Search

We report a pediatric case of multiple sclerosis mimicking malignant brain tumor. A 11-year-old male presented with high fever, vomiting and partial convulsion of left lower extremity followed by left visual impairment. Magnetic resonance imaging (MRI) revealed a mass lesion in the right frontal lobe with significant peripheral edema. Incomplete ring-like enhancement by gadolinium administration was also noted. Open biopsy of the lesion was undertaken that provided pathological confirmation of demyelinating changes. Luxol fast blue stain and Bodian stain demonstrated extensive myelin loss and good preservation of axons. The patient was given intravenous high-dose methyl-prednisolone and sequential oral low-dose prednisone, which improved his neurological status progressively. The lesion was dramatically decreased in size and finally disappeared. Although many tumor-like demyelinating lesions were reported previously, pediatric cases of multiple sclerosis mimicking malignant brain tumor are extremely rare. Pathological examinations including Luxol fast blue stain and Bodian stain are essential for exact diagnosis.

Biliary atresia (BA) is a rare disease, characterized by progressive and obliterative cholangiopathy, and is one of the major causes of secondary vitamin K deficiency in infancy. We describe 15 infants (10 female, 5 male) with BA, presenting with intracranial hemorrhage (ICH), including 10 subdural hemorrhages, 4 subarachnoid hemorrhages, 2 intraventricular hemorrhages, and 1 intraparenchymal hemorrhage. The age at onset of ICH ranged from 26 to 79 (mean 54.2) days. Eight patients underwent successful surgical evacuation of ICH, following administration of vitamin K. All 15 patients underwent Kasai portoenterostomy for BA 8–30 days after onset. During a mean follow-up period of 86.8 (range 2–352) months, 4 patients died of liver failure despite lack of neurological sequelae. Two patients underwent living-related donor and 1 patient living-unrelated donor liver transplantation. Only 2 patients suffered neurological signs and symptoms, including mental retardation and epilepsy, whereas 3 were noted to have temporary hemiparesis which recovered completely during the follow-up period. The possibility of BA should be considered in the treatment of ICH due to vitamin K deficiency, since it is reported to be one of the major causes of secondary vitamin K deficiency. Urgent surgical intervention for ICH can be performed successfully following sufficient administration of vitamin K or fresh frozen human plasma. Moreover, early performance of Kasai portoenterostomy is possible even for patients who have undergone craniotomy.

[1] Atmospheric sphericity is an important factor that must be considered in order to evaluate an accurate ozone loss rate in the polar stratosphere. The built-in plane-parallel radiative transfer scheme of a nudging chemical transport model (CTM) and an atmospheric general circulation model (AGCM) with coupled chemistry is modified by a pseudospherical approximation. The plane-parallel atmosphere radiative transfer version (PPA version) is compared with the pseudospherical atmosphere radiative transfer version (SA version) for both the nudging CTM and AGCM. The nudging CTM can isolate the chemical effects for a given dynamical field, while the interaction among the chemical, radiative, and dynamical processes can be studied with the AGCM. The present analysis focuses on Antarctica during an ozone hole period. In the ozone loss period over Antarctica, ozone starts to decrease earlier and minimum value of total ozone becomes lower in the SA versions of both the nudging CTM and the AGCM than in the corresponding PPA versions. The ozone mixing ratio decreases earlier in the SA version because of an earlier increase of ClO concentration initiated by the upward actinic flux at solar zenith angles greater than 90°. Dynamics plays an important role as well as the chemical processes. During the ozone recovery period, the ozone distribution becomes almost the same in the SA and PPA versions of the nudging CTM, while in the AGCM the ozone amount in the SA version remains at lower values compared to those of the PPA version. In the AGCM, a decrease of ozone over Antarctica enhances the latitudinal gradient of temperature and thus strengthens the polar vortex in the SA version. A resultant delay of the polar vortex breakup causes the delay of the ozone recovery. For the AGCM, ensemble runs are performed. The ensemble experiment exhibits large ozone variances after the middle of December, when the ozone recovery is dynamically controlled. Most ensemble members of the AGCM show a delay of the polar vortex breakup in the SA version, while a few members show opposite results. In the latter members, the polar vortex breakup is strongly affected by the enhanced EP flux from the troposphere around 100 hPa, which causes the variances in the ozone recovery period. Most members, however, do not show large statistical variances; that justifies the conclusions from the ensemble means.

[1] We analyze surface air temperature datasets simulated by a coupled climate model forced with different external forcings, to diagnose the relative importance of these forcings to the observed warming in the early 20th century. The geographical distribution of linear temperature trends in the simulations forced only by natural contributions (volcanic eruptions and solar variability) shows better agreement with observed trends than that does the simulations forced only by well-mixed greenhouse gases. Using an optimal fingerprinting technique we robustly detect a significant natural contribution to the early 20th century warming. In addition, the amplitude of our simulated natural signal is consistent with the observations. Over the same period, however, we could not detect a greenhouse gas signal in the observed surface temperature in the presence of the external natural forcings. Hence our analysis suggests that external natural factors caused more warming in the early 20th century than anthropogenic factors.

