목 적 : 교모세포종은 흔한 원발성 뇌종양이며 생물학적 특성상 빠른 성장률을 보이는 것 외에 침습성이 강하여 종양과 인접한 부분을 파괴 시킬 뿐 아니라 직접접촉하지 않는 부분의 파괴도 일어나게 되어 치료 예후가 매우 불량한 것으로 되어 있다. 광역학치료는 광감각제를 이용하며 광감각제는 적절한 파장의 광원에 노출되면 세포 내에서 산소독성 물질을 생성하여 세포괴사를 유도하는 것이 주 살해작용의 기전이다. 본 실험에서는 사람의 신경교종 세포주인 U87 세포를 이용하여 실험관 내에서 광감각제 photofrin을 이용한 광역학치료가 종양의 침습성에 미치는 영향을 알아보고 동시에 이를 뇌종양치료의 새로운 방법으로 사용될 수 있는지의 여부를 알아보고자 하였다. 재료 및 방법 : 교모세포종 세포주인 U87 세포를 여러 농도의 photofrin으로 처리한 후 632nm $100mJ/cm^2$의 고정된 광선조건에서 본 실험을 시행 하였으며 Microculture tetrazolium(MTT) assay를 이용하여 세포 살해능력을 측정하고 침습성은 matrigel artificial basement membrane assay 및 tumor spheroid fetal rat brain aggregate(FRBA) confrontation assay를 이용하여 측정하였다. 결 과 : MTT assay를 이용하여 측정한 광역학 치료의 세포살해능력은 $100mJ/cm^2$의 광선 세기에서 광감각제인 photofrin의 농도에 비례하여 세포 살해 능력을 보였다. Matrigel artificial basement membrane assay 를 이용한 종양 침습성 검사에서 광역학치료가 종양침습의 억제효과를 나타냄을 알 수 있었으며 특히 세포 살해능력을 별로 보이지 않았던 photofrin 농도 2.5ug/ml에서 뚜렷한 침습억제효과를 나타내고 있었다(p<0.05). tumor spheroid fetal rat brain aggregate(FRBA) confrontation assay에서는 brain aggregate의 파괴와 종양의 침습을 관찰할 수 있었는데 파괴의 모양은 생체내에서 보이는 것과 비슷 하였다. 또한 그 정도와 범위는 처리된 Photofrin의 농도에 비례하여 종양침습이 억제됨을 알 수 있었다. 결 론 : 이러한 결과를 종합해 보았을 때 PDT는 종양세포의 침습성에 중요한 역할을 함을 알 수 있었으며 PDT 는 세포 살해능력뿐 아니라 침습성에도 영향을 미침으로써 종양 치료에 유용한 방법으로 사용될 수 있을 것으로 사료된다.

Objective : The purpose of this study is to evaluate and compare surgical results of pterional(fronto-temporal) approach and interhemispheric approach for the high positioned anterior communicating artery aneurysm with our surgical experience. Methods : During the period between May 1990 and May 2001, 263 anterior communicating aneurysms were treated at the department of neurosurgery of Dong-A university hospital. Among them, 175 patients were operated by same operator. Thirty six out of the 175 cases were high positioned anterior communicating artery aneurysms located more than 15mm above the anterior clinoid process. Results : Pterional approaches were applied in 32 cases and interhemispheric approaches were applied in 4 cases of total 36 cases of the high positioned anterior communicating artery aneurysms. The 32 cases of pterional approach resulted in Good Recovery 20/32(63%), Moderate Disability 6/32(19%), Severe Disability 4/32(12%) and Dead 2/32(6%), and 4 cases of interhemispheric approach resulted in GR 3/4(75%) and MD 1/4(25%). Relatively, pterional approach showed poorer result on high positioned anterior communicating artery aneurysm located more than 19mm above the anterior clinoid process with GR 5/13(39%), MD 3/13(23%), SD 3/13(23%) and Dead 2/13(15%). Conclusion : Interhemispheric approach is preferable to pterional approach for certain cases of high positioned anterior communicating artery aneurysm located more than 19 mm above the anterior clinoid process because it provides adequate orientation to the regional anatomy, less retraction of frontal lobe and preservation of the olfactory tract and gyrus rectus without any surgical complications.

목 적 : Paraclinoidal aneurysm은 두개강내 내경동맥 근위부에서 후교통동맥 기시부까지 생기는 뇌동맥류를 말한다. 이들 동맥류의 수술의 기술적인 문제는 근위혈관의 지혈과 안전한 동맥류로의 접근 및 뇌동맥류 경부의 완전한 노출을 고려해야 한다. 저자들은 최소침윤법의 개념으로 수술의 효율성에 대해서 관심을 가지고 수술하였다. 대상 및 방법 : 저자들은 과거 4년간 171명의 뇌동맥류 수술환자를 경험하였으며 그중 10명의 paracliniodal aneurysm환자를 수술하였고 10명중 2명은 비파열된 동맥류를 가지고 있었다. 평균 연령은 47세 였으며 전부 여자 환자였다. 그중 3명의 환자는 proximal posterior carotid artery에서 기원하였으며 4명의 환자는 carotid-ophthalmic artery에서 기원했고 나머지 3명은 superior hypophyseal artery에서 기원하였다. 결 과 : 전례에서 결찰술을 시행했으며 수술결과는 매우 양호했으며, 이들 중 뇌수두증이 있었던 1례를 제외하고 신경학적인 결손과 사망한 환자는 없었다. 시력장애증상은 4명의 환자에서 호소했지만 그중 2명은 수술후 회복되었고 나머지 2명은 더 이상 악화되지는 않았다. 결 론 : 최근 저자들의 경험에 비추어 볼 때, 수술전 진단적 혈관조형술의 정교함이 크기와 무관하게 모든 paraclinoidal aneurysm의 분류에 도움이 된다고 생각하며, 이러한 분류가 각각의 동맥류에 따른 수술적 접근을 용이하게 함으로서 대부분의 환자에서 시각능력 향상뿐만 아니라 좋은 수술결과를 초래 할 수 있고 불필요한 수기를 배제함으로서 수술시간도 단축될 수 있을 것으로 사료된다.

