1.Glymphatic System of the Brain: Anatomy, Physiology, and Clinical Implications
Min Young CHUN ; Seok Jong CHUNG ; Seong Ho JEONG
Journal of the Korean Neurological Association 2026;44(1):8-21
Cerebrospinal fluid (CSF) dynamics are increasingly recognized as central to brain waste clearance. Beyond the classical view of unidirectional CSF circulation, recent studies have identified the glymphatic system and meningeal lymphatic vessels as major complementary pathways. Glymphatic transport is driven by arterial pulsation, respiration, vasomotion, and strongly enhanced during slow-wave sleep. Advances in neuroimaging, including DTI-ALPS, EPVS quantification, contrast-enhanced magnetic resonance imaging (MRI), and ultrafast functional MRI, have enabled in vivo assessment of these mechanisms. Impaired glymphatic function has been linked to neurodegenerative and cerebrovascular diseases, highlighting its clinical relevance. Potential interventions range from lifestyle measures such as sleep optimization, exercise, and vascular risk control, to pharmacological and experimental strategies aiming to modulate CSF flow. These insights open new opportunities to target the glymphatic-lymphatic axis for the prevention and treatment of neurological disorders.
2.Measuring Trends in Disability-adjusted Life Years and Life Expectancy in Korea: 2008 to 2021
Chung-Nyun KIM ; Dawit Urgi GURMU ; Young-Eun KIM ; Yoon-Sun JUNG ; Yongseok CHOI ; Minsu OCK ; Seok-Jun YOON
Journal of Preventive Medicine and Public Health 2026;59(1):25-34
Objectives:
This study, part of the ongoing Korean National Burden of Disease (KNBD) updates, assesses disability-adjusted life years (DALYs) and disability-adjusted life expectancy (DALE) in Korea, taking into account the effects of coronavirus disease 2019 and emphasizing the importance of analyzing these metrics jointly.
Methods:
Data were obtained from Statistics Korea, the National Health Insurance Service, and the Korea Disease Control and Prevention Agency. DALYs and DALE were calculated using an incidence-based approach, following disease classification, disability weights, and estimation procedures consistent with prior KNBD research.
Results:
Compared with earlier estimates, DALYs showed a slight decline in 2020 followed by an increase in 2021, with this pattern observed across all income quintiles. For DALE, both men and women experienced modest gains relative to earlier studies; however, a decrease occurred across all income levels in 2021 compared with 2020. Regional disparities in DALE also narrowed beginning in 2020, with a more marked reduction among women.
Conclusions
Unlike previous studies, this research presents DALYs and DALE concurrently, offering a more comprehensive perspective on summary measures of population health. The post-2020 rise in DALYs underscores the growing need for effective chronic disease management. Additionally, widening income-based disparities in DALE highlight the urgency of addressing health inequities. Continued monitoring and updates of DALYs and DALE are necessary to understand and respond to these evolving trends.
3.Impact of Additional Occipital Involvement in Parkinson’s Disease With Posterior Cortical Hypoperfusion
Chan Wook PARK ; Su Hong KIM ; Phil Hyu LEE ; Yun Joong KIM ; Young H. SOHN ; Yong JEONG ; Seok Jong CHUNG
Journal of Movement Disorders 2026;19(1):58-66
Objective:
This study aims to investigate the clinical relevance of occipital hypoperfusion in patients with Parkinson’s disease (PD) with respect to clinical phenotype and the risk of dementia conversion.
Methods:
We enrolled 349 patients with newly diagnosed PD and 48 healthy controls who underwent dual-phase 18F-N-(3-fluoropropyl)-2β-carboxymethoxy-3β-(4-iodophenyl) nortropane (18F-FP-CIT) positron emission tomography (PET). Patients with PD were classified into three groups based on posterior cortical perfusion patterns on early-phase 18F-FP-CIT PET images: PD with preserved posterior cortical perfusion (n=186), PD with parieto-temporal hypoperfusion (n=84), and PD with parieto-temporo-occipital hypoperfusion (n=79). Baseline clinical features and dementia conversion risk were compared across PD groups.
