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A 38-year-old man presented with progressive cervical myelopathy due to atlas hypoplasia associated with non-traumatic retro-odontoid mass. The neuroimaging findings suggested hypertrophy of the transverse ligament of the atlas. No histological confirmation of the retro-odontoid mass was obtained. Clinical manifestations improved after posterior decompression. Decompressive laminectomy of the atlas with or without fusion can achieve a good outcome in such cases.

Vascular endothelial growth factor (VEGF) is a key mediator of tumor angiogenesis. Interferons (IFNs) have been widely used in the treatment of malignant or recurrent gliomas with only marginal benefit. The association between IFNs and VEGF expression remains unclear and should be an intensively investigated subject. The present study therefore examined the effects of different types of IFNs on VEGF expression in human T98G, A172 and U251 glioblastoma cells by quantitative RT-PCR and ELISA. Both type I (alpha, beta) and type II (gamma) IFNs upregulated VEGF expression in a cell-specific but p53-independent manner. Actinomycin D experiments demonstrated that IFNs did not alter VEGF mRNA stability. In contrast, induction of VEGF mRNA by IFNs was blocked by the protein synthesis inhibitor cycloheximide. Interestingly, cycloheximide also blocked IFN-induced activation of the p44/p42 mitogen-activated protein kinase, which was partially required for induction of VEGF by IFNs. These findings suggest that VEGF might be an indirect target gene of IFNs, and might provide insights into therapeutic applications of IFNs against angiogenesis-dependent tumors.

A 58-year-old man presented with an extremely rare case of "pure type" spinal tanycytic ependymoma associated with hematomyelia manifesting as sensory disturbance of the bilateral hands and weakness of the right arm. Magnetic resonance imaging demonstrated a tumor in the spinal cord from C-2 to C-4 levels. The soft gelatinous tumor was subtotally resected and the adjacent chronic liquid hematoma was aspirated. The immunohistochemical and ultrastructural findings indicated a diagnosis of tanycytic ependymoma.

Intracranial epithelioid hemangioendothelioma (E-HE) is an extremely rare, vasoformative tumor with variable biological behavior. A huge E-HE confined to the upper side of the tentorium has not been documented previously. Recognizing E-HE as a specific vascular tumor is important, and complete tumor removal guarantees long-term survival. Here, we report an intracranial E-HE of a 24-year-old woman with the initial symptoms of progressive headache over several years. Magnetic resonance imaging revealed a huge tumor attached to the upper side of the right tentorium, with tentorial and tonsillar herniation, and secondary syringomyelia in the upper cervical spinal cord. The initial surgical attempt to remove the lesion was abandoned due to profuse bleeding from the tumor. One year after irradiation and 5 days after vascular embolization, the tumor could be removed totally. The final definitive diagnosis as E-HE was made by special immunohistochemical and electron microscopic study. The patient is free from the tumor 9 years after the second operation. Thus, E-HE is a highly vascular-rich tumor to excise, and we stress need for preoperative embolization and/or irradiation to remove huge tumor completely.

We report a case of dural arterio venous fistula (DAVF) within the left hypoglossal canal in a 64-year-old man who presented with tinnitus and ocular symptoms. Angiography revealed DAVF with the fistulous pouch medial to the left jugular bulb. The fistula was feeded by meningeal branches of the bilateral ascending pharyngeal arteries and the branches from the left vertebral artery. The fistula shunted into the left jugular bulb, with reflux into the left inferior petrosal (IPS) and cavernous sinuses (Cses), left superior ophthalmic vein (SO V) and cortical veins over the cerebral convexity. We performed transvenous coil embolization to occlude the fistula resulting in complete resolution of symptoms and signs.

We have applied an automated helical computerized tomography (CT) scanner gantry on floor-embedded rails in an ordinary operating room to estimate the extent of resection by intra-operative CT (In-CT). The same mobile CT scanner system was also installed in an ordinary radiotherapy room to determine the targets of stereotactic radiosurgery (SRS) and fractionated stereotactic radiotherapy (SRT). In-CT images, including reconstructed 2D CT (coronal and sagittal) and 3D CT, were obtained within 15 min without transporting patients for 324 operations, mainly 156 brain tumors and 69 cervical spinal degenerative disorders. For radiosurgery, the isocenter of irradiation can be aligned with the center of the mobile CT gantry by rotating the couch. SRS using this system was applied to 40 intracranial lesions. SRT also has been utilized for 10 intracranial and 16 extra-cranial whole body lesions. In-CT images were readily available to assess the extent of removed lesions of both brain tumors and cervical spinal disorders. In cases of cervical spinal disorders, more than 50% of cases required further removal of lesions after assessment of first In-CT. A mobile CT enabled SRS and SRT to be performed quickly and accurately with image fusion using MRI or angiography, and micro-multileaf collimators.

Development of chronic cerebral vasospasm (VS) after sub-arachnoid hemorrhage (SAH) must be one of the most critical factors influencing morbidity and mortality in patients with ruptured cerebral aneurysm. We studied how neuronal cells are affected by alteration of cerebral circulation and metabolism during VS in a primate model. The SAH was induced in the right basal cisterns in monkeys. Angiography presented VS maximally 7 days after SAH. In the area of VS, cerebral blood flow (CBF) showed a significant reduction accompanied by an impairment of CBF autoregulation from the acute to maximum stage of VS. In this region, cerebral energy metabolism was critically depleted and microcirculation was impaired in a state of impaired CBF autoregulation. The observation by proton magnetic resonance spectroscopy (MRS) in an experimental model demonstrated a small but significant loss of neuronal cells during development of VS. The MRS study in SAH patients also demonstrated the injury in a subpopulation of neurons during development of VS or after SAH. The results indicated that the brain areas of VS are so seriously affected to exist near ischemic threshold, in states of impaired autoregulation. These critical states possibly influence the neuronal cells to survive during development of VS after SAH.

We present frameless stereotactic radiosurgery using mobile CT, thermal plastic mask fixation, a vacuum-form body immobilizer and micro-multileaf collimators. A linear accelerator and a self-moving helical CT scanner gantry were installed in the same room. The isocenter of irradiation can be also aligned with the center of the CT gantry by rotating the couch. A thermal plastic mask and vacuum-form body immobilizer was used for registration and immobilization. The advantages of this system are as follows: 1) Accurate and painless frameless fractionated irradiation can be performed smoothly, as the patient's head is fixed without exchanging the couch from CT scanning to irradiation system. 2) This mask system can be applied to children, infants or adults with a previous craniotomy bone flap that must have a fixation pin placed into it. This system can be also used for fractionated radiotherapy without painful skull pin-fixed frame. 3) 1 mm micro-multileaf collimators enable irregular contour irradiation. 4) Image fusion (among CT, MRI, angiography, and PET) and 3D images can be used for irradiation planning. 5) This system can be used on any part of the body. 6) This system can be installed in any irradiation room without any extension or new construction.

We present frameless stereotactic radiotherapy (SRT) using mobile computed tomography (CT), thermal plastic mask fixation, a vacuum-form body immobilizer and micro-multileaf collimators. A linear accelerator (LINAC, Siemens Mevatron KD2 Primus, Germany) and a self-moving helical CT scanner gantry (Toshiba Xvision/GX, Japan) were installed in the same room. The Fischer CBI system (Leibinger, Germany) was used for stereotactic treatment planning with micro-multileaf collimators. Using a mobile CT gantry mounted on floor-embedded rails, CT scanning and LINAC irradiation can be performed on the same couch by rotating it. The isocenter of irradiation can also be aligned with the center of the CT gantry by rotating the couch. A thermal plastic mask and vacuum-form body immobilizer was used for registration and immobilization. The advantages of this system are as follows. (1) Accurate and painless frameless fractionated irradiation can be performed smoothly, as the patient's head is fixed without exchanging the couch from CT scanning to irradiation system. (2) This mask system can be applied to children, infants or adults with a previous craniotomy bone flap that must have a fixation pin placed into it. This system can be also used for fractionated radiosurgery without painful skull pin-fixed frame. (3) Micro-multileaf collimators of 1 mm enable irregular contour irradiation. (4) Image fusion (among CT, MRI, angiography and PET) and 3D images can be used for irradiation planning. (5) This system can be used on any part of the body. (6) This system can be installed in any irradiation room without any extension or new construction.

Object. It remains unclear whether elderly patients with compressive cervical myelopathy can be expected to experience a promising surgery-related outcome after undergoing expansive laminoplasty. The purposes of this study were to evaluate the efficacy of expansive laminoplasty in elderly patients with cervical myelopathy due to multisegmental spondylotic canal stenosis and to analyze the effect of preoperative prognostic factors on outcome in elderly compared with younger patients. Methods. The authors reviewed the cases of 22 elderly (> 70 years of age) and 39 younger patients in whom expansive open-door laminoplasty was performed for cervical myelopathy due to multisegmental spondylotic canal stenosis. The pre- and 12-month postoperative clinical symptoms were evaluated using the Japanese Orthopaedic Association (JOA) disability scale. Factors affecting the clinical outcome were statistically analyzed by evaluating the recovery rate calculated from the JOA scale. There were no significant differences in the mean value of the preoperative factors, especially preoperative duration of symptoms and severity of preoperative disease, between the elderly and younger patient groups. In all patients, age at the time of the operation was shown to exert no significant influence on clinical outcome. The mean recovery rate was 58.8% in the elderly group and 61.8% in the younger group, and there was no significant intergroup difference. Improvement or attenuation in impaired upper- and lower-leg motor function was shown in all patients as was an absence in decline of sensory impairment of the extremities. In the elderly group, both the duration of symptoms and the severity of canal stenosis significantly (p < 0.05) affected the clinical outcome. In the younger group, the severity of preoperative symptoms had a significant (p < 0.05) influence on clinical outcome, whereas duration of the symptoms did not appreciably affect clinical improvement. Conclusions. Open-door expansive laminoplasty showed a promising effect on clinical outcome in elderly and younger patients with multisegmental cervical canal stenosis. Significant predictive factors for clinical outcome in the elderly patients were the duration of symptoms and the severity of stenosis, which may involve the static factor causing the cervical myelopathy. To improve the elderly patients' disability, surgery must be performed as early as possible before irreversible changes in the spinal cord develop.

1. The effects of mechanical clot removal during early surgery on pharmacological cerebrovascular reactivity after subarachnoid haemorrhage (SAH) were investigated in the monkey. 2. Contractions to potassium chloride, 5-hydroxytryptamine and noradrenaline in rings of proximal parts of middle cerebral arteries (MCP), surrounded with clot, and basilar arteