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Each year, the Japan Neurosurgical Society (JNS) reports up-to-date statistics from the Japan Neurosurgical Database regarding case volume, patient demographics, and in-hospital outcomes of the overall cohort and neurosurgical subgroup according to the major classifications of main diagnosis. We hereby report patient demographics, in-hospital mortality, length of hospital stay, purpose of admission, number of medical management, direct surgery, endovascular treatment, and radiosurgery of the patients based on the major classifications and/or main diagnosis registered in 2018 and 2019 in the overall cohort (523283 and 571143 patients, respectively) and neurosurgical subgroup (177184 and 191595 patients, respectively). The patient demographics, disease severity, proportion of purpose of admission (e.g., operation, 33.9-33.5%) and emergent admission (68.4-67.8%), and in-hospital mortality (e.g., cerebrovascular diseases, 6.3-6.5%; brain tumor, 3.1-3%; and neurotrauma, 4.3%) in the overall cohort were comparable between 2018 and 2019. In total, 207783 and 225217 neurosurgical procedures were performed in the neurosurgical subgroup in 2018 and 2019, respectively, of which endovascular treatment comprised 19.1% and 20.3%, respectively. Neurosurgical management of chronic subdural hematoma (19.4-18.9%) and cerebral aneurysm (15.4-14.8%) was most common. Notably, the proportion of management of ischemic stroke/transient ischemic attack, including recombinant tissue plasminogen activator infusion and endovascular acute reperfusion therapy, increased from 7.5% in 2018 to 8.8% in 2019. The JNS statistical update represents a critical resource for the lay public, policy makers, media professionals, neurosurgeons, healthcare administrators, researchers, health advocates, and others seeking the best available data on neurosurgical practice.

Secure reconstruction in transsphenoidal surgery (TSS) is important for the prevention of the major and serious complication of postoperative cerebrospinal fluid (CSF) leak. Although abdominal fat can be safely and effectively used as a reconstruction tissue, harvesting it from the abdominal wall is traumatic and invasive, resulting in cosmetic problems. In this report, we present a method of harvesting abdominal fat using a minimally invasive liposuction technique to avoid cosmetic issues. Since 2016, we have been using fat harvested from the abdominal wall by suctioning with a dedicated syringe for reconstruction after TSS in selected cases. The liquefied fat obtained by the liposuction technique was wrapped with an oxycellulose sheet and changed its form to what we termed "fatty candy". In this form, the fat maintained its configuration and could be handled almost as easily as a conventional fat graft. In our experienced series, there was no case with wound complication nor postoperative or late-onset CSF leak during a postoperative follow-up of at least 3 months. The fat harvested by this simple and minimally invasive liposuction technique can be expected to provide an autologous graft that is adequate not only for prevention of cosmetic problems but also for prevention of postoperative CSF leak.

The nasal cavity is the exclusive surgical corridor for endoscopic endonasal surgery; however, it is sometimes too narrow to allow extensive surgical maneuvering. Here we show the technique of submucosal inferior turbinectomy (SIT) to widen this surgical corridor. Its effectiveness is evaluated quantitatively by comparing pre- and intraoperative magnetic resonance images. Between March 2015 and October 2018, we performed endoscopic endonasal resection of 57 skull base tumors with 3T intraoperative magnetic resonance imaging (iMRI). Among these resections, cases with previous endonasal surgery and cases for which the iMRI did not cover the entire nasal cavity were excluded. Finally, six cases with and 19 cases without SIT were included in the subsequent retrospective analysis. We measured the dimensions of the narrowest area in inferior nasal cavity on pre- and intraoperative coronal plane gadolinium (Gd)-enhanced T1-weighted MR images using dedicated software, and compared them. The incidence rates of postoperative nasal complaints at outpatient clinics were also compared. Considerable widening of the inferior nasal cavity could be achieved with the SIT, which was statistically significant compared with those without the SIT (111.1 ± 56.5% vs. 39.4 ± 59.4%, respectively; P = 0.0093). In terms of the incidence rate of postoperative nasal complaints at 6 months, there was no statistical difference between the groups (33.3% vs. 15.8%, respectively; P = 0.35). SIT is effective for widening the surgical corridor while keeping nasal function and is especially helpful for lower clivus and laterally extended skull base lesions.

