Anomalous origin of the anterior choroidal artery

SUMMARY

We describe a very rare case of anomalous origin of the anterior choroidal artery. In our case the anterior choroidal artery arises from the internal carotid artery proximal to the posterior communicating artery.

Morphologic evaluation of the caudal end of the inferior petrosal sinus using 3D rotational venography

BACKGROUND AND PURPOSE

The inferior petrosal sinus (IPS) is the main transvenous access route used to examine or treat lesions involving the cavernous sinus. To carry out these procedures successfully, one must have a detailed knowledge of the anatomy of the venous system around the junction of the IPS and the internal jugular vein (IJV).

MATERIALS AND METHODS

Eighty-three sides in 63 patients (26 men, 37 women; mean, 56.5 years of age) were examined by using 3D rotational venography (3DRV).

RESULT

The drainage patterns of the IPS could be classified into the following 6 types, with emphasis on the level of IPS-IJV junction: type A, the IPS drains into the jugular bulb in 1/83 sides (1.2%); type B, the IPS drains into the IJV at the level of the extracranial opening of the hypoglossal canal in 29/83 sides (34.9%); type C, the IPS drains into the lower extracranial IJV in 31/83 sides (37.3%); type D, the IPS forms a plexus and has multiple junctions to the IJV near the jugular foramen in 5/83 sides (6.0%); type E, the IPS drains directly into the vertebral venous plexus (VVP) with no connection to the IJV in 3/83 sides (3.6%); and type F, the IPS is absent in 14/83 sides (16.9%). Each type is also characterized by the way of anastomosis with the VVP.

CONCLUSION

This classification seemed to be rational from the embryologic viewpoint, and it may be useful in establishing treatment strategies that involve endovascular manipulation via the IPS.

Atypical spinal dural arteriovenous fistula with supply from the lateral sacral artery

We report a dural arteriovenous fistula (AVF) that developed at a site on the midline dorsal surface of the dura mater that had been damaged by repeated lumbar punctures. A 61-year-old male patient had undergone repeated lumbar punctures and discectomy for severe lumbago 40 years before the present admission. After surgery, the lumbago symptoms resolved. However, 30 years after the operation, he started to experience dysaesthesia, motor weakness in both legs, and urinary disturbance. Physical examination revealed bilateral leg weakness, diminished deep tendon reflexes in the patellar and Achilles tendons bilaterally, and decreased superficial sensation below L1. Magnetic resonance imaging revealed swelling with intramedullary high intensity and multiple flow voids around the conus and spinal cord on T(2)-weighted images, and adhesive arachnoiditis. Spinal angiography revealed an AVF between the left lateral sacral artery and the S1 radicular vein at the site of the previous operation. Surgery was conducted to carry out excision of the dural AVF at the shunting point, the arterialized intradural vein, and lysis of the arachnoiditis. This case of dural AVF may have been caused by repeated lumbar punctures.

Reduced-intensity unrelated cord blood transplantation for treatment of metastatic renal cell carcinoma: first evidence of cord-blood-versus-solid-tumor effect

We report a 69-year-old man with cytokine-resistant metastatic renal cell carcinoma treated with reduced-intensity unrelated cord blood transplantation. The patient achieved durable donor engraftment with minimal graft-versus-host disease. The patient showed regression of metastatic disease, providing the first evidence of a graft-versus-tumor effect on a solid tumor resulting from cord blood graft.

Hemangioblastoma of hippocampus without von Hippel-Lindau disease: case report and review of literature

A rare case of hemangioblastoma located in the region of hippocampus is reported. A 27-year-old female presented with a single episode of generalized convulsion. The vascular and cherry red color hemangioblastoma was resected by a temporo-zygomatic approach. There has been no recurrence of tumor at a follow-up of 11 years.

Selection of two-phase flow patterns at a simple junction in microfluidic devices

We study the behavior of a confined stream made of two immiscible fluids when it reaches a T junction. Two flow patterns are witnessed: the stream is either directed in only one sidearm, yielding a preferential flow pathway for the dispersed phase, or splits between both. We show that the selection of these patterns is not triggered by the shape of the junction nor by capillary effects, but results from confinement. It can be anticipated in terms of the hydrodynamic properties of the flow. A simple model yielding universal behavior in terms of the relevant adimensional parameters of the problem is presented and discussed.

Pitfalls during the Embolization and Evaluation after the Embolization for the Skull Base Meningiomas

Pitfall during the embolization and evaluation after the embolization for skull base meningiomas supplied by meningeal arteries of internal carotid artery (ICA) are reported. This study includes 15 cases of skull base meningiomas (two males and 13 females) that supplied by meningeal branches of internal carotid artery. The preoperative embolization was performed by these feeders. MRI findings and serum levels of C-reactive protein (CRP) after the embolization were examined. In ten patients among 15 patients the meningeal branches of ICA were dominant feeders. In ten patients out of 15 patients, the embolization from the meningeal branches of ICA was possible. Eight patients out of these ten patients were suffered from high fever and increase of serum level of CRP after the embolization. During the embolization for skull base meningiomas, the existence of collateral pathways between the ICA system and external carotid artery system were identified. The increase of serum levels of CRP might be recognized in the patients that effective embolization were performed.

Spinal arteriovenous malformation associated with a radicular arteriovenous fistula suggested a metameric disease. A case report

SUMMARY

A spinal intramedullary arteriovenous malformation (AVM) associated with a radicular arteriovenous fistula (AVF) is reported. The patient had mild myelopathy and low back pain. Spinal angiography revealed the AVM fed by the anterior spinal artery via left T10, T11 and right L1 radiculomedullary arteries and the radiculopial arteries of left L1, L2 and right T11, L3 levels and the radicular AVF at the left L4 level. There were three radiculomedullary arteries within four levels in our case. This spinal AVM associated with a radicular AVF is considered a genetic nonhereditary lesion with metameric link.

Three-dimensional rotation venography using the digital subtraction angiography unit with a flat-panel detector: usefulness for the transtemporal/transtentorial approaches

We obtained the venograms using the two-dimensional digital subtraction angiography (2D DSA) images and three dimensional rotation venography (3D RV) images and investigated the potential usefulness of the 3D RV compared with venograms of 2D DSA using the newly developed three-dimensional rotation angiography unit with a flat-panel detector (FPD). This study included 26 sides (11 left, 15 right) in 20 cases (4 males and 16 females) who underwent radiographic examination for management of intracranial tumors and vascular diseases between May 2003 and December 2003. Each patient underwent diagnostic angiography performed on a DSA unit with a FPD. In all patients, the 2D DSA images, including anteroposterior view and lateral view of the carotid artery, were obtained in two stereoscopic views. The 3D RV was used to produce volume-rendered images. Two neuroradiologists investigated the venous configuration of 3D RV compared with that of 2D DSA about the relationship of the venous drainage system on the temporal lobe according to Guppy et al.'s classification. Twenty-four sides of the 26 sides enabled the precious visualization on 3D RV images. In investigation of 2D DSA, 9 sides (37.5%) were classified into type A, 13 (54.2%) into type B, two (8.3%) into type C, and no sides into types D, E, and F. In investigation of 3D RV images, 10 sides (41.7%) were classified into type A, 9 (37.5%) into type B, 1 (4.2%) into type C, 2 (8.3%) into type E, and 2 (8.3%) into type F. Seven of 24 sides demonstrated discrepancy in results between 2D DSA and 3D RV. The 3D RV could be performed by setting the adequate delay in between the injection of the contrast material and starting time of third rotation to acquire the opacified images. In Guppy et al.'s classification, the 3D RV images could demonstrate the precious venous drainage including the venous lakes with use of multiple views and variable reconstruction compared with 2D DSA. Our DSA system with FPD could provide good 3D RV images. These images are very useful for the skull-base surgery because we can understand the three-dimensional vascular anatomy preoperatively.

Lift-up laminoplasty for myelopathy caused by ossification of the posterior longitudinal ligament of the cervical spine

BACKGROUND AND AIMS

We have utilized lift-up laminoplasty to treat patients with myelopathy caused by ossification of the posterior longitudinal ligament (OPLL) of the cervical spine. The preliminary surgical outcome with computer-assisted morphological assessment is presented.

MATERIAL AND METHODS

The surgical technique of lift-up laminoplasty includes standard posterior exposure of the cervical spine, en-bloc laminectomy, and expansion of the cervical canal by lift-up of the laminae with custom-designed hydroxyapatite laminar spacers and stabilization of the laminae using titanium miniplates. From 1998 to 2003, 10 consecutive patients with cervical myelopathy secondary to OPLL have been treated with this method and comprehensively evaluated. Care was taken to tailor the treatment to individual patients by using different sizes of spacers to adjust the degree of expansion depending on the amount of stenosis of the cervical spine. The degree of expansion of the cervical canal was altered by design, based on the preoperative imaging simulation.

RESULTS

Preliminary surgical outcome, evaluated at 6 months after surgery, revealed a significant improvement of neurological function. Image analysis revealed that the cervical canals were significantly expanded, with a mean reduction of 13.1% in the stenosis ratio. Lift-up laminoplasty was effective in the treatment of patients with myelopathy secondary to cervical OPLL, and the amount of expansion could be individually adjusted at the discretion of the surgeon.

CONCLUSION

Although analysis with a larger population and a longer follow-up period needs to be undertaken, our method of lift-up laminoplasty appears to be a viable choice among standard posterior cervical approaches for cervical OPLL.

Development of malignant glioma 15 months after anterior temporal lobectomy in a patient with temporal lobe epilepsy

We report a 36-year-old woman, who had previously undergone anterior temporal lobectomy for intractable temporal lobe seizures; fifteen months later, magnetic resonance (MR) images showed a space-occupying lesion in the temporal lobectomy cavity. After a second operation, a histopathological examination showed a grade III astrocytoma. The fortuitous co-occurrence of temporal lobe epilepsy and a tumour was suspected, but histopathological and immunohistochemical examination of original resected temporal lobe parenchyma did not show evidence of neoplasm. The patient had not undergone postoperative radiotherapy and had not experienced viral infections. We propose that two factors possibly associated with the development of glioma were chemical exposure from anticonvulsant agents and trauma from resection of the anterior temporal lobe during initial surgery.

