Eun-Ik Son

Intracranial Fusiform Aneurysms: It's Pathogenesis, Clinical Characteristics and Managements

OBJECTIVE The objective of this study is to investigate clinical characteristics, management methods and possible causes of intracranial fusiform aneurysm. METHODS Out of a series of 2,458 intracranial aneurysms treated surgically or endovascularly, 22 patients were identified who had discrete fusiform aneurysms. Clinical presentations, locations, treatment methods and possible causes of these aneurysms were analyzed. RESULTS Ten patients of fusiform aneurysm were presented with hemorrhage, 5 patients with dizziness with/without headache, 4 with ischemic neurologic deficit, and 1 with 6th nerve palsy from mass effect of aneurysm. Two aneurysms were discovered incidentally. Seventeen aneurysms were located in the anterior circulation, other five in the posterior circulation. The most frequent site of fusiform aneurysm was a middle cerebral artery. The aneurysms were treated with clip, and/or wrapping in 7, resection with/without extracranial-intracranial (EC-IC) bypass in 6, proximal occlusion with coils with/without EC-IC bypass in 5, EC-IC bypass only in 1 and conservative treatment in 3 patient. We obtained good outcome in 20 out of 22 patients. The possible causes of fusiform aneurysms were regard as dissection in 16, atherosclerosis in 4 and collagen disease or uncertain in 2 cases. CONCLUSION There is a subset of cerebral aneurysms with discrete fusiform morphology. Although the dissection or injury of internal elastic lamina of the cerebral vessel is proposed as the underlying cause for most of fusiform aneurysm, more study about pathogenesis of these lesions is required.

Expression of Cancer-Testis Genes in Brain Tumors

OBJECTIVE Cancer-testis (CT) genes are considered promising candidates for immunotherapeutic approaches. The aim of this study was to investigate which CT genes should be targeted in immunotherapy for brain tumors. METHODS We investigated the expression of 6 CT genes (MAGE-E1, SOX-6, SCP-1, SSX-2, SSX-4, and HOM-TES-85) using reverse-transcription polymerase chain reaction in 26 meningiomas and 32 other various brain tumor specimens, obtained from the patients during tumor surgery from 2000 to 2005. RESULTS The most frequently expressed CT genes of meningiomas were MAGE-E1, which were found in 22/26 (85%) meningioma samples, followed by SOX-6 (9/26 or 35%). Glioblastomas were most frequently expressed SOX-6 (6/7 or 86%), MAGE-E1 (5/7 or 71%), followed by SSX-2 (2/7 or 29%) and SCP-1 (1/7 or 14%). However, 4 astrocytomas, 3 anaplastic astrocytomas, and 3 oligodendroglial tumors only expressed MAGE-E1 and SOX-6. Schwannomas also expressed SOX-6 (5/6 or 83%), MAGE-E1 (4/6 or 67%), and SCP-1 (2/6 or 33%). CONCLUSION The data presented here suggest that MAGE-E1 and SOX-6 genes are expressed in a high percentage of human central nervous system tumors, which implies the CT genes could be the potential targets of immunotherapy for human central nervous system tumors.

Helenalin-induced apoptosis is dependent on production of reactive oxygen species and independent of induction of endoplasmic reticulum stress in renal cell carcinoma.

Helenalin, a sesquiterpene lactone, exhibits anti-inflammatory and anti-tumor activities. Here, we investigated whether helenalin could induce apoptosis in human renal carcinoma Caki cells. Helenalin increased apoptosis in dose dependent manner in Caki cells, and also induced apoptosis in other carcinoma cells, such as human renal carcinoma ACHN cells, human colon carcinoma HT29 and HCT116 cells. We found that helenalin markedly induced endoplasmic reticulum (ER) stress-related genes, such as regulated in development and DNA damage responses (REDD) 1, activating transcription factor-4 (ATF4) and/or the CCAAT enhancer-binding protein-homologous protein (CHOP). However, down-regulation of ATF4 and/or CHOP expression by siRNA had no effect on helenalin-induced apoptosis in Caki and HCT116 cells. Helenalin increased production of intracellular reactive oxygen species (ROS). Furthermore, ROS scavengers, N-acetylcystine (NAC), and glutathione ethyl ester (GEE), reduced helenalin-induced apoptosis. Taken together, helenalin induced apoptosis via ROS generation in human renal carcinoma Caki cells.