SUMMARY Estimates of annual-mean stratospheric temperature trends over the past twenty years, from a wide variety of models, are compared both with each other and with the observed cooling seen in trend analyses using radiosonde and satellite observations. The modelled temperature trends are driven by changes in ozone (either imposed from observations or calculated by the model), carbon dioxide and other relatively well-mixed greenhouse gases, and stratospheric water vapour. The comparison shows that whilst models generally simulate similar patterns in the vertical proe le of annualand global-mean temperature trends, there is a signie cant divergence in the size of the modelled trends, even when similar trace gas perturbations are imposed. Coupled-chemistry models are in as good agreement as models using imposed observed ozone trends, despite the extra degree of freedom that the coupled models possess. The modelled annual- and global-mean cooling of the upper stratosphere (near 1 hPa) is dominated by ozone and carbon dioxide changes, and is in reasonable agreement with observations. At about 5 hPa, the mean cooling from the models is systematically greater than that seen in the satellite data; however, for some models, depending on the size of the temperature trend due to stratospheric water vapour changes, the uncertainty estimates of the model and observations just overlap. Near 10 hPa there is good agreement with observations. In the lower stratosphere (20‐70 hPa), ozone appears to be the dominant contributor to the observed cooling, although it does not, on its own, seem to explain the entire cooling. Annual- and zonal-mean temperature trends at 100 hPa and 50 hPa are also examined. At 100 hPa, the modelled cooling due to ozone depletion alone is in reasonable agreement with the observed cooling at all latitudes. At 50 hPa, however, the observed cooling at midlatitudes of the northern hemisphere signie cantly exceeds the modelled cooling due to ozone depletion alone. There is an indication of a similar effect in high northern latitudes, but the greater variability in both models and observations precludes a e rm conclusion. The discrepancies between modelled and observed temperature trends in the lower stratosphere are reduced if the cooling effects of increased stratospheric water vapour concentration are included, and could be largely removed if certain assumptions were made regarding the size and distribution of the water vapour increase. However, given the uncertainties in the geographical extent of water vapour changes in the lower stratosphere, and the time period over which such changes have been sustained, other reasons for the discrepancy between modelled and observed temperature trends cannot be ruled out.

Hyperosmotic opening of the blood-brain barrier (BBB) by mannitol is being used to enhance drug transport in human brains. Recently, cooling of the solution has been reported to have potential to open the BBB. However, the mechanism in barrier opening and closure remains elusive. We studied the rapid changes in cerebrovascular permeability after hyperosmotic and hypothermic BBB opening in rats, and then demonstrated that the Na+/Ca++ exchange blocker (KB-R7943) prolongs opening.

Between 1985 and 1998, 415 shunt dysfunctions occurred at Kobe Children's Hospital. The main reasons for shunt revision were obstruction of the catheter, shunt infection, and shunt disconnection. This report presents an analysis of 35 patients (36 cases) who underwent a ventriculoperitoneal (VP) shunt revision because of shunt catheter fracture. All patients were less than 18 years old. We researched their age at the time of revision, site of disruption, postoperative period, shunt system, clinical symptoms, and other factors. The mechanical aspects of shunt catheter fracture are also discussed in this report. The peak time of shunt catheter fracture was the time when children were growing up and were entering elementary school. In other words, when their height was increasing rapidly. At that time, the distal catheter is subjected to traction between the valve and the abdomen at the site of insertion in either the upper or lower direction. However, physical examination of the shunt catheter showed normal range. Additional contributory factors were chronic stimulation at the occipital bone, clavium bone, and costal arch, while movement of the neck and body rotation also caused shunt catheter fracture. These factors all originated from shearing strain at the shunt catheter. We look forward to the introduction of a stronger shunt catheter, because surgical repair time must be minimized to protect the child's mental development. In addition, shearing strain at the shunt catheter needs special attention.

Histologically proven eosinophilic myelitis has rarely been reported except in connection with parasitism. To clarify its clinicopathological features, we conducted a nationwide survey of biopsy-proven eosinophilic myelitis of unknown cause throughout Japan. Six such cases were collected and studied immunologically and pathologically. All were young to middle-aged men. All showed a protracted and fluctuating course with mild disability for 3-25 (mean 12.5) months before biopsy. Magnetic resonance imaging revealed localized lesions of T2-high and T1-iso signal intensity with a partial gadolinium enhancement in all cases. Cerebrospinal fluid (CSF) examinations were completely normal except for modest pleocytosis in two cases. Eosinophilia was present in the peripheral blood in two cases but was absent from the CSF of all cases. In spite of the chronic nature of the disease, spinal cord pathology revealed very active lesions with marked cell infiltration consisting mainly of CD8(+) T cells and varying numbers of eosinophils in the perivascular areas and the parenchyma. Both the myelin and axons were severely disrupted in all cases. Moreover, eosinophil cationic protein (ECP), an activated eosinophil product, was heavily deposited in the tissues. All but one case had hyperIgEemia and mite antigen-specific IgE in the sera, and two had accompanying atopic disorders. The present study thus revealed idiopathic eosinophilic myelitis to be a localized and persistent inflammation of the spinal cord, with distinct clinicopathological features, that has a possible link to atopic diathesis.