Photodynamic therapy for malignant biliary obstruction: a case series

We describe four elderly patients (age range 73-85 years) with bile duct carcinoma who were treated with photodynamic therapy. These patients could not be treated surgically because of the presence of cardiopulmonary disease and the extent of the bile duct carcinoma. Prior to photodynamic treatment the patients underwent percutaneous transhepatic biliary drainage (PTBD) to relieve jaundice. The photodynamic therapy was carried out under percutaneous transhepatic cholangioscopy, 2 days after intravenous administration of sodium porfimer (2 mg/kg). Excimer dye laser was used to irradiate the obstructive lesion with an energy dosage of 50 J/cm2 (total irradiation dose 150-250 J/cm2) and stenotic site with a dosage of 50-100 J/cm2. Photodynamic therapy was achieved safely without occurrence of cholangitis in all patients, and was followed by metallic stent placement, resulting in the improvement of performance levels in three patients who did not have liver metastases. Photodynamic therapy via the PTBD route is a safe and promising palliative therapy for selected elderly patients with bile duct carcinoma.

Extra-axial subarachnoid ependymoma of the cerebral convexity

A 29-year-old man had two episodes of seizures in 9 months. Following the first seizure he developed hemiparesis, which gradually progressed. Investigations revealed a large cerebral convexity mass lesion simulating a meningioma. During operation, a reddish-brown and well-defined tumor located in the subarachnoid space was encountered. Histopathological examination revealed a typical ependymoma. Extra-axial cerebral convexity ependymomas are extremely rare. The case is reported and a brief review of six similar cases reported in the literature is undertaken.

Tentorial schwannoma: a case report

A rare case of tentorial schwannoma in a 29-year-old male is described. The schwannoma was located within the leaves of the tentorium. MRI showed a wedge-shaped enhancing tumour. Exact nerve of origin of the tumour could not be identified. We speculate that the tumour arose from the tentorial branch of the trigeminal nerve. The literature concerning intracranial schwannoma unrelated to a major cranial nerve is reviewed.

A hypothesis of epiarachnoidal growth of vestibular schwannoma at the cerebello-pontine angle: surgical importance

AIMS

The purpose of this study is to clarify the rearrangement of the arachnoid membrane on the vestibular schwannoma during its growth in relation to adjacent neurovascular structures for a better understanding of dissecting plane of arachnoid during surgery.

METHODS

Arachnoid membrane over the tumour was investigated during surgery with suboccipital transmeatal approach in twenty-six tumours. All microsurgical procedures were recorded with a video and reviewed. The tumour growth was classified into five stages depending upon the tumour diameter in the cerebello-pontine (CP) angle: Stage 1; purely intracanalicular (2 cases), Stage 2; less than 5 mm (2 cases), Stage 3; > or = 5 and <15 mm (8 cases), Stage 4; > or = 15 and <25 mm (9 cases) and Stage 5; > or = 25 mm (5 cases). Rearrangement of the arachnoid on the tumour was conceptualised throughout all stages.

RESULTS

All tumours of Stage 1 and 2 were entirely located in the subarachnoid space of the cerebello-pontine cistern without arachnoidal rearrangement, while all tumours of Stages 3 to 5 were enveloped, in the CP angle, with invaginated arachnoid membrane consisting of cerebello-pontine cistern except two surfaces; the medial pole and the tumour surface under the facial and cochlear nerves near the porus.

CONCLUSION

The tumour originates subarachnoidally within the internal auditory meatus (IAM) and grows epiarachnoidally in the CP angle. Rearrangement of the arachnoid begins with its adhesion on the medial pole of the tumour along the porus, resulting in the arachnoidal invagination into the cerebello-pontine cistern with further growing of the tumour.

Intracranial adenoid cystic carcinoma of suprasellar region

Adenoid cystic carcinoma (ACC) is a relatively common head and neck tumor which grows slowly but locally aggressive and prone to recurrence. ACC most commonly arises in the major and minor salivary glands. Some rare cases of intracranial ACC with an unknown primary site have been reported. The authors present the first case of primary intracranial ACC of the suprasellar region. A 34 year-old female presented with one month's duration of visual disturbance and galactorrhea. Magnetic resonance image (MRI) showed intra- and suprasellar mass mimicking a craniopharyngioma. There was no evidence of invasion from an extracranial site. The operative findings showed the mass existed under the arachnoid membrane and seemed to originate from the pituitary stalk. Pathological diagnosis was ACC. After the first operation, local recurrence and CSF dissemination to the lower clivus occurred within two months. Recurrence repeatedly treated by Gamma knife radiosurgery 10 times and 4 times by surgery during a 3 year follow-up period. But total removal of the tumor at the first operation along with radiosurgery may control the lesion and prevent further recurrence.