Results:
Patients with preserved posterior cortical perfusion were younger than those in the other PD groups. Compared with the other groups, the parieto-temporo-occipital hypoperfusion group tended to have lower Cross-Cultural Smell Identification Test scores, a higher prevalence of rapid eye movement sleep behavior disorder, higher Unified PD Rating Scale motor scores, and more severe reductions in striatal dopamine transporter availability. The risk of dementia conversion was lower in patients with preserved posterior cortical perfusion than in those with posterior cortical hypoperfusion. However, the risk of dementia conversion did not differ between the parieto-temporal and parieto-temporo-occipital hypoperfusion groups.
Conclusion
Additional occipital hypoperfusion was not associated with an imminent risk of dementia conversion in patients with PD with posterior cortical hypoperfusion. Nonetheless, occipital involvement may serve as an indicator of the diffuse malignant subtype of PD.
4.Bisphosphonates as a Tacrolimus-Sparing Strategy in Kidney Transplantation: Insights from a Retrospective Analysis
Hee Byung KOH ; Hyo Jeong KIM ; Ga Young HEO ; Namki HONG ; Yaeji LEE ; Seung Hwan SONG ; Hoon Young CHOI ; Chan-Young JUNG ; Hyung Woo KIM ; Jaeseok YANG ; Kyu Ha HUH ; Chung Mo NAM ; Beom Seok KIM
Yonsei Medical Journal 2026;67(1):17-26
Purpose:
Due to chronic toxicity, tacrolimus-sparing is an important issue in kidney transplant recipients (KTRs). Several studies have shown that bisphosphonate use is associated with favorable graft outcomes in KTRs. We investigated whether the association between tacrolimus trough levels (TTLs) and graft outcomes differed according to bisphosphonate use in KTRs.
Materials and Methods:
We conducted a retrospective study encompassing 1441 KTRs who were administered tacrolimus-based immunosuppressants. The primary exposure was a time-dependent cross-product of TTLs (low TTLs vs. normal-high TTLs with a reference of 6 ng/mL) and bisphosphonate use. Two primary outcomes were evaluated: overall graft loss (death or conversion to kidney replacement) and an estimated glomerular filtration rate (eGFR) <30 mL/min/1.73 m 2 .
Results:
During the median follow-up of 6.1 (3.4–9.7) years, overall graft loss occurred in 157 (10.9%) patients. Cox regression revealed that normal-high TTLs without bisphosphonate use were associated with a reduced risk of overall graft loss [adjusted hazard ratio (aHR), 0.65; 95% confidence interval (CI), 0.45–0.95] compared to low TTLs without bisphosphonate use. The use of bisphosphonate in conjunction with normal-high TTLs correlated with an even lower risk of overall graft loss (aHR, 0.25; 95% CI, 0.08–0.80) compared with low TTLs without bisphosphonate use. In patients with low TTLs, bisphosphonate use was associated with a reduced risk of overall graft loss compared with non-use (aHR, 0.20; 95% CI, 0.09–0.43). Similar trends were observed in the eGFR outcome.
Conclusion
The use of bisphosphonate was associated with favorable graft outcomes, even with low TTLs. Incorporating bisphosphonate into a conventional immunosuppressant regimen may potentially reduce tacrolimus requirement.
