The Effect of Antifibrinolytic Therapy in Prevention of Rebleeding before Early Aneurysm Surgery

OBJECT: This study was conducted to evaluate whether short-term intravenous infusion of tranexamic acid (AMCA) was able to improve the management outcome by preventing rebleeding without increasing vasospasm and hydrocephalus associated with the long-term administration of this agent in the patients with aneurysmal subarachnoid hemorrhage(SAH) who were planned for the early surgery. METHODS: During the period from June, 1996 to May, 1998, 137 patients admitted within 3 days of their SAH and planned for early surgical intervention were subject to study population. Of these, 60 patients who had been treated with AMCA were classified as AMCA treated group and 77 patients without AMCA treatment as AMCA untreated group. Initially, prognostic factors for rebleeding, vasospasm, hydrocephalus and outcome following SAH including age, sex, clinical grade, CT grade, site of ruptured aneurysms, admission day after SAH, surgery day after SAH, number of aneurysms and hypertension history, were analyzed and compared between AMCA treated group and untreated group. Secondly, the incidence of rebleeding, symptomatic vasospasm and hydrocephalus were compared between the two groups. Also, the management outcome of the patients was compared between the two groups. RESULTS: There were no significant differences in prognostic factors between the two groups. The rebleeding rate was 0% in the AMCA treated group whereas the rate was 7.8% in the untreated group. This difference was statistically significant. The incidences of symptomatic vasospasm and hydrocephalus were found not to be significantly different between the two groups. Of the treated group, 31.7% of patients developed hydrocephalus compared to 32.5% of those at the untreated group. Fourteen(23.3%) patients in treated group developed symptomatic vasospasm and 6 of them(10%) suffered stroke whereas incidences of these in untreated group were 25.9% and 11.7%, respectively. The AMCA treated group showed more favorable outcome than that of untreated group. There was no case of death by rebleeding in the AMCA treated group while one of the main causes of death in the untreated group was rebleeding. CONCLUSION: Short-term high-dose AMCA administration is considered beneficial in improving outcome and diminishing the risk of rebleeding in the patients who suffer from an aneurysmal SAH prior to early surgical intervention.

The Value of MRI in Diagnosis of Peripheral Nerve Disorders

OBJECTIVE: The development of magnetic resonance neurography(MRN) has made it possible to produce high-resolution images of peripheral nerves themselves, as well as associated intraneural and extraneural lesions. We evaluated the clinical application and utility of high-resolution MRN techniques for the diagnosis and treatment of a variety of peripheral nerve disorder(PND)s. MATERIAL AND METHOD: MRN images were obtained using T1-weighted spin echo, T2-weighted fast spin echo with fat suppression, and short tau inversion recovery(STIR) fast spin-echo pulse sequences. Fifteen patients were studied, three with brachial plexus tumors, five with chronic entrapment syndromes, and seven with traumatic peripheral lesions. Ten patients underwent surgery. RESULTS: In MRN with STIR sequences of axial and coronal imagings, signals of the peripheral nerves with various lesions were detected as fairly bright signals and were discerned from signals of the uninvolved nerves. Increased signal with proximal swelling and distal flattening of the median nerve were seen in all patients of carpal tunnel syndrome. Among the eight patients with brachial plexus injury or tumors, T2-weighted MRN showed increased signal intensity in involved roots in five, enhanced mass lesions in three, and traumatic pseudomeningocele in three. Other associated MRI findings were adjacent bony signal change, neuroma, root adhesion and denervated muscle atophy with signal change. CONCLUSION: MRN with high-resolution imaging can be useful in the preoperative evaluation and surgical planning in patients with peripheral nerve lesions.

The Surgical Results of Carpal Tunnel Syndrome: Open Versus Endoscopic Method

No abstract available.

