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C K Chung

Publications and source records attributed to C K Chung.

At least 19 recordsLinked to original sources

Effect of seizure on hippocampus in mesial temporal lobe epilepsy and neocortical epilepsy: an MRS study.

This study was performed to evaluate the effect of seizures on the bilateral hippocampus in mesial temporal lobe epilepsy (mTLE) and neocortical epilepsy by single voxel proton magnetic resonance spectroscopy (MRS). Forty-one patients with mTLE having unilateral hippocampal sclerosis and 43 patients with a neocortical epilepsy who underwent subsequent epilepsy surgery were recruited. Ninety-five percent confidence intervals of N-acetyl aspartate/choline (NAA/Cho) and NAA/creatine (NAA/Cr) ratios in 20 healthy control subjects were used as threshold values to determine abnormal NAA/Cho and NAA/Cr. NAA/Cho and NAA/Cr were significantly lower in the ipsilateral hippocampus of mTLE and neocortical epilepsy. Using asymmetry indices for patients with bilaterally abnormal ratios of NAA/Cho and NAA/Cr in addition to using unilateral abnormal ratio, the seizure focus was correctly lateralized in 65.9% of patients with mTLE and 48.8% of neocortical epilepsy patients. Bilateral NAA/Cho abnormality was significantly related to a poor surgical outcome in mTLE. No significant relationship was found between the results of NAA/Cho or NAA/Cr and surgical outcome in neocortical epilepsy. The mean contralateral NAA/Cr ratio of the hippocampus in mTLE was significantly lower in patients with a history of secondary generalized tonic-clonic seizure (SGTCS) than in those without. Our results demonstrate effects of seizures on the hippocampi in neocortical epilepsy and the relation between SGTCS and NAA/Cr of the contralateral hippocampus in mTLE. This proves the presence of a seizure effect on the hippocampus in neocortical epilepsy as well as in mTLE.

Adult↗

Idiopathic spontaneous spinal subarachnoid hemorrhage.

INTRODUCTION: Spontaneous spinal subarachnoid hemorrhage (SAH) occurs in less than 1% of all cases of SAH, and idiopathic spontaneous spinal SAH is even more rare. METHODS: A 48-year-old man presented with a sudden onset of low back pain without any neurological deficit. There was no history of either trauma or the use of anticoagulants. Magnetic resonance (MR) imaging of the lumbar spine revealed an intradural linear mass from T12 to L3, ventral to the conus medullais and cauda equina. The mass was of iso-signal intensity in T2-weighted images, of high signal intensity in T1-weighted images, and was not enhanced following injection of gadolium. Lumbar tapping revealed bloody cerebrospinal fluid, confirming SAH. At 1 month after the onset of symptom, his pain subsided spontaneously and no vascular abnormality was found by spinal angiography. Follow-up MR imaging confirmed the complete resolution of the SAH. CONCLUSION: We report a case of idiopathic spontaneous spinal SAH at the lumbar level in a 48-year-old man.

Humans↗

Sclerosing meningioma: immunohistochemical analysis of five cases.

Sclerosing meningioma is a rare morphologic subtype of meningioma and may be mistaken for atypical or malignant meningioma and astrocytoma or schwannoma because of marked collagen deposits and a sparse population of cells with little resemblance to meningothelial cells. Authors describe the histopathologic and immunophenotypic features of five cases of sclerosing meningioma. Histologically, all the cases consisted of paucicellular collagenous tissue containing spindle cells with or without small foci of meningothelial cell proliferation. The morphology and immunohistochemical profile of the spindle cells were different from those of conventional meningothelial cells. The meningothelial cells showed a typical immunoreactivity of conventional meningiomas, while the spindle cells displayed a strong expression of vimentin. The Ki-67 labelling index was uniformly low in all cases, and none of cases expressed p53 protein. In summary, the recognition of meningothelial cells in massively sclerotic lesions is helpful for a correct diagnosis. In the cases with a total absence of meningothelial cells, however, the vague collagenous whorls are more diagnostic rather than immunohistochemistry. Considering association with clear cell meningioma, prospective and retrospective long-term follow-up is necessary for deciding whether reminiscent clear cell meningiomas should be separated from sclerosing meningioma or not.

