Tackeun Kim

Prof. Tackeun Kim

orcid

Research Focus & Metrics

Academic Career Length

15Years (2012-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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31 January 2016 in Journal of Stroke
Verified
Journal Article
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TKTackeun Kim
Tackeun Kim
COChang Wan Oh
Chang Wan Oh
JBJae Seung Bang
Jae Seung Bang
JKJeong Eun Kim
Jeong Eun Kim
WCWon-Sang Cho
Won-Sang Cho
Although the pathogenesis of moyamoya disease (MMD) has not been fully elucidated, the effectiveness of surgical revascularization in preventing stroke has been addressed by many studies. The main mechanism of surgical revascularization is augmenting the intracranial blood flow using an external carotid system by either direct bypass or pial synangiosis. This can improve resting cerebral blood flow as well as vascular reserve capacity. For direct revascularization, the superficial temporal artery is used as the donor artery in most cases, although the occipital artery may be used in limited cases. Usually, the cortical branch of the middle cerebral artery is selected as the recipient of direct anastomosis. As for indirect revascularization, various techniques using different kinds of connective tissues have been introduced. In some cases, reinforcing the anterior cerebral artery and the posterior cerebral artery territories can be considered. The effectiveness of surgical revascularization for preventing ischemic stroke had been generally accepted by many studies. However, for preventing hemorrhagic stroke, new evidence has been added by a recent randomized controlled trial. The incidence of peri-operative complications such as stroke and hyperperfusion syndrome seems to be high due to the nature of the disease and technical demands for treatment. Preventing and adequately managing these complications are essential for ensuring the benefits of surgery.

1 June 2016 in Journal of Neurosurgery
Verified
Journal Article
Closed access
TKTackeun Kim
Tackeun Kim
COChang Wan Oh
Chang Wan Oh
OKO-Ki Kwon
O-Ki Kwon
GHGyojun Hwang
Gyojun Hwang
JKJeong Eun Kim
Jeong Eun Kim
JBJae Seung Bang
Jae Seung Bang
OBJECT: Moyamoya disease (MMD) is a progressive disease that can cause recurrent stroke. The authors undertook this retrospective case-control study with a large sample size in an attempt to assess the efficacy of direct or combined revascularization surgery for ischemia in adults with MMD. METHODS: The authors investigated cases involving patients with moyamoya disease presenting with ischemia who visited Seoul National University Bundang Hospital and Seoul National University Hospital between 2000 and 2014. Among 441 eligible patients, 301 underwent revascularization surgery and 140 were treated conservatively. Variables evaluated included age at diagnosis, sex, surgical record, Suzuki stage, and occurrence of stroke. Patients were stratified into 2 groups based on whether or not they had undergone revascularization surgery. Actuarial 1-, 5-, and 10-year stroke rates were calculated using the life table method. Risk factor analysis for 5-year stroke occurrence was conducted with multivariate regression. RESULTS: Of the 441 patients, 301 had been surgically treated (revascularization group) and 140 had not (control group). The mean follow-up durations were 45 and 77 months, respectively. The actuarial 10-year cumulative incidence rate for any kind of stroke was significantly lower in the revascularization group (9.4%) than in the control group (19.6%) (p = 0.041); the relative risk reduction (RRR) was also superior (52.0%) in the revascularization group, and the number needed to treat was 10. The 10-year rate of ischemic stroke was greater (13.3%) in the control group than in the revascularization group (3.9%) (p = 0.019). The RRR for ischemic stroke in the revascularization group was 70.7%, and the number needed to treat was 11. However, the actuarial 1- and 5-year rates of ischemic stroke did not significantly differently between the groups. Overall, revascularization surgery was shown to be an independent protective factor, as revealed by multivariate analysis. CONCLUSIONS: Direct or combined revascularization for patients with adult-onset moyamoya disease presenting with ischemia can prevent further stroke.