Caudal Epidural Injectioin in Treatment of Lumbosacral Radicular Leg Pain

An spinal epidural injection is a relatively benign procedure and widely used for symptomatic relief of back and radicular leg pain. The authors evaluated the efficacy of caudal epidural injection with corticosteroids and local anesthetics which was performed by a neurosurgeon for the treatment of ongoing lumbosacral radicula, symptoms. Between July 1997 and June 1998, 20 patients with back pain and radiating leg pain invloving lumbosac ral degenerative spine disease, who refused operation or were unsuitable for general anesthesia, were treated and followed for more than 6 months. All procedure was done under radiogaphical guidance aseptically. The authors used the mixed solution of 1% lidocaine(6 cases) or 0.25% bupivacaine(14 cases) with methylprednisolone acetate(1- 2ml). The mean total volume of the mixture was 15.6 ml. The preoperative neurosurgical diagnosis included 11 lumbar disc herniation,6 lumbar stenosis and 3 spondylolisthesis and the invloved nerve roots presenting with typical radiculopathy were L5 root(17 patients), S1 root(15 patients), L4 root (4 patients), and S2 root(1 patient). The responses from patients were classified into 4 groups, and excellent or good results with marked reduction on radicular leg pain we re noted in 19 cases. There were a few transient complications such as headahce, leg numbness, perisacral hypesthesia, injection pain, constipation and malpositioned spinal needle. The authors suggest that the cadual epidural injections is a reasonable alternative to spinal surgery if patients pain is severe enough and you a re exhausted other methods to relieve the pain.

Recurrent Hemorrhage from New Growth Aneurysms in Patients with Previous Surgery for Cerebral Aneurysms

Among 875 patients with intracranial aneurysm operated on during the past 14 years, the authors encountered eleven who had experienced recurrent hemorrhage caused by the rupture of aneurysms which had not been noticed at the time of the initial operation and the interval between initial and recurrent hemorrhage varied between 4 and 16 years. Age at the time of initial hemorrhage was relatively young(average 43.7 years). Multiple aneurysms occurred in four cases and hypertension in four others. Clinical grades at the time of the second admission were relatively poor, and in eight patients there were complications with intracerebral hematomas, intraventricular hemorrhages or acute subdural hematoma. Retrospective evaluation of the first angiograms disclosed suspicious tiny aneurysms in five cases, and these grew and ruptured at recurrent hemorrhage. In eight patients, the outcome was good; One remained moderately disabled, and two died. We conclude that the possibility of recurrent hemorrhage, after the clipping of a ruptured aneurysm, should be considered in all aneurysmal patients, especially in those who are young or have multiple aneurysms. To defermine whether or not suspicious tiny aneurysms are present in these patients, their angiograms should be subjected to detailed examination. Late postoperative follow-up angiography to determine the growth or development of another aneurysm might also be needed.

An Analysis of Factors Related to Symptomatic Vasospasm and Outcome in Patients with Aneurysmal Subarachnoid Hemorrhage

Symptomatic vasospasm is still one of the major causes of death and disability in patients who suffer an aneurysmal subarachnoid hemorrhage(SAH). To identify risk factors related to symptomatic vasospasm, to determine the outcome in patients with SAH, and to determine the differences identified risk factors between patients with good and bad outcomes, we performed this retrospective study. From a total of 279 SAH patients who were admitted to our hospital between January 1993 and December 1995, 212 were chosen for study. These were patients who had been admitted within 7 days of SAH, had undergone brain computed tomography(CT) within 3 days of SAH and had survived more than 6 days after SAH. Nine variables were examined as to their relationship to symptomatic vasospasm: age, sex, admission day after SAH, hypertension history, frequency of SAH, clinical grade, CT grade, operation day after SAH, and outcome. Data were analyzed by the univariate and multivariate logistic regression method using the Statistical Analysis System(SAS). Symptomatic vasospasm was demonstrated in 30 cases(14.2%). Univariate analysis showed that admission more than 4 days after SAH(p=0.07), clinical grades III-V(p=0.001), and CT grade III(p=0.00001) were associated with a higher risk of symptomatic vasospasm. When study cases were grouped into either good or bad outcome groups, and multivariate logistic regression analysis was performed, these factors were associated with a higher risk of symptomatic vasospasm only in the good outcome group. This suggests that there is a group of patients with a predisposition to symptomatic vasospasm that is independent of these risk factors, and that in these patients, the outcome may be worse.