An unusual middle fossa interdural epidermoid tumor. Case report

The authors report an unusual case of an intracranial, interdural epidermoid tumor and cyst in a 72-year-old woman who presented with longstanding, mild numbness over her right cheek. She was initially treated conservatively, but on follow-up review the mass was found to have grown and evidence of hemorrhage was present, and therefore a subtotal resection was performed. This case should probably be classified as a paratrigeminal, interdural epidermoid cyst; this is the first known report in which magnetic resonance and computerized tomography images of such an entity are presented and discussed.

Development of lumbosacral spina bifida: three-dimensional computer graphic study of human embryos at Carnegie stage twelve

There is still some controversy as to whether sacral spina bifida in humans is the result of a defect of the primary or secondary neural tube. As somites are related to the development of vertebrae and the primary neural tube is related to the development of the spinal cord in embryos, it is very important to determine the number of somites in normal human embryos at the time of closure of the primary neural tube to understand the contribution of primary neural tube defects to the development of spina bifida. However, in the literature, the number of somites in stage 12 human embryos is still controversial. The aim of this study is to find the number of somites in human embryos at Carnegie stage 12. Four human embryos at Carnegie stage 12 were selected from the laboratory of the Congenital Anomaly Research Center in Japan. The neural tube and somites were reconstructed from their slices by a three-dimensional computer graphic reconstruction technique. The reconstructed embryos were examined from multidirectional magnified images. Thirty-three pairs of somites were present in all these reconstructed embryos. As the 33rd pair of somites corresponds to the fifth sacral segment, the presence of 33 pairs of somites at Carnegie stage 12 suggests that spina bifida develops from defects of the primary neural tube.

The role of diffusion-weighted imaging in patients with brain tumors

BACKGROUND AND PURPOSE

Diffusion-weighted images (DWIs) have been used to study various diseases, particularly since echo-planar techniques shorten examination time. Our hypothesis was that DWIs and tumor apparent diffusion coefficients (ADCs) could provide additional useful information in the diagnosis of patients with brain tumors.

METHODS

Using a 1.5-T MR unit, we examined 56 patients with histologically verified or clinically diagnosed brain tumors (17 gliomas, 21 metastatic tumors, and 18 meningiomas). We determined ADC values and signal intensities on DWIs both in the solid portion of the tumor and in the peritumoral, hyperintense areas on T2-weighted images. We also evaluated the correlation between ADC values and tumor cellularity in both gliomas and meningiomas.

RESULTS

The ADCs of low-grade (grade II) astrocytomas were significantly higher (P =.0004) than those of other tumors. Among astrocytic tumors, ADCs were higher in grade II astrocytomas (1.14 +/- 0.18) than in glioblastomas (0.82 +/- 0.13). ADCs and DWIs were not useful in determining the presence of peritumoral neoplastic cell infiltration. The ADC values correlated with tumor cellularity for both astrocytic tumors (r = -.77) and meningiomas (r = -.67).

CONCLUSION

The ADC may predict the degree of malignancy of astrocytic tumors, although there is some overlap between ADCs of grade II astrocytomas and glioblastomas.

Syringomyelia associated with adhesive spinal arachnoiditis: MRI

We reviewed the MRI of seven patients with syringomyelia associated with surgically proven adhesive spinal arachnoiditis to describe clinical and MRI findings in this condition. Using 0.5, 1.0 or 1.5 tesla units, we obtained sagittal T1- and T2-weighted spin-echo and axial T1-weighted images. Additional sagittal T2-weighted images were obtained without using motion-artefact suppression. Contrast medium was given intravenously to five patients. The syrinx cavities were thoracic in five cases, cervicothoracic in one, and extended from C4 to L1 in one. No Chiari malformation or craniovertebral junction anomaly was demonstrated. Meningeal thickening was seen on T2-weighted sagittal images only in one case. Cord deformity due to adhesion or displacement due to an associated arachnoid cyst was seen in all cases best demonstrated on axial images. Focal blurring of the syrinx wall on axial images was seen in six patients. Flow voids were seen in the syrinx fluid in all cases on T2-weighted images obtained without motion-artefact suppression. No abnormal contrast enhancement was demonstrated.

Neurenteric cyst with alteration of signal intensity on follow-up MR images

SUMMARY

Intracranial neurenteric cysts are uncommon and usually have low intensity on T1-weighted MR images and high intensity on T2-weighted MR images. We report a case of a neurenteric cyst that was situated in front of the medulla oblongata and the size of which increased with alteration of MR signal from high to isointense compared with that of brain on T1-weighted images obtained 33 months after the initial MR images. We think that the signal change of the cyst was probably caused by a change of protein concentration.

Surgical management of syringomyelia associated with spinal adhesive arachnoiditis

The authors describe a new surgical technique to minimise the postoperative recurrence of adhesion after microlysis of adhesion to treat syringomyelia associated with spinal adhesive arachnoiditis. A 47 year old male presented with numbness of the lower extremities and urinary disturbance and was demonstrated to have a case of syringomyelia from C1 to T2 which was thought to be secondary to adhesive spinal arachnoiditis related to a history of tuberculous meningitis. Following meticulous microlysis of the adhesions, maximal expansion of a blocked subarachnoid space was performed by expansive duraplasty with a Gore-Tex surgical membrane, expansive laminoplasty and multiple tenting sutures of the Gore-Tex graft. Postoperatively, the syringomyelia had be en completely obliterated and improvement of the symptoms had been also achieved. The technique described may contribute to improvement of the surgical outcome following arachnoid dissection by maintaining continuity of the reconstructed subarachnoid space.

