Effects of Sense and Antisense Expression of Protein Kinase Calpha on the Proliferation and Radiosensitization of U-87 Human Glioblastoma Cells

OBJECTIVE: It has been suggested that protein kinase C(PKC) may be one of a number of important regulatory enzymes influencing the tumor cell proliferation and intracellular sensitivity to irradiation. In this study, authors investigate the role of PKC in the growth and radiosensitization of glial brain tumors. METHODS: Human glioblastoma cell line U-87 was stably transfected with sense and antisense complementary deoxyribonucleic acid(cDNA) encoding PKCalpha. The effect of sense and antisense PKCalpha cDNA transfection on PKCalpha expression, PKC activity, cell proliferation, and radiosensitivity of tumor cells was determined. RESULTS: There was no significant difference in cell proliferation between control cells and cDNA(sense and antisense) transfected cells on thiazolyl blue(microculture tetrazolium, MTT) assay. PKC activity was increased by 68% in cells transfected with the sense PKCalpha cDNA(U-87/sPKCalpha), and was reduced by 32% in cells transfected with the antisense PKCalpha cDNA(U-87/aPKCalpha) compared to control cells(p<0.05). Western blotting with a polyclonal antibody against PKCalpha and scanning densitometric analysis of autoradiograms revealed that PKCalpha expression was enhanced by about 5 times of that of control cells in U-87/sPKCalpha cells and was suppressed by more than 30% of that of control cells in U-87/aPKCalpha cells. After exposure to 6 Gy irradiation, cell viability on MTT assay was increased by 43.7% in U-87/sPKCalpha cells and was reduced by 24.3% in U-87/aPKCalpha cells compared to control cells(p<0.001). CONCLUSION: The results of this study demonstrate that PKCalpha overexpression confers a relative radior-esistance and PKCalpha suppression enhances a radiosensitivity on U-87 cells. These observations suggest that PKCalpha plays an important role in regulating cell response to irradiation and a specific modulation of PKCalpha expression in malignant gliomas may influence the radiosensitivity of them.

The Effect of Ethanol and Microwave Treated into the Feline Brain on Brain MRI

OBJECTIVE: The purpose of this study is to ascertain whether magnetic resonance(MR) images taken after ethanol injection or microwave irradiation into feline brain can verify changes within the brain and offer valuable information about the spatial extent of the induced lesion. METHODS: In the ethanol injection experiment, nine male cats were divided into three groups including group I(n =3) treated with 0.1cc ethanol injection, group II(n=3) 0.2cc ethanol, and group III(n=3) 0.3cc ethanol into the feline brains. In the microwave irradiation experiment, twelve male cats were divided into four groups including group I(n=3) irradiated with 30 watt electrical power with 10 sec duration, group II(n=3) same power with 30 sec duration, group III(n=3) irradiated with 60 watt power with 10 sec duration, and group IV irradiated with 60 watt power with 30 sec duration. MR images were obtained in both ethanol injection and microwave irradiation experiments. Pathologic examinations were done after completion of MR imagings. RESULTS: Contrast-enhanced T1-weighted MR images showing nodular or rim enhancement were most reliable in delineating the extent of the necrosis induced by ethanol injection and microwave irradiation. The contrast enhancement corresponded with gliosis in normal brain surrounding the necrotic area and hypervascularity in ongoing necrotic area and adjacent normal brain. There were various enhancement patterns after ethanol injection with reflux of ethanol. In case of microwave irradiation, round or oval enhancements were shown with clear margin. The size of the enhancement was well correlated with the amount of injected ethanol and the amount of electrical power. Application time was not correlated with the size of enhancement in high electrical power group. The feature of the edema after ethanol injection was unpredictable and predictable in case of microwave irradiation. CONCLUSION: It is easy to predict the result in case of microwave irradiation, and the achieved results can be used as basic information in performing these procedures.

Syringostomy Using Myringostomy Tube in Syringomyelia Associated Type I Chiari Malformation

We describe a case of syringomyelia associated with type I Chiari malformation treated with syringostomy using myringostomy tube. The syrinx was found at C2 to C5 level, and the patient presented with quadriparesis and both shoulder pain. We performed extensive suboccipital craniectomy, C1 laminectomy, duroplasty, and then syringostomy using myringostomy tube. Postoperatively, the clinical and neurological improvement was noted and MRI showed reduced size of syrinx.

Surgical Approaches to the Middle Cranial Base Tumors

OBJECTIVE: We analysed various surgical approaches and surgical results of 28 middle cranial base tumors for the purpose of selecting optimal surgical approach to the middle cranial base tumor. METHODS: In this retrospective review, 28 patients, including 16 meningioma, 6 trigeminal neurinoma, 2 pituitary adenoma, 2 craniopharyngioma, 1 facial neurinoma, and 1 metastatic tumor, underwent surgical treatment using skull base technique. Of theses, 16 tumors were mainly confined to middle cranial fossae, 5 tumors with extension into both anterior and middle fossa, and 7 tumors with extension into both middle and posterior fossa. Tumors that confined to the middle cranial fossa or extended into the anterior cranial fossa were operated with modified pterional, orbitozygomatic or Dolen'c approach, and tumors that extended into the posterior cranial fossa were operated with anterior, posterior or combined transpetrosal approach. Completeness of tumor resection, surgical outcome, postoperative complication, and follow up result were studied. RESULTS: Total tumor removal was achieved in 9 tumors of 10 tumors that did not extended to the cavernous sinus, and was achieved in 7 tumors of 8 tumors that extended to the lateral wall of the cavernous sinus. Of 10 tumors that extended to the venous channel of the cavernous sinus, only 2 were removed totally. Surgical outcome was excellent in 14 patients, good in 10, fair in 2 and poor in 2. There were no death in this series. Dumbell type tumor which extended into both middle and posterior fossae showed tendency of poor prognosis as compared with tumors that confined middle cranial fossa and extended into both anterior and middle cranial fossa. Postoperative dysfunctions were trieminal hypesthesia in 3, oculomotor nerve palsy in 2, abducens nerve palsy in 2, hemiparesis in 2, cerebellar sign in 1, facial palsy in 1 and hearing impairment in 1. CONCLUSION: Based on our findings and a review of the literature, we conclude that, when selecting the surgical approach to the middle cranial fossa tumors, the most important factors to be considered were exact location of the tumor mass and existence of the cavernous sinus invasion by tumor mass. We recommend modified pterional or orbitozygomatic approach in cases with tumors located anterior and middle cranial base, without cavernous sinus invasion. In cases with tumors invading into cavernous sinus, we recommend Dolen'c or orbitozygomatic approach. And in lateral wall mass and the cavernous sinus, it is preferred to approach the tumor extradurally. For the tumor involing with middle fossa and posterior fossa(dumbell type) a combined petrosal approach is necessary. In cases with cavernous sinus invasion and internal carotid artery encasement, we recommend subtotal resection of the tumor and radiation therapy to prevent permanent postoperative sequele.

Efficacy of Unilateral Pallidotomy for Parkinson's Diesease

OBJECTIVES: For Parkinsonian patients who had not reacted favorably on drug therapy are good candidate for ventroposterolateral pallidotomy, although not curative. We studied these patients after unilateral pallidotomy, to confirm the effectiveness and safety of this procedure. METHODS: We evaluated the 17 patients with idiopathic Parkinson's diesease who had undergone unilateral posteroventral pallidotomy. All patients responded to levodopa initially. Mean age was 55 years(38-75years), and mean duration of disease was 9.8 years(3-20years). Pre-and postoperative evaluation at 3 month intervals included Unified Parkinson's Disease Rating scale(UPDRS) scoring, Hoehn and Yahr(H and Y) staging, and neuropsychological examinations. RESULTS: Pallidotomy significantly improved parkinsonian symptom(tremor, rigidity, bradykinesia, dyskinesia, sensory symptom). Nine of 10 patients who showed dyskinesia preoperatively significant improvement. The mean dose of levodopa in 9 patients was lowered. The mean H and Y score and UPDRS score were improved in on and/or off time in 15 patients. Among patients who were not improved, one patient worsened, and the others showed no change. The mean overall UPDRS off score changed from 76 preoperatively to 44(33%) at 6 months and from 70 to 52(25%) at 1 year. Transient surgical morbidity was showen in four patients and included dysarthria, hypotonia and confusion. CONCLUSION: We conclude that pallidotomy is safe and effective in patients who have levodopa-reponsive parkinsonism with severe symptom fluctuation. Unilateral pallidotomy also considered helpful to ipsilateral symptom. Unilateral pallidotomy can improve all of parkinsonian's symptom and allow to reduce the levodopa medication. Most of patients show satisfactory results.

in vitro and in vivo Photodynamic Activity Study of U-87 Human Glioma Cell with Photofrin

OBJECTIVE: The objective of this study was to determine the photodynamic therapeutic response of U-87 human glioma cell in vitro as well as in the nude rat xenograft model using photofrin as photosensitizer. MATERIAL AND METHOD: U-87 cells were cultured on 96-well culture plates, photofrin(Quadralogic Technologies Inc., Vancouver, Canada) was added into the cell culture medium at concentration of 1ng/ml, 2.5ng/ml, 5ng/ml, 10ng/ml and 20ng/ml. 24 hour after drug treatment, cells were treated with optical(632nm) irradiation of 100mJ/cm2, 200mJ/cm2 and 400mJ/cm2. Photofrin(12.5mg/kg, i.p.) was administered to 28 nude rats containing intracerebral U-87 human glioma as well as 26 normal nude rats. 48 hours after administration, animals were treated with optical irradiation(632nm) of 35J/cm2, 140J/cm2 and 280J/cm2 to exposed tumor and normal brain. The photofrin concen-tration was measured in tumor and normal brain in a separate population of animals. RESULTS: By MTT assay, there was 100% cytotoxicity at any dose of photofrin with optical irradiation of 200mJ/cm2 and 400mJ/cm2. But at the optical irradiation of 100mJ/cm2 cells were killed in dose dependent manner 28.5%, 49.1%, 54.4%, 78.2%, and 84.6% at concentration of 1ng/ml, 2.5ng/ml, 5ng/ml, 10ng/ml and 20ng/ml, respectively. Dose dependent PDT lesions in both tumor and normal brain were observed. In the tumor lesion, only superficial tissue damage was found with optical irradiation of 35J/cm2. However, in the optical irradiation group of 140J/cm2 and 280J/cm2 the volume of lesions was measured of 7.2mm3 and 14.0mm3 for treatment at 140J/cm2 and 280J/cm2, respectively. The U-87 bearing rats showed a photofrin concentration in tumor tissue of 6.53+/-2.16ng/g, 23 times higher than that found in the contralateral hemisphere of 0.28+/-0.15ng/g. CONCLUSION: Our data indicate that the U-87 human glioma in vitro and in the xenografted rats is responsive to PDT. At these doses, a reproducible injury can be delivered to human glioma in this model. Strategies to spare the normal brain collateral damage are being studied.

Pallidotomy Guided by MRI and Microrecording for Parkinson's Disease

OBJECTIVE: The exact position of the lesion during the pallidotomy is critical to obtain the clinical improvement of parkinson's disease without damage to surrounding structure. Ventriculogrphy, CT(computed tomograpy) or MRI(magnetic resonance imaging) have been used to determine the initial coordinates of stereotactic target for pallidotomy. The goal of this study was to determine whether microelectrode recording significantly improves the neurophysiologic localization of the target obtained from MRI. METHODS: Twenty patients were studied. They underwent a unilateral pallidotomy. Leksell frame was applied and T1 axial images parallel to the AC-PC(anterior commissure-posterior commissure) plane using a 1.5 Tesla MRI with 3mm slice thickness were obtained. Anteroposterior coordinate of target was chosen at 2mm in front of the midcommissural point and lateral coordinate between 19 and 22mm from the midline. The vertical coordinate was calculated on coronal slice using a fast spin echo inversion recovery sequence(FSEIR) related to the position of the choroidal fissure and ranged over 4-5mm below the AC-PC plane. Confirmation of the anatomical target was done on axial slices using the same FSEIR sequence. Microrecording was done at the pallidum contralateral to the symptomatic side using an electrode with a tip diameter of 1nm diameter tip and 1.1-1.4 mOhm impedance at 1000Hz. Electrophysiologic localization of the target was also confirmed intraoperatively by macrostimulation. RESULTS: Microrecording techniques were reliable to define the transition from the base of the pallidum which was characterized by the disappearance of spike activity and by the change of the audible background activity. Signals from high amplitude neurons firing at 200-400Hz were recorded in the pallidal base. X, Y and Z coordinates of target obtained from the MRI were within 1mm from the X, Y, Z coordinates obtained with microrecording in 16 patients (80%), 15 patients(75%), 10 patients(50%) respectively. The difference of Y coordinate between on MRI and on microrecording was 4mm in only one patient. CONCLUSION: The MRI was accurate to localize the target within 1mm of the error from microrecording target in 70% of the patients. 4mm discrepancy was observed only once. We conclude that MRI alone can be used to determine the target for pallidotomy in most patients. However, microrecording technique can still be extremely valuable in patents with aberrant anatomy or unusual MRI coordinates. We also consider physiologic confirmation of the target using macrostimulation to be mandatory in all cases.

The Relationship between Intracellular Protein Kinase C Concentration and Invasiveness in U-87 Malignant Glioma Cells

OBJECTIVES: Glioblastomas, the most common type of primary brain tumors, are highly invasive and cause massive tissue destruction at both the tumor invading edges and in areas that are not in direct contact with glioma cells. As a result, patients with high-grade gliomas are faced with a poor prognosis. Such grim statistics emphasize the need to better understand the mechanisms that underlie glioma invasion, as these may lead to the identification of novel targets in the therapy of high grade gliomas. Protein kinase C(PKC) is a family of serine/threonine kinases and an important signal transduction enzyme that conveys signals generated by ligand-receptor interaction at the cell surface to the nucleus. PKC appears to be critical in regulating many aspects of glioma biology. The purpose of this study was to assess accurately the role of PKC in the invasion regulation of human gliomas based on hypothesis that protein kinase C(PKC) is functional in the process of glial tumor cell invasion. METHOD: To test this hypothesis, U-87 malignant glioma cell line intracellular PKC levels were up and down regulated and their invasiveness was tested. Intracellular PKC level was characterized using PKC activity assays. Invasion assays including barrier migration and spheroid confrontation were used to study the relationship between PKC concentration and invasiveness. RESULT: The cell line which were treated by PKC inhibitor tamoxifen and hypericin exhibited decreased PKC activity and decreased invasive abilities dose dependently both in matrigel invasion assay and tumor spheroid fetal rat brain aggregates(FRBA) confrontation assay. However, the cell line that was treated by PKC activator 12-O-tetradecanylphorbol-13acetate(TPA) did not exhibit increases in either PKC activity or invasive ability. CONCLUSION: These studies suggest that PKC may be a useful molecular target for the chemotherapy of glioblastoma and other malignancies and that a therapeutic approach based on the ability of PKC inhibitors may be helpful in preventing invasion.

Surgical Management of Trigeminal Neurinoma

No abstract available.

Bypass Graft for Cerebral Revascularization / 대한뇌혈관학회지

OBJECTIVE: The authors were performed bypass graft for cerebral revascularization in the treatment of hemodynamic cerebral ischemia and unclippable traumatic aneurysm, which acute sacrifice of the internal carotid artery is necessary. The aim of this study was to assess effectiveness bypass graft for cerebral revascularization. METHOD: Of 6 patients, Four patients were hemodynamic cerebral ischemia and two patients were traumatic cerebral aneurysm and traumatic carotid-cavernous fistula (CCF). Revascularization was performed external carotid artery (ECA) to middle cerebral artery (MCA) bypass with radial artery (n=1), ECA to MCA bypass with long saphenous vein (n=1), main trunk of superficial temporal artery (STA) to MCA with short saphenous vein (n=2), and internal carotid artery (ICA) to MCA with long saphenous vein (n=2). RESULTS: There were two graft occlusion, which one is recanalization case of preoperative MCA obstruction and the other is traumatic CCF. Four patients with good patiency through bypass showed significant increase of postoperative cerebral blood flow and good surgical outcome. There was not operative complication except for graft failure of 2 cases. CONCLUSION: Extracranial to intracranial bypass graft with radial artery or saphenous vein is thought to alternative method for cerebral revascularization in cases with unsuitable STA to bypass, and ICA reconstruction, which acute sacrifice of ICA is necessary.

Solitary Plasmacytoma of the Skull: A Case Report

No abstract available.

Potentials and limitations of adenovirus-p53 gene therapy for brain tumors

We investigated the antineoplastic potentials of recombinant adenovirus containing wild-type p53 cDNA (Ad5CMV-p53) for malignant gliomas. In four human glioma cell lines (U-251 and LG expressing endogenous mutant p53, and U-87 and EFC-2 expressing wild-type p53) and two rat glioma cell lines (9L and C6, each expressing mutant and wild-type p53), gene transfer efficiency determined by X-gal staining and Western blotting was varied (10-99% at 10-500 multiplicity of infection, MOI). Growth inhibitory effect was drastic (>90% at 100 MOI) in U-251 cells and only moderate or minimal in other cell lines harboring wild-type p53 or low gene transfer efficiency. Ex vivo transduction of U-251 cells with Ad5CMV-p53 suppressed the in vivo tumorigenicity of the cells. Histopathologic examination for Ad5CMV-p53 toxicity to rat brains showed inflammatory reactions in half of the tested brains at 10(8) MOI. U-251 cells were inoculated intracerebrally in nude mice and injected Ad5CMV-p53 into the tumor, in which neither the tumor suppression nor the survival benefit was observed. In conclusion, heterogeneity of the cellular subpopulations of malignant glioma in p53 status, variable and insufficient gene delivery to tumor, and adenoviral toxicity to brain at higher doses may be limiting factors to be solved in developing adenovirus-p53 gene therapy for malignant gliomas.

Potentials and limitations of adenovirus-p53 gene therapy for brain tumors

We investigated the antineoplastic potentials of recombinant adenovirus containing wild-type p53 cDNA (Ad5CMV-p53) for malignant gliomas. In four human glioma cell lines (U-251 and LG expressing endogenous mutant p53, and U-87 and EFC-2 expressing wild-type p53) and two rat glioma cell lines (9L and C6, each expressing mutant and wild-type p53), gene transfer efficiency determined by X-gal staining and Western blotting was varied (10-99% at 10-500 multiplicity of infection, MOI). Growth inhibitory effect was drastic (>90% at 100 MOI) in U-251 cells and only moderate or minimal in other cell lines harboring wild-type p53 or low gene transfer efficiency. Ex vivo transduction of U-251 cells with Ad5CMV-p53 suppressed the in vivo tumorigenicity of the cells. Histopathologic examination for Ad5CMV-p53 toxicity to rat brains showed inflammatory reactions in half of the tested brains at 10(8) MOI. U-251 cells were inoculated intracerebrally in nude mice and injected Ad5CMV-p53 into the tumor, in which neither the tumor suppression nor the survival benefit was observed. In conclusion, heterogeneity of the cellular subpopulations of malignant glioma in p53 status, variable and insufficient gene delivery to tumor, and adenoviral toxicity to brain at higher doses may be limiting factors to be solved in developing adenovirus-p53 gene therapy for malignant gliomas.

Surgical Results of Microvascular Decompression and Partial Sensory Rhizotomy in the Treatment of 154 Patients with Trigeminal Neuralgia

OBJECTIVE: To evaluate the efficacy of microvascular decompression(MVD) for trigeminal neuralgia(TN) and to discuss current understanding of the mechanism of MVD for this disorder. PATIENTS AND METHODS:Since 1987, 154 patients treated for trigeminal neuralgia(TN) had been followed for an average 4.3 years. Among these patients, 145 had vascular compression of the nerve and underwent microvascular decompression(MVD). Remaining 9 patients had no offending vessels, so partial sensory rhizotomy(PSR) was performed in these patients. RESULTS: Immediate pain relief was achieved in 95%(147/154) of all patients, but the rate dropped to 90%(140/154) during the follow-up period. Recurrence rate in the MVD group was 2% and in the PSR group 55%. Among those patients underwent MVD, permanent sequelae occurred in only 1 patient(sensorineural hearing loss) and transient complications(impaired hearing due to hemotympanum, minor sensory deficit etc.) were more frequent. There were no differences in the outcome, considering age, sex and the duration of symptoms. There was a close relationship between operative findings of arterial compression on the nerve and long-term complete pain relief. Prognosis for patients with severe arterial compression was better than that for patients with mild or venous compression. CONCLUSION: MVD provides a high rate of success with a minor risk of complications, and this study gives support to the hypothesis that in most cases of TN is caused by neurovascular compression.

Improvement of Cerebrovascular Reserve Capacity by Bypass Surgery in Patients with Hemodynamic Cerebral Ischemia

To study the effect of extracranial-intracranial(EC/IC) bypass on symptomatic patients with hemodynamic cerebral ischemia, we prospectively reviewed 14 patients who underwent EC/IC bypass surgery. A series of 14 patients treated in a 2 years period met the following criteria, 1) symptomatic internal carotid artery(ICA) or middle cerebral aetery(MCA) obstruction or stenosis over 80M, 2) decrease in basal cerebral blood flow(CBF) over 10%, 3) hyporeactivity to acetazolimide of CBF Amomg these, the type of ischemic episode was transient ischemic attack(TIA) or reversible ischemic neurological deficit(RIND) in 4, minor stroke in 8, and major stroke in 2. Of these, 10 patients had multiple episode of ischemic attack. CT or MRI were showed infarction of the MCA territory in 3, border zone infarction in 5, basal ganglia infarction in 2 and multiple lacunar infarction in 4. Based on our criteria, superficial temporal artery(STA)-MCA anastomosis was performed in 13 cases and EC-IC bypass grafting using radial artery in one. Average follow up period was 24 months. Postoperative course was uneventful in 12 patients. One patient suffered a postoperative stroke with complete recovery and another suffered operative wound infection. Of the 14 patients 12(85.7 % ) have had an excellent to good outcome with complete resolution or significant improvement of preoperative neurologic symptom, remaining two show no improvement of preoperative neurologic deficit. Bypass patency was confirmed by postoperative angiography in all cases except for one. Postoperative follow up studies of the basal CBF and response to the acetazolamide of the CBF showed significant increased CBF activity to acetazolamide in 12 cases(85. 7%) while the basal CBF was essentially unchanged in all cases except for two. In view of these finding, the authors suggest that EC-IC bypass surgery to be considered as an appropritate therapy for improvement of the cerebrovascular reserve capacity in patients with hemodynamic cerebral ischemia, defined using the strict selection criteria employed in this study.

Early Change of Intracranial Pressure, Regional Cerebral Blood Flow and Cerebral Edema Depending on the Occlusion Site of the Superior Sagittal Sinus in Cats

OBJECTIVE: Although it is well known that cerebral sinus thrombosis or resection of large cerebral veins during surgery may cause venous hypertension, often leading to brain edema and intracerebral hemorrhage and the outcome is widely variable with symptoms from headache to coma, the pathophysiology of cerebral venous circulatory disturbance is poorly understood. The purpose of this study was to investigate the pathophysiological change of cerebral venous circulatory disturbance by measurement of intracranial pressure, regional cerebral blood flow and cerebral water content, and histological examination for extravasation of Evans blue dye and cerebral edema for 2 hours after occlusion of the superior sagittal sinus and diploic veins in cats. METHODS: Thirty five cats were divided into 4 groups: (1) control group, 5 cats with sham operation, (2) experiment group I, 10 cats with occlusion at the anterior 1/3 of the superior sagittal sinus, (3) experiment group II, 10 cats with occlusion at the middle 1/3 of the superior sagittal sinus, (4) experiment group III, 10 cats with occlusion at the posterior 1/3 of the superior sagittal sinus. RESULTS: The results were as follows: 1) After occlusion of the superior sagittal sinus, intracranial pressure was elevated with increased cerebral water content and regional cerebral blood flow was reduced in all experiment groups. The degree of their changes was the least in experiment group I, the most in experiment group III, and intermediate in experiment group II. 2) Extravasation of the Evans blue dye was not observed in any experiment groups 120 minutes after occlusion of the superior sagittal sinus. 3) On the histological examination, pericellular edematous change of the brain was observed in all experiment groups 120 minutes after occlusion of the superior sagittal sinus. The degree of edema also showed similar pattern in magnitude to that of changes of other parameters. CONCLUSION: These results suggest that occlusion of the middle or posterior 1/3 of the superior sagittal sinus could bring a significant harmful effect to the cerebral hemodynamics, leading to secondary brain injury and the hydrostatic edema is responsible for the cerebral swelling in early stage after occlusion of the superior sagittal sinus.

Microvascular Decompression for Hemifacial Spasm

The authors analysed the results of 300 microvascular decompression(MVD) procedures for hemifacial spasm. The follow up period ranged from 6months to 3years. Of these, 70% were women(mean age 54). The vessel most frequently found to compress the facial nerve was the posterior inferior cerebellar artery(43.3%) followed by anterior inferior cerebellar artery(26.7%). For the surgical results, 210 patients(70%) had complete relief of spasm within 3 days after MVD, 65 patients(21.7%) subsequently experienced complete relief, noted in 4 days to 6 months after MVD, ten patients had delayed partial relief and remaining 15 patients showed no improvement. Twelve patients of these 15 unresponsive patients underwent reoperation without beneficial results. Recently the authors have monitored facial elctromyography(EMG) intraoperatively to observe the abnormal late response. There were few cases of permanant major complications, including two cases of ipsilateral hearing loss, ataxia and no operation-related death. These results suggest that MVD is a safe and definite treatment for hemifacial spasm, if performed by experienced surgeon with gentle operative technique, and with intraoperative monitoring such as auditory evoked potential and facial EMG, better surgical results with less complications can be expected.

Surgical Management of Suprasellar Meningioma

OBJECTIVE: Suprasellar meningioma have in general been difficult lesions to treat because of their vicinity to the optic apparatus and major vessels, and high vascularity. This study was performed to analyze clinical outcome of patients with histopathologically identified suprasellar meningioma. METHOD: Between 1989 and 1998, 37 patients(30 women, 7 men: average 47.5years) with histopathologically identified meningiomas originating from the suprasellar region underwent surgical tumor removal in our institution. The medical records and clinical data of these patients are retrospectively analyzed. RESULT: The tumor size ranged from 2.1cm to 6.5cm(average 5.1cm) in diameter. The tumors have been approached basically through the pterional and bifrontal routes. Skull base technique was also applied in large or complicated cases. Total resection rates and overall outcome including visual function was better in patients with tumor of less then 3cm. A considerable increase of mortality, morbidity and failure of visual improvement were seen in case of the tumors size of 3cm or more. CONCLUSION: Early diagnosis and treatment were important factors in the successful management of these suprasellar meningioma. In large complicated cases encasing major vessels or invading cavernous sinus or anterior skull base, surgeons need to operate with extreme caution and piecemeal removal of the tumor without injuring optic apparatus and major vessels utilizing skull base technique.

Responses of Trigeminal Ganglion Neurons to Electrical and Mechanical Stimulation of the Middle Meningeal Artery, Superior Sagittal Sinus and Transverse Sinus in Rats

The intracranial blood vessels of the dura and the pia receive sensory afferent innervations from trigeminal nerve which has been believed to play a critical role in the mediation of vascular headache such as migraine. The purpose of this study was to discover the mechanism by which the interaction between trigeminal ganglion neurons and the function of cerebral blood vessels. Using electrophysiological recording, we studied the responses of trigeminal ganglion neurons to electrical stimulation of middle meningeal artery(MMA), superior sagittal sinus(SS) and transverse sinus(TS) in rats. Sumatriptan is a highly selective agonist for 5-HT1D receptor subtype which mediates vasoconstriction of cerebral blood vessels. We observed responses to electrical stimulation in trigeminal ganglion neurons and meningeal blood flow(MBF) after intravenous injection of sumatriptan. The results were as follows: 1) The presumed mean conduction velocities of the cells activated MMA, SS and TS by electrical stimulation were approximately 1.5, 2.9 and 2.9m/s, respectively. These were presumed to be nociceptive small myelinated or unmylinated sensory fibers. 2) The action potential discharges of trigeminal ganglion neurons on MMA, SS and TS in the experimental control groups were 671+/-39.49, 856+/-63.95 and 494+/-21.54microV, respectrely. The action potential discharges of sumatriptan groups on MMA, SS and TS(393+/-20.10, 562+/-32.26 and 262+/-18.94microV, respectively) were significantly decreased compared to that of the experimental control groups. 3) The mean MBF of normal control group was 63.29+/-7.54ml/100g/min. The mean MBF of the experimental control groups on MMA, SS and TS were 97.13+/-9.91, 104.28+/-12.54 and 91.82+/-6.41ml/100g/min, respectively(p<0.05). MBF of sumatriptan group before stimulation was significantly decreased(compared to normal: 37.17+/-4.76ml/100g /min vs 63.29+/-7.54ml/100g/min). The mean MBF of sumatriptan groups on MMA, SS and TS were 57.11+/-4.48, 66.56+/-6.23 and 56.07+/-5.00ml/100g/min, respectively. Compared to that of the experimental control groups, the MBF of the sumatriptan groups were significantly decreased. In conclusion, the activation of trigeminal sensory afferents by the electrical stimulation of the dural vessel may create vasodilatation and increase cerebral blood flow which may lead to vascular headaches via trigeminal ganglion to brain stem This pathway can be important for understanding the neural mechanism for the development of pharmacological and surgical approach to alleviate vascular headache.

Fractionated Stereotactic Radiation Therapy Using Linear Accolerator in Brain Tumor and Arteriovenous Malformation

With a frame-based system, stereotactic dose of radiation is delivered to the target in one day. The patient is uncomfortable with a frame based system and the staff is forced to produce a treatment plan under time pressure. And then a single dose of radiation is delivered. Our frameless fractionated conformal stereotactic radiotherapy system uses markers, permanently placed in the head. There is more time to prepare and perform the treatment. The point reference system is a frameless system, allowing a separation in time between all of the steps in a stereotactic procedure. And these reference points allow physician precisely to set up the patient again and again. Our system is made to spare normal cells within target volume by fractionating the tumor dose. We have treated 43 patients with multifraction regimen using 6-MV linear accelerator. All patient tolerated the treatment well and no significant complication were seen. Although small in number experienced, this technique seems to be feasible and safe for treating brain tumor and vascular malformation.