Objective : The present study was performed to analyze treatment results for 22 cases of arachnoid cyst and to have appropriate surgical method in our department. Material and Methods : We performed a retrospective study in 22 cases in 11 years between 1989 to 2000 that could be followed up. The analysis was based on the results of patients age, sex distribution, developed area, clinical symptom, treatment method, and complication. Results : The age range of cyst development was between 7 months to 60 years with the average age of 21 years. As for sex distribution, 20 were male and 2 were female, with significantly more cyst development in males than females. Thirteen cases were developed in the sylvian fissure, 3 cases in the posterior fossa, 4 cases in the cerebral convexity of the supratentorial area, 1 case in the suprasella and 1 case in interhemiphere. Those cases with the sylvian fissure involvement included 6 cases of Type I, 4 cases of Type II, and 3 cases of Type III. As for the distribution according to hemisphere, more arachnoidal cysts were seen in the right hemisphere. The most common clinical symptom was headache, followed by seizure and speech disturbance. As for the treatment method in 22 cases, surgery was performed in 17 cases and conservative treatment in 5 cases. Fenestration was performed in 14 cases. 13 cases of them showed good outcome, and 1 case with delayed development showed no improvement. Cyst-peritoneal shunt was done in 2 cases. Both fenestration and cyst-peritoneal shunt were done in 1 case. Conclusion : Patients who perforemed fenestration were showed good outcome with few complication. We concluded that fenestration is the most appropriate surgical method for arachnoid cyst.

Objective : Cranioplasty is required to protect underlying brain, to correct major aesthetic deformities, or both. The ideal material for this purpose is autogenous bone. When this is not available, alloplastic or artificial materials may be used. In this study authors compared the infection rate according to the cranioplasty materials(the frozen autologous bone vs. bone cement), and duration of the skull defect. Materials : Between May 1994 and December 1999, 111 patients with skull defect treated with cranioplasty(82 cases of frozen autologous bone and 29 cases of artificial bone material) were included in this study. There were 77 males and 34 females with a mean age of 41.4 years(range 1-85 years). 57 patients had head trauma and 54 had non-traumatic insults. According to the duration of skull defect, there were 28 cases under 1 month, 33 cases of 1-2 months, 15 cases of 2-3 months, 20 cases of 3-6 months and 15 cases over 6 months of duration. Results : Overall infection rate was 9.9%. In cases with frozen autologous bone and artificial bone material, the infection rate was 8.5% and 13.7%, respectively. The infection rate according to the duration of skull defect was 3.6%(among 28 cases) under 1 month of age, while those were 12%(4 among 33 cases) at 1-2 months, 20%(3 among 15 cases) at 2-3 months, 5%(1 among 20 cases) at 3-6 months and 13%(2 among 15 cases) over 6 months. Accoring to the underlying disease, the infection rate in traumatic cases was 12%(7 among 57 cases) and that in non-traumatic one was 3.7%(2 among 54 cases). Conclusion : From this study, it appears that skull defect should be repaired as soon as possible, because early cranioplasty can lower the infection rate. And surgeons could save the patients' cranial bone as possible as they can because autologous bone is not only cost effective in cosmatic purpose but lower the infection rate.

Objective : The therapeutic impact of tumor resection in glioblastomas is poorly defined and still questionable. Therefore, we conducted the current study to verify the role of tumor resection in the treatment of these highly malignant tumors. Methods : A retrospective study was performed(1990-1999) to compare the treatment results of surgical resection plus radiotherapy(130 patients) with those of stereotactic biopsy plus radiotherapy(19 patients) in glioblastomas. Only adult patients with supratentorial, de novo glioblastoma located in one lobe were included. Survival time/rate was analysed with Kaplan-Meier method, and prognostic variables were obtained from the univariate log-rank test and the multivariate Cox's proportional hazards model. Results : The resection group and the biopsy group did not differ in terms of age, gender, duration of symptoms, presenting symptoms, tumor location, tumor side, tumor size, and the frequency of midline shift. Patients in the biopsy group more often were found to have worse preoperative Karnofsky performance status(KPS)(p=0.001). On univariate analysis, age, KPS, and tumor side were associated with survival(p=0.0053, 0.0001, and 0.0331 respectively). Median survival time and 1-year survival rate were also statistically improved by tumor resection ; resection group - 13 months and 61.2%, and biopsy group - 8 months and 19.7%, respectively(p=0.0001). In patients with midline shift of the tumor, resection was highly effective comparing to biopsy(p=0.0001), but in patients without midline shift, external beam radiation alone was as effective as tumor resection(p=0.0605). Other prognostic variables did not affect survival. On multivariate analysis after variable selection, survival was independently associated with KPS(p=0.001), but not the surgical resection(p=0.2837). Even in biopsy group with midline shift of the tumor, survival rate was not different from that seen after tumor resection(p=0.3505). Conclusions : Radiotherapy alone was as effective as tumor resection plus radiotherapy in patients without midline shift of the tumor. Although there was not statistically significant, tumor resection looked like effective in patients with midline shift. For supratentorial, lobar glioblastoma patients without mass effect of the tumor, biopsy with radiotherapy is one of rational treatment strategies. We consider that tumor resection should be performed in patients with pretreatment midline shift.