Immunohistochemical analysis for histopathological subtypes in pediatric medulloblastomas

Medulloblastomas occurring in children represent a histological spectrum of varying anaplasia and nodularity. In order to determine whether immunohistochemical markers might be useful parameters in subclassifying these tumors, 17 pediatric medulloblastomas, including nine diffuse/non‐anaplastic, four diffuse/anaplastic, three nodular/non‐anaplastic and one nodular/anaplastic subtypes, were studied. In the present report, we investigate the expression of neural cell adhesion molecule (NCAM), nerve growth factor receptor (NGFR), neurofilament (NF), synaptophysin (SYN), glial fibrillary acidic protein (GFAP), S100, Bcl‐2, and Ki‐67 by using the immunohistochemistry against specific antibodies. This study showed that NGFR, NF, GFAP and S100 were not detected in anaplastic subtypes of medulloblastomas (0/5), while non‐anaplastic subtypes were mainly expressed within the nodules. All 17 tumors were reactive for NCAM, SYN and Bcl‐2. In addition, Ki‐67 labeling indices for anaplastic subtypes (39.0 ± 7.42%) were significantly higher than that of non‐anaplastic medulloblastomas (11.4 ± 8.04%; P < 0.0001). These results suggest that immunohistochemical markers are a useful adjunct in characterizing subtypes of pediatric medulloblastomas.

Comparison between Initial and Recent Surgical Outcome of 15-Year Series of Surgically Remediable Epilepsy

OBJECTIVE The aim of this study is to compare the surgical outcome of the initial and recent surgical cases, during our 15-years experience, in terms of the surgical strategies and the prognostic factors for surgically remediable epilepsy. METHODS We retrospectively reviewed and compared the surgical outcomes between the initial 256 (Group I) and recent 139 (Group II) patients according to the time period of operation for a total of 518 consecutive epilepsy surgeries at our institution since 1992. The patients of the middle intermediate period, which were subjected to changed surgical strategies, were excluded. RESULTS The surgical outcome data from the initial and recent groups showed a much improved outcome for patients who underwent temporal lobe epilepsy (TLE) surgery over time. The number of patients with a good outcome (Engel class I-II) was much increased from 87.7% (178 TLE cases of Group I) to 94.8% (79 TLE cases of Group II) and this was statistically significant (p = 0.0324) on univariate analysis. Other remarkable changes were the decreased performance of intracranial invasive studies from 43.5% in Group I to 30.9% in Group II due to the advanced neuroimaging tools. The strip/grid ratio was reduced from 131/32 in Group I to 17/25 in Group II, because of a markedly reduced mesial TLE surgery and an increased extratemporal epilepsy surgery. CONCLUSION Our results show that surgical outcome of epilepsy surgery has improved over time and it has shown to be efficient to control medically intractable epilepsy. Appropriate patient selection, comprehensive preoperative assessments and more extensive resection are associated with good postoperative outcomes.

Emerging surgical strategies of intractable frontal lobe epilepsy with cortical dysplasia in terms of extent of resection.

Objective Cortical dysplasia (CD) is one of the common causes of epilepsy surgery. However, surgical outcome still remains poor, especially with frontal lobe epilepsy (FLE), despite the advancement of neuroimaging techniques and expansion of surgical indications. The aim of this study was to focus on surgical strategies in terms of extent of resection to improve surgical outcome in the cases of FLE with CD. Methods A total of 11 patients of FLE were selected among 67 patients who were proven pathologically as CD, out of a total of 726 epilepsy surgery series since 1992. This study categorized surgical groups into three according to the extent of resection : 1) focal corticectomy, 2) regional corticectomy, and 3) partial functional lobectomy, based on the preoperative evaluation, in particular, ictal scalp EEG onset and/or intracranial recordings, and the lesions in high-resolution MRI. Surgical outcome was assessed following Engels classification system. Results Focal corticectomy was performed in 5 patients and regional corticectomy in another set of 5 patients. Only 1 patient underwent partial functional lobectomy. Types I and II CD were detected with the same frequency (45.45% each) and postoperative outcome was fully satisfactory (91%). Conclusion The strategy of epilepsy surgery is to focus on the different characteristics of each individual, considering the extent of real resection, which is based on the focal ictal onset consistent with neuroimaging, especially in the practical point of view of neurosurgery.

Spectrum of neurosurgeon's role in epilepsy surgery.

It is well known that there is high quality evidence of epilepsy surgery as an effective and safe option for patients with drug refractory epilepsy by advanced imaging technology and computerized electrophysiological facilities during recent three decades. However, it still remains debate regarding necessities of epilepsy surgery in terms of less satisfactory surgical outcome, especially in non-lesional neocortical epilepsies. This review is for the role of epileptic neurosurgeon rather than the role of epilepsy surgery, namely, the necessity of neurosurgeons positive participation starting from the first visit of epilepsy patients followed by pertaining process by stages and its degree of contribution. All experienced epilepsy centers also need innovative or challenging trial absolutely through this kind of standpoint, because all of the present protocols and techniques are coming from the past. In any event, the interdepartmental and interpersonal cooperation is inevitable especially for improving patients quality of life. Serious neurosurgical considerations are needed for patients with intractable epilepsies, especially in referred cases from other center for the purpose of double check, and incongruent cases with contrary opinions by epileptologist.