Rathke's cleft cyst associated with hypophysitis: MRI

We report a symptomatic Rathke's cleft cyst associated with hypophysitis in a 61-year-old woman. We demonstrate the MRI features and discuss the pathophysiology. To the best of our knowledge this is the first description of a Rathke's cleft cyst shrinking after high-dose steroid therapy.

Contralateral approach to carotid cave aneurysms

BACKGROUND

To evaluate the surgical approach and clipping of aneurysms located at the carotid cave region.

METHOD

Between 1980 and 1998 we have adopted the well known ipsilateral approach for exposure and securing of carotid cave aneurysms. In four patients, we had the opportunity to use a contralateral approach to carotid cave aneurysms, with easier dissection and application of a simple aneurysmal clip. The visual acuity of the patients did not deteriorate from the pre-operative level.

FINDING AND INTERPRETATION

Aneurysms located at the carotid cave region may be approached easily and safely through a contralateral craniotomy with application of the aneurysm clip from an angle medial and inferior to the optic nerve.

Contralateral approach to junctional C2-C3 and proximal C4 aneurysms of the internal carotid artery: microsurgical anatomic study

OBJECTIVE

To evaluate a contralateral approach to aneurysms located in the internal carotid artery cave and proximal C4 segments.

METHODS

In six adult cadaveric head sides, proposed aneurysms in the carotid cave or proximal C4 segments were approached via contralateral craniotomies. We summarize the approach in the following steps: 1) frontotemporal orbital craniotomy, 2) drilling of the lateral sphenoid wing and opening of the dura along the frontotemporal base, 3) drilling of the planum sphenoidale and the tuberculum sellae more extensively toward the aneurysm side and opening of the sphenoid sinus, 4) drilling of the medial part of the anterior clinoid process on the side of the aneurysm and removal of the superior, medial, and inferior walls of the optic canal, 5) opening of the optic sleeve, and 6) opening of the space between the medial wall of the internal carotid artery C2-C3 segments and the lateral edge of the pituitary gland.

RESULTS

The contralateral approach to expose the opposite internal carotid artery cave and proximal C4 segments provided excellent views of the region, without mobilization or retraction of either the optic nerve or the carotid artery.

CONCLUSION

We recommend that this approach be used only for selected aneurysms, which are small and directed medially, anteriorly, or inferiorly, in the defined locations.

Intracranial papillary endothelial hyperplasia: occurrence of a case after surgery and radiosurgery

Papillary endothelial hyperplasia (PEH) is considered a form of endothelial proliferation rather than a true neoplasm and is usually located in the skin or subcutis. We report a case of intracranial PEH that occurred after surgery for glioma and subsequent radiosurgery. CT and MR revealed an enhancing extra-axial mass located left posterolateral to the brainstem. Intracranial PEH is rare; to our knowledge, development of an intracranial PEH after surgery and radiosurgery has not been previously reported.

Posterior approach for cervical intramedullary arteriovenous malformation with diffuse-type nidus. Report of three cases

The treatment of spinal intramedullary arteriovenous malformations (AVMs) with a diffuse-type nidus that contains a neural element poses different challenges compared with a glomus-type nidus. The surgical elimination of such lesions involves the risk of spinal cord ischemia that results from coagulation of the feeding artery that, at the same time, supplies cord parenchyma. However, based on evaluation of the risks involved in performing embolization, together with the frequent occurrence of reperfusion, which necessitates frequent reembolization, the authors consider surgery to be a one-stage solution to a disease that otherwise has a very poor prognosis. Magnetic resonance (MR) imaging revealed diffuse-type intramedullary AVMs in the cervical spinal cords of three patients who subsequently underwent surgery via the posterior approach. The AVM was supplied by the anterior spinal artery in one case and by both the anterior and posterior spinal arteries in the other two cases. In all three cases, a posterior median myelotomy was performed up to the vicinity of the anterior median fissure that divided the spinal cord together with the nidus, and the feeding artery was coagulated and severed at its origin from the anterior spinal artery. In the two cases in which the posterior spinal artery fed the AVM, the feeding artery was coagulated on the dorsal surface of the spinal cord. Neurological outcome improved in one patient and deteriorated slightly to mildly in the other two patients. Postoperative angiography demonstrated complete disappearance of the AVM in all cases. Because of the extremely poor prognosis of patients with spinal intramedullary AVMs, this surgical technique for the treatment of diffuse-type AVMs provides acceptable operative outcome. Surgical intervention should be considered when managing a patient with a diffuse-type intramedullary AVM in the cervical spinal cord.