Objective : The goal of this study was to identify variables that were predictive of recurrence in primary intracranial ependymomas. Methods : We analyzed variables affecting recurrence in 30 patients with primary intracranial ependymomas. Age, location, CSF cytology, seeding on neuroimaging study, tumor grade, extent of surgery, use of chemotherapy, chemotherapy regimen, use of radiotherapy, and radiotherapy field were entered to test their impacts on recurrence. Results : Follow-up ranged from 2 to 110 months. Tumors were recurred at the primary tumor site only in 13 patients (43.3%). The overall average recurrence free period was 55 months, with overall recurrence free rates at 3 and 6 years of 61.0% and 20.9%, respectively. Extent of surgery was the strongest variable affecting recurrence. The median recurrence free period and 3-year recurrence free rate were 72 months and 78.4% for patients having complete excision and 33 months and 0% for those having incomplete excision(p=0.05). Other prognostic variables like age, location, tumor grade, use of chemotherapy, and use of radiotherapy did not affect recurrence(p=0.2848, 0.7899, 0.1714, 0.2157, 0.7076, respectively). Conclusions : Intracranial ependymomas have a propensity to recur after treatment, and recurrence at the primary site is still the main obstacle to cure. Among various variables, only extent of resection had the strongest impact on recurrence. Additional studies may still be needed to precisely define the prognostic variables on recurrence in intracranial ependymomas.

Objective : Controversy exists which surgical treatment better in lumbar grade I spondylolisthesis, decompressive laminectomy with or without lumbar instrumentation. Methods : Out of Sixty-four patients with lumbar spondylolisthesis underwent surgery, 18 patients operated with decompressive laminectomy alone and 44 patients with decompession and lumbar instrument, during recent 5-years between January, 1994 and December, 1998. The author studied a long term follow-up in the above two groups to analyzing the overall clinical outcomes in each group and to determining the incidence of pos-toperative radiologic instability. Results : 1) Overall postoperative symptoms improvement were not so different in both groups. 2) Postoperative progressive subluxation is more common after decompressive laminectomy without instrumentation than with instrumentation group. 3) Overall clinical outcomes were slightly better in decompressive laminectomy without instrumentation than with instrumentation group but there was no significant difference. 4) Postoperative radiologic changes did not seem to influence the patient-reported clinical outcomes. 5) Postoperative complications is more common in decompressive laminectomy with instrumentation group than without instrumentation group. Conclusion : In the surgical management of grade I spondylolisthesis, the efficiency and superiority of surgical treatments requires the cost effectiveness and risk/benefit analysis of decompressive laminectomy with or without instrumentation. Therefore, Further detailed studies of long term follow up in a large number of patients in each group are needed for choice of best treatment.

Objective : The short hospitalization or outpatient care for patients undergoing laminectomy is not popular practice in Korea. We evaluated the clinical and economical significance of short hospitalization for patients undergoing microdiscectomy for their lumbar disc herniation. Material and Methods : From March 1999 to December 2000, patients were hospitalized for intended short period hospitalization for lumbar disc surgery. Their radiological and clinical data were analyzed for their clinical and economical results. We compared these data with 20 patients who hospitalized conventionally. Results : Total of 64 patients were evaluated. Three were lost to follow-up. Mean postoperative hospitalization period is 2.0 days(excluding one patient). Excellent to good outcome was achieved in 90.6 % of the patients. They payed about half expenses for hospitalization compared with conventional group. Their mean number of outpatient visit was 3.0. Conclusion : Short hospitalization for lumbar disc surgery is an acceptable option in Korea. It is also economically beneficial while achieving acceptable clinical results.

Objective : In general, to perform posterior lumbar interbody fusion(PLIF), it has been used more invasive procedure than simple discectomy. However we try to perform PLIF with TFC with smaller invasion almost same as in simple discectomy. This study is about its procedure and clinical results. Materials and Methods : The authors retrospectively analyzed 43 cases of minimally invasive PLIF with TFC from July 1998 to May 2000. Operative procedure, operative complication, change of disc height, blood loss, ambulation time, hospitalization period, clinical success rate, and bony fusion rate were analyzed. Results : 40 patients were capable to walk on the 2nd day of the post-operation. The average hospitalization period is 5.6 days. The average blood loss was 0.19L/level with no transfusion or wound drainage. The height of disc changed from 8.84mm to 13.54mm. Clinical success rate is 95% when evaluated by the Prolo's scale. The complication was delayed wound infection(2) and transient paresthesis(1). The bony fusion was shown in 17 patients (94.4%) out of 18 patients who passed one year. Conclusion : As a result of minimally invasive PLIF, pain was decreased and early ambulation and short hospitalization was possible. Complication was similar or lower than other studies, and the bony fusion rate and clinical success rate were also similar during follow-up.