Adolescent↗

Intracranial ictal onset zone in nonlesional lateral temporal lobe epilepsy on scalp ictal EEG.

OBJECTIVE: To determine the ictal focus and the role of seizure characteristics, fluorodeoxyglucose (FDG) PET, and subtraction ictal SPECT in patients diagnosed as having nonlesional lateral temporal lobe epilepsy by long-term scalp video-EEG monitoring. METHODS: The authors studied 33 consecutive patients with nonlesional neocortical epilepsy who had a scalp ictal onset zone localized in the temporal lobe and good surgical outcome after focal neocortical resection. All patients were evaluated using intracranial recordings prior to resection. Semiology, FDG-PET, and ictal-interictal subtraction SPECT were used to verify the diagnostic role of these methods in the localization of epileptic foci. RESULTS: The ictal onset zones, confirmed by intracranial study, were the lateral temporal (22 patients), parietal (5), frontal (3), temporoparietal (2), and occipital (1) areas. FDG-PET analyzed by statistical parametric mapping correctly localized the epileptogenic lobe in 18 of 33 patients and subtraction ictal SPECT correctly localized it in 13 of 25 patients. However, in patients with extratemporal ictal onset zones, FDG-PET and ictal SPECT in combination correctly localized the epileptogenic lobe in only 3 of 11 cases. CONCLUSIONS: An extratemporal ictal onset zone was encountered in patients with nonlesional lateral temporal lobe seizures based on scalp video-EEG monitoring. FDG-PET and subtraction SPECT had localizing value in no more than half of patients.

Adult↗

Intramedullary spinal cord astrocytoma in adults: postoperative outcome.

Intramedullary spinal cord astrocytomas are relatively rare and usually low-grade lesions with a long natural history. The rarity of the condition and its indolent clinical course has made the evaluation of treatment efficacy difficult. To clarify postoperative outcome and prognostic factors, we performed a retrospective analysis of intramedullary spinal cord astrocytomas in a single institute. Twenty-eight patients were surgically treated between 1978 and 1999; of median age 36 years (range, 19-68 years); nineteen patients were males and nine females. All patients presented with pain and neurological deficits. The cervical cord was involved in fifteen patients, cervico-thoracic in five, thoracic in six and thoraco-lumbar in two. Gross total removal was performed in three patients, subtotal removal in six, partial removal in fourteen and biopsy only in five. Nineteen patients received radiation therapy postoperatively. The mean follow-up period was 31.9 months (range, 0.5-184 months). Low-grade astrocytomas were found in 18 cases, anaplastic astrocytoma in three cases and glioblastomas in seven cases. The median survivals of patients with low- and high-grade astrocytoma were 184 months and 8 months, respectively (p < 0.05). The median survivals of irradiated and non-irradiated patients with low-grade astrocytoma were 184 months and 102 months. Neither the extent of resection, nor radiation influenced the survival rate. In summary, the histological grade was the most significant predictor of survival in patients with astrocytoma of the spinal cord.

Adult↗

Surgical treatment for thoracic spinal stenosis.

