Hung-Seob Chung

Korea University, Sŏul, Seoul, South Korea

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Publications (15)22.56 Total impact

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    ABSTRACT: We describe a rare case of cerebral abscess in an immunocompetent 67-year-old male with Gemella morbillorum as the causative agent. Gemella morbillorum is an aerobic gram positive coccus and is deemed to be a normal inhabitant of the oral cavity. The aim of this report is to introduce Gemella morbillorum as the emerging pathogen involved in brain abscesses. To the best of our knowledge only eight cases of Gemella morbillorum brain abscess have been reported in the literature. An exhaustive review of the literature is included with emphasis on the primary source of infection, clinical presentation, radiological diagnosis, and treatment modalities.
    Turkish neurosurgery 05/2012; 22(3):374-7. DOI:10.5137/1019-5149.JTN.3634-10.0 · 0.53 Impact Factor
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    ABSTRACT: In vitro study about angiogenic potentiality of ligamentum flavum (LF) cells using coculture of human lumbar LF cells and activated macropage-like THP-1 cells. To test our hypothesis that activated LF, which was exposed to inflammation, induces angiogenesis, thus resulting in hypertrophy. Inflammatory reactions after mechanical stress produce fibrosis and scarring of the LF that result in hypertrophy, a major pathological feature of spinal stenosis. This study evaluated the roles of LF cells in the pathomechanism of hypertrophy, focusing on angiogenesis. To determine their response to the inflammatory reaction, human LF cells were cocultured with phorbol myristate acetate-stimulated macrophage-like THP-1 cells. The conditioned media were assayed for tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, IL-8, vascular endothelial growth factor (VEGF), and transforming growth factor (TGF)-β1. Naïve and macrophage-exposed LF cells that responded to TNF-α/IL-1β were compared using the same outcome measures. Hypertrophied LF tissue was stained by TGF-β1 primary antibody using immunohistochemical method. Larger quantities of IL-6, IL-8, and VEGF were secreted by cocultured cells than by macrophages alone and LF cells alone combined. Prior macrophage exposure increased the secretion of IL-8 and VEGF in response to TNF-α/IL-1β stimulation whereas IL-6 production was increased in response to IL-1β. The coculture appeared to increase TGF-β1 secretion but the level was lower than that for macrophage-like cells alone and LF cells alone combined. LF cells interact with macrophage-like cells to produce angiogenesis-related factors except TGF-β1. Activated LF cells that have been exposed to macrophage, can impact the inducement of angiogenesis-related factors, suggesting that fibrosis and scarring during inflammatory reaction is the major pathomechanism of LF hypertrophy.
    Spine 06/2011; 37(3):E147-55. DOI:10.1097/BRS.0b013e3182269b19 · 2.45 Impact Factor
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    ABSTRACT: Anterior cervical discectomy and fusion (ACDF) using stand-alone cages is an effective method of treating degenerative disease. However, stand-alone cages are reported to have a relatively high incidence of implant subsidence with secondary kyphotic deformity particularly after multilevel ACDF. The purpose of our article was to investigate clinical and radiological outcomes after ACDF using stand-alone cages, at two contiguous levels, with a particular focus on changes in regional alignment and the correlation between alignment of the operated cervical levels and the entire cervical spine. Twenty-seven patients with 54 levels and a mean age of 50.8 years were enrolled between January 2005 and August 2006. They underwent ACDF using polyetheretherketone cages packed with demineralized bone matrix without plate fixation at two contiguous levels. Mean follow-up period was 25.5 months (range, 13-60). Clinical outcome was evaluated using two Visual Analog Scales and the Neck Disability Index (NDI). We assessed fusion, regional alignment (RA) of the operated levels and cervical global alignment (GA) preoperatively in the immediate 1-week postoperative period and at the final follow-up. An interspinous distance ≥2 mm was used as an indicator of pseudoarthrosis at each level. All patients showed improvements in clinical outcome, with 96% of patients showing mild NDI scores (<14). Radiological solid fusion was obtained at 48 of 54 levels (88.9%) and in 21 of 27 patients (77.8%). Lower cervical levels were significantly more vulnerable to pseudoarthrosis (100%). Fusion rate had no significant correlation with outcome (p > 0.05). RA of the operated levels was improved at the final follow-up compared with preoperatively in 76% of patients, although it had decreased compared with the immediate postoperative period due to subsidence in 84% of patients. In total, 80.8% of patients showed improvements in GA. Furthermore, improvements in RA showed a significant positive correlation with those in GA (p = 0.001), although improvement in RA and GA did not correlate significantly with clinical outcome (p > 0.05). Though some degree of subsidence occurred in most cases, RA had improved at the last follow-up compared with preoperatively, which contributed to the significant improvement in GA. However, improvement of RA and GA was not correlated with outcomes.