Background Choroid plexus papilloma (CPP) in the third ventricle is a rare benign intracranial tumor. Methods We report 3 pediatric cases of CPP in the third ventricle. The lesions were totally removed by a different surgical approach in each case. Results When remarkable hydrocephalus is present, the transcortical approach is easier to perform, but may expose the patient to epilepsy and subdural effusion postoperatively. The transcallosal approach offers direct exposure of the ventricle system with minimal risk of cortical damage. The transcallosal-transforaminal approach with posterior enlargement of the foramen of Monro along the choroidal fissure provides a direct trajectory into the third ventricle through the natural cleft. The transcallosal-interforniceal approach does not depend on the size of the foramen of Monro, but it carries a risk for damage to the both fornices. The midline plane of the septum pellucidum and the forniceal columns in children are sometimes easily identifiable and separable, and in such cases the transcallosal-interforniceal approach appears to be a safe route for tumors extending to the posterior third ventricle. The interforniceal approach should be reserved for lesions that cannot be removed safely via the transforaminal approach. Conclusions Young children have a small total blood volume and fragile cardiovascular status. Therefore, it is critical to preserve the venous system and to ligate the feeding artery before extirpation of the tumor. The surgical approach to the third ventricular CPPs should be tailored to individual children based on tumor size, location, and vascularity.

Background: Current studies for Medulloblastoma (MB)/ supratentorial primitive neuroectodermal tumors (sPNETs) which consist of maximal surgical resection, craniospinal radiation therapy (RT) at a dose of 24 Gy and chemotherapy (CT) have demonstrated an increasing survival rate. However, RT related morbidity of neurologic and psychological problems remains a major issue, especially in young children. We report here the preliminary result of multidisciplinary treatment in attempt to reduce the dose of craniospinal RT in our institution. Methods: Between 2002 and 2013, 34 patients aged 0.5-14.11 years (median 4.1 years) with newly diagnosed MB/sPNETs were retrospectively analyzed. Criteria used to categorize patients as high risk (HR) included M1-4 disease by modified Chang staging classification, sPNETs, and infant ( Results: The median follow-up period was 23 months. Twenty-six of 34 children were survived. Two-year progression-free survival were 64.8 ± 16.5% in SR group (N = 12), 90.9 ± 8.7% in HR group (N = 11), and 54.5 ± 15.0% in infants (N = 11), respectively. Two-year overall survival estimates were 77.7 ± 13.8% in SR, 90.9 ± 8.7% in HR, and 60.6 ± 15.7% in infant, respectively. Conclusions: Our preliminary results showed that intensified systemic chemotherapy might contribute to reduction of craniospinal RT without reduction of survival rate. However, the validity of risk-stratification still remains as an issue to be solved.

A huge prepontine-suprasellar arachnoid cyst was identified by fetal sonography and magnetic resonance imaging. It was successfully treated with a two-stage operation using a neuroendoscope. The first operation during the neonatal period consisted of implantation of a cyst-peritoneal shunt. In the second operation, the cyst was fenestrated with the aid of a neuroendoscope. The cyst membrane was seen to cover the foramen magnum and to extend continuously to the ventral surface of the brain stem. At the foramen magnum, it was pulsating synchronously with the pulsation of the vertebral artery, which was suggestive of the mechanism of cyst growth. A ventriculo-peritoneal shunt was inserted to replace the cyst-peritoneal shunt. Endoscopic cyst fenestration is a less invasive alternative for the treatment of arachnoid cysts and can also be used for young children. In that case, however, special care should be taken to avoid complications, especially if the cyst exerts considerable pressure on the critical areas of the brain.

Surgical techniques and their results for tuberculum sellae meningiomas were studied. Thirty-three cases, the first of which was operated in 1980, were analysed. There were 4 men and 29 women with an average age of 46.7 years. Eight cases underwent reop erations. The mean follow-up was 10.7 years. Approaches were pterional for 15 patients, FOZ/FO for 10, bilateral subfrontal for 6, and others for 2. Simpson's grade (I, II, III, IV) were 12, 9, 0, and 12 cases respectively. Recurrence rate was 0% for gra de I and 58.3% for grade IV. The FOZ/FO approach resulted in a lower Simpson's grade ( P =0.05), but other factors were not related to Simpson's grade ( P =0.05). The postoperative visual outcome did not depend on total (grade I and II) or subtotal (grade III and IV) removal ( P =0.01). We conclude that radical removal of the tumours may result in lower recurrence rate without increasing surgical complications. Furthermore, skull base approaches can improve the rate of radical removal of tuberculum sellae meningiomas.