Objective : The terminology of degenerative disc disease lacks official standardization. Lacks of such standardization may provoke some clinical and litigation problems. The authors investigated interobserver and intraobserver variability in interpretation of lumbar disc abnormality. Methods : Magnetic resonance imaging studies of the lumbar spine performed prospectively in 50 patients, were read blindly by three doctors dealing spinal disorders, using two nomenclature. Nomenclature I was normal, bulging, protrusion, extrusion. Nomenclature II was normal, bulging, herniation without neural compression, with neural compression. Intraobserver and interobserver variation were measured statistically. Results : Interobserver agreement was 70.4-80.8% for nomenclature I, 76.2-80.2% for nomenclature II. Intraobserver agreement was 84.0-88.0% for nomenclature I, 79.2-86.8% for nomenclature II. Interobserver Kappa statistic was 0.53-0.56 for nomenclature I, 0.54-0.57 for nomenclature II. Intraobserver Kappa statistic was 0.60-0.85 for nomenclature I, 0.53-0.72 for nomenclature II. Conclusion : Experienced doctors showed only moderate interobserver agreement when interpreting disc status on lumbar magnetic resonance imaging. Intraobserver agreement was superior to interbserver. The standardization of nomenclatures for lumbar disc extension beyond interspace are needed.

Objectives : Spontaneous intracerebral hemorrhage(S-ICH) is generally considered to be a mon-ophasic event. But some patients with ICH continued to bleed even after hospitalization. In order to evaluate the rebleeding and growth factor of hematoma in small volume S-ICH, 125 cases of S-ICH were reviewed retrospectively. Methods : We assesed age, sex, initial mental state, location of hemorrhage, systolic and diastolic blood pressure, blood pressure patterns, hematologic profile, trauma and stroke history, alcohol consumption and smoking history. Two subgroups-rebleeding groups versus no rebleeding groups-were compared, in terms of data analysis, with student T-test and chi-square test. Results : Substantial growth in the volume of S-ICH occurred in 21 cases(16.8%)-putamen(7 cases), thalamus(6 cases), subcortex(5 cases), cerebellum(2 cases), pons(1 case)-of the 125 patients. There was no significant difference in any of the parameters except initial systolic blood pressure(p=0.037) when patients with and without rebleeding were compared. Conclusion : The rebleeding and growth of the small volume S-ICH was related to the markedly elevated initial systolic blood pressure(${\geq}180mmHg$) and labile pattern of blood pressure.

Objectives : Chemotherapy remains part of the treatment triad that includes surgery and radiotherapy for the management of glioblastomas, but disappointing results of chemotherapy have raised the suggestion that chemotherapy should perhaps be abandoned. In order to determine the chemotherapy effect given in addition to radiotherapy, we performed a randomized clinical study of irradiation alone and combination of irradiation with chemotherapy in the treatment of glioblastomas. Methods : From 1991 to 1999, 204 consecutive patients suffering from supratentorial glioblastomas were treated in our hospital. We compared the survival rates/times of these patients according to the treatment modalities[group I-67 patients treated by surgery with radiotherapy and adjuvant chemotherapy(ACNU, paclitaxel, tamoxifen, and others) ; group II-106 by surgery with radiotherapy ; and group III-31 by surgery only]. Results : The overall median survival time was 12 months, with overall survival rates at 1 and 2 year of 46.7% and 16.6%, respectively. On univariate analysis, median survival and 1- and 2-year survival rates were statistically improved by the use of chemotherapy ; group I-15 months, 75.7%, and 25.9%, group II-11 months, 39.3%, and 15.4%, and group III-3 months, 9.7%, and 6.5%, respectively(p=0.0001). But, on multivariate analysis considering compounding variables, survival was independently associated only with radiotherapy(p=0.0112). Conclusion : These results suggest that the addition of chemotherapy to radiotherapy does not affect the overall survival in glioblastomas. Mainly long-survivor glioblastoma patients might benefit by adjuvant chemotherapy, which probably means patients with initial favorable prognostic factors(young age, minimal residual tumors, good performance status). It is necessary to continue to search for an effective chemotherapy regimen to prolong survival of patients with glioblastomas.