Surgical outcome of intramedullary spinal cord ependymoma

Surgical outcome of intramedullary spinal cord ependymoma was investigated in order to define the treatment strategy. We have operated on 18 cases of intramedullary spinal cord ependymoma based on the principle of radical resection. The follow-up periods ranged from 10 months to 249 months with an average of 86.2 months. Postoperative neurological status in the long follow-up periods was compared to the pre-operative status and was correlated with the histological grade of malignancy. Total removal of the tumour was achieved in 17 cases, and subtotal removal followed by radiation therapy was conducted in 1 case. There was neither surgical mortality nor radiological evidence of recurrence in the long-term follow-up periods. The final outcome of the neurological condition was improved in 1 case, unchanged in 15 cases (including a case of subtotal removal) and deteriorated in 2 cases. The deterioration was in the form of gait disturbance due to the worsening of proprioception in 2 cases and dysaethesia in 1 case. Histological examination showed no evidence of anaplasia in 6 cases, evidence of early anaplasia in 10 cases, and moderate evidence of anaplasia in 2 cases. No relationship between the histological malignancy and clinical course was found. Intramedullary spinal cord ependymoma should be removed radically as early as possible while taking great care to avoid posterior column injury. Histologically malignant ependymoma might be a clinical exception.

Efficacy of induced hypotension in the surgical treatment of large cavernous sinus cavernomas

OBJECT

Cavernous sinus cavernomas are rare lesions associated with high rates of intraoperative mortality and morbidity resulting from profuse bleeding. In this paper, the authors report their experience in treating five patients with histologically confirmed cavernous sinus cavernomas and describe the efficacy of induced hypotension in facilitating excision of the lesion.

METHODS

All five patients were women ranging in age from 25 to 54 years, with an average age of 42 years. The mass was small in one and large (>3 cm in diameter) in four. In one patient with a large mass, cardiac arrest occurred after the craniotomy, and remarkable reduction in the size of the cavernoma was evident on postmortem examination. The other three large lesions were successfully removed piecemeal after induction of hypotension (60-80 mm Hg systolic pressure), which remarkably reduced the mass and the bleeding during surgery. In the remaining patient, who had a small lesion, the cavernoma was removed in one piece.

CONCLUSIONS

Cavernous sinus cavernoma can be thought of as a cluster of sinusoidal cavities, the size of which varies depending on the systemic blood pressure. During surgery, reduction of the mass and control of bleeding from the cavernoma can be achieved by inducing hypotension, which enables the safe excision of this lesion. This technique should be considered by surgeons resecting a cavernous sinus tumor, especially when cavernoma is suspected.

Adsorption effects of activated charcoal on metaldehyde toxicity in rats

Metaldehyde has been widely used as a main ingredient of solid fuel for making fire and slug baits in Japan. It is also marketed as a color flame tablet for party goods (ENGELFIRE). Consequently, children have been poisoned by eating such tablets which they mistook for candy. As a result, poison information center calls are increasing. According to POISINDEX, the treatment for metaldehyde poisoning consists in prevention of adsorption by activated charcoal, seizure control and airway protection. However, the optimum dose of charcoal is not established. We studied the quantitative adsorption capacity of activated charcoal for acute oral toxicity of metaldehyde in rats. In vivo toxicity and absorption tests for metaldehyde in Wister rats were done. The detoxifying effect of activated charcoal on metaldehyde toxicity and inhibition of metaldehyde absorption were investigated. Ratios used of po activated charcoal given 30 min after dosing to 400 mg metaldehyde/kg po were 5:1, 2:1, 1:1, 0.5:1. Serum metaldehyde was determined by gas chromatography in the control group (no charcoal) and the various experimental groups. Metaldehyde mortality was completely prevented at the ratio of 5:1. Gastrointestinal absorption of metaldehyde was reduced significantly by 45.3% in comparison to the control rats. There was no acetaldehyde detected in the serum of the metaldehyde-dosed rats. Metaldehyde poisoning may be prevented by early po administration of activated charcoal in a ratio of > 5:1 compared to metaldehyde. The theory that acetaldehyde is the primary toxic agent in metaldehyde poisoning should be re-evaluated.

Aetiology of delayed facial palsy after vestibular schwannoma surgery: clinical data and hypothesis

A patient developed delayed facial nerve palsy at the level of House-Brackmann grade I to grade III 10 days after vestibular schwannoma surgery by the suboccipital transmeatal approach. The palsy had completely recovered after one month. Immunological study showed reactivation of herpes simplex and magnetic resonance (MR) imaging demonstrated an abnormal enhancement pattern of the facial nerve; intense enhancement of the distal intracanalicular segment and labyrinthine segment, similar to the MR findings for Bell's palsy. A prospective control study on the enhancement pattern of the functionally preserved facial nerve after vestibular schwannoma surgery in six cases showed a similar pattern to that of the normal facial nerve. Based on these findings, we propose the hypothesis that herpes simplex reactivation is an underlying cause of delayed facial palsy after vestibular schwannoma surgery.

Occlusion of the sigmoid sinus after surgery via the presigmoidal-transpetrosal approach

OBJECT

In this paper the authors report on sigmoid sinus occlusion as a surgical complication in seven of 143 operations in which a presigmoidal-transpetrosal approach was used.