The Japan Neurosurgical Database (JND) is a prospective observational study registry established in 2017 by the Japan Neurosurgical Society (JNS) to visualize real-world clinical practice, promote science, and improve the quality of care and neurosurgery board certification in Japan. We summarize JND's aims and methods, and describes the 2018 survey results. The JND registered in-hospital patients' clinical data mainly from JNS training institutions in 2018. Caseload, patient demographics, and in-hospital outcomes of the overall cohort and a neurosurgical subgroup were examined according to major classifications of main diagnosis. Neurosurgical caseload per neurosurgeon in training in core hospitals in 2018 was calculated as an indicator of neurosurgical training. Of 523,283 cases (male 55.3%) registered from 1360 participating institutions, the neurosurgical subgroup comprised of 33.9%. Among the major classifications, cerebrovascular diseases comprised the largest proportion overall and in the neurosurgical subgroup (53.1%, 41.0%, respectively), followed by neurotrauma (19.1%, 25.5%), and brain tumor (10.4%, 12.8%). Functional neurosurgery (6.4%, 3.7%), spinal and peripheral nerve disorders (5.1%, 10.1%), hydrocephalus/developmental anomalies (2.9%, 5.3%), and encephalitis/infection/inflammatory and miscellaneous diseases (2.9%, 1.6%) comprised smaller proportions. Most patients were aged 70-79 years in the overall cohort and neurosurgical subgroup (27.8%, 29.4%). Neurotrauma and cerebrovascular diseases in the neurosurgical subgroup comprised a higher and lower proportion, respectively, than in the overall cohort in elderly patients (e.g. 80 years, 46.9% vs. 33.5%, 26.8% vs. 54.4%). The 2018 median neurosurgical caseload per neurosurgeon in training was 80.7 (25-75th percentile 51.5-117.5). These initial results from 2018 reveal unique aspects of neurosurgical practice in Japan.

Mechanical thrombectomy using the stent retriever has been proven to be effective for select patients with acute ischemic stroke. We evaluated our early experience using the device after its approval in 2014 in Japan, with a special emphasis on the occlusion site. Fifty consecutive endovascular revascularization procedures for treating anterior acute large vessel occlusion were performed using the Trevo ProVue as the first-line device at our institute between April 2015 and March 2016. Focusing on the involvement of the M1-M2 bifurcation with deployment or retrieval of the stent retriever, we regarded the middle cerebral artery M1 mid-portion as the boundary and divided the cases into proximal (n = 26) and distal (n = 24) groups. We assessed the overall clinical outcome and compared the outcome between the two groups. Among 50 patients (median age, 80 years; National Institutes of Health Stroke Scale score (NIHSS) score, 20), successful (modified Thrombolysis in Cerebral Infarction score (TICI) 2b or 3) or complete revascularization (TICI 3) was achieved in 41 patients (82%; 88% in the proximal group vs 75% in the distal group, P = 0.28) and in 27 patients (54%; 73% vs 33%, P = 0.01), respectively. Symptomatic intracranial hemorrhage occurred in three patients (6%; 4% vs 8%, P = 0.60). A good outcome (mRS score 0 to 2) was obtained in 25 patients at 90 days (50%; 54% vs 46%, P = 0.78). Mechanical thrombectomy using the Trevo ProVue was safe and effective in patients with acute cerebral artery occlusion, especially for proximal occlusions. The efficacy of the procedure for distal occlusions was somewhat inferior to those for proximal occlusions, which might be resolved by next generation devices.

A 33-year-old woman presented with rare brain metastases from undifferentiated high-grade sarcoma manifesting as headache and vomiting. Magnetic resonance (MR) imaging demonstrated multiple tumors in the brain, subcutaneous soft tissue, and mediastinum. The patient underwent surgery, followed by chemotherapy and radiotherapy. The histological diagnosis was undifferentiated high-grade sarcoma. Radiotherapy was effective, but the brain tumors recurred 6 months later. The patient underwent high-dose methotrexate therapy, but showed no response. Promoter hypermethylation in the O6 methylguanine-deoxyribonucleic acid methyltransferase (MGMT) genes was detected and MGMT protein expression was negative in the recurrent tumor, so temozolomide (TMZ) salvage chemotherapy was given, and follow-up MR imaging showed tumor reduction. This case suggests that TMZ may be effective for brain metastasis of undifferentiated sarcoma without MGMT protein expression.

A 27-year-old woman presented with headache and occasional numbness over her right face. Computed tomography revealed a hypodense mass in the middle cranial fossa and another adjacent hyperdense mass in the posterior fossa with erosion of the right petrous apex. Magnetic resonance imaging revealed the lesion in the middle cranial fossa as iso- to hypointense on T(1)-weighted and hyperintense on T(2)-weighted imaging, with peripheral enhancement after gadolinium administration, and the adjacent lesion in the posterior fossa as hyperintense on T(1)-weighted and hypointense on T(2)-weighted imaging. During surgery, these lesions mimicking two adjacent distinct tumors were revealed to connect through Meckel's cave. The hypodense lesion in the middle cranial fossa consisted of pearly-like solid contents, and the hyperdense lesion in the posterior cranial fossa consisted of viscid dark-green materials. The tumors were gross totally resected with endoscopic assistance. Histological examination confirmed that the tumor was an epidermoid cyst. The present case cyst indicates that although the diffusion-weighted imaging sequence is useful for detection of intracranial epidermoid cysts, epidermoid cysts including viscous materials with unusual radiological findings could complicate the preoperative diagnosis.