Osmotic disruption of the blood-brain barrier (BBB) by mannitol is currently being used to enhance drug delivery in human brains. Despite clinical and experimental interest, to date the time course in the early phase of disruption has not been accurately identified. The mechanism in barrier closure also remains elusive. We first studied the rapid change in cerebrovascular permeability after BBB disruption in rats, and then demonstrated that the Na(+)/Ca(++) exchange blocker (KB-R7943) prolongs osmotic disruption. Osmotic BBB disruption was attained by using intra-arterial infusion of hypertonic mannitol in Sprague-Dawley (SD) rats. To measure the changes in cerebrovascular permeability, perfusate containing [14C]-sucrose was infused intra-arterially at different time points following osmotic stress. Cerebrovascular permeability was then measured with the in situ brain perfusion technique. This is the first in vivo study demonstrating that osmotic disruption is prolonged by the Na(+)/Ca(++) exchange blocker, which did not affect the peak level of BBB disruption. The exact time course of cerebrovascular reversibility was studied and the earliest BBB disruption was seen to occur 5 min after osmotic stress. Histopathological examination after osmotic disruption with the Na(+)/Ca(++) exchange blocker showed no neuronal damage in rat brains. Our findings represent important experimental information regarding pharmacological manipulation of BBB disruption. The possibility of prolonging the transient opening of the BBB has major clinical implications.

To clarify the pathogenesis of syringomyelia, we examined MRI and histological changes in experimental syringomyelia in progress. Syringomyelia was induced in 19 rabbits by intracisternal injection of a kaolin solution. MRI was performed at 3, 7, 14, or 21 days after the injection. The rabbits were killed immediately after the last MRI and histological examinations were then performed. MRI showed two types of syrinx: hydromyelia accompanied by ventriculomegaly, and cervical cord cavitation in the posterior horn without ventriculomegaly. All changes observed on MRI findings were verified by histological examination. The first type of syrinx had enlarged central canals that were lined with ependyma, but there was no marked presence of spongy tissue around the central canal. The obex was completely filled with kaolin solution. The second type featured small central canals and sponginess or cavities of gray matter in the upper or middle spinal cords. Kaolin was observed around the obex but it was not completely filled. Fourteen days after kaolin injection, the shapes of syrinxes had remained almost the same. MRI showed the chronological changes very clearly, and histological differences of the syrinx correlated with the degree to which the obex was filled with kaolin.

Foramen magnum decompression (FMD) for syringomyelia associated with Chiari I malformation comprises a midline suboccipital expansive cranioplasty, CI laminectomy, opening of the dura (with the arachnoid intact), and expansive duraplasty using Gore-Tex membrane. In this study we assess the utility of intraoperative ultrasound study for FMD. A Sonolayer α SSA-260A was used to perform an ultrasound study during FMD of 12 patients (7 women and 5 men), ranging in age from 13 to 60 years (average, 25.8 years). After craniotomy and laminectomy, the ultrasound scan was performed with the aid of a 7-MHz sector transducer both before and after the dura was opened. Before opening the dura, the ultrasound study demonstrated that the cerebellar tonsils abruptly descended during cardiac systole and ascended during diastole in all patients and that the syrinx contracted in synchrony with tonsillar descent. Opening of the dura reduced the amplitude of the pulsatile movement of the cerebellar tonsils and eliminated contraction of the syrinx. Postoperatively, all the patients were followed up (3 months-13 years; mean, 4.8 years) with neurological and radiological evaluations. MR imaging was used for all patients until the syrinx had disappeared. Increase in syrinx size was not observed in any patient. Ultrasound could detect craniocervical lesions very clearly in all cases. Pulsation of cerebrospinal fluid across the foramen magnum after surgery was confirmed intraoperatively. Ultrasound is quick, convenient, noninvasive, is performed in real time, and can be easily repeated to determine whether sufficient decompression has been achieved.

Two-dimensional phase-contrast (2D-PC) images can be used to evaluate cerebrospinal fluid (CSF) flow dynamics. The fast and active movement of CSF corresponds to cardiac pulsation. This report concerns the quantitative analysis of CSF flow dynamics using 2D-PC images. Since September 1996, we have obtained 35 2D-PC images each from 19 patients. We measured craniocaudal maximum CSF flow (peak velocity) and the position of peak velocity as a percentage of the R-R interval of the cardiac cycle (peak velocity position). In normal volunteers, peak velocity and peak velocity position were 4.67 cm/s and 19.3%, respectively, at the foramen magnum and 4.73 cm/s and 17.5% at the spinal subarachnoid space. In the 14 cases of syringomyelia, preoperative 2D-PC images showed delayed peak velocity position. Postoperative 2D-PC images showed shortened peak velocity position in improved patients. Preoperative CSF flow velocity in syringes was low and showed a phase contrary to that in the subarachnoid space. Postoperative CSF dynamics in syringes showed a normal pulsate pattern, although peak velocity was still low. 2D-PC images are useful for the evaluation of CSF flow dynamics and prediction of surgical results.