METHODS

Five patients (Cases 1-5) developed occlusion within 40 days after surgery, and in the remaining two (Cases 6 and 7) occlusion was detected 5.4 and 6.4 years postsurgery by means of cerebral venography, which was performed in 40 of the remaining 138 patients. Of the two patients with occlusion of the hypoplastic transverse sinus, one (Case 1) did not develop symptoms and the other (Case 2) developed brain edema with transient aphasia. Of the three patients suffering from occlusion of the dominant sigmoid sinus, one (Case 3) developed severe intracerebral hemorrhages and had a poor prognosis; one (Case 4) developed profuse supra- and infratentorial brain edema with consciousness disturbance; and the other (Case 5) developed hemorrhagic infarction in the temporal lobe accompanied by aphasia. Two patients whose sinus occlusion was detected later (Cases 6 and 7) did not develop symptoms and displayed well-communicated transverse sinuses. In Case 7, a dural arteriovenous malformation formed at the site of the sinus occlusion. Laceration of the sigmoid sinus was suspected as the cause of occlusion in Cases 2, 3, and 7; compression of the sinus in Cases 5 and 6, sinus laceration and postoperative dehydration in Case 4; and laceration and compression of the sinus in Case 1.

CONCLUSIONS

Differences in the clinical course among these patients were attributed to anatomical variations in the venous system. Occlusion of the sigmoid sinus should be weighed as a potential complication when selecting candidates for the presigmoidal-transpetrosal approach.

Examination of DNA-binding activity of neuronal transcription factors by electrophoretical mobility shift assay

Electrophoretical mobility shift assay (EMSA) is a simple, rapid, and highly sensitive technique for detection of single- or double-stranded DNA-binding proteins such as transcription factors in crude nuclear extracts (F.M. Ausubel, R. Brent, R.E. Kingston, D. D. Moore, J.G. Seidman, J.A. Smith, K. Struhl (Eds.), Current Protocols in Molecular Biology, Greene Publishing Associates and Wiley-Interscience, 1989, pp. 12.0.1-12.2.10 [1]; J. Carey, Gel Retardation. Methods Enzymol., 208 (1991) 103-117 [2]). By using this technique, it is possible to quantify the abundance, relative affinity and binding specificity of DNA-binding proteins. Since proteins which bind specifically to radiolabeled DNA probes retard the mobility of the probe during electrophoresis (it also called gel retardation assay), discrete bands correspond to the individual DNA-protein complexes. Furthermore, EMSA allows one to determine which member(s) of a certain protein family are included in the DNA-protein complex by means of specific antibodies raised against the DNA-binding protein (supershift assay).

Intramedullary spinal cord tumour associated with neurofibromatosis type 1

We investigated the characteristic features of intramedullary spinal cord tumour associated with neurofibromatosis type 1 (NF-1). We have experienced 44 cases of pathologically confirmed intramedullary spinal cord tumour. Diagnosis of NF-1 was done according to the criteria set by the National Institute of Health Consensus Development Conference. Within the described population NF-1 was diagnosed in two patients. Both the patients were male and histopathologically the tumours were anaplastic astrocytoma and glioblastoma multiforme respectively. 6 cases of NF-1 associated with intramedullary spinal cord tumour based on the above diagnostic criteria have so far been reported, including our 2 cases. Of these 6 cases, 5 were male and in one sex was not described. The tumour was an astrocytoma in all 6 cases. This finding suggested that intramedullary spinal cord tumour associated with NF-1 tends to occur predominantly in males and that histopathologically the tumour is likely to be an astrocytoma. We conclude that the criteria proposed by the National Institute of Health Consensus Development Conference are contributory in making an accurate pre-operative pathological diagnosis of intramedullary spinal cord tumour associated with NF-1.

Structural organization and chromosomal assignment of the swine endothelin-1 gene

Cosmid clone containing swine endothelin-1 (EDN1) gene, cosEDN1, was isolated from swine cosmid library using swine EDN1 cDNA as a probe. The sequence analysis of cosEDN1 DNA revealed that the swine EDN1 gene consists of 5 exons, spanning approximately 6.5 kb. In the 5'-upstream region of the EDN1 gene, AP-1 and NF-1 elements were found, suggesting the possibility that the expression of swine EDN1 gene is controlled by protooncogene products Fos and Jun, and TGF-beta. Fluorescence in situ hybridization (FISH) using cosEDN1 DNA as a probe demonstrated that EDN1 gene resides on swine chromosome 7p13- > pter.