Objectives : The purpose of this study is to assess the long-term outcome and delayed complications of Gamma Knife radiosurgery for low grade glioma(LGG). Methods : Among 31 patients of LGG who had been treated by using Leksell Gamma Knife between March 1992 and December 1996, we could follow up more than 5 years(range 5-9 years) in 17 patients and evaluated their clinical feature, changes of tumor volume and post-radiosurgical complications. Results : During the mean follow-up period of 7.6 years, the tumor was decreased in 5 patients(29.4%), unchanged in 4(23.5%), increased in 4(23.5%) and recurred in 4(23.5%). The tumor control rate was 52.9%(9/17). We have experienced eighteen postradiosurgical complications in 10 patients(58.8%). Early complication was none and delayed complications included radiation necrosis with cyst in ten cases, bleeding in five, radiation-induced edema in one and malignant transformation in one. Two patients ultimately died as a result of tumor progression during the follow-up period. The mortality rate was 11.7%. Conclusion : Gamma Knife radiosurgery may be useful as an adjunctive therapy for small volume, deep-seated LGG. Although radiosurgery can effectively prevent growth of solid tumor, several delayed complications such as radiation necrosis, cyst formation, bleeding or malignant transformation can develop during the long-term followup period. Because of the possible slow growth rate of LGG and development of the delayed complications, the long-term efficacy of radiosurgery requires further analysis.

Objectives : The purpose of this study is to evaluate the usefulness of SSEP monitoring during intracranial aneurysm surgery and compare the characteristics of wave change in relation to neurologic changes between ACA aneurysms and MCA aneurysms. Methods : During recent three years(between January 1997 and November 1999), intraoperative SSEP monitoring had been done in 63 operations for intracranial aneurysms. We had monitored the median nerve SSEP during surgery for aneurysms of MCA and the posterior tibial nerve SSEP for aneurysms of ACoA or ACA. A more than 50% reduction of any cortical SEP response was considered to be a significant SEP change, compared to its baseline value before the start of surgery. Changes in the SEPs were categorized as follows : Type IA, no significant amplitude changes without temporary clipping ; Type IB, no significant amplitude changes with temporary clipping ; Type II, significant changes with temporary clipping and complete return to control amplitude ; Type III, significant changes with temporary clipping and incomplete return to control amplitude ; Type IV, significant changes with temporary clipping and more decreased amplitude changes. Results : Among the 63 intraoperative monitoring, there were 37 cases of ACA aneurysms(An), and 26 of MCA An. The temporary proximal arterial occlusion during surgery were performed in 31(83.8%)cases of ACA An, 22(84.6%) of MCA An. Seven of the 31 ACA An(22.6%) and ten of the 22 MCA An(45.5%) had significant changes. The type were as follows : 4 patients with type II and 3 with type III in the ACA An ; 3 patients with type II and 3 with type III and 4 with type IV in the MCA An. In both group type II changes had no new postoperative neurological deficit. All 6 patients with type III had new neurological deficits ; However, One case in the ACA An and two cases in the MCA An. had transient neurologic deficit and improved markedly over the next two months. All 4 type IV changes in the MCA An. had permanant neurologic deficits. Two out of 30 cases(6.7%) in the ACA An. and one out of 16 cases(6.3%) in the MCA An. without significant amplitude change had new neurologic deficit postoperatively. Conclusion : Based on this study, Intraoperative SSEP monitoring during aneurysm surgery would provide useful information for detecting cerebral ischemia. SSEP response during surgery for MCA An. is more sensitive than ACA An. Otherwise, there were no meaningful difference in rate of false negativity.

Objectives : The optimal treatment of craniopharyngioma is controversial. Despite recent advances in microsurgical management, complete surgical removal of craniopharyngioma remains very difficult. Radiation added to surgery is effective, but radiation therapy resulted in untoward side effect in young patient. Gamma knife radiosurgery offers the theoretical advantage of a reduced radiation dose to surrounding structures during the treatment of residual or recurrent craniopharyngioma compared with fractionated radiotheraphy. We described retrospective analysis of tumor size and clinical symptoms of patients after gamma knife radiosurgery in residual or recurrent craniopharyngioma were performed. Material and Methods : From September 1990 to January 2000, 18 patients of craniopharyngioma were treated by gamma knife radiosurgery. All patient had undergone surgery, but residual or recurrent tumor was found and all of them treated postoperative gamma knife radiosurgery. The mean age was 19(from 6 to 66) and male to female ratio was 10 to 8 and 8 patients were below 15 years old. In young age group(below age 15), the average volume of the tumor was $2904.8mm^3$ and mean maximal gamma knife dose was 34.9Gy. In old age group(older than 15), the average volume of the tumor was $2590.4mm^3$ and mean maximal gamma knife dose was 45.2Gy. The size of the tumor was average $2730.1mm^3$($88-12000mm^3$), mean average radiation dose was 40.7Gy and the mean prescription dose was 17.6 Gy(4-35Gy) delivered to a median prescription 50.7% isodose. Results : The follow up was from 1 year to 9 years(mean 59.1 months) after gamma knife radiosurgery. The tumor was controlled in 13(72.2%) patients. The tumor decreased in 9 patients and not changed in 4 patients. The tumor size increased in 4(22.2%) patients during follow up period. In two cases the tumor size increased because of its cystic portion was increased, but their solid portion of the tumor was not changed. In another two patients, the solid portion of the tumor was increased. So, one patient underwent reoperation and the other patient underwent operation and repeated gamma knife radiosurgery. The tumor recurred in one case(5.6%) that is a outside of irradiated site. The presenting symptoms were improved in 4 patients(improved visual acuity in 1, controlled increased intracranial presure sign in 3 patients). In one case, visual acuity decreased after gamma knife radiosurgery. The endocrine symptoms were not influenced by gamma knife radiosurgery. Conclusion : Craniopharyngioma can be treated successfully by gamma knife radiosurgery. Causes of the tumor regrowth are inadequate dose planning because of postoperatively poor margination of the tumor, close approximation of optic nerve and residual tumors outside the target lesion. Recurrence can develop 4 years after gamma knife radiosurgery. Volume is important, but the accurate targeting is more important to prevent tumor recurrence. If the tumor definition is not clear during planning gamma knife surgery, long-term image follow up is required.