Biomechanical and hydrodynamic analysis of the spinal cord was performed to understand the pathogenesis of syringomyelia associated with Chiari I malformation. A finite element analysis of intraspinal stress distribution was done by a newly developed two-dimensional elastic craniocervical model of Chiari I malformation. The finite element model was refined to simulate the effect of the generation of an intraspinal cavity on stress distribution. Three different models—normal, Chiari I malformation, and Chiari I malformation with syrinx—were constructed with triangular elastic elements. Different material properties such as brain, spinal cord, disk, bone, and cerebrospinal fluid (CSF) were added to each element. On neck extension and flexion, the calculated intraspinal stress was concentrated in the upper cervical spinal cord where the cerebellar tonsil had herniated. The presence of the intraspinal cavity generated stress around the cavity itself. Intraspinal stress concentration associated with the presence of Chiari I malformation may play a role in syrinx initiation, after which the formation of a small syrinx promotes further stress concentration around it and results in the progression of the syrinx.

Syringomyelia associated with tuberculous meningitis tends to be intractable because of its complex pathophysiology. There is almost always a long interval between the diagnosis of tuberculous meningitis and the onset of syringomyelia. Magnetic resonance imaging (MRI) findings, hydrodynamics, pathophysiology, and treatment of this difficult condition were analyzed. We treated five cases of syringomyelia associated with tuberculous meningitis with an age distribution from 35 to 72 years old. Syringomyelia developed 6 months to 30 years after tuberculous meningitis. All patients showed incomplete or total paraplegia, sensory deficit below the thoracic level, and ascending sensory-motor disturbance of the upper extremities. All were examined with MRI. Cine-MRI and computed tomography (CT) myelography were useful for assessing patency of the subarachnoid space. When the cranial subarachnoid space was intact, a syringosubarachnoid (SS) shunt was selected, but when it was obliterated, a syringoperitoneal (SP) shunt was selected. Three patients underwent an SP shunt and one underwent an SS shunt. A flexible endoscope helped with accurate placement of the shunt tube in the subarachnoid space. Local arachnoid adhesion was dissected, and expansive dural plasty was performed with an artificial dural patch to prevent postoperative adhesion. In two cases, arachnoid adhesion was so diffuse that aggressive dissection could not be performed. The surgically treated patients were neurologically stable after the last operation. Careful dissection of arachnoid adhesion and reestablishment of normal cerebrospinal fluid (CSF) hydrodynamics is essential. For diffuse arachnoid adhesion, an SP shunt should be used.

BACKGROUND Torcular or sinus confluence meningioma is rare and surgically formidable. This reported sinus confluence meningioma was associated with peritumoral intracerebral hemorrhage. The surgical strategy and the mechanism of peritumoral hemorrhage are discussed. CASE DESCRIPTION A 42-year-old woman presented with a history of headache, vomiting, and cerebellar dysfunction for 2 months. Plain computed tomography (CT) scan and magnetic resonance imaging (MRI) demonstrated a high-density mass in the torcular region involving both lateral sinuses. MR angiography demonstrated complete occlusion of the left lateral sinus and straight sinus and stenosis of the right lateral sinus. Two years after her first operation she experienced sudden headache and left upper quadrant hemianopsia. Plain CT scan and MRI showed a hyperintense tumor in the torcular region with an intracerebral hematoma in the right occipital lobe. An angiogram demonstrated occlusion of the caudal part of the superior sagittal sinus, bilateral transverse sinuses, and straight sinus. Gross total removal of the tumor was done along with the left lateral sinus through a suboccipital and a supratentorial occipital craniotomy in the first operation. The patient underwent total resection of the tumor at second operation through a bilateral occipital and suboccipital craniotomy along with resection of the dura including the confluence, the caudal part of the superior sagittal sinus, the right lateral sinus, and the straight sinus. The postoperative course was uneventful and postoperative MRI showed total removal of the tumor. CONCLUSION Sinus confluence meningioma may present with peritumoral hemorrhage. Radical removal may be possible when the sinus confluence is completely occluded and there is good collateral drainage.

Human umbilical vein endothelial cells (HUVECs) were transplanted in athymic mouse brain and neovascularization of grafted endothelial cells was studied. HUVECs were transfected by a reporter gene pEGFPE-N1 in vitro and grafted stereotactically in unilateral striatum of adult nude mice. Histological studies in 4 weeks revealed that grafted HUVECs newly formed microvessels in brain, which were migrated and fused with host vessels. Intravenous injection of Evans blue before sacrificing animals resulted in no extravasation of dye, indicating that a blood-brain barrier (BBB) was formed by the grafted HUVECs. Immunohistochemistry demonstrated that host astrocytes extended glial feet on the grafted endothelial cells and a part of the newly formed vessels was positive with glucose transporter-1. These results indicate that endothelial cells from an ectopic origin have the potential to form a BBB after grafting in the central nervous system.