5.Emerging Innovations in Acne Management: A Focus on NonPharmacological Therapeutic Devices
Ji Yeon HONG ; Joon SEOK ; Hye Sung HAN ; Kui Young PARK
Journal of Korean Medical Science 2025;40(9):e118-
Acne is a chronic inflammatory condition affecting the sebaceous glands, with approximately 80% of individuals experiencing it at some point in their lives. Among adolescents, the incidence is reported to exceed 85%. The disease can significantly impact both physical and emotional aspects of a person’s quality of life, leading to permanent scarring, poor self-image, depression, and anxiety. The standard first-line treatment for acne vulgaris includes conventional pharmacological approaches such as keratolytics, topical or oral antibiotics, retinoids, and hormonal agents. However, these treatments are not universally effective due to patient noncompliance, adverse drug effects, and the emergence of antibiotic resistance in Cutibacterium acnes, often resulting in high rates of recurrence. Consequently, non-pharmacological therapies have been developed as safe and effective alternatives or supplements to pharmacological treatment. These non-pharmacological approaches can serve as standalone treatment modalities, adjuncts to pharmacological therapy, or maintenance treatments. Current literature lacks comprehensive data on the classification of these non-pharmacological treatment options. This paper aims to provide a brief overview of recent research on the practical applications and potential mechanisms of nonpharmacological therapies for both acne and acne scars. Through elucidating the distinct mechanisms and therapeutic roles of these treatments, we aim to assist dermatologists and other healthcare providers in formulating more effective disease management strategies, thereby encouraging further research in this area.
7.A Case of a Cataract Patient with Equatorial and Posterior Zonular Weakness in Both Eyes
Jeong Woo KWON ; In Seok JEONG ; In Young CHUNG ; Seong Wook SEO ; Seong Jae KIM
Journal of the Korean Ophthalmological Society 2025;66(4):209-213
Purpose:
We present a case of equatorial and posterior zonular weakness observed during cataract surgery in both eyes with no prior history of trauma or surgery.Case summary: A 73-year-old woman visited out clinic and reported decreased visual acuity. She was found to have a best corrected visual acuity of 0.5 in both eyes. Cataracts were noted during a slit lamp examination and cataract surgery was subsequently performed. During the left eye surgery, although there was no evident weakening during the anterior capsulotomy, the equatorial and posterior zonules were damaged during phacoemulsification. This led to consistent aspiration of the equatorial and posterior capsule (PC) into the phaco-handpiece tip during epinucleus and cortex removal. The PC eventually ruptured necessitating anterior vitrectomy and a 3-piece intraocular lens insertion into the ciliary sulcus. Two weeks later, the right eye surgery encountered similar challenges in removing the epinucleus and cortex. The surgery was completed successfully by elevating the irrigation bottle, frequently injecting an ophthalmic viscoelastic device (OVD), and removing the remaining lens material using a bimanual irrigator/aspirator.
Conclusions
This case highlights that equatorial and posterior zonular weakness can occur in the absence of trauma or prior to surgery. To manage such cases, it is advisable to elevate the irrigation bottle height, continuously inject OVD during surgery, and use a bimanual irrigator/aspirator.
8.Incidence and Risk Factors of Postoperative Ileus in Oblique Lumbar Interbody Fusion Surgery: A Retrospective Study
Young-Seok LEE ; Myeong Jin KO ; Seung Won PARK
Neurospine 2025;22(1):222-230
Purpose:
Postoperative ileus (POI) typically occurs after abdominal surgery but can also affect patients undergoing spinal surgery via the lateral retroperitoneal approach, such as oblique lumbar interbody fusion (OLIF). Therefore, this study aimed to investigate the incidence and risk factors associated with POI in OLIF.
Methods:
This retrospective study examined a cohort of 465 patients who underwent OLIF from 2015 to 2023. Patient demographics, comorbidities, pre- and postoperative laboratory test results, and perioperative status were assessed. General condition of patients was assessed using the modified frailty index-11 (mFI-11), prognostic nutrition index, and geriatric nutrition risk index. In OLIF, the size and location of the psoas muscle involved in retraction and its relationship with the vertebral body were also investigated.
Results:
POI occurred in 19 patients (4%). Lower mFI-11 was linked to a higher risk of POI. While psoas muscle size had no significant effect on the risk of POI, the anterior location of the psoas muscle relative to the vertebral body was associated with a higher occurrence of POI. Multivariate logistic regression analysis of POI identified mFI-11 as the most significant risk factor (p = 0.003).