Objectives : CT-guided stereotactic evacuation for spontaneous intracerebral hemorrhage can minimize the brain damage and can be performed safely and simply under local anesthesia. But that procedure is time consuming and has a risk of rebleeding because of the stress during head pin fixation. So authors describe easy and precise guidelines for FHA of putaminal hemorrhage without stereotactic instrument. Methods and Materials : We analyzed the data of 298 patients who underwent CT-guided stereotactic aspiration of putaminal hematoma in our hospital between January 1990 and December 2000. We divided the patients into three groups according to the location of hematoma : anterior portion, middle portion and posterior portion of putamen. Total number of catheters inserted into the hematoma were 345 and there were with regard to the direction and depth of catheters. Results : Proposed guidelines of catheter insertion to putaminal hemorrhage in our institution. 1) hematoma at the anterior portion of putamen ; Direction of catheter was the midpupillary line of the eye and the point intersecting a line drawn from the burr hole to a point between external auditory meatus(EOM) and 1cm posterior to EOM. Depth of catheter was 6-6.5cm. 2) hematoma at the middle portion of putamen ; Direction of catheter was the midpupillary line of the the eye and the point intersecting a line drawn from the burr hole to a point between 1cm and 2cm posterior to EOM. Depth of catheter was 6.5-7cm. 3) hematoma at the posterior portion of putamen ; Direction of catheter was 15 degree laterally from the midpupillary line of the eye and the point intersecting a line drawn from the burr hole to a point between 2cm and 3cm posterior to EOM. Depth of catheter was 7-7.5cm. We have performed FHA of putaminal hemorrhage in 48 cases according to this guideline. All catheter were inserted exactly at the center of hematoma and average operation time was about 30 minutes. Conclusion : Our proposed guidelines for putaminal hemorrhage are considered to be safe and simple method with similar accuracy and rapid decompression compared with traditional stereotactic method. Main advantages of this technique were unnecessity of stereotactic frame application and less time requirement for hematoma removal.

Objectives : Anterior cervical discectomy and interbody fusion has become a well-accepted surgical treatment of degenerative cervical diseases. Implatable cages have a stabilizing effect without plates and no need for autogenous bone graft. The authors evaluates the effect of implatable titanium cage(RABEA) on the clinical and radiological outcomes. Methods : 34 patients with symptomatic cervical degenerative diseases due to one level disc pathology were underwent anterior cervical discectomy and interbody fusion with titanium cages(RABEA) which were not filled with cancallous bone grafts from January 1999 to May 2001. Patients with osteoporosis and older than 65 years were not included. Among them, 15 patients could be followed-up for at least 1 year. The authors retrospectively reviewed the charts and radiographic data. Mean follow-up period was $1.3{\pm}0.2years$. Results : Clinical results according to the Odom's criteria was exellent and good in 14(93%) patients. One patient with fair result showed complete loss of the disc space height due to settlement of the cage. Preoperatively, the mean height of the disc space(${\pm}$standard deviation) was $3.42{\pm}1.10mm$(range 2.0-5.5mm), and at 1 day postoperatively it was $7.88{\pm}0.90mm$(range 6.50-9.0). The mean height of the disc space after 1 year was $6.50{\pm}1.38mm$(range 3.0-8.0). The restoration of the height was statistically significant(p<0.05). The mean height after 1 year was $82.7{\pm}15.9%$ of the height at 1 day postoperatively. Preoperatively the mean value of the cervical lodortic angle was $21.8{\pm}11.8^{\circ}$ and 1 year postopertively, it was $24.5{\pm}8.3^{\circ}$, which was statistically not significant. All patients showed no abnormal movements on flexion and extension lateral film after 6 months. Conclusion : Implantable titanium cages appear safe and effective in selected patients, and their use helps to avoid complications associated with bone graft harvest. Subsidence of the cage seems to be a potential risk factor for recurrence of the symptoms. For long-term results, a longer follow-up is required.