A 55-year-old woman presented with a rare xanthogranuloma of the sellar region after complaining of severe headache and visual disturbance 3 months previously. Clinical examination showed she was alert with early signs of bitemporal hemianopsia. Endocrinological examination revealed hypopituitarism. Magnetic resonance imaging showed an intrasellar mass extending into the suprasellar region and compressing the optic chiasma, which appeared homogeneously hyperintense on T(1)-weighted images. Endonasal transsphenoidal resection of the tumor was performed. Histological examination disclosed granulomatous tissue with cholesterol clefts, hemosiderin deposits, fibrous tissues, and macrophages containing rich fat. The histological diagnosis was xanthogranuloma of the sellar region. Her visual symptoms recovered postoperatively although the hypopituitarism remained. Xanthogranuloma of the sellar region is rare, but must be considered in the differential diagnosis of tumors of the sellar region.

A 54-year-old man with Klinefelter syndrome presented with glioblastoma multiforme manifesting as a 2-week history of motor weakness of the bilateral extremities. Magnetic resonance imaging showed multiple heterogeneously enhanced tumors in the bilateral frontal lobes. Angiography showed no tumor stain or arteriovenous shunt. The tumor was partially removed through a right craniotomy. The histological diagnosis was glioblastoma. Immunohistochemical examination showed no O(6)-methylguanine-deoxyribonucleic acid methyltransferase protein expression. Postoperative local radiotherapy (60 Gy/30 fractions) combined with temozolomide (75 mg/m(2) x 42 days) and interferon-beta (3,000,000 U, 3 times/week) was performed. The patient's clinical status rapidly deteriorated during chemoradiotherapy, and he died of tumor progression 3.5 months after the surgery. Postmortem examination revealed widespread glioblastoma infiltrating the basal ganglia and thalamus. Klinefelter syndrome is associated with increased cancer predisposition, especially for male breast cancer and germ cell tumors, but glioma is extremely rare. The abnormal genetic constitution of this patient may have been directly responsible for the poor outcome.

An 18-year-old male presented with multiple cavernous angiomas of the cauda equina manifesting as acute onset of severe low back pain radiating into the bilateral legs. Magnetic resonance imaging revealed a 20 mm by 15 mm nonenhanced, heterogeneous intensity intradural mass at the L-1 level, which had completely obliterated the spinal canal. After laminectomy at T12-L1 and dural incision, a 20 mm dark-bluish, mulberry-like tumor was seen, displacing the cauda equina circumferentially. After total removal of this tumor, four more small tumors were found adhering to different nerve roots, which were not resected. Histological examination revealed cavernous angioma. Although the postoperative course was uneventful, close observation of the residual tumors is required.

A 35-year-old woman presented with a non-functioning pituitary adenoma manifesting as amenorrhea and impaired visual acuity in 1984. The tumor was grossly totally resected through a right frontotemporal craniotomy. The patient underwent surgery for three recurrences in the next 5 years. She was treated with gamma knife surgery for the residual tumor in 1994. Follow-up magnetic resonance (MR) imaging revealed a tumor in the right frontal base in 1999, and the left middle fossa in 2002. Total removal of these tumors was performed. Follow-up MR imaging showed regrowth of the primary pituitary tumor in 2003, which was partially excised. Histological examination of the specimens from the last three surgeries revealed typical pituitary adenoma without malignant transformation. Pituitary carcinomas have a poor prognosis. However, the present patient survived for 22 years from onset and 6 years from the first dural metastasis. Distant lesions should be removed for histological evaluation to assist the subsequent management.

A 30-year-old man presented with a supratentorial malignant glioma manifesting as isolated progressive left oculomotor nerve paresis. Computed tomography and magnetic resonance imaging showed an intra-axial tumor in the left temporal lobe, extending to the basal and prepontine cisterns, and compressing the brainstem. The tumor was removed subtotally. The histological diagnosis was anaplastic astrocytoma. Malignant glioma with exophytic growth in the temporal lobe should be considered in the differential diagnosis of isolated oculomotor nerve paresis.

A 28-year-old man attempted to kill himself with a knife stab into the parietal area. Neuroimaging showed no vascular impairment except slow venous flow around the knife due to tamponading. After obtaining informed consent, the knife was removed through a craniotomy without new brain injury. Postoperative neurological findings showed no deficit. Follow-up angiography revealed no vascular impairment. No infection occurred. Brain stab wounds cause numerous complications, such as intracranial hemorrhage, injury of important vessels, and infections. Minimal blade movement during removal and precautions to prevent massive hemorrhage are essential.

