and risk stratification capability in patients with chest pain or discomfort.
Methods:
We measured hs-cTnI in 4,678 patients suspected of NSTE-ACS between August 2022 and July 2023, using an Atellica IM Analyzer (Siemens Healthineers, Erlangen, Germany). We categorized patients into rule-in, observe, or rule-out groups according to the algorithm and assessed its diagnostic performance for NSTE-ACS. The final diagnosis of NSTE-ACS was adjudicated by two independent physicians. Additionally, we evaluated 30-day all-cause mortality, hazard risk, and ED length of stay across the three groups.
Results:
The algorithm categorized 3,408 (72.9%), 573 (12.2%), and 697 (14.9%) patients into the rule-out, observe, and rule-in groups, respectively. Among 90 patients diagnosed as having NSTE-ACS, none were falsely categorized into the rule-out group. Survival analysis revealed significant differences (P < 0.001), with Cox hazard ratios of 2.38 (95% confidence interval: 1.20–4.71) and 6.39 (3.45–11.86) in the observe and rule-in groups, respectively. ED stays shortened in the order of rule-out, observe, and rule-in groups (P < 0.001).
Conclusions
The 2020 ESC 0-hr/1-hr algorithm demonstrates excellent diagnostic accuracy without false rule-outs and effective risk stratification, and contributes to efficient ED throughput, supporting its clinical utility in real-world emergency settings.
5.Lateral Closing Wedge Supramalleolar Osteotomy with Inframalleolar Correction as a Joint-Preserving Procedure for Valgus Ankle Osteoarthritis: A Case Report
Ju Hwan PARK ; Jin Soo SUH ; Ji-Ye KIM ; Jun Young CHOI
Journal of Korean Foot and Ankle Society 2026;30(2):73-79
A medial closing wedge supramalleolar osteotomy, along with corrections for pes plano-valgus, including medial displacement calcaneal osteotomy, and deltoid ligament repair or reconstruction, is most commonly considered for the joint-preserving surgery of valgus ankle arthritis. In cases of ‘opposing coronal plane deformities,’ however, where the tibial plafond is varus-aligned to the long axis of the tibia and the ground, while the talus is conversely valgus-aligned, medial closing wedge supramalleolar osteotomy may paradoxically risk exacerbating the valgus ankle arthritis. This paper reports the radiological and clinical outcomes of an otherwise healthy, physically active 55-year-old male patient with valgus ankle arthritis and opposing coronal-plane deformities, along with a literature review. The patient underwent joint-preserving surgery consisting of lateral closing wedge supramalleolar osteotomy, fibular osteotomy, medial displacement calcaneal osteotomy, and deltoid ligament augmentation with suture tape. This paper discusses the critical considerations and surgical precautions necessary when deciding on joint-preserving procedures for valgus ankle arthritis.
6.Full-Endoscopic Paraspinal Foraminotomy for Lumbar Foraminal Stenosis
Young Hwan KIM ; Jae Ho KIM ; Pius KIM ; Chang Il JU ; Jong Hun SEO
Journal of Minimally Invasive Spine Surgery and Technique 2026;11(1):169-176
Transforaminal endoscopic lumbar foraminotomy (TELF) is widely performed as a full-endoscopic surgical procedure for the treatment of lumbar foraminal stenosis. The technique involves the use of a small-caliber endoscopic system introduced through Kambin triangle to accomplish the primary surgical steps. However, anatomical barriers are frequently encountered in the lower lumbar segments, particularly at L4–5 and L5–S1, which may limit the feasibility of the transforaminal approach. Although various advanced transforaminal techniques have been developed to overcome these anatomical barriers, these techniques often make the procedure more technically demanding and may prolong operative time. In this video presentation, we report 2 cases in which a full-endoscopic paraspinal lumbar foraminotomy was performed to achieve adequate decompression of the exiting nerve root (ENR) without being constrained by these anatomical limitations. We also outline the procedural details and technical characteristics of this approach. Both patients presented with lumbar foraminal stenosis at the L5–S1 level, where anatomical barriers such as a high iliac crest, large transverse process, and sacral ala were present. A full-endoscopic paraspinal foraminotomy was performed at this level using a large-caliber endoscopic system, allowing sufficient decompression of the ENR and resulting in marked relief of radicular leg pain. We report a surgical procedure for full-endoscopic paraspinal lumbar foraminotomy using a large-caliber endoscopic system that permits the use of instruments of various sizes and configurations. When applied in appropriate clinical scenarios, this technique may facilitate more convenient and expedited decompression of the ENR.