Results of Cervical Interbody Fusion Using the Anterior Plate System

In order to evaluate long-term effects of the anterior cervical plating system, we report the results of 59 patients who were treated with anterior decompression, autogenous iliac bone graft, and anterior cervical plate. Operations were performed on 59 patients for a variety of reasons; 40 for fracture and/or dislocation, 7 for degenerative spondylosis, 4 for ossification of posterior longitudinal ligament, 5 for pyogenic or tuberculous spondylitis, and 3 for metastatic tumor. Our study consisted of 41 male and 18 female patents whose ages ranged from 14 to 76 years. Immediate fixation was obtained in 56 cases(95%). Satisfactory fusion was obtained in ll but five cases of which the result could not be judged due to death of the patients(3 cases of metastatic disease) and removal of the instrument(2 cases of fracture). Specific complications included 5 cases of screw loosening, 2 cases of screw fracture, 2 cases of dysphagia, and 1 case of esophageal fistula. The anterior plate system is thought to provide a valuable means of treating cervical instabilities.

Review of 10 Cases of Pyogenic Epidural Abscess of the Spine

Spinal epidural abscess is a rare disorder with poor prognosis. In order to understand its clinical feature and method of treatment, a retrospective study of spinal epidural abscess spanning 8 years and encompassing 10 patients was done. There were 6 males and 4 females aged 12 to 64 years with peak incidence at the sixth decade. In one patient, epidural abscess recurred at the site previously treated 10 years ago. In addition to fever and leukocytosis in 8 patients, other frequent symptoms according to lesion site were abdominal pain and motor weakness in thoracic epidural abscess and low back pain and sciatica in lumbar epidural abscess. Staphylococcus aureus was the most common causative organism. Magnetic resonance imaging(MRI) showed variable signal on T1-weighted images and hyperintensity on T2-weighted images, which was studied in 6 patients. Two patterns in gadolinium-enhanced MRI were a central focus of low signal intensity surrounded by ring enhancement(2 patients) gadolinium-enhanced MRI were a central focus of low signal intensity surrounded by ring enhanement(2 patients) and heterogeneous enhancement(4 patients). MRI offered the advantage of noninvasive early recognition and anatomical localization, which made it the imaging modality of choice. Although laminectomy was the standard operative procedure, the result of window laminectomy with catheter drainage for prevention of kyphosis was proven effective in a girl. Complete improvement following surgery was obtained in patients, while a man resulted in paraplegia and a boy paraparesis with mild kyphosis in thoracic abscess as sequelae.

Seasonal and diurnal Variations of Predisposing Factors to Cerebral Aneurysm Rupture

In order to determine the predisposing factors to cerebral aneurysm rupture and to examine the relationship between circadian periodicity of blood pressure change and the rupture of an aneurysm, the authors investigated activities of the patients of events as well as diurnal and seasonal variations in the onset of subarachnoid hemorrhage (SAH) in 766 consecutive patients. The authors also compared the difference of these data between patients with a history of hypertension and patients without a history of hypertension. The results showed that the onset of SAH was associated with defecation and/or urination in 12.3%, working on the jab in 11.8%, housework including washing clothes in 10.3%, sleeping in 7.4% and bathing and/or washing up in 7.2%. The incidence of the onset of SAH associated with defecation an/or urination was higher in patients with a history of hypertension than in patients without a history of hypertension(p<0.05). The diurnal variation of the onset of SAH showed two broad peak times from 6 to 10 a.m.(21.8%) and from 5 to 8 p.m.(18.3%). The seasonal variation of the onset of SAH showed the incidence to be slightly higher in winter than in any other seasons autumn and winter, the leading activities of the patients or events in the onset of SAH was defecation and/or urination and, in summer, it was job performing. We concluded that the onset of the SAH is related not only to the physiological circadian periodicity of blood pressure change but also to the activities or events which induced a sharp rising blood pressure and changing the venous and cerebrospinal fluid pressure.