A 67-year-old man with generalized fatigue and weight loss developed hyponatremia. Endocrinologic examination demonstrated panhypopituitarism. Magnetic resonance imaging showed a pituitary mass extending slightly to the suprasellar region. Transsphenoidal resection of the tumor was performed. Histological examination found exclusively granulomatous tissue with cholesterol clefts, and no epithelial component. This cholesterol granuloma may be classified as xanthogranuloma of the sellar region.

A 21-year-old man developed cervical spinal epidural hematoma one month after a snowboarding injury. He fell down while snowboarding and hit his occiput. Immediately after the injury, he suffered hypesthesic pain in the C-8 area associated with dull neck pain, which persisted for a month. Radiography of the cervical spine detected no pathological findings. The second attack of pain occurred when he was resting, followed by paraparesis and loss of urinary sensation within 24 hours. Emergent magnetic resonance (MR) imaging demonstrated an epidural hematoma at the levels of C-7 to T-2 which compressed the spinal cord. During the operation for removal of the hematoma, arterial rebleeding occurred from a small artery in the dural sac on the right C-8 root, which was thought to be responsible for the hematoma. The patient was discharged with no neurological deficits. Snowboarding-related injuries occur with higher frequency and involve greater risks compared to skiing-related injuries. Repeat MR imaging is strongly recommended to follow up any spinal injury, particularly in cases associated with focal neurological signs.

A 50-year-old male presented with back pain and numbness of the lower extremities persisting for 10 years. He had played volleyball for a long period until recently. He had no history of meningitis or traumatic injury. Magnetic resonance imaging revealed a syringomyelia located in the region from T8 to T9 without contrast enhancement or Chiari malformations. Computed tomography showed T9-10 spinal stenosis caused by the right enlarged ossified yellow ligament. Decompressive laminectomy was performed and the ossified ligament removed. Due to the finding of arachnoid thickening and adhesions during the intradural operation, shunting was also performed. Postoperatively, the neuroimaging and clinical findings improved. Syringomyelia is often associated with Chiari malformations, trauma, spinal tumor, hemorrhaging, and meningitis. We suggest that repeated minor mechanical damage caused by physical exercise in addition to long-standing compression of the spinal cord due to spinal spondylosis could induce severe arachnoid fibrotic change similar to adhesive arachnoiditis, which may be one of the main triggers of syringomyelia. Extradural decompressive surgery is considered to be the initial treatment for syringomyelia associated with spinal spondylosis.

A 35-year-old female complained of right-sided watery nasal discharge persisting for 2 weeks. Neuroimaging investigations revealed a defect in the lateral side of middle cranial fossa, temporal lobe encephalocele protruding into the lateral extension of the sphenoid sinus, and cerebrospinal fluid (CSF) collection on the right side of the sphenoid sinus. The transcranial approach was performed for resection of the encephalocele and obliteration of the cranial base defect anterolateral to the foramen spinosum with transcranial multilayered closure of the defect using autologous fat, cranial bone graft, and vascularized split temporal muscle. At 1-year follow up, the CSF rhinorrhea had not recurred. Transcranial multilayered closure of the defect is safe and reliable, particularly for large CSF fistula at the far lateral sphenoid sinus.

A 49-year-old man was admitted suffering from headache persisting for a month. He had a history of primary spinal intramedullary malignant melanoma at the T6 level 18 years previously, which had remained stable for 18 years. Magnetic resonance imaging revealed central nervous system (CNS) dissemination of malignant melanoma. Whole brain radiation therapy (30 Gy), local radiation therapy (15 Gy), and routine intrathecal injection of interferon beta were performed. The progression of CNS dissemination of malignant melanoma was controlled without neurological deterioration for 38 months. The prognosis for primary CNS malignant melanomas better than that for cutaneous melanoma. However, the clinical course is still unknown, and CNS dissemination is regarded fatal. The unusually long survival in the present case indicates the effectiveness of the combined radiotherapy and interferon therapy.

Restenosis following carotid endarterectomy is not a rare condition. Among 122 endarterectomies we experienced, five restenoses (4.1%) were encountered and treated by the second surgery. The present report clarifies the clinical profiles and pathological findings of restenosis following carotid endarterec-tomy. Mean age of restenosis group (59 years old) was not significantly different from the group without restenosis (62 years old). Average duration between the first endarterectomy and the second surgery was 17 months (8-30 months). Initial symptoms were transient ischemic attack in three sides, minor stroke in one side, and asymptomatic in one. Degree of stenosis was tight (≥90%) in two and moderate (70-89%) in three. It is interesting to note that no ulcer was noted in the first endarterectomy specimen. At surgery for restenosis, two cases had symptoms and another two cases were asymptomatic, though all had neck bruits. Four of five lesions were treated by short venous graft from common carotid artery to distal internal carotid artery and another lesion was treated by second endarterectomy and Dacron patch graft. Pathology was studied in four and all showed myointimal hyperplasia. Three of four reste-nosis tissues showed mutant form p53 by immunohistochemistry. The present study indicates that reste-nosis following carotid endarterectomy is not a rare status. Short venous bypass across the stenotic por-tion is the treatment of choice. Monoclonal growth of smooth muscle with mutant form p53 might be related to the restenosis.