7.Spatiotemporal Remodeling of Enteric Neural Pathways Underlies ColonicDysmotility Following Spinal Cord Injury in Rats
Min Seob KIM ; Sei KIM ; Se Eun HA ; Hyun Seok CHOI ; Myeong Hwan YU ; Jisong YOU ; Dahyun SEON ; Do Hee LEE ; Min Cheol JOO ; Yong Sung KIM ; Suck Chei CHOI ; Joong Goo KWON ; Kyung Sik PARK ; Hyun Jin KIM ; Seungil RO ; Moon Young LEE
Journal of Neurogastroenterology and Motility 2026;32(1):86-98
Background/Aims:
Spinal cord injury (SCI) frequently impairs defecation, severely affecting the quality of life. This study examines compensatory neural remodeling after SCI, focusing on basal colonic contractility, neural responses to electrical field stimulation, and alterations in excitatory cholinergic and inhibitory nitrergic pathways.
Methods:
Female Sprague–Dawley rats underwent either sham surgery or T10 spinal cord transection and were categorized into 3 groups: sham, 1-week post-SCI (acute), and 4-week post-SCI (chronic). Colonic contractility was assessed in an organ bath using electrical field stimulation in the presence of a nitric oxide synthase inhibitor. Neural protein expression was analyzed by immunofluorescence and Western blotting.
Results:
SCI produced region- and time-dependent impairments in colonic contractility, with distinct alterations in the proximal circular and longitudinal muscles across acute and chronic phases. Neural excitability shifted dynamically, showing enhanced excitatory activity in the proximal longitudinal muscle at 1-week and the distal circular muscle at 4-week post-SCI. Protein analysis revealed increased neuronal nitric oxide synthase in the proximal colon, decreasedsoluble guanylyl cyclase in the distal colon, upregulated muscarinic M3 receptor in the proximal colon, and reduced vaso-active intestinal peptide receptor 1 in both proximal and distal regions.
Conclusion
SCI induces spatiotemporal remodeling of excitatory and inhibitory neural pathways, contributing to colonic dysmotility and revealing potential targets for therapeutic intervention.
8.Revisiting human sparganosis: a pathologic review from a single institution
Jeemin YIM ; Young A KIM ; Jeong Hwan PARK ; Hye Eun PARK ; Hyun Beom SONG ; Ji Eun KIM
Journal of Pathology and Translational Medicine 2026;60(1):83-91
Sparganosis is a rare parasitic infection caused by Spirometra species. Although it was relatively common in the past, it is now often overlooked. In this study, we review cases diagnosed through histopathological examination at a single institution in recent years to raise awareness of this neglected parasitic disease. Methods: We retrospectively analyzed cases of human sparganosis identified in the pathology archives of a single institution in South Korea between 2004 and 2025. A comprehensive review was conducted, including demographic data, clinical features, lesion locations, imaging findings, exposure history (such as dietary habits), and histopathologic findings. Results: A total of 15 patients were identified, including 10 females and 5 males, with a mean age of 65.1 years. Lesions were most commonly located in the lower extremities and breast. Imaging findings were largely nonspecific, with ultrasonography being the most frequently used modality. In most cases, clinical suspicion of sparganosis was absent, and excision was performed under the impression of a benign or malignant tumor. Histologically, variably degenerated parasitic structures were identified within granulomatous inflammation. However, preserved features such as calcospherules and tegumental structures facilitated definitive diagnosis. Conclusions: This study underscores the importance of recognizing the characteristic histopathological features of sparganosis, which can allow for accurate diagnosis even in the absence of clinical suspicion. Although rare, sparganosis remains a relevant diagnostic consideration in endemic regions, particularly in East Asia.