OBJECTIVES: To describe the underlying causes, surgical results and prognostic factors in thoracic stenosis causing myelopathy. METHODS: The underlying causes and surgical results were analyzed retrospectively in 28 cases of thoracic spinal stenosis which caused myelopathy. Degenerative spondylosis was the most common cause, and three cases were associated with systemic diseases. Decompressive laminectomy was performed in 24 cases, anterior decompression in five cases, and combined decompression in one case. Ossification of ligamentum flavum was found in 18 cases, facet hypertrophy in 13, ossification of posterior longitudinal ligament in six, and ventral spur in four. Postoperatively 16 patients improved and four patients worsened. Follow-up ranged from 2 months to 5 years and 8 months). Statistical analysis was performed using a chi(2) test to investigate the relationship between subjects. Multivariant analysis (general linear model) was used to determine the factors which influence surgical outcome. RESULTS: There were neurological improvements in 16 patients, in whom Nurick grade changed from 3.3 preoperatively to 1.8 postoperatively. Eight patients showed no significant change in functional grade and four patients deteriorated after decompressive laminectomy. The group of which initial symptom duration was less than 2 years showed better results (P=0.006). The group with sufficient decompression and no additional proximal stenosis had better treatment outcome (P=0.005, P=0.002). CONCLUSION: Chronic severe myelopathy caused by thoracic spinal stenosis can be reversible with appropriate decompression. Surgical outcome was dependent on initial symptom duration, sufficient decompression and presence of additional proximal stenosis. SPONSORSHIP: This study was supported by a grant No. 02-1997-071-0 from the Seoul National University Hospital Research Fund.

Adolescent↗

Neuroimaging findings of cortical dyslamination with cytomegaly.

PURPOSE: Our aims were to identify (a) the characteristic magnetic resonance imaging (MRI) findings of cortical dyslamination with cytomegaly, including dysplastic and destructive lesions; (b) the relationship between MRI findings and pathologic characteristics; (c) the diagnostic role of functional neuroimaging studies in patients with these pathologies. METHODS: The series consisted of 23 adult patients who had proven cortical dyslamination with cytomegaly. The abnormalities found on MRI were subdivided according to the patterns of involvement. They also were compared with the patients' pathologic characteristics. With visual qualitative analysis, [18F]fluorodeoxyglucose with positron emission tomography (FDG-PET), and ictal single-photon emission computed tomography (SPECT), observations were classified as localizing, lateralizing, nonlateralizing, false-localizing, and false-lateralizing. The standard for correct localization of neuroimages was defined to be the resected lobe. RESULTS: Focal abnormalities were found in 14 cases by MRI. Six cases showed typical MRI findings of focal cortical dysplasia, with focal areas of cortical thickening with or without poor grey-white matter differentiation. Focal subcortical high signal intensities on T2-weighted images occurred in two cases. Six patients had the focal destructive pattern. Three of eight cases with normal MRI and four of eight cases with the nondestructive cortical dysplasia pattern had balloon cells. However, these were not found in six patients with the destructive MRI pattern. FDG-PET localized the pathologic lobe in 13 (65%) of 20 cases, and ictal SPECT achieved this in 11 (61.1%) of 18 cases. FDG-PET and ictal SPECT also correctly localized the pathologic lobe in four and two cases with normal MRI, respectively. CONCLUSIONS: Two distinct patterns of abnormal MRI were found in the pathology of cortical dyslamination with cytomegaly. These dysplastic and destructive patterns might reflect different pathogeneses, such as the time of insult. FDG-PET and ictal SPECT have confirmatory and independent diagnostic roles in localizing epileptogenic foci.

Adult↗

Diagnostic performance of [18F]FDG-PET and ictal [99mTc]-HMPAO SPECT in occipital lobe epilepsy.

PURPOSE: We investigated whether interictal F-18 fluorodeoxyglucose positron emission tomography ([18F]FDG-PET) or ictal [99mTc]-HMPAO single-photon emission computed tomography (SPECT) was useful to find epileptogenic zones in occipital lobe epilepsy (OLE). METHODS: We reviewed visually and quantified patterns of hypometabolism in interictal [18F]FDG-PET and those of hyperperfusion in ictal SPECT in 17 OLE patients (27 plus minus 6.8 years old; M/F, 10/7; injection time, 30 plus minus 17 s). OLE was diagnosed based on invasive electroencephalography, surgery, and postsurgical outcome (Engel class I in all at an average of 26 months after surgery). RESULTS: Epileptogenic zones were correctly localized in nine (60%) of 15 patients by interictal [18F]FDG-PET, and asymmetric indices corroborated visual diagnosis. Epileptogenic hemispheres were correctly lateralized in 14 (93%) of 15 patients on [18F]FDG-PET. Epileptogenic hemispheres were correctly lateralized in 13 (76%) of 17 patients using ictal SPECT, but localization was possible in only five (29%) patients. Interictal [18F]FDG-PET was helpful in two of the patients who showed no abnormality on magnetic resonance imaging (MRI) and no possible localization with ictal SPECT. CONCLUSIONS: In OLE, ictal SPECT was helpful in lateralization, but less helpful in localization. Interictal [18F]FDG-PET was helpful in localization or lateralization of epileptogenic zones, even in patients with ambiguous MRI or ictal SPECT findings.