A new technique for decompressive craniectomy with duraplasty was developed for cases in which brain swelling was present at dural closure. Expanded polytetrafluoroethylene (ePTFE) membrane is placed under the dura, covering the brain surface, without the use of sutures. The dura is then loosely sutured. The procedure was used in 13 patients. No leakage of cerebrospinal fluid into the epidural space or signs of infection were observed. Sutureless insertion of an ePTFE membrane at external decompression may increase the ease of duraplasty, decrease operating time, and avoid injury to the brain resulting from suturing the dura. The technique might be especially useful in emergency cases.

A 61-year-old female complained of low back pain, and had been treated by spinal anesthetic injection more than 70 times over 14 years. Magnetic resonance (MR) imaging, performed at the age of 47 years, revealed no abnormal lesion. However, she developed irritable hypesthetic pain in the left leg at 61 years of age. MR imaging revealed a round mass appearing isointense on the T 1 -weighted and slightly hyperintense on the T 2 -weighted images. Laminectomy revealed an epidermoid cyst, which was removed. This case clearly demonstrates that adults can acquire epidermoid tumor which very probably has an iatrogenic origin. The incidence of epidermoid tumor is low, but we should be aware of the potential adverse complications such as formation of epidermoid tumors after lumbar puncture.

In cases of severe uncontrollable brain swelling, simple skin closure often increases intracranial pressure. This study examined the efficacy of a new technique of decompressive skinplasty to decrease intracranial pressure following decompressive craniectomy in cases of severe traumatic brain injury with uncontrollable brain swelling. In our technique, we use artificial dermis to avoid elevation of intracranial pressure. After performing decompressive craniectomy and duraplasty with artificial dura, decompressive skinplasty with artificial dermis was performed in 5 patients for whom simple skin closure caused the intracranial pressure to elevate under intracranial pressure monitoring. Artificial dermis was grafted onto the region to cover the skin defect and sutured to the skin with 4-0 nylon sutures. Two weeks after surgery, the silicone layer of the artificial dermis was removed and ointment treatment was continued until complete epithelialization was achieved. In all cases, decompressive skinplasty contributed dramatically to decreasing the intracranial pressure in patients with uncontrollable brain swelling. The technique of decompressive skinplasty with artificial dermis contributed to dramatically decreasing the intracranial pressure. More cases are required to investigate the indications for this technique.

A 42-year-old female presented with recurrent primary central nervous system lymphoma mimicking the roentgenographic appearance of diffuse brain degeneration. Betamethazone was administered, but her condition worsened. Biopsy of a swollen neck lymph node demonstrated lymphoma cells. Computed tomography and magnetic resonance (MR) imaging showed no contrast-enhanced lesions. T2-weighted MR imaging revealed diffuse, high intensity areas in the white matter of the bilateral cerebrum, basal ganglia, and brainstem. Despite chemotherapy for systemic lymphoma, she died of respiratory arrest. Histological examination of autopsy specimens showed diffuse infiltration of lymphoma cells in the perivascular space of the cerebral cortex, but little neovascularization. The absence of contrast enhancement may have been due to preservation of the blood-brain barrier. Histological confirmation of roentgenographic findings of brain degeneration is important in patients treated for primary central nervous system lymphoma.

A 44-year-old woman with microscopic polyangiitis (MPA) presented with a ruptured cerebral aneurysm. She was admitted to our hospital for further examination of progressive renal failure. She was found lying on the ward floor. Computed tomography showed subarachnoid hemorrhage, and digital subtraction angiography revealed a saccular-like aneurysm arising from the right distal posterior inferior cerebellar artery (PICA) at the non-branching site. We performed neck clipping of the right distal PICA aneurysm, which recurred 5 days after the operation. Second angiography demonstrated a right distal PICA aneurysm just above the site of the clip. Therefore, we performed trapping of the affected lesion with emergent bypass of the contralateral occipital artery to the ipsilateral PICA. Her postoperative course was uneventful until she coughed up blood and had gross hematuria 3 days after the second surgery. Histological examination of a renal biopsy specimen revealed crescentic glomerulonephritis. MPA was diagnosed on the basis of the cardinal symptoms, including progressive glomerular nephritis and the lung abnormality, as well as the presence of myeloperoxidase-antineutrophil cytoplasmic antibodies. After intensive treatment, she was discharged for rehabilitation without neurological deficit. MPA commonly affects small-sized vessels mainly in the kidneys and lungs and may lead to crescentic glomerulonephritis and pulmonary hemorrhage. MPA is rarely associated with aneurysms of medium-sized muscular vessels. Cerebral aneurysm is extremely rare in patients with MPA, but rupture of an intracranial fusiform aneurysm can be lethal, so screening of the intracranial vessels should be performed by magnetic resonance imaging in patients with MPA.