Conclusion
This study demonstrated that frailty and nutritional status can influence the occurrence of POI after OLIF. Additionally, bowel manipulation associated with the location of psoas muscle and vertebral body was identified as a risk factor. Proper assessment and improvement in patient frailty and nutritional status before surgery can help predict and prevent the occurrence of postoperative POI.
9.Korean Guidelines for Diagnosis and Management of Interstitial Lung Diseases: Connective Tissue Disease Associated Interstitial Lung Disease
Ju Hyun OH ; Jae Ha LEE ; Sung Jun CHUNG ; Young Seok LEE ; Tae-Hyeong KIM ; Tae-Jung KIM ; Joo Hun PARK ;
Tuberculosis and Respiratory Diseases 2025;88(2):247-263
Connective tissue disease (CTD), comprising a range of autoimmune disorders, is often accompanied by lung involvement, which can lead to life-threatening complications. The primary types of CTDs that manifest as interstitial lung disease (ILD) include rheumatoid arthritis, systemic sclerosis, Sjögren’s syndrome, mixed CTD, idiopathic inflammatory myopathies, and systemic lupus erythematosus. CTD-ILD presents a significant challenge in clinical diagnosis and management due to its heterogeneous nature and variable prognosis. Early diagnosis through clinical, serological, and radiographic assessments is crucial for distinguishing CTD-ILD from idiopathic forms and for implementing appropriate therapeutic strategies. Hence, we have reviewed the multiple clinical manifestations and diagnostic approaches for each type of CTD-ILD, acknowledging the diversity and complexity of the disease. The importance of a multidisciplinary approach in optimizing the management of CTD-ILD is emphasized by recent therapeutic advancements, which include immunosuppressive agents, antifibrotic therapies, and newer biological agents targeting specific pathways involved in the pathogenesis. Therapeutic strategies should be customized according to the type of CTD, the extent of lung involvement, and the presence of extrapulmonary manifestations. Additionally, we aimed to provide clinical guidance, including therapeutic recommendations, for the effective management of CTD-ILD, based on patient, intervention, comparison, outcome (PICO) analysis.
10.Clinical impact of drug-coated balloon treatment of coronary artery disease in elderly patients.
Eun-Seok SHIN ; Mi Hee JANG ; Sunwon KIM ; Dong Oh KANG ; Ki-Bum WON ; Bitna KIM ; Ae-Young HER
Journal of Geriatric Cardiology 2025;22(1):150-158
BACKGROUND:
Data on drug-coated balloon (DCB) treatment in elderly patients are limited. This study was to evaluate the efficacy of DCB treatment in percutaneous coronary intervention (PCI) among elderly patients.
METHODS:
A retrospective analysis included 232 patients aged 75 years or older with coronary artery disease who underwent successful PCI using either DCB alone or in combination with drug-eluting stent (DES) based on pre-dilation results (DCB-based PCI). These patients were compared with 1818 elderly patients who underwent second-generation DES implantation (DES-only PCI). The endpoint was major adverse cardiovascular events (MACE) at 2-year follow-up.
RESULTS:
In the DCB-based PCI, 61.2% of patients received DCB-only treatment. Compared to DES-only PCI, the DCB-based PCI group had fewer stents (0.5 ± 0.7 and 1.7 ± 0.8, P < 0.001), shorter stent lengths (13.3 ± 20.9 mm and 37.4 ± 23.0 mm, P < 0.001), and lower usage of small stents with a diameter of 2.5 mm or less (15.6% and 28.7%, P = 0.010). The DCB-based PCI group exhibited lower rate of MACE (5.5% and 13.1%, P = 0.003), target vessel revascularization (1.1% and 5.6%, P = 0.017) and major bleeding (0.7% and 5.1%, P = 0.009) at 2-year follow-up. The reduced risk in 2-year MACE was consistently observed across various matching procedures, with the most significant reduction noted in target vessel revascularization and major bleeding.
CONCLUSION
The DCB-based PCI reduced stent burden, particularly in the usage of small diameter stents, and was associated with lower risks of MACE, target vessel revascularization, and major bleeding compared to DES-only PCI in elderly patients.

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