Adolescent↗

Analysis of radiation workers' dose records in the Korean National Dose Registry.

Data are presented on the externally received personal dose equivalent for radiation workers who used the Korea Radioisotope Association's personal monitoring and dose record keeping service since 1984, and provide initial statistics on Korean workers who have been exposed to ionising radiation in different occupations. The total number of workers registered during the period of 1984 to 1999 was 64,518. The number increased steadily and the accumulated dose also increased. The proportion of radiation workers by occupation was 38.4% for nuclear power plants, 20.3% for industrial organisations and 12.4% for non-destructive industry. The annual collective dose of radiation workers was 31.72 man.Sv in 1999. The mean annual dose by sex was 1.49 mSv for males and 0.56 mSv for females and the mean annual dose for a worker was 1.41 mSv with the highest mean dose being received by non-destructive industry (3.53 mSv). Very few workers (0.8%) received more than 20 mSv (2 rem) and only one more than 50 mSv, the legal limit for an annual dose increase. There has been a steady decline in the mean dose since 1984, showing a significant decrease in dose with time (p<0.001). The data showed that radiation protection in Korea was improving, though annual doses were still higher than other countries.

Adolescent↗

Cerebral dissection from syringomyelia demonstrated using cine magnetic resonance imaging. Case report.

A 16-year-old boy presented at the authors' emergency department with a sudden deterioration of respiration. He had been paraparetic for 3 years and had become quadriplegic 2 days previously. Magnetic resonance images revealed a Chiari I malformation and a hydromyelic cavity extending from C-1 to T-11. Rostrally, a small cylindrically shaped lesion extended from the cervicomedullary junction to the left semioval center. The patient made a dramatic neurological recovery following suboccipital craniectomy and upper cervical laminectomies with augmentation duraplasties followed by placement of a syringoperitoneal shunt.

Adolescent↗

Incidence and clinical profile of extra-medial-temporal epilepsy with hippocampal atrophy.

We tried to investigate the incidence and the clinical profile of intractable epilepsy with hippocampal atrophy and ictal onset zones located in areas other than the hippocampus (extra-medial-temporal epilepsy; EMTE). We included patients who had hippocampal atrophy confirmed by MRI but with extra-medial-temporal ictal onset zones as verified by invasive intracranial electrodes or video-EEG monitoring. The case histories, interictal EEG, ictal semiology, other MRI findings in addition to hippocampal atrophy, and results of ictal SPECT and PET scans were evaluated. Results were compared with those of surgically proven medial temporal lobe epilepsy with hippocampal atrophy recruited during the same period. 8.5% of the intractable epilepsy patients with hippocampal atrophy had extra-medial temporal epileptogenic zones. A history of encephalitis and hemiconvulsion-hemiparesis were significantly common in the EMTE group. Most of the interictal EEGs of EMTE patients showed extratemporal irritative zones. MRI, ictal SPECT, and FDG-PET seemed to be helpful at localizing the true epileptogenic zones. The predominant EMTE seizure type was focal motor seizure with secondary generalization. Some portion of intractable epilepsy patients with hippocampal atrophy had extra-medial-temporal epileptogenic foci and careful analysis of semiology and neuroimagings could yield clues to correct diagnosis.

Adult↗

Lateralizing ability of single-voxel proton mr spectroscopy in hippocampal sclerosis: comparison with mr imaging and positron emission tomography.