틈새뇌실증후군은 수두증으로 션트술을 시행받은 환아에서 CT나 MRI소견상 틈새처럼 좁은 뇌실을 가지고 있으면서 간헐적으로 두통, 구토 또는 의식장애등이 동반되는 질환이다. 1986년부터 1996년까지 총 821명의 환자가 수두증으로 션트술을 시행받았다. 이 환자들의 수두증의 원인은 뇌종양(140명), 출혈(62명), 정상압수두증(64명), 뇌수막염(58명), 외상(54명), 선천성(48명), 뇌낭미충증(31명), 그리고 이유를 알 수 없었던 경우가 364명으로 나타났다. 평균 추적 관찰 기간은 68개월이었으며 총 232명에서 재수술을 시행하였으며 1인당 1.28회의 재수술율을 보였다. 이들중 틈새뇌실 증후군은 6예로 0.7%였다. 틈새뇌실증후군 대부분의 환자는 영아기에 수술을 시행받았다. 처음 수술로부터 틈새뇌실증후군이 발생하기까지의 기간은 4~8년으로 평균 6년후 틈새뇌실증후군이 발생하였다. 동위원소 검사상 6예에서 션트의 기능은 모두 정상이었다. 증상이 경미한 2명의 환자에서는 보존적 치료를 시행하였는데 치료후 증상의 호전을 보였다. 이 환자들은 뇌압측정을 시행하지 않았다. 6명중 1명은 뇌압 측정시 높게 나타나 기존과 같은 압력밸브를 이용하여 재수술을 시행하였다. 3명의 환자는 낮은 뇌압을 보여 안티사이펀밸브나 기존보다 높은 압력의 밸브를 이용하여 재수술을 시행하였다. 틈새뇌실증후군의 치료는 첫째, 증후군의 양상을 정확하게 판단하여, 둘째, 증상을 완화시킬 수 있는 방향으로 치료방침을 설정해야 할 것으로 생각되었다.

Objectives : The goal of this study is to evaluate the usefulness of mild hypothermia treatment in patients with increased intracranial pressure(ICP). Material and Method : From November 1999 to May 2001, 11 patients were treated with mild hypothermia ($32-34^{\circ}C$) in whom ICP maintained at higher than 20mmHg in spite of decompressive surgery and high dose barbiturate therapy. The patient's rectal temperature were lowered by external cooling. Hypothermia was maintained for not more than 7 days and then the patients were rewarmed slowly for 24 hours. If increased ICP persisted for 2 days of hypothermia, this treatment was continued for several days. The functional outcome of each patient was assessed according to Glasgow Outcome Scale(GOS). Results : All cases except two cases showed decrease of ICP after hypothermia therapy. In 1 case which was right middle cerebral artery(MCA) infarct, ICP re-increased after 24 hours and in another 1 case, ICP was not controlled initially. Among 11 cases, 3 cases showed favorable outcome. Conclusion : Mild hypothermia treatment in patients with increased ICP was effective in controlling ICP and mortality was so decreased. More clinical experience and controlled study was need to determine the effectiveness.

Objectives : There are many kinds of method to evaluate neural decompression during operation. They are direct visual and manual inspection, intraoperative ultrasound, endoscope, intraoperative computed tomography and intraoperative myelography. We used intraoperative myelography to evaluate the proper decompression of neural elements during the decompressive surgery. Methods : We injected 10-20cc of nonionic water-soluble contrast materials through direct puncture site of exposed dura during operation or lower lumbar level or lumbar drain inserted preoperatively. 12 patients were included in this study. They were 7 patients of centrally herniated lumbar disc disease, 1 patient of multiple lumbar spinal stenosis, 2 patients of thoracic extradural tumor and 2 cervical fracture & dislocations. Results : 5 of 12 patients showed remained neural compression through intraoperative myelography, so they were operated further through other approach. Myelographic dye is heavier than CSF, so the dependent side of subarachnoid space was visualized only. In one case, CSF leakage through hemovac was detected, but it was treated only bed rest for 5 days after hemovac removal. Conclusion :Intraoperative myelography is an effective method to evaluate neural decompression during spinal surgery. This technique is easy and familiar to us, neurosurgeons.

Trigeminal schwannoma is an uncommon intracranial tumor and constitutes less than 0.08-8% of all intracranial schwannoma. Trigeminal shchwannoma is even rarer in childhood and only 11 cases of trigeminal schwannoma under the age of 14 have been reported including our case. We experienced a case of trigeminal schwannoma in a 9 year-old girl without the stigmata of neurofibromatosis. She presented with a 2 week-history of right abducens nerve palsy. Magnetic resonance image demonstrated a dumbbell-shaped tumor extending into right middle and posterior fossas with a size of $60{\times}45{\times}35mm$. The tumor was successfully removed by right transzygomatic subtemporal extradural approach. Pathologic examination of the mass revealed typical features of schwannoma.

This 18-year-old male patient had a massive epistaxis after motorcycle traffic accident on 1st day of admission. There were no other significant brain parenchymal lesion on initial brain CT exam, except multiple pneumocephalus and basal skull fracture lines. We treated epistaxis conservatively till vital signs were corrected, and then conventional cerebral angiogram was followed. On angiogram, there was traumatic pseudoaneurysm on C5 portion(by Fischer) of ICA, so we treated it only by endovascular stenting. For the purpose of sparing parent arterial patency, endovascular stenting on pseudoaneurysm may play a role with safety and good results.

The development of completely new intracranial aneurysms after previous successfully treated aneurysm is uncommon. A 50-year-old female presented with a case of multiple de novo aneurysm which were an aneurysm of right ophthalmic segment of internal carotid artery and an aneurysm of right A1 artery, 6 years after the clipping of an aneurysm of right posterior communicating artery. She had no history of hypertension, cigarette smoking and use of oral contraceptives, and had no evidence of genetic disorder. The laboratory findings were normal. All de novo aneurysms were clipped by basal anterior interhemispheric approach in one stage due to the direction of the aneurysm of the ophthalmic segment of the internal carotid artery.