Effect of Epidural Steroid Injection in the Low Back Pain

In order to evaluate the effect of the lumbar epidural steroid injection in the low back pain and/or radicular pain. We studied 66 patients who were treated and followed for an average of 8.6 months. In the initial evaluation, main pain sites were as follows: low back pain in 41 patients, buttock pain in 7 patients, and leg pain. In 18 patients. Immediate response and delayed response in the patients were studied. Immediate response within 1 day after injection revealed the following : dramatic improvement in 3.0%;some improvement in 56.1%; no improvement in 27.3%; and more aggravated in 13.6%. Delayed response after 1 month revealed the following : 15.2% continuously maintained improvement; 9.1 showed progressive improvement;36.4% experienced recurring pain; 27.3% had no improvement; and 10.6% had aggravating pain. The effect of the lumbar epidural steroid injection was not affected by the severity of pain in the initial evaluation. Better improvements were noted in patients who suffered radicular pain than those who suffered low back or buttock pain. Good prognostic factors were young age and male. Complications that the patients suffered were transient injection pain(6), edema of the face or extremity(10), transient leg weakness(5) and dural puncture(1). The number of patients who wanted to recommend this procedure to others were 22(33.3%). In conclusion, epidural steroid injection was one of the methods in the management of the patients who suffered low back pain and/or radicular pain and had no effect by any other therapies.

Intracrebral Hemorrhage Remote from the Site of Aneurysm Surgery

In order to find out possible causes and measures for prevention of intracerebral hemorrhage remote from the site of cerebral aneurysm surgery, the authors analyzed five patients who developed such a complication following aneurysm surgery among 720 surgical cases of cerebral aneurysm. The aneurysm sites were posterior communicating artery(Pcom) in two cases, anterior communicating artery(Acom) in two, and Acom and middle cerebral artery(MMCA) in one. The hemorrhages in three cases occurred in the cerebellum. One in the contralateral hemisphere and one in the ipsilateral hemisphere to the operation site. All hemorrhages except one occurred vasospasm preoperatively. Fluctuation of blood pressure with sudden elevation to high level was noticed in three cases preoperatively and in all cases postoperatively. We conclude that sudden elevation of blood pressure during the remission stage of vasospasm seems to be possible cause for remote hemorrhage. To prevent this complication, we recommend meticulous control of blood pressure during surgery and in the postoperative period, especially in cases that showed fluctuation of blood pressure preoperatively.

Expression of c-myc mRNA in the Hippocampus of Pentylenetetrazol Kindling Rat

Kindling development is a good animal model of epilepsy and neural plasticity. It is induced by repeated subconvulsive electrical or chemical stimulations. This leads to progressive and permanent amplification of seizure activity resulting in permanent brain changes. Immediate early genes(IEGs) are proposed as the master switch for turning on molecular events in long term neural plasticity. The role of c-myc, an IEG, in the development of kindling is not known. This study was conducted to investigate the role of c-myc in the neural plastic changes underlying kinding. Among 115 adult male Spargue-Dawley rats, 51 were kindled by repeated administrations of subconvulsive doses(15-25mg/kg) of pentylenetetrazol(PTZ). Twenty-eight rats experienced various degree of convulsions induced by a single injection of convulsive dose(30-60mg/kg) of PTZ. Eighteen rats experienced mild or severe convulsions induced by a single injection of convulsive dose(30-60mg/kg) of PTZ. Eighteen rats experienced mild or severe convulsion by a single electroconvulsive shock(ECS). Eighteen rats received normal saline as a control group. Animals were sacrificed in 30 minutes, 1 hour and 48 hours after convulsion. C-myc mRNA levels in the hippocampus were quantified using slot-blot hybridization analysis. In the experiment of PTZ kindling, c-myc mRNA expression 30 minutes after convulsion was elevated about 3-8 times compared with controls. C-myc mRNA expression 1 hour after convulsion was elevated about 4 times at stage I, II, and V, ut was not elevated at stage III and IV. C-myc mRNA expression 48 hours after convulsion was elevated about 2-3 times compared with controls. In the experiment of PTZ-induced seizures, c-myc mRNA expression 30 minutes after convulsion was elevated 5-6 times compared with controls. C-myc mRNA expression 1 hour after convulsion was elevated 4-6 times. C-myc mRNA expression 48 hours after convulsion was elevated approximately 2 times. In the experiment of ECS-induced seizures, c-myc mRNA expression was elevated 4 times at 30 minutes and 1 hour after mild convulsion, but decreased at 30 minutes and 1 hour after severe convulsion compared with control. C-myc mRNA expression 48 hours after convulsion was elevated approximately 2 times. These results suggest that the enhanced expression of c-myc mRNA is a non-specific consequence in the development of PTZ kindling. In addition, c-myc does not seem to play an important role in turning on a molecular program underlying kindling.