BACKGROUND AND PURPOSE: Proton MR spectroscopy (MRS) is still in the early stages in the evaluation of epilepsy, and comparisons with MR imaging and positron emission tomography (PET) in the same patients have rarely been documented. The purpose of this study was to evaluate the lateralizing ability of single-voxel MRS in comparison with MR imaging and PET in patients with hippocampal sclerosis. METHODS: Thirty-three patients with intractable temporal lobe epilepsy whose MR imaging diagnosis was unilateral hippocampal sclerosis and who underwent anterior temporal lobectomy and had good postsurgical outcome over 1-year follow-up were included in the study. MR spectra were obtained from the hippocampus bilaterally, using the point-resolved spectroscopy sequence. Metabolite ratios of NAA/Cho and NAA/Cr were calculated from the relative peak height measurements. An NAA/Cho ratio of 0.8 or less and an NAA/Cr ratio of 1.0 or less were regarded as abnormal. The MRS results were compared retrospectively with those of MR imaging and PET as to the ability to lateralize the epileptogenic focus. RESULTS: The sensitivity of MRS and PET (concordance with MR imaging) was 85% each in the lateralization of the ipsilateral lesion side. Bilateral abnormalities were seen in 30% of the patients. False-lateralization rates for MRS and PET were 3% and 6%, respectively. The concordance rate of MRS and PET was 73%, when comparing the results of the ipsilateral lesion side. CONCLUSION: MRS may be used as an adjunct tool in the evaluation of hippocampal sclerosis, like PET, although its sensitivity has to be improved and the clinical significance of bilateral abnormality is still to be determined.

Adolescent↗

Comparative analysis of MR imaging, positron emission tomography, and ictal single-photon emission CT in patients with neocortical epilepsy.

BACKGROUND AND PURPOSE: MR imaging, positron emission tomography (PET), and single-photon emission CT (SPECT) play important roles in presurgical localization of epileptic foci. However, comparative study of these imaging methods for cases of neocortical epilepsy has been limited. The purpose of this study was to compare the sensitivities of these three imaging methods for presurgical localization of neocortical epileptogenic foci. METHODS: We studied 117 consecutive patients who underwent surgery for intractable neocortical epilepsy. The pathologic substrates were neuronal migration disorder (n = 77), tumor (n = 15), and others (n = 25). MR imaging was compared retrospectively with (18)F-fluorodeoxyglucose PET and ictal technetium-99m hexamethylpropyleneamine oxime SPECT regarding their capability to correctly localize the epileptogenic foci. The pathologic findings were used as the standard of reference. RESULTS: Overall, MR imaging, PET, and ictal SPECT correctly localized the lesions for 59.8%, 77.7%, and 70.3% of the patients, respectively, with a 38% concordance rate among the three methods. PET was most sensitive (71-100%) in detecting all substrates. MR imaging was as sensitive (100%) as PET in detecting tumor but was least sensitive (48.1%) in detecting neuronal migration disorder. Ictal SPECT was more sensitive (75.8%) than MR imaging in detecting neuronal migration disorder. Patients with imaging abnormalities achieved good outcomes in 81.4% of the cases, in contrast to 59.5% for those without imaging abnormalities (P <.05). CONCLUSION: PET and ictal SPECT were overall more sensitive than was MR imaging, despite the low concordance rate and variable sensitivity depending on substrates. The detection of abnormalities by MR imaging was associated with good outcome. PET or ictal SPECT can be well used as complementary tools, particularly in cases of negative MR imaging findings.

Brain Diseases↗

Intramedullary spinal cord ganglioglioma: a report of five cases.

We report five cases of ganglioglioma in various locations. The tumours were removed with gross total resection in most cases without any further neurological deterioration. Without any additional treatment, no evidence of recurrence or regrowth of tumours was observed in the mean follow-up period of 4.1 years. We suggest that intramedullary spinal cord gangliogliomas be resected totally due to the high risk of recurrence and regrowth rate of the tumours with subtotal resection in the long term considering especially that these tumours affect predominantly young patients.