Object. The role of nitric oxide (NO) in reperfusion injury of the brain is still controversial. The authors demonstrate that NO injures the brain capillary endothelial cells in a reoxygenation state by the formation of peroxynitrite.

The histological changes associated with syringomyelia after reduction of the syrinx size were investigated after cerebrospinal fluid shunting in experimental syringomyelia in the rabbit. Five weeks after syringomyelia was induced by the injection of kaolin into the cisterna magna in Japanese white rabbits, ventriculosubgaleal shunting or syringoepidural shunting were performed. After 1 week magnetic resonance (MR) imaging and histological examination were then carried out. Five of 11 shunted animals showed postoperative reduction of syrinx size on MR imaging. Grossly, some specimens showed cavity collapse and parenchymal healing, and others showed a small residual syrinx in the dorsal horn. The most dramatic histological changes occurred in the gray matter. Specimens with syrinx collapse showed rarefaction and tearing of the gray matter, with mild glial reaction. The edematous gray matter showed both degeneration and regeneration, with neuronal processes surrounded by edema fluid. Reactive astrocytes were observed mainly at the margin of the residual syrinx. Some astrocytic processes invested the extraaxonal space and gray matter lacked supportive tissue. Greater reduction of the syrinx after shunting operation was correlated with more regeneration and less degeneration, and the white matter was edematous and histological changes were milder. Syrinx shrinkage occurred after shunting in this experimental model of syringomyelia. The selective vulnerability of gray matter even after shunting may explain discrepancies between imaging findings and clinical features in this disease. The study supports the potential benefit from early treatment, considering the associated morphological findings of regeneration.

BACKGROUND Acute paraplegia attributable to disc herniation is known to occur most frequently at the thoracic level. We report a rare case of non-traumatic acute paraplegia caused by disc herniation at the cervical level. Preoperative magnetic resonance imaging (MRI) of the present case demonstrated a spinal cord lesion as a cause of paraplegia. Although this symptom is believed to disappear rapidly after surgical treatment, there have been a few reported cases with poor neurologic recovery and permanent deficits. CASE DESCRIPTION A 61-year-old female with a history of minor neck pain suffered from non-traumatic acute paraplegia attributable to cervical disc herniation. She underwent emergency surgery consisting of vertebrectomy, removal of herniated discs, and anterior fusion. Postoperative neurologic improvement was slow due to the cervical spinal cord lesion at the central portion of the cord, which was detected by the preoperative and postoperative MRIs. CONCLUSION We emphasize that the MRI study is crucial for the management of patients with acute neck pain associated with cervical canal stenosis. Surgical treatment should not be delayed to avoid permanent neurologic deficits. Anterior decompression with vertebrectomy is recommended to decompress the injured spinal cord in the narrow cervical spinal canal; however, a cord lesion detected by MRI may indicate an incomplete surgical outcome.

Background It has been reported that cerebral ischemia induces a dissociation between cerebral blood flow and blood–brain barrier glucose transport, but mechanisms of the dissociation are not yet clearly understood. Recent immunohistochemical studies reveal discrepancies of the results between physiologic and immunochemical studies. The purpose of this study was to quantify changes of the blood–brain barrier glucose transporter kinetics following cerebral ischemia by an in situ brain perfusion technique. Methods Fifty-six adult male Sprague-Dawley rats were divided into control and ischemia groups, and four-vessel occlusion was done as an ischemic insult. To obtain regional capillary permeability surface area products of glucose and regional perfusion fluid flow rates, the perfusion fluid (HCO 3 -buffered saline) was dually labeled with [ 14 C]-2-Deoxyglucose and [ 3 H]-Diazepam, and the brain was perfused at a constant rate via the external carotid artery. After sampling tissues from three regions (frontal, frontoparietal lobe, and caudoputamen), dual scintillation counting was performed. From the results, we determined kinetic parameters, including V max , K m , and K d as described in the Michaelis–Menten equation, by weighted nonlinear least squares method. Results In the ischemia group, the affinity (1/ K m ) and the maximum glucose transport rate ( V max ) decreased significantly. Conclusions The results suggest that severe cerebral ischemia downregulates the blood–brain barrier glucose transporter kinetics, and the discrepancies between physiologic and immunohistochemical studies may be derived from redistribution of transporters, some deformation of transporters, production of some inhibitors, recruitment of capillaries with different types of transporters, and/or the effect of surrounding glial reaction.

The authors present an extremely rare case of histologically benign cerebellar pilocytic astrocytoma that had already disseminated to the leptomeninges at the initial presentation.

OBJECTIVE: Split bone graft reconstruction was performed after a standard transpetrosal-transtentorial approach to correct the cosmetic deformity in 18 patients. TECHNIQUE: The split bone graft was made by dividing the inner table of the temporosuboccipital bone graft and covered the bone defect created by petrosectomy and mastoidectomy. The split bone graft was created and shaped during closure of the dura, so that the operation was not prolonged. RESULTS: This technique produced excellent cosmetic results immediately after surgery; the results were maintained during the follow-up period of between 20 and 46 months. No complication associated with this technique was recognized. CONCLUSION: Split bone graft reconstruction is a simple and safe technique for preventing the cosmetic deformity associated with a transpetrosal-transtentorial approach.