The Changes of Cell Mediated Immunity Correlated with Severity of Head Injury

Severe head injury results in the suppression of cellular immunity associated with dysfunctioning of effector lymphocytes, such as helper T cells(CD4) (and cytotoxic T cells(CD8). Despite progress in the management of increased intracranial pressure following head injury, infection remains the most common complication and the primary cause of prolonged hospitalization and death. This study attempts to assess the cellular immune function following head injury according to the degree of severity, and to establish the clinically available parameters of cell mediated immune(CMI) function, which can then be used for coherent prediction of infection risk. Eighteem head injury patients without severe systemic injury, who divided into three subgroups depending on the severity of head injury, were estimated with the use of CMI multitest kit(Merieux Institute, France) to test delayed-type hypersensitivity(DTH) and enumerated the circulating lymphocyte subpopulation(pan T-cell marker CD3, helper T cell marker CD4, cytotoxic T cell marker CD8 and B-cell marker CD19) on the 1st, 7th, and 21th day of injury. Patients were monitored for evidence of infection for this period. Fourteen patients had no reaction to any antigens of the DTH skin test(anergy) and the remaining four patients had also some degree of anergy. Seven patients became infected and all of them were anergic. There were significant decrease of circulating effector T lymphocytes, both CD4-positive and CD8-positive cells, within 24 hours of injury in the mild as well as the moderate and severe head injury group. CD4-positive cells were nearly completely recovered by the 7th day of injury. CD8-positive cells had sustained significant decrease even after 3 weeks of injury. There was no significant change in pan T-cells(CD3-positive cells) and B-cells(CD19-positive cells). The results suggest that DTH skin test and effector T cell enumeration are both relatively simple and highly sensitive parameters for monitoring CMI function. Especially, anergy of DTH skin test can be used for indicator to predict risk of infection. Mild as well as moderate and severe head injuries may result in the suppression of cellular immunity associated with the dysfunctioning of effector T cell.

Angiographically Occult Cerebral Vascular Malformations

In order to obtain more accurate pathological diagosis of the angiographically occult vascular malformations(AOVM) of the brain in the future and to examine the clinical, and radiological characteristics and management outcome of the AOVM, the authors retrospectively reviewed the 30 cases of AOVM in which patients were treated at our instituition during the past 11-year period. The pathological specimens were reexamined, and the lesions were reclassified according to the strict histopathological criteria. The clinical characteristics, radiological features, the difference between the clinical and pathological diagnosis and the management results were studied. There were 15 males and 15 females. The mean age at the time of diagnosis was 31 years, ranging from 3 months to 74 years. The clinical diagnosis were arteriovenous malformation(AVM) in 18 cases, cavernous angioma in 11 and mixed lesion in 1. The pathologic diagnosis was AVM in 14 cases, cavernous angioma in 2, and unclassified lesion in 12. The common presenting symptoms were hemorrhage(53.3%), seizure(20.0%) and mass lesions(20.0%). Twenty four lesions were located at the supratentorial region, 4 at cerebellum and 2 at pons. Most of the lesions were revealed as high density masses with minimal or no contrast enhancement on CT and a core of mixed signal intensity with a peripheral low signal intensity rim on T2-weight MRI. Preoperative clinically significant recurrent hemorrhages were noted in 8 cases and one of them showed marked deterioration of the neurological functions a result of recurrent hemorrhage. Twenty-eight patients underwent surgery and all except one improved neurologically. Six patients initially presented with seizure showed improvement in seizure frequency after operation. One patient who had the lesion at the pons was managed by a radiosurgery and one patient who refused surgery was managed by a conservative method. The conservatively managed patient and another patient who was not found AVM at the hematoma cavity during initial operation rebled about 2 years later following diagnosis and surgery. Thse findings suggest that the complete microsurgical excision, which prevents rebleeding and suppresses seizure activity, represents the treatment of choice for patients with clinically symptomatic AOVM. Avoiding the injury of the vascular mass, obtaining sufficient biopsy specimen during surgery, together with careful histopathological observation of operative specimens through complete clinical-radiological-pathological context are necessary to obtain more accurate pathological diagnosis.

Comparison of Clinical Findings and Results of Treatment According to Classification of C-2 Fractures

There are some debates on the best method of treatment of C-2 fractures. Clinical findings and results of treatment were evaluated in forty-three patients with C-2 fractures. These fractures were classified into five types according to the classification by Benzel4);1) odontoid fractures(14), 2) horizontal C-2 body fractures(13), 3) sagittally oriented vertical C-2 body fractures (2), 4) coronally oriented vertical C-2 body fractures(8), 5) traumatic spondylolisthesis of the axis(6). Primary fusion appears to be justified in odontoid process fractures due to a high rate of non-union. In horizontal C-2 body fractures, unilateral facet dislocation was visible in six patients which was the cause of malalignment in closed reduction. In sagittally oriented vertical C-2 body fractures, combined facet fractures were always visible because the mechanism of injury was axial compression. The choice of management schemes may depend on the mechanism of injury and fracture type defined by Benzel.

The Effect of Nimodipine, Indeced Hypertension, and Combined Nimodipine Therapies with Induced Hypertension on Experimental Cerebral Infarction

The treatment with nimodipine is recommended as an effective therapy for the delayed ischemic neurological deficits(DIND) caused by cerebral vasospasm following aneurysmal subarachnoid hemorrhage. The induced hypertension is also widely accepted as a treatment method to reverse the DIND caused by cerebral vasospasm. Therefore, the combination of these two regimens may be considered as a more effective treatment method for the DIND than nimodipine or induced hypertension alone. The authors performed this experimental study to clear up this subject. In a series of 60 adult rats, a surgical occlusion of the middle cerebral artery(MCA) was carried out by a microsurgical technique. The animals were divided into 4 groups as follows ; group I(N=15) : control group, group II(N=15) : nimodipine treated group, group III(N=15) : induced hypertension group, group II(N=15) : combined nimodipine treated with induced hypertension group. Group II animals were treated with an infusion of nimodipine intravenously(1 microgram/Kg/min), and group III animals were maintained high blood pressure(B.P) to 160 mmHg by an infusion of dopamine intravenously(2 microgram/Kg/min), and group IV animals were treated with an infusion of nimodipine and dopamine intravenously. All animals of each group were sacrificed at 6,12 and 24 hours after MCA occlusion. Then the brain slices were obtained and stained with triphenyltetrazolium chloride(TTC). The size of the infraction area was quantified by a computer image analysis system and the size of the infraction area compared among each groups. The results showed that each size of the infraction area according to sacrifice time at 6, 12 and 24 hours after MCA occlusion was significantly smaller in group II, III, IV than that of group I(p<0.05). The total size of the infraction area was significantly smaller in group II, III and IV than that of group I(group I vs. II vs. III vs. IV ; 13.23+/-2.60 vs. 9.17+/-2.23 vs. 10.24+/-2.23 vs. 8.85+/-2.23%, respectively. group I vs. II, III and IV : p<0.05). However, there was not noticed any significant difference in the size of the infarction area among group II, III and IV. This study concludes that the treatment of the combined nimodipine with induced hypertension has no more benefit for the improving infarction in the permanent focal ischemic model than nimodipine or induced hypertension treatment alone.