Adolescent↗

Inhibitory effect of sodium salicylate on nitric oxide production from TM4 sertoli cells.

Nitric oxide (NO) has been proposed to play a role in a variety of inflammatory diseases. Sodium salicylate (NaSal) is the most commonly used anti-inflammatory agent. We investigated whether NaSal can diminish the production of NO in TM4 Sertoli cells. TM4 Sertoli cells produced a small amount of NO upon treatment with recombinant interferon-gamma (rIFN-gamma). The effect of rIFN-gamma was enhanced markedly by the addition of recombinant TNF-alpha (rTNF-alpha) in a dose-dependent manner. NaSal (10 and 20 mM) significantly inhibited NO production from TM4 Sertoli cells induced by rIFN-gamma plus rTNF-alpha. In addition, rIFN-gamma in combination with rTNF-alpha showed a marked increase of the expression of inducible NO synthase (iNOS) protein. Western blot analysis revealed that NaSal (10 and 20 mM) blocked a step of iNOS protein synthesis. The rIFN-gamma plus rTNF-alpha-induced nuclear factor-kappaB (NF-kappaB) activation was significantly blocked by NaSal (10 and 20 mM). On the other hand, neither staurosporine nor polymyxin B significantly inhibited NO production from TM4 Sertoli cells induced by rIFN-gamma plus rTNF-alpha. The present results indicate that NaSal inhibits rIFN-gamma plus rTNF-alpha-induced NO production in TM4 Sertoli cells via the signal transduction pathway of NF-kappaB activation.

Animals↗

Dysembryoplastic neuroepithelial tumor: radiological findings (including PET, SPECT, and MRS) and surgical strategy.

In order to elucidate the radiological features of dysembryoplastic neuroepithelial tumor (DNT), and to clarify the optimal surgical strategy for this tumor, the authors retrospectively analyzed 20 cases of DNT treated at our institution. Magnetic resonance (MR) imaging (all cases), 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET) (eight cases), ictal/interictal Tc99m-HMPAO single photon emission computed tomography (SPECT) (seven and five cases respectively) and proton magnetic resonance spectroscopy (1H MRS) (one case) were performed preoperatively. Invasive monitoring/intraoperative electrocorticography (ECoG) was performed in four cases in order to determine the epileptogenic zone. A well-demarcated lobulating tumor located in the cortical with/without subcortical area was the typical MR finding. 18F-FDG PET showed glucose hypometabolism in all cases. Ictal Tc99m-HMPAO SPECT showed hyperperfusion of the lesion in three cases and interictal Tc99m-HMPAO SPECT showed hypoperfusion of the lesion in one case. 1H MRS showed nonspecific findings. Gross total resection was performed in all cases. Histologically, associated cortical dysplasia was found in 11 cases. The mean duration of follow-up after surgery was 37.9 months, and the overall seizure free rate was 90%. Follow-up MR imaging was performed in 14 cases (mean duration of follow-up: 21.6 months) and showed no recurrence of tumor in any of these cases. Invasive monitoring/intraoperative ECoG and the presence of cortical dysplasia showed no significant relationship with seizure control rate (p = 1.25 and p = 1.62 respectively).

Adolescent↗

Spontaneous spinal subdural hematoma with spontaneous resolution.

STUDY DESIGN: Single patient case report. OBJECTIVES: To present and discuss a case of spontaneous spinal subdural hematoma that was not associated with coagulation abnormality. SETTING: Seoul National University Hospital, Seoul, Korea. METHODS: Clinical and radiological magnetic resonance imaging follow-up of the patient between August 1997 and December 1998. RESULTS: The hematoma was initially extensive, ranging from T5 to L3. However, it resolved spontaneously with the subsequent development of an adhesive arachnoid cyst. CONCLUSION: Even though urgent surgical decompression is necessary in most cases of spinal subdural hematoma, conservative management could be an option in cases with rapid resolution of the neurological deficit.

Female↗