[Operative indication and risk factors for unruptured cerebral aneurysms]

Operative indication and risk factors for unruptured cerebral aneurysms were discussed. During the past 11 years, 38 aneurysms in 33 patients with a mean age of 54 years were operated on. All aneurysms were located in the anterior circulation; 16 were of carotid artery, 15 of the middle cerebral artery, 4 of the anterior communicating artery, and 3 of the distal anterior cerebral artery. Six cases (18.2%) developed neurological deficits postoperatively. The deficits were permanent in 3 cases (morbidity 9.1%). There was one operative death (mortality 3.0%). Operative risk factors were analyzed in 4 particular cases. Of these 4 cases, two cases had large aneurysms (14 and 16mm in diameter) located at carotid-ophthalmic and at the inferior wall of the carotid arteries, respectively. One developed unilateral blindness possibly due to operative manipulation, and the other showed hemiparesis with aphasia due to postoperative carotid stenosis caused by clipping. Of the rest 2 cases; one with multiple (carotid and middle cerebral) aneurysms developed hemiparesis because of postoperative stenosis of the atheromatous parent artery caused by clipping, and the other, with a large (17mm) aneurysm at the distal anterior cerebral artery, died of postoperative intracerebral hematoma. Both of these cases were associated with cerebral ischemic disease. All cases that developed postoperative neurological deficits had varying degrees of hypertension. Reviewing our series and other reports, it can be said that age is one of the most important factors that influence operative mortality. However, a lower risk of rupture develops as age increases. For those under 70 years of age, operation is considered safe in healthy individuals, especially among those without hypertension. However, in cases where there are large aneurysms, multiple lesions, less accessible locations and cerebral ischemic disease, operative risks should be kept in mind. Operative morbidity in these cases is relatively high compared to that found among others. Therefore, planning a meticulous surgical strategy and further careful operative manipulation are essentials, when surgical treatment is indicated.

A biorbitofrontobasal interhemispheric approach for suprasellar lesions

Suprasellar tumors including pituitary adenomas and craniopharyngiomas, in the case of normofixed or postfixed chiasma and ruptured anterior communicating artery aneurysms in the acute stage, can be approached with minimum brain retraction, increased exposure, and safe manipulation in the shortest possible distance via biorbitofrontobasal interhemispheric approach. Fourteen patients with pituitary adenomas, 3 with craniopharyngiomas, 7 with meningiomas, 2 with mucoceles, 1 with osteoma, and 3 with ruptured anterior communicating aneurysms in the acute stage were operated on, using this approach with excellent results. The operative technique and its results are detailed.

Malignant fibrous histiocytoma of the temporal bone with endocranial extension

Cranial malignant fibrous histiocytomas are rare tumors. Most are hypervascular, destructive masses that are similar to other malignant lesions and to malignant fibrous histiocytomas found elsewhere in the body. We describe a myxoid malignant fibrous histiocytoma of the temporal bone, possibly of dural origin, with features that more closely resembled a meningioma at CT, MR imaging, and angiography.

[A case of middle cerebral artery occlusion caused by dissecting aneurysm]

We reported a case of middle cerebral artery occlusion caused by a dissecting aneurysm that was successfully treated by intra-arterial fibrinolysis. A 38-year-old man suddenly developed left hemiparesis and became confused. He was transferred to our hospital one hour and 27 minutes after the ictus. Right carotid angiogram (CAG) revealed aneurysmal dilatation of the horizontal portion of the middle cerebral artery and occlusion of the anterior trunk. Twelve million IU of tissue plasminogen activator was injected to fibrinolyze the thrombus of the occlusion site through a microcatheter. After this, the patient became alert and hemiparesis disappeared. It took three hours and 30 minutes to gain recanalization after the ictus. Right CAG obtained the next day demonstrated the patency of the anterior trunk and the characteristic finding of the dissecting aneurysm viz "double lumen" as a result of fibrinolysis of the thrombus in the false lumen. Right CAG obtained two weeks later demonstrated "string and pearl sign" instead of the "double lumen" as a result of partial thrombosis in the false lumen. Follow-up CAG obtained nine months after the ictus demonstrated marked reduction of the aneurysmal size as the result of progressing thrombosis of the false lumen. The characteristic angiographic findings of the dissecting aneurysm such as "double lumen" and "string and pearl sign" seemed to be mostly influenced by the status of the thrombus in the false lumen. In case of major cerebral arterial occlusion caused by the embolus or thrombus from the dissecting aneurysm, intra-arterial fibrinolysis seems to be a possible treatment modality, even though it is accompanied by the risk of giving rise to subarachnoid hemorrhage.

Studies on the ileum-contracting mechanisms and identification as a complement C3a receptor agonist of oryzatensin, a bioactive peptide derived from rice albumin

Oryzatensin (Gly-Tyr-Pro-Met-Tyr-Pro-Leu-Pro-Arg) is an ileum-contracting and immunostimulating peptide derived from rice albumin. The mechanisms for the ileal contraction that it induces, consisting of rapid and slow components, were examined. The rapid contraction was mediated by histamine release and the slow contraction by a prostaglandin E2-like substance, judging from the effects of various pharmacological inhibitors and antagonists on ileal contraction and titration of histamine release. The contractile profile was very similar to that of human complement C3a(70-77), which is the COOH-terminal octapeptide of C3a and has, although less potent, qualitatively the same biological activities as C3a. Oryzatensin showed homology with C3a(70-77) and affinity for C3a receptors (IC50 = 44 microM) by radioreceptor assay. This is the first report of a food-derived bioactive peptide acting through complement C3a receptors.