Hung Seob Chung

Spontaneous spinal epidural hematoma: An urgent complication of adding clopidogrel to aspirin therapy

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.

Oncocytic paraganglioma of the cauda equina in a child: Case report and review of the literature

The authors report a case of oncocytic paraganglioma of the cauda equina in a 12-year-old girl who presented with lower back and leg pain on the right side of 6 months’ duration. Magnetic resonance imaging revealed an ellipsoidal, intradural, extramedullary mass causing cord compression at the level of L1. Total laminectomy was performed on T12 and L1, and the tumor was excised completely without difficulty despite adherence of the tumor to the spinal cord. Postoperatively, the leg pain and motor weakness were much improved. The use of electron microscopy, and the immunohistochemical demonstration of synaptophysin in this tumor, allowed a confident diagnosis of an oncocytic paraganglioma to be made. To the authors’ knowledge, this patient represents the first definite case of an oncocytic paraganglioma of the cauda equina in a child.

The angiogenic capacity from ligamentum flavum subsequent to inflammation: a critical component of the pathomechanism of hypertrophy.

Study Design. 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. Objective. To test our hypothesis that activated LF, which was exposed to inflammation, induces angiogenesis, thus resulting in hypertrophy. Summary of Background Data. 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. Methods. 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)-&agr;, interleukin (IL)-1&bgr;, IL-6, IL-8, vascular endothelial growth factor (VEGF), and transforming growth factor (TGF)-&bgr;1. Naïve and macrophage-exposed LF cells that responded to TNF-&agr;/IL-1&bgr; were compared using the same outcome measures. Hypertrophied LF tissue was stained by TGF-&bgr;1 primary antibody using immunohistochemical method. Results. 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-&agr;/IL-1&bgr; stimulation whereas IL-6 production was increased in response to IL-1&bgr;. The coculture appeared to increase TGF-&bgr;1 secretion but the level was lower than that for macrophage-like cells alone and LF cells alone combined. Conclusion. LF cells interact with macrophage-like cells to produce angiogenesis-related factors except TGF-&bgr;1. 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.

Transient recovery of synaptic transmission is related to rapid energy depletion during hypoxia

Transient recovery (TR) of evoked synaptic potential during the late stage of hypoxic hypoglycemia (HH) insult was investigated in rat hippocampal slices using extracellular recording methods. TR was observed in association with a rapid deterioration of antidromic population spikes (aPSs) following HH insult. TR was not elicited in normoglycemic hypoxia (NH), in which a gradual and delayed deterioration of aPSs was noted. TR was not modulated by either Ca(2+)- or PKC-dependent processes. When a glycolytic inhibitor was added, NH resulted in a rapid deterioration of aPSs and prompted appearance of TR. TR was also seen in slices using lactate to generate energy via oxidative phosphorylation, when hypoxic conditions were subsequently created. Other pharmacological interventions that aimed to cause rapid deterioration of aPSs without depleting energy stores failed to reproduce TR. The evidence thus suggests that the underlying mechanisms of TR appearance during HH insult are highly correlated with rapid energy depletion.

Radiological Significance of Ligamentum Flavum Hypertrophy in the Occurrence of Redundant Nerve Roots of Central Lumbar Spinal Stenosis

Objective There were previous reports of redundant nerve roots (RNRs) focused on their clinical significance and pathogenesis. In this study, we investigated the significant radiologic findings that correlate with RNRs occurrence. These relations would provide an advanced clue for clinical significance and pathogenesis of RNRs. Methods Retrospective research was performed with data from 126 patients who underwent surgery for central lumbar spinal stenosis (LSS). Finally, 106 patients with common denominators (inter-observer accuracy : 84%) were included on this study. We divided the patients into two groups by MRI, patients with RNRs and those with no RNRs (NRNRs). Comparative analyses were performed with clinical and radiologic parameters. Results RNRs were found in 45 patients (42%) with central LSS. There were no statistically significant differences between the two groups in severity of symptoms. On the other hand, we found statistically significant differences in duration of symptom and number of level included (p<0.05). In the maximal stenotic level, ligamentum flavum (LF) thickness, LF cross-sectional area (CSA), dural sac CSA, and segmental angulation are significantly different in RNRs group compared to NRNRs group (p<0.05). Conclusion RNRs patients showed clinically longer duration of symptoms and multiple levels included. We also confirmed that wide segmental angulation and LF hypertrophy play a major role of the development of RNRs in central LSS. Together, our results suggest that wide motion in long period contribute to LF hypertrophy, and it might be the key factor of RNRs formation in central LSS.