A 50-year-old male presented with back pain and numbness of the lower extremities persisting for 10 years. He had played volleyball for a long period until recently. He had no history of meningitis or traumatic injury. Magnetic resonance imaging revealed a syringomyelia located in the region from T8 to T9 without contrast enhancement or Chiari malformations. Computed tomography showed T9-10 spinal stenosis caused by the right enlarged ossified yellow ligament. Decompressive laminectomy was performed and the ossified ligament removed. Due to the finding of arachnoid thickening and adhesions during the intradural operation, shunting was also performed. Postoperatively, the neuroimaging and clinical findings improved. Syringomyelia is often associated with Chiari malformations, trauma, spinal tumor, hemorrhaging, and meningitis. We suggest that repeated minor mechanical damage caused by physical exercise in addition to long-standing compression of the spinal cord due to spinal spondylosis could induce severe arachnoid fibrotic change similar to adhesive arachnoiditis, which may be one of the main triggers of syringomyelia. Extradural decompressive surgery is considered to be the initial treatment for syringomyelia associated with spinal spondylosis.

A 33-year-old woman presented with rare brain metastases from undifferentiated high-grade sarcoma manifesting as headache and vomiting. Magnetic resonance (MR) imaging demonstrated multiple tumors in the brain, subcutaneous soft tissue, and mediastinum. The patient underwent surgery, followed by chemotherapy and radiotherapy. The histological diagnosis was undifferentiated high-grade sarcoma. Radiotherapy was effective, but the brain tumors recurred 6 months later. The patient underwent high-dose methotrexate therapy, but showed no response. Promoter hypermethylation in the O(6)-methylguanine-deoxyribonucleic acid methyltransferase (MGMT) genes was detected and MGMT protein expression was negative in the recurrent tumor, so temozolomide (TMZ) salvage chemotherapy was given, and follow-up MR imaging showed tumor reduction. This case suggests that TMZ may be effective for brain metastasis of undifferentiated sarcoma without MGMT protein expression.

A 55-year-old woman presented with a rare xanthogranuloma of the sellar region after complaining of severe headache and visual disturbance 3 months previously. Clinical examination showed she was alert with early signs of bitemporal hemianopsia. Endocrinological examination revealed hypopituitarism. Magnetic resonance imaging showed an intrasellar mass extending into the suprasellar region and compressing the optic chiasma, which appeared homogeneously hyperintense on T(1)-weighted images. Endonasal transsphenoidal resection of the tumor was performed. Histological examination disclosed granulomatous tissue with cholesterol clefts, hemosiderin deposits, fibrous tissues, and macrophages containing rich fat. The histological diagnosis was xanthogranuloma of the sellar region. Her visual symptoms recovered postoperatively although the hypopituitarism remained. Xanthogranuloma of the sellar region is rare, but must be considered in the differential diagnosis of tumors of the sellar region.

A 35-year-old female complained of right-sided watery nasal discharge persisting for 2 weeks. Neuroimaging investigations revealed a defect in the lateral side of middle cranial fossa, temporal lobe encephalocele protruding into the lateral extension of the sphenoid sinus, and cerebrospinal fluid (CSF) collection on the right side of the sphenoid sinus. The transcranial approach was performed for resection of the encephalocele and obliteration of the cranial base defect anterolateral to the foramen spinosum with transcranial multilayered closure of the defect using autologous fat, cranial bone graft, and vascularized split temporal muscle. At 1-year follow up, the CSF rhinorrhea had not recurred. Transcranial multilayered closure of the defect is safe and reliable, particularly for large CSF fistula at the far lateral sphenoid sinus.

A 54-year-old man with Klinefelter syndrome presented with glioblastoma multiforme manifesting as a 2-week history of motor weakness of the bilateral extremities. Magnetic resonance imaging showed multiple heterogeneously enhanced tumors in the bilateral frontal lobes. Angiography showed no tumor stain or arteriovenous shunt. The tumor was partially removed through a right craniotomy. The histological diagnosis was glioblastoma. Immunohistochemical examination showed no O(6)-methylguanine-deoxyribonucleic acid methyltransferase protein expression. Postoperative local radiotherapy (60 Gy/30 fractions) combined with temozolomide (75 mg/m(2) x 42 days) and interferon-beta (3,000,000 U, 3 times/week) was performed. The patient's clinical status rapidly deteriorated during chemoradiotherapy, and he died of tumor progression 3.5 months after the surgery. Postmortem examination revealed widespread glioblastoma infiltrating the basal ganglia and thalamus. Klinefelter syndrome is associated with increased cancer predisposition, especially for male breast cancer and germ cell tumors, but glioma is extremely rare. The abnormal genetic constitution of this patient may have been directly responsible for the poor outcome.

A 49-year-old man was admitted suffering from headache persisting for a month. He had a history of primary spinal intramedullary malignant melanoma at the T6 level 18 years previously, which had remained stable for 18 years. Magnetic resonance imaging revealed central nervous system (CNS) dissemination of malignant melanoma. Whole brain radiation therapy (30 Gy), local radiation therapy (15 Gy), and routine intrathecal injection of interferon beta were performed. The progression of CNS dissemination of malignant melanoma was controlled without neurological deterioration for 38 months. The prognosis for primary CNS malignant melanomas better than that for cutaneous melanoma. However, the clinical course is still unknown, and CNS dissemination is regarded fatal. The unusually long survival in the present case indicates the effectiveness of the combined radiotherapy and interferon therapy.

A 35-year-old woman presented with a non-functioning pituitary adenoma manifesting as amenorrhea and impaired visual acuity in 1984. The tumor was grossly totally resected through a right frontotemporal craniotomy. The patient underwent surgery for three recurrences in the next 5 years. She was treated with gamma knife surgery for the residual tumor in 1994. Follow-up magnetic resonance (MR) imaging revealed a tumor in the right frontal base in 1999, and the left middle fossa in 2002. Total removal of these tumors was performed. Follow-up MR imaging showed regrowth of the primary pituitary tumor in 2003, which was partially excised. Histological examination of the specimens from the last three surgeries revealed typical pituitary adenoma without malignant transformation. Pituitary carcinomas have a poor prognosis. However, the present patient survived for 22 years from onset and 6 years from the first dural metastasis. Distant lesions should be removed for histological evaluation to assist the subsequent management.

An 18-year-old male presented with multiple cavernous angiomas of the cauda equina manifesting as acute onset of severe low back pain radiating into the bilateral legs. Magnetic resonance imaging revealed a 20 mm by 15 mm nonenhanced, heterogeneous intensity intradural mass at the L-1 level, which had completely obliterated the spinal canal. After laminectomy at T12-L1 and dural incision, a 20 mm dark-bluish, mulberry-like tumor was seen, displacing the cauda equina circumferentially. After total removal of this tumor, four more small tumors were found adhering to different nerve roots, which were not resected. Histological examination revealed cavernous angioma. Although the postoperative course was uneventful, close observation of the residual tumors is required.

A 62-year-old male presented with an unusually large mycotic aneurysm mimicking a saccular aneurysm manifesting as coma and hypotension. Computed tomography showed intracerebral and intraventricular hemorrhage. He was in septic shock due to acute infectious endocarditis. Cerebral angiography disclosed a large distal anterior cerebral artery aneurysm. The diagnosis was mycotic aneurysm based on the morphological features and associated endocarditis. The aneurysm and the parent artery were successfully occluded by endovascular embolization. High-dose antibiotic therapy in the following 6 weeks resulted in resolution of the infectious endocarditis. Early exclusion of ruptured mycotic aneurysm is mandatory because of the high risk of rerupture. Endovascular treatment is an effective alternative for mycotic aneurysms, especially if the patient's general condition is poor. Parent artery occlusion can be safely tolerated if the aneurysm is located distally.

A 30-year-old man presented with a supratentorial malignant glioma manifesting as isolated progressive left oculomotor nerve paresis. Computed tomography and magnetic resonance imaging showed an intra-axial tumor in the left temporal lobe, extending to the basal and prepontine cisterns, and compressing the brainstem. The tumor was removed subtotally. The histological diagnosis was anaplastic astrocytoma. Malignant glioma with exophytic growth in the temporal lobe should be considered in the differential diagnosis of isolated oculomotor nerve paresis.

A 61-year-old female complained of low back pain, and had been treated by spinal anesthetic injection more than 70 times over 14 years. Magnetic resonance (MR) imaging, performed at the age of 47 years, revealed no abnormal lesion. However, she developed irritable hypesthetic pain in the left leg at 61 years of age. MR imaging revealed a round mass appearing isointense on the T1-weighted and slightly hyperintense on the T2-weighted images. Laminectomy revealed an epidermoid cyst, which was removed. This case clearly demonstrates that adults can acquire epidermoid tumor which very probably has an iatrogenic origin. The incidence of epidermoid tumor is low, but we should be aware of the potential adverse complications such as formation of epidermoid tumors after lumbar puncture.

A 28-year-old man attempted to kill himself with a knife stab into the parietal area. Neuroimaging showed no vascular impairment except slow venous flow around the knife due to tamponading. After obtaining informed consent, the knife was removed through a craniotomy without new brain injury. Postoperative neurological findings showed no deficit. Follow-up angiography revealed no vascular impairment. No infection occurred. Brain stab wounds cause numerous complications, such as intracranial hemorrhage, injury of important vessels, and infections. Minimal blade movement during removal and precautions to prevent massive hemorrhage are essential.