We studied the mechanism of reoxygenation injury of cerebral microvessels in cultured rat brain capillary endothelial cells (BCECs). BCECs were isolated from rat cerebral cortices by a two step enzymatic treatment. The monolayers of BCECs were subjected to anoxia for 20 minutes followed by reoxygenation for 3 hours. Cell damage was assessed by measuring the leakage of intracellular lactic dehydrogenase (LDH). The control group was anoxia/reoxygenated BCECs without any protective reagents. To study the protective effect of free radical scavengers and antioxidants, superoxide dismutase, catalase, deferoxamine, oxypurinol, indomethacin, or NG-nitro-L-arginine methyl ester (L-NAME) was applied during anoxia/reoxygenation. Thus 7 experimental conditions were established.

Despite clinical and experimental interest in the osmotic opening of the blood-brain barrier (BBB), the mechanism underlying the phenomenon remain undetermined. The aim of this study is to investigate the mechanism of intracellular Ca2+ change in brain microvascular endothelial cells subjected to hyperosmotic stress.

Capillary endothelial cells are critical targets in both ischemia and reperfusion of the brain. Arachidonic acids and oxygen free radicals have been shown to cause disruption of blood-brain barrier (BBB) by destruction of capillary endothelial cell membrane. However, the exact mechanism of BBB breakdown by cerebral ischemia/reperfusion remains undetermined. The aim of the present study is to clarify the mechanism of intracellular calcium ion ([Ca2+]i) change in brain capillary endothelial cells under anoxia/reoxygenation. Brains capillary endothelial cells were isolated from ten male Sprague-Dawley rats by a two step enzymatic process. [Ca2+]i was measured by means of a confocal laser scanning microscope using Indo 1-A/M as a calcium indicator. The endothelial cells were subjected to anoxia and reoxygenization under different conditions. [Ca2+]i increased gradually during anoxia and slightly decreased after reoxygenation. Indomethacin and SOD suppressed the elevation of [Ca2+]i during anoxia. NG-nitro-L-arginine methyl ester and catalase moderately suppressed the elevation, however nifedipine did not suppress it at all. In this model, rapid [Ca2+]i change was not observed during the reoxygenation phase. The results indicate that the anoxia induced elevation of [Ca2+]i in the brain capillary endothelial cells depends on superoxide and peroxynitrite generation.

Brain edema is an important clinical condition. Pathophysiological findings on behavioral changes may be helpful for a comprehensive understanding of brain edema. However, only few reports on behavioral studies of brain edema have so far appeared. Experiments using psychological techniques on animals are rather time-consuming and may not be suitable for the study of transient conditions, as brain edema caused by trauma, vascular accidents, or others. We have developed a method for avoidance learning of rats using a running wheel apparatus with computer assistance. This model was employed in studies on brain edema from water intoxication in rats. As a result, avoidance learning was significantly impaired by water intoxication. Either direct overhydration of the brain or indirect effects, as a decrease in cerebral blood flow, or both, are suggested as mechanisms underlying the impairment of behavior.

Metameric spinal arteriovenous malformations (AVMs) refer to the lesions completely outside of the spinal cord and the surrounding dura. This paper presents an unusual metameric spinal AVM that was fed by multiple radiculomeningeal arteries and was located totally within the extradural space and the vertebral bodies. The metameric spinal AVM has an exclusive epidural venous drainage and presents as a distinct mass from the dural and the intradural spinal AVMs. Total removal of metameric spinal AVMs are sometimes difficult because of wide extension, profound bleeding, and spinal instability after resection. Therefore, the basic management strategy for these lesions is preoperative arterial or venous embolization and resection.

Between 1991 and 1995 we totally removed 24 cerebral arteriovenous malformations (AVMs), employing preoperative embolization in 9 patients and intraoperative digital subtraction angiography (DSA) in all 24. There was 1 patient with Spetzler grade I lesion, 6 with grade II, 9 with grade III, 5 with grade IV and 3 with grade V. Nine patients with large AVMs underwent preoperative embolization to occlude surgically inaccessible feeders and to reduce arterial blood supply by 50%. Surgery was performed 3–11 days after embolization. Twenty-one patients did well. One patient died of postoperative bleeding complications, and a mild neurological deficit appeared in 2 patients. We believe that intraoperative DSA is essential for the total removal of cerebral AVMs. The operative mortality and morbidity rates could be reduced with preoperative embolization of large AVMs.

Intradural spinal lipomas that are not associated with spinal dysraphism are rare. We report four cases of adult patients with intradural spinal lipomas. All of the patients were young adults, three women and one man, who ranged in age from 22 to 37 years (mean, 30.3 yr). The clinical presentation of these lesions varied, depending upon the size and location of each lipoma. It is interesting that the symptoms in the women gradually deteriorated during pregnancy or after delivery. Magnetic resonance imaging was very useful in determining the exact location of lipoma. In three of four patients, neurological improvement was obtained after decompressive laminectomy and partial removal of the lipoma.

BACKGROUND Intracerebral cystic lesions can easily be identified by computed tomography (CT) and magnetic resonance imaging (MRI). Cystic gliomas, brain abscesses, or metastatic carcinoma are the usual underlying causes for this neuroradiologic finding. CASE PRESENTATION We report here the case of a patient with multiple sclerosis who has two intracerebral cystic lesions. CONCLUSIONS Central nervous system (CNS) tissue destruction, necrosis, and cyst formation are very unusual in multiple sclerosis. Diagnostic difficulty therefore arises when patients suspected of having multiple sclerosis have radiologic evidence of cystic CNS lesions.

Three-dimensional (3D) images reconstructed from the data obtained by helical volume computed tomography (CT) clearly demonstrated the spatial relationship among complex structures, such as bones, vessels and tumours in the skull base. It was helpful for surgical planning and postoperative studies of skull base lesions. We present our early experience using 3D CT images in 11 patients with skull base lesions. The structures of major arteries, veins and skull base bone were clearly and accurately visualised on 3D images. Among the skull base tumours, well-enhanced tumours, such as meningiomas were easily reconstructed by routine procedures. However, less enhanced tumours or cystic tumours such as epidermoids or cystic neuromas were difficult to visualise on 3D images. Some techniques can improve the 3D image, but it is important to keep in the mind that the 3D image has pitfalls and should be checked by original slice image.

The purpose of this study is to quantify the relative contribution of the mechanisms in the absorption of edema fluid. The convection/diffusion and the comprehensive bulk flow model were applied for the finite element analysis of peritumoral brain edema. For clinical analysis, 90 meningiomas studied by MRI were selected. Serial CT scan and MRI were performed at 0, 2, 4, 6 hours after injection of Iopamidol or Gadpenteic acid respectively. Then the tracer distributions in the edematous brain was analyzed.

Water intoxication brain edema was produced in rats by intraperitoneal loading of excessive amounts of distilled water (DW). In 10% and 20% groups, DW in amounts of 10 or 20% of body weight was injected, respectively. Water content of brain tissue increased proportionally to the amount of injected water, as follows: 79.8% of wet weight in control, 80.5 and 82.4 in 10% and 20% DW groups, respectively. Since cerebral blood flow (CBF) values measured by laser Doppier (LD) flowmetry were found to give a good correlation with those by hydrogen clearance method in a preliminary experiment, CBF measurement were carried out using LD flowmetry thereafter. Before the injection, CBF values were around 50 ml/ min/100 g. Two hours after the water loading, CBF values in 10% and 20% DW groups were 25.6 and 20.3 ml/100 g/min, respectively. CBF values under these edematous condition decreased significantly (p < 0.001 by paired t-test) in proportion to the severity of the brain edema.

Cerebral hemodynamics were evaluated in 7 patients with large high-flow arteriovenous malformations (AVMs) using an intra-operative thermo-gradient flowmeter. The maximum post-excision/ pre-excision blood flow ratio was determined. Special clamps made from silicone tubes with absorbable threads were applied on the proximal feeding arteries.

The role of leukotrienes as mediator of brain edema is still controversial. Recently, the ability of γ-GTP to act as enzymatic barrier and to inactivate leukotrienes in normal brain capillaries was pointed out.

Thirty cases of giant and large carotid-ophthalmic aneurysms were treated surgically in our hospital between 1974 and May 1992. Twelve out of these thirty patients had giant or large aneurysms (>20mm). Seven of twelve patients, all female, were treated by direct clipping utilizing the “trapping-evacuation” technique, which has been devised by the authors. All aneurysms were completely clipped with preservation of patency of the internal carotid artery, which was confirmed by intra- or post-operative angiography. The postoperative outcome was good in six cases and fair in one. The “trapping-evacuation” technique enabled us to completely clip giant and large aneurysms of the paraophthalmic region of the internal carotid artery with greater safety.

The incidence and clinical significance of peritumoral brain edema in pediatric patients is not well understood. The purpose of this study is to clarify the clinical significance of peritumoral brain edema in pediatric patients. Seventy seven pediatric patients (under 15 year old) with brain tumor were studied by MRI. The volume of peritumoral edema and brain tumor were measured by integration of the cross-sectional area on serial MRI. The severity of brain edema was expressed by the ratio of edema volume to tumor volume. The results were compared with that of 408 adult patients with brain tumor.

The authors treated a patient with a huge, ventrally located spinal meningioma, extending from the foramen magnum to the second thoracic vertebral body. Vertebral body corpectomies were performed between the bottom of the second cervical vertebral body and the top of the first thoracic vertebral body, and the tumor was completely resected. Neurological symptoms and signs improved postoperatively.