    Acta Neurochirurgica 03/2011; 153(3):559-65. DOI:10.1007/s00701-010-0879-z · 1.79 Impact Factor
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    ABSTRACT: Intramedullary teratomas, particularly adult cervicothoracic lesions, are extremely rare. Up to now only 6 cases of intramedullary cervical teratomas have been reported in adults, and all of these were histologically mature. The authors present the case of a 35-year-old man with progressive myelopathic symptoms who was admitted through an outpatient clinic and was surgically treated. The characteristics, diagnosis, epidemiology, and treatment of cervical intramedullary teratomas in adults are also reviewed. Postoperative MR imaging showed that the tumor had been near totally removed, and severely adherent tissue remained ventrocranially with tiny focal enhancement on follow-up MR imaging. Pathological examinations revealed immature teratoma without any malignant component. Adjuvant therapy was not performed. Although no change in neurological findings and symptoms was apparent postoperatively, lesion regrowth was demonstrated on MR imaging 4 months after surgery. At 8 months postoperatively, myelopathic symptoms had developed and a huge intramedullary tumor recurred according to MR imaging. This case is the seventh reported instance of intramedullary cervical teratoma in an adult, and the first case report of the immature type with malignant features.
    Journal of neurosurgery. Spine 08/2010; 13(2):283-7. DOI:10.3171/2010.3.SPINE09461 · 2.36 Impact Factor
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    ABSTRACT: A 74-year-old man presented with a cervical juxtafacet cyst on the right side of C5-6 and prominent myelopathy. He had been treated with anterior cervical discectomy and fusion at C4-5 as well as anterior foraminotomy of the right C5-6 lesion 20 months previously. The patient underwent complete surgical excision of the lesion. The patient recovered uneventfully, and the myelopathy resolved. Reexamination of the images revealed that we failed to investigate a suspicious minimal cervical juxtafacet cyst on the initial preoperative images and that the degree of subluxation at C5-6 on flexion radiography had increased postoperatively. Therefore, the surgeon should be aware that juxtafacet cyst can be progressive in planning of cervical spinal surgery which can cause or aggravate instability in the presence of an incidental, suspicious juxtafacet cyst on preoperative imaging at the same level, even if the lesion is very small and subclinical.
    Neurologia medico-chirurgica 01/2010; 50(12):1129-31. DOI:10.2176/nmc.50.1129 · 0.65 Impact Factor
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    ABSTRACT: We describe a technique to induce in vitro traumatic brain injury in an organotypic slice culture (OTC).
    01/2010; 6(2):89. DOI:10.13004/jknts.2010.6.2.89
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    ABSTRACT: Potassium channels are ubiquitously expressed in all organisms and constitute the most diverse class of ion channels. Their action is regulated by various factors and is involved in neuronal excitability. 4-aminopyridine (4-AP) is a voltage-sensitive K+ channel inhibitor used in studies of experimental neuronal excitation and in the treatment of demyelinating diseases. It is also known as having a strong convulsant activity on hippocampal slices. We investigated the effect of several K+ channel antagonists on evoked potentials during normoxia and hypoxia.