Adult cervical intramedullary teratoma: first reported immature case

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.

Surgical consideration of the intraspinal component in extradural dumbbell tumors

BACKGROUND The dumbbell tumor is considered a distinct group of tumors of the spinal nerve sheath owing to its intriguing clinical and radiological characteristics. More than half of dumbbell tumors are completely restricted to the extradural space, although preoperative MRI in some cases suggests the presence of intradural/extradural tumors. The aim of this retrospective investigation is to elucidate the clinical features and to suggest the surgical strategy to reduce the operating time and prevent additional complications in extradural type. METHODS The medical records and radiological studies of 7 consecutive cases (4 male, 3 female, mean age 40.4 years) who underwent removal of the intraspinal component of their extradural dumbbell tumors between January 1996 and December 2005 were analyzed. Diagnosis and preoperative evaluation were performed with MRI and myelogram/CTs. RESULTS The relationship of the tumor mass to dural sac in preoperative MRIs was so indistinct as to suggest an intradural mass in 5 cases. We found that extradural portion was covered with an attenuated dura and that the dural ring was invaginated into the intradural portion in these cases. Therefore, the author began with the epidural removal of the intraspinal and extraspinal component, followed by carefully extracting the intradural-like mass. CONCLUSIONS In conclusion, we suggest that invagination of the dural ring is the anatomical feature that may be confused with an intradural/extradural tumor during operations for extradural dumbbell tumors. Initial epidural mass removal, extraction of intradural/extradural tumors subsequent to dural opening, and affirmation of presence of intradural tumor remnant could save time during dumbbell tumor surgery.

C-1 root schwannoma with aggressive lateral mass invasion

Schwannomas are relatively common, benign tumors that are thought to arise from the nerve sheath cell. Schwannomas of the C1 root are extremely rare and seldom invade lateral masses because they gradually increase in size and can extend through the wide space behind the lateral mass instead of the intervertebral foramen. We present here an unusual case of a benign schwannoma that aggressively invaded the lateral mass of C-1.

Accumulation of Intraventricular Fat in an Intracranial Epidermoid Tumor: Case Report

OBJECTIVE AND IMPORTANCE A fat component within the ventricles or subarachnoid space in fat-containing tumors such as an epidermoid or a dermoid has been observed in rare instances. However, there have been no reports regarding an increase in the size of such a fat component. We describe the case of an epidermoid tumor with intraventricular fat that showed an increase in size and amount. CLINICAL PRESENTATION A 26-year-old woman was admitted with headache and diplopia. Computed tomography and magnetic resonance imaging of the brain revealed a fat-containing suprasellar tumor and widespread fat globules in adjacent sulci and cisterns and within the frontal horn of the lateral ventricle. INTERVENTIONThe patient underwent a pterional craniotomy. Removal of the suprasellar tumor was nearly total. Histopathological examination revealed an epidermoid tumor. Sequential magnetic resonance imaging throughout the ensuing 65-month period revealed no evidence of tumor recurrence; however, the intraventricular fat remained and increased in size. The patient underwent surgery via the transcallosal approach at 69 months after the initial operation, and the presence of free-floating oily fat globules was confirmed. CONCLUSIONIn the case of a fat-containing tumor with free fat in the cerebrospinal fluid spaces, careful serial examination is necessary, with particular attention to the possibility of changes in size.

Intracranial Undifferentiated Sarcoma Arising from a Low-Grade Glioma: A Case Report and Literature Review.

Undifferentiated sarcomas are rarely identified in the intracranial region. A 23-year-old man was admitted with a chief complaint of headache. Initial magnetic resonance images showed signs of low-grade glioma in the frontal lobe. Stereotactic biopsy was performed, and a diagnosis of diffuse astrocytoma was confirmed. Three months later, the patient presented with a high-grade tumor as seen on imaging studies. He underwent total resection of the tumor and histopathological tests identified an undifferentiated sarcoma. The patient died eight months later due to massive tumor bleeding. To the best of our knowledge, this is the first report of undifferentiated sarcoma arising from low-grade glioma without any chemotherapy or radiotherapy.