Arachnoid cysts are defined as duplicated arachnoids and their splitting with congenital, intra-arachnoid, and leptomeningeal malformations. They are most commonly located in the middle cranial fossa followed by suprasellar and quadrigeminal cisterns, posterior fossa, and very rare in cerebral convexities. They are often ruptured by trauma or spontaneously and cause subdural hygroma or subdural hematoma. Authors report a case of a 32-year-old woman with a convexity arachnoid cyst mimicking subdural hygroma associated with a separate middle fossa arachnoid cyst. Preoperatively, the convexity arachnoid cyst was misinterpreted as subdural hygroma resulted from a ruptured middle fossa cyst. The patient underwent craniotomy and cyst fenestration into the basal cistern. Two separate arachnoid cysts were found in the cerebral convexity and middle cranial fossa during the operation. Finally, cysts were resolved and she was discharged without any complication.

Intramedullary spinal tuberculoma is a rare form of central nervous system tuberculosis. The authors presented a case of 41 years old male with intramedullary and intradural extramedullary tuberculoma of the thoracic spinal cord without systemic involvement. The preoperative diagnosis was a metastatic cancer. Subtotal removal of intradural extramedullary and intramedullary mass was performed and pathological diagnosis was tuberculosis granuloma. We suggest that Intramedullary spinal tuberculoma must be considered in the differential diagnosis of the spinal cord compressive lesions in our country.

Hemangioblastoma is a benign tumor of vascular origin that develops usually in the posterior cranial fossa. We report a case of supratentorial leptomeningeal hemangioblastoma occurring in a 45-year-old man who received total removal of recurrent cerebellar hemangioblastoma four years ago. He was admitted for the evaluation of severe headache and magnetic resonance image showed a well-enhanced, extra-axial mass in the right parietal region. A presumptive diagnosis was meningioma. It was completely removed with the attached dura. Histological examination including immunohistochemical study showed typical findings of hemangioblastoma. It is emphasized that close observation may be necessary for hemangioblastoma, even after total removal.

The authors report two cases of familial hemifacial spasm according to the clinical and three dimensional shortrange magnetic resonance angiography(3D-SRMRA) findings. In the family of the first case, there were five patient's with acquired hemifacial spasm in successive generations. Three male and two female patients in successive generations of the same family developed acquired hemifacial spasm. Four patients were on the left side and one was on the right side. In the family of the second case, there were three patient's with acquired hemifacial spasm in successive generations. Two brothers developed left-sided hemifacial spasm. 3D-SRMRA finding of the probands demonstrated that both anterior inferior cerebellar artery in first case and anterior inferior cerebellar artery & vertebral artery in second case offend the 7th cranial nerve respectively. The presence of familial clustering of these rare disorders suggest an underlying genetic predisposition. All family pedigrees suggest that a pattern of autosomal-dominant inheritance with partial penetrance.

Malignant peripheral nerve sheath tumor(MPNST, primary malignant schwannoma) within the spinal canal is very rare. The prognosis of MPNST in the spinal canal is very poor due to the tendency of perineural spread, dissemination throughout subarachnoid space and local recurrance. This report details the authors' experience on the case of primary malignant spinal schwannoma with review of the literatures and other studies.

Intradural extramedullary hemangioblastoma of the spinal cord is uncommon tumor. Symptom onset is typically in the forth decade. Complete excision offers the best chance for cure. We report a case of extramedullary hemangioblastoma of the spinal cord in old age. A 76 -year old man presented with 1 month history of paraparesis. Multiple enhancing lower thoracic and lumbar spinal masses were seen on magnetic resonance imaging(MRI). Surgical exploration for symptomatic lesion revealed intradural-extramedullary mass, which had hypervascularity. The excised spinal masses were diagnosed as hemangioblastoma. Postoperative course was uneventful and symptoms improved gradually.

A 4-month-old female patient admitted because of hydrocephalus. She was premature infant with germinal matrix hemorrhage at gestational period 27 wks. A ventriculoperitoneal shunt with a low-pressure type valve was placed. Follow-up CT scan obtained 3 months after VP shunt placement, revealed a new Lt. middle cranial fossa cyst. The girl was readmitted to hospital at 7 months after VP shunt placement, complaining of lethargy and vomiting. A CT scan was demonstrated a increase in size of a cyst, She subsequently underwent a left-sided pterional craniotomy with partial excision of membrane and cyst fenestration into the basal cisterns. Follow-up CT scan after 18 months revealed reaccumulation of cyst, the girl was reoperated on. After 2 months, the size of cyst was not decreased. Finally, She underwent a cystoperitoneal shunt. Follow-up CT scan after 5 months was demonstrated disappeared cyst and reexpansion of brain parenchyma. We report the development of a symptomatic sylvian fissure arachnoid cyst developed after ventriculoperitoneal shunt.

Arteriovenous malformations of the face and scalp are uncommon. We report a patient with facial AVM feeding from external carotid artery. This 26-year old man presented with an arteriovenous malformation involving left forehead. The patient first noted a coin-sized lesion on the site 20 years previously after blunt trauma which progressively enlarged. Surgical resection of AVM was performed after ligation of feeding artery.