    01/2010; 6(2):97. DOI:10.13004/jknts.2010.6.2.97
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    ABSTRACT: We report a 56-year-old patient who had been taking antihypertensive medication in combination with prophylactic aspirin for 19 years who was diagnosed with stable angina with significant coronary artery stenosis on angiography. He was treated with drug-eluting coronary stent placement. Clopidogrel was added to the previous treatment regimen after stent placement. He visited the emergency room with complaints of severe back pain accompanied by radiculopathy and left leg weakness. The patient had an excellent outcome after immediate diagnosis by MRI and emergent evacuation of spontaneous spinal epidural hematoma (SSEH). The present case is interesting because it is the first case in spine which corresponds to the findings of MATCH study that bleeding tendency would be raised by dual antiplatelet treatment (aspirin+clopidogrel). With the popularity of antiplatelet medications, physicians should be aware of this critical side effect and provide urgent treatment. Furthermore, we should be cautious when we prescribe clopidogrel in addition to aspirin because it could cause bleeding complications like SSEH.
    Journal of the neurological sciences 08/2009; 285(1-2):254-6. DOI:10.1016/j.jns.2009.06.028 · 2.26 Impact Factor
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    ABSTRACT: An 11-year-old girl presented with a very rare traumatic retroclival epidural hematoma manifesting as bilateral abducens nerve palsy, deviation of the uvula to the left, and weakened movement of tongue, which developed after a motor vehicle accident. The patient was treated conservatively and showed good outcome. Retroclival hematoma is a mainly pediatric entity usually associated with ligamentous injury at the craniocervical junction, and can be treated conservatively with good outcome.
    Neurologia medico-chirurgica 09/2008; 48(8):347-50. DOI:10.2176/nmc.48.347 · 0.65 Impact Factor
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    ABSTRACT: We report a case of recurrent scalp dermatofibrosarcoma in a 30-year-old woman who underwent surgical intervention on three separate occasions during a 60-month period, and who received post-operative radiotherapy. A small, hard, elastic mass on the right parieto-occipital scalp was initially treated by simple resection in another clinic. Despite surgical intervention and radiotherapy, a recurrent tumor associated with infiltration to the calvarium was detected. The patient was then referred to our institution and a wide resection performed. Two years later, however, the patient was readmitted to our institution as a result of tumor recurrence with intracranial involvement. Scalp dermatofibrosarcoma is an uncommon but aggressive scalp tumor; therefore, wide local excision with good margins is essential to decrease the risk of regional recurrence. Close surveillance in these cases is necessary due to late tumor recurrences.
    Clinical Neurology and Neurosurgery 03/2007; 109(2):172-5. DOI:10.1016/j.clineuro.2006.04.007 · 1.25 Impact Factor
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    ABSTRACT: Aneurysms arising from nonbranching sites of the ICA, so-called dorsal wall aneurysm, are rare entity, and present as blister type or saccular type. Occasionally configurational changes have been observed on serial cerebral angiography: a small blister-like bulge on ICA wall on initial angiography progressing to a saccular appearance within a few weeks. Such aneurysm showing configurational change has been regarded as a false aneurysm with fragile wall just like blister-type aneurysm, and direct surgical approach has been considered highly risky. A 42-year-old woman with a subarachnoid hemorrhage revealed small "blister-like" aneurysm at the medial wall of the ICA on initial angiography. After 12 days, the following angiograms demonstrated increased aneurysmal size and change of shape into a saccular configuration. Direct surgical approach was performed. The aneurysm had a relatively firm neck, and was successfully clipped without intraoperative rupture. The dome of aneurysm was resected after clipping and the histologic examination revealed it as a true aneurysm. This case suggests that all dorsal wall aneurysms with configurational change are not false aneurysms, and that angiographic findings do not always correlate with the nature of the aneurysmal wall; therefore, we should give more credence to direct surgical observation rather than preoperative angiographic findings when considering the most suitable surgical option.