9.A Prospective Cross-sectional Screening Using Non-mydriatic Fundus Photography and Optical Coherence Tomography in Patients on Tamoxifen Therapy
Sang Cheol YANG ; Jun Young LEE ; Dong Seon KIM ; Tae Yeon KIM ; Young Hwan JEONG ; Bo Hyun PARK ; IkSoo BYON ; Sung Who PARK
Journal of Retina 2026;11(1):44-49
Purpose:
To determine the prevalence of tamoxifen retinopathy and assess the utility of a screening protocol using non-mydriatic fundus photography and optical coherence tomography (OCT).
Methods:
Between May and October 2024, patients on tamoxifen therapy at a breast surgery clinic were offered screening including non-mydriatic fundus photography and OCT. Among those who consented, 290 patients (580 eyes) were included after excluding other retinal diseases. We investigated tamoxifen duration, cumulative dose, central retinal thickness, BMI, underlying diseases, menopausal status, and history of chemotherapy, hormone therapy, or oral contraceptives.
Results:
All patients were taking 20 mg of tamoxifen daily. The mean treatment duration was 55.7 ± 29.5 months for those treated longer than two years (n = 193), with a mean BMI of 22.1 ± 3.0 kg/m2. Systemic comorbidities included dyslipidemia (n = 27, 14.0%), hypertension (n = 19, 9.8%), diabetes mellitus (n = 13, 6.7%), and cardiovascular disease (n = 4, 2.1%). Additionally, patient histories included chemotherapy (n = 84, 43.7%), postmenopausal status (n = 56, 29.1%), hormone therapy (n = 52, 27.0%), and oral contraceptive use (n = 14, 7.2%). Tamoxifen retinopathy was not observed in any of the patients.
Conclusions
In this cross-sectional study, the prevalence of tamoxifen retinopathy, as assessed by non-mydriatic fundus photography and OCT in this study, was 0%, which is lower than previously reported rates (0.9%–12%). Although specialized examination by an ophthalmologist, including a dilated fundus examination and OCT remains the diagnostic gold standard, practical constraints can limit its routine clinical use. Our study evaluated a screening protocol performed without ophthalmologist intervention. However, we found that limitations in image quality compromised the detection of subtle lesions, such as crystalline deposits. Consequently, this approach may be insufficient to serve as a primary screening strategy.
10.Predictors and patterns of early liver regeneration after major hepatectomy
Seoyeong KU ; Garam LEE ; Hyung Hwan MOON ; Hyungjune KU ; Won Jong YANG ; Junho SONG ; Suyeon KIM ; Chol Min KANG ; Amy CHOI ; Dong Hyeon GIM ; Young Il CHOI ; Dong Hoon SHIN ; Namkee OH ; Jinsoo RHU
Kosin Medical Journal 2026;41(1):58-66
Background:
Postoperative liver regeneration is essential for maintaining hepatic function. This study evaluated the rate, determinants, and volumetric patterns of early liver regeneration after hemihepatectomy.
Methods:
A retrospective review was conducted of 50 patients who underwent right or left hemihepatectomy between April 2019 and March 2025. Liver and spleen volumes (SV) were assessed preoperatively, at postoperative day (POD) 1 week, and at POD 3 months. Early liver regeneration rate (LRR) was defined as the percentage increase in remnant liver volume at POD 1 week relative to the preoperative future liver remnant (FLR), and patients were categorized into low (<50%) and high (≥50%) LRR groups. Clinical, biochemical, and volumetric variables were compared, and predictors of regeneration were identified using multivariable analyses. Regeneration patterns were also examined according to whether the FLR/standard liver volume (SLV) ratio was <50% or ≥50%.
Results:
FLR/SLV was the strongest independent predictor of rapid early liver regeneration (p<0.001). Remnants with FLR/SLV <50% exhibited rapid and sustained regeneration, whereas those with FLR/SLV ≥50% showed slower regrowth that plateaued after reaching approximately 90% of SLV. SV increased at POD 1 week in all patients; however, only the FLR/SLV ≥50% group showed a reduction by POD 3 months, whereas the <50% group maintained elevated volumes.
Conclusions
FLR/SLV reliably predicts early postoperative liver regeneration. Smaller remnants regenerate more rapidly, whereas persistent splenic enlargement suggests a sustained portal hemodynamic burden. Combined evaluation of FLR/SLV and SV may enhance perioperative risk assessment and surgical planning.

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