The Correlation Between the Clinical and Pathological Findings of the Intracranial Ependymomas

The clinical and pathological features were analyzed for 11 cases with intracranial ependymoma treated surgically at the Keimyung University Dongsan Medical Center during the years 1987 to 1992. Tumor histology was reviewed individually and grouped into three categories(Categories I to III) according to the pathologic grade used by Nazar, et al. There were 2 cases(18%) with category I histology, 5(45%) with category II histology, and 4(36%) with category III histology. The high recurrent rate, short recurrent interval, high rate of cerebrospinal fluid seeding and poor outcome were noted in patients with category III histology. The authors also investigated the recurrent interval according to the degree of tumor resection. The mean recurrent interval after surgery was 12 months in cases of subtotal resection and 33 months in a case of total resection. Tumors resected subtotally showed response to radiation and chemotherapy. In conclusion, the pathologic grade and the degree of tumor resection were regarded as important prognostic factors after surgery. Aggressive surgery with chemotherapy or radiotherapy were required in the management of intracranial ependymoma.

Arteriovenous Malformations of the Brain Associated with Cerebral Aneurysms

No abstract available.

Neuroepithelial Tumor Relevant Genes

Cancer may be a disease of genes, arising from genetic damage of diverse sorts-recessive and dominant mutations, large rearrangement of DNA and gene translocation on chromosomes, all leading to distorisions of either the expression or biochemical function of genes. The search for these genetic damage in neoplastic cells now is the most important in cancer research. It has been found that the cancer relevant genes were located on the specific regions of chromosomes. To determine whether epidermal growth factor receptor(EGFR), P53 and bcr genes located in chromosomes 7, 17 and 22 are altered, we examined 12 neuroepithelial tumor with Southern blot analysis(five low grade astrocytoma, two high grade astrocytoma, two medulloblastoma, on oligodendroglioma, one ependymoma, one choroid plexus papilloma). The loss of heterozygosity(LOH) of EGFR gene was detected in two cases of medulloblastoma. The rearrangement of EGFR gene was detected in a case of ependymoma. The LOH of P53 gene was found in a case of choroid plexus papilloma and low grade astrocytoma. The rearrangement of P53 gene was founs id a case of oligodendroglioma. The LOH of bcr gene was observed in two cases of medulloblastoma and low grade astrocytoma. The rearrangement of bcr gene was observed in two cases of high grade astrocytoma. These results suggested that tumorigenesis and tumor development in the neuroepithelial tumor may invlove specific gene changes in chromosomes 7, 17 and 22.

Dumbbell-Shaped Hypoglossal Neurinoma: Case Report and One-stage Operation

A case of dumbbell-shaped hypoglossal neurinoma is reported. Neurinomas of the hypoglossal nerve are very rare, only 35 cases reported. Of these cases, most are intracranial and only 7 were dumbbell-shaped with both intracranial and extracranial components. The clinical feature of the patient was marked ipsilateral atrophy of the tongue. Magnetic resonance imaging should be included in the examination of tumors, and great aids in planning the radical removal of the tumor. In this one-stage operation which was modified lateral inferior suboccipital craniectomy, the most important aspect was removal of the posterior wall of anterior condylar canal and lateral mass of C1. This approach requires a thorough understanding of microsurgical anatomy of the region of foramen magnum. Patient's postoperative course was uneventful. The literatures concerning this lesion were reviewed.