    Surgical Neurology 11/2006; 66(4):441-3; discussion 443. DOI:10.1016/j.surneu.2005.12.030 · 1.67 Impact Factor
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    ABSTRACT: A 67-year-old man presented with dizziness, nausea, and ataxia. Magnetic resonance imaging showed a large (5.5 x 4 x 4 cm) cystic lesion in the left cerebellar hemisphere with internal septation, a mural nodule, and thin rim enhancement. Cystic cerebellar tumor such as hemangioblastoma was initially suspected. Following surgery, the cyst was identified as cerebellar neurocysticercosis. Neurocysticercosis is the most common parasitic disease of the central nervous system but is occasionally misdiagnosed as tumor because of the varying neuroimaging presentation. This case shows that neurocysticercosis should be considered in the differential diagnosis of giant cystic lesions in the cerebellum as surgical intervention may be unnecessary.
    Neurologia medico-chirurgica 09/2006; 46(8):412-4. DOI:10.2176/nmc.46.412 · 0.65 Impact Factor
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    ABSTRACT: Adenosine plays the principal role in synaptic depression during various energy-depleted conditions. However, additional inhibitory factors not associated with A1 adenosine receptors appear to be involved in hypoxic insults. Monocarboxylate accumulation and consequent acidic changes during hypoxia may be responsible for this remaining depression in synaptic activity. Field evoked potentials were recorded in the CA1 region of rat hippocampal slices. Preincubation with 8-cyclopentyl-1,3-dipropylxanthine (DPCPX) disclosed 43% of DPCPX-resistant synaptic depression (DRSD) during oxygen deprivation (OD). In contrast, no DRSD was detected in various conditions with limited glucose utilization, such as glucose deprivation and oxygen-glucose deprivation. Inhibition of anaerobic glycolysis (iodoacetate, sodium fluoride) abolished DRSD during OD, whereas blockade of monocarboxylate utilization with alpha-cyano-4-hydroxycinnamic acid (4-CIN) provoked DRSD in normoxic medium. These observations suggest that an intracellular accumulation of monocarboxylates is responsible for DRSD during hypoxia.
    Neuroscience Letters 08/2006; 403(1-2):141-6. DOI:10.1016/j.neulet.2006.04.032 · 2.06 Impact Factor
  • Journal of Neurosurgery 11/2002; 97(3 Suppl):397. DOI:10.3171/spi.2002.97.3.0397 · 3.23 Impact Factor
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    ABSTRACT: A clinical and radiological follow-up study was undertaken to assess the safety, efficacy, and complication rate associated with instrumented facet fusion of the lumbar and lumbosacral spine. This study involved 99 patients with degenerative lumbar disorders who were treated surgically at the authors' neurosurgical department and followed for more than 2 years. Eighty-two patients underwent one-level fusion for the treatment of Grade I or II degenerative spondylolisthesis and accompanying spinal canal stenosis (44 patients) or recurrent disc herniation (38 patients). Seventeen patients underwent two-level fusion for the treatment of either double instances of the above indications (seven patients) or concurrent stenosis at the adjacent level (10 patients). There were no technique-related complications. The overall 2-year success rate of fusion was 96%; the success rates by fusion type were 99% in one-level fusions and 88% in two-level fusions. Degenerative spondylolisthesis had the highest success rate at 100%, whereas the success rate in patients who had not responded to previous discectomy was 93%. Patients with concurrent stenosis experienced the lowest success rate: 80%. Excellent or good clinical results were obtained for 85% of patients with one-level fusions and for 65% of patients with two-level fusions. Instrumented facet fusion alone is a simple, safe, and effective surgical option for the treatment of patients with single-level disorders, especially patients with degenerative spondylolisthesis.
    Neurosurgery 08/2002; 51(1):88-95; discussion 95-6. DOI:10.1097/00006123-200207000-00014 · 3.03 Impact Factor