This study evaluated the clinical validity of frameless stereotaxy using high-field intraoperative magnetic resonance (iMR) imaging combined with an in-room neuronavigation system. A 1.5 Tesla MR scanner in conjunction with a ceiling-mounted neuronavigation system was used during 32 frameless stereotaxy procedures consisting of 19 brain biopsies and 13 catheter placements between April 2002 and mid-October 2003. Evaluation of the procedure was based on either the rate of histological diagnostic yield or the ability to accurately position the catheter in the target region. This technique allowed successful registration with a mean error of 1.2 +/- 0.8 mm and resulted in successful placement of the instrument within the target tissue. Intraoperatively, frozen section analysis showed all biopsy samples contained pathological tissue and locations of sampling points were confirmed by iMR imaging. Specific final diagnosis was made in all 19 brain biopsies. The tip of the catheter was successfully placed into the target in all 13 patients confirmed by iMR imaging. The catheter was repositioned based on iMR imaging in four of 13 patients, increasing the rate of successful placement. There were no procedure-related neurological deficits or mortality, but we encountered two cases of wound infection, one needing surgical revision. Total additional procedure time related to the induction of iMR imaging was 76.7 +/- 23.3 minutes. This initial experience of the combination of conventional frameless stereotaxy and high-field iMR imaging improved the quality of frameless stereotaxy with low morbidity and mortality, but did not translate into a significant reduction of procedure-related time.

A 61-year-old male developed acute cerebellar swelling after thrombolytic therapy for basilar artery occlusion. He was treated with intra-arterial tissue plasminogen activator 12 hours following symptomatic onset, and did well in the immediate post-treatment period but deteriorated the next day. Computed tomography demonstrated acute cerebellar edema and hydrocephalus. Suboccipital external decompression and ventricular drainage were performed. He survived and 1 year later he could perform daily activities at home. Computed tomography and angiography are essential to monitor the post-treatment course following thrombolysis of vertebrobasilar occlusive disease.

A 77-year-old man suffered subarachnoid hemorrhage due to a ruptured aneurysm of the distal anterior inferior cerebellar artery (AICA). He had a history of hearing disturbance in the left ear for more than 3 years. Computed tomography on three separate occasions had found no abnormalities. One month before the hemorrhage, he came to our outpatient service complaining of vertigo. Magnetic resonance (MR) imaging and MR angiography detected no abnormality. Conventional angiography demonstrated an aneurysm of 8 mm diameter in the distal AICA region after the hemorrhage. Filling and wash out of the aneurysm sac by contrast medium was markedly delayed, which suggested that MR imaging had failed to detect the flow void because of the slow blood flow in the dome. The aneurysm was clipped successfully. He was discharged with mild dysarthria on the 33rd postoperative day. MR angiography has limitations in detecting unruptured aneurysms and there is certainly a high risk group of false negatives, including aneurysms located in the distal region of the main trunk.

A 67-year-old man with generalized fatigue and weight loss developed hyponatremia. Endocrinologic examination demonstrated panhypopituitarism. Magnetic resonance imaging showed a pituitary mass extending slightly to the suprasellar region. Transsphenoidal resection of the tumor was performed. Histological examination found exclusively granulomatous tissue with cholesterol clefts, and no epithelial component. This cholesterol granuloma may be classified as xanthogranuloma of the sellar region.

A 21-year-old man developed cervical spinal epidural hematoma one month after a snowboarding injury. He fell down while snowboarding and hit his occiput. Immediately after the injury, he suffered hypesthesic pain in the C-8 area associated with dull neck pain, which persisted for a month. Radiography of the cervical spine detected no pathological findings. The second attack of pain occurred when he was resting, followed by paraparesis and loss of urinary sensation within 24 hours. Emergent magnetic resonance (MR) imaging demonstrated an epidural hematoma at the levels of C-7 to T-2 which compressed the spinal cord. During the operation for removal of the hematoma, arterial rebleeding occurred from a small artery in the dural sac on the right C-8 root, which was thought to be responsible for the hematoma. The patient was discharged with no neurological deficits. Snowboarding-related injuries occur with higher frequency and involve greater risks compared to skiing-related injuries. Repeat MR imaging is strongly recommended to follow up any spinal injury, particularly in cases associated with focal neurological signs.

The authors describe a case of multiple intracerebral arteriovenous malformations (AVMs) in a 23-year-old male with two distinct, deep-seated AVMs. One was located in the left basal ganglia, which had bled twice, and the other in the splenium. They were removed separately. He recovered satisfactorily with only a mild dysphasia. The authors emphasize that the therapeutic principle for multiple AVMs is the same as that for a solitary AVM. Multiplicity alone does not dictate the operability. Dissection just adjacent to the nidus and direct coagulation of an AVM are the indicated techniques, especially in cases of deep-seated AVMs in order to reduce postoperative neurological deficit.