14 May 2015 in Cancer
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Journal Article
Open access
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YKYoung‐Hoon Kim
Young‐Hoon Kim
TKTackeun Kim
Tackeun Kim
JJJin‐Deok Joo
Jin‐Deok Joo
JHJung Ho Han
Jung Ho Han
YKYu Jung Kim
Yu Jung Kim
CKCHAE-YONG KIM
CHAE-YONG KIM
BACKGROUND: A chemosensitizing effect of levetiracetam (LEV) has been suggested because LEV inhibits O‐6 methylguanine‐DNA methyltransferase (MGMT). However, the survival benefit of LEV has not been clinically documented. The objective of this study was to assess the survival benefit of LEV compared with other antiepileptic drugs as a chemosensitizer to temozolomide for patients with glioblastoma.METHODS: In total, 103 consecutive patients with primary glioblastoma who received concomitant chemoradiotherapy and adjuvant chemotherapy with temozolomide were retrospectively reviewed, and 58 patients (56%) received LEV during temozolomide chemotherapy for at least 3 months. A Cox regression survival analysis was performed to adjust for confounding factors, including age, extent of lesion, Karnofsky performance scale score, extent of removal, and MGMT promoter methylation status.RESULTS: The median progression‐free survival (PFS) and overall survival (OS) for patients who received LEV in combination with temozolomide (PFS: median, 9.4 months; 95% confidence interval [CI], 7.5‐11.3 months; OS: median, 25.7 months; 95% CI, 21.7‐29.7 months) were significantly longer than those for patients who did not receive LEV (PFS: median, 6.7 months; 95% CI, 5.8‐7.6 months; OS: median, 16.7 months; 95% CI, 12.1‐21.3 months; P = .010 and P = .027, respectively). In multivariate analysis, the variables that were identified as significant prognostic factors for OS were preoperative Karnofsky performance scale score (hazard ratio [HR], 0.37; P = .016), MGMT promoter methylation (HR, 0.30; P = .002), and receipt of LEV (HR, 0.31; P < .001.CONCLUSIONS: LEV may provide a survival benefit in patients with glioblastoma who receive temozolomide‐based chemotherapy. A prospective randomized study may be indicated. Cancer 2015;121:2926–2932. © 2015 American Cancer Society.

12 March 2020 in Scientific Reports
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Journal Article
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YKYong Dae Kim
Yong Dae Kim
KNKyoung Jin Noh
Kyoung Jin Noh
SBSeong Jun Byun
Seong Jun Byun
SLSoochahn Lee
Soochahn Lee
TKTackeun Kim
Tackeun Kim
SPSang Park
Sang Park
Retinal fundus images are used to detect organ damage from vascular diseases (e.g. diabetes mellitus and hypertension) and screen ocular diseases. We aimed to assess convolutional neural network (CNN) models that predict age and sex from retinal fundus images in normal participants and in participants with underlying systemic vascular-altered status. In addition, we also tried to investigate clues regarding differences between normal ageing and vascular pathologic changes using the CNN models. In this study, we developed CNN age and sex prediction models using 219,302 fundus images from normal participants without hypertension, diabetes mellitus (DM), and any smoking history. The trained models were assessed in four test-sets with 24,366 images from normal participants, 40,659 images from hypertension participants, 14,189 images from DM participants, and 113,510 images from smokers. The CNN model accurately predicted age in normal participants; the correlation between predicted age and chronologic age was R2 = 0.92, and the mean absolute error (MAE) was 3.06 years. MAEs in test-sets with hypertension (3.46 years), DM (3.55 years), and smoking (2.65 years) were similar to that of normal participants; however, R2 values were relatively low (hypertension, R2 = 0.74; DM, R2 = 0.75; smoking, R2 = 0.86). In subgroups with participants over 60 years, the MAEs increased to above 4.0 years and the accuracies declined for all test-sets. Fundus-predicted sex demonstrated acceptable accuracy (area under curve > 0.96) in all test-sets. Retinal fundus images from participants with underlying vascular-altered conditions (hypertension, DM, or smoking) indicated similar MAEs and low coefficients of determination (R2) between the predicted age and chronologic age, thus suggesting that the ageing process and pathologic vascular changes exhibit different features. Our models demonstrate the most improved performance yet and provided clues to the relationship and difference between ageing and pathologic changes from underlying systemic vascular conditions. In the process of fundus change, systemic vascular diseases are thought to have a different effect from ageing. Research in context. Evidence before this study. The human retina and optic disc continuously change with ageing, and they share physiologic or pathologic characteristics with brain and systemic vascular status. As retinal fundus images provide high-resolution in-vivo images of retinal vessels and parenchyma without any invasive procedure, it has been used to screen ocular diseases and has attracted significant attention as a predictive biomarker for cerebral and systemic vascular diseases. Recently, deep neural networks have revolutionised the field of medical image analysis including retinal fundus images and shown reliable results in predicting age, sex, and presence of cardiovascular diseases. Added value of this study. This is the first study demonstrating how a convolutional neural network (CNN) trained using retinal fundus images from normal participants measures the age of participants with underlying vascular conditions such as hypertension, diabetes mellitus (DM), or history of smoking using a large database, SBRIA, which contains 412,026 retinal fundus images from 155,449 participants. Our results indicated that the model accurately predicted age in normal participants, while correlations (coefficient of determination, R2) in test-sets with hypertension, DM, and smoking were relatively low. Additionally, a subgroup analysis indicated that mean absolute errors (MAEs) increased and accuracies declined significantly in subgroups with participants over 60 years of age in both normal participants and participants with vascular-altered conditions. These results suggest that pathologic retinal vascular changes occurring in systemic vascular diseases are different form the changes in spontaneous ageing process, and the ageing process observed in retinal fundus images may saturate at age about 60 years. Implications of all available evidence. Based on this study and previous reports, the CNN could accurately and reliably predict age and sex using retinal fundus images. The fact that retinal changes caused by ageing and systemic vascular diseases occur differently motivates one to understand the retina deeper. Deep learning-based fundus image reading may be a more useful and beneficial tool for screening and diagnosing systemic and ocular diseases after further development.

1 January 2015 in Journal of Korean Neurosurgical Society
Verified
Journal Article
Open access
PDF file
TKTackeun Kim
Tackeun Kim
HLHeeyoung Lee
Heeyoung Lee
JBJae Seung Bang
Jae Seung Bang
OKO-Ki Kwon
O-Ki Kwon
GHGyojun Hwang
Gyojun Hwang
COChang Wan Oh
Chang Wan Oh
Kim T, et al. J Korean Neurosurg Soc. 2015 Jun;57(6):390-395. http://dx.doi.org/10.3340/jkns.2015.57.6.390

1 January 2012 in Journal of Korean Neurosurgical Society
Verified
Journal Article
Open access
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TKTackeun Kim
Tackeun Kim
CLChang-Hyun Lee
Chang-Hyun Lee
SHSeung-Jae Hyun
Seung-Jae Hyun
SYSang Hoon Yoon
Sang Hoon Yoon
KKKi-Jeong Kim
Ki-Jeong Kim
HKHyun-Jib Kim
Hyun-Jib Kim
The incidence of spontaneous spinal epidural hematoma (SSEH) is rare. Patients with SSEH, however, present disabling neurologic deficits. Clinical outcomes are variable among patients. To evaluate the adequate treatment method according to initial patients' neurological status and clinical outcome with comparison of variables affecting the clinical outcome. We included 15 patients suffered from SSEH. Patients were divided into two groups by treatment method. Initial neurological status and clinical outcomes were assessed by the American Spinal Injury Association (ASIA) impairment scale. Also sagittal hematoma location and length of involved segment was analyzed with magnetic resonance images. Other factors such as age, sex, premorbid medication and duration of hospital stay were reviewed with medical records. Nonparametric statistical analysis and subgroup analysis were performed to overcome small sample size. Among fifteen patients, ten patients underwent decompressive surgery, and remaining five were treated with conservative therapy. Patients showed no different initial neurologic status between treatment groups. Initial neurologic status was strongly associated with neurological recovery (p=0.030). Factors that did not seem to affect clinical outcomes included : age, sex, length of the involved spinal segment, sagittal location of hematoma, premorbid medication of antiplatelets or anticoagulants, and treatment methods. For the management of SSEH, early decompressive surgery is usually recommended. However, conservative management can also be feasible in selective patients who present neurologic status as ASIA scale E or in whom early recovery of function has initiated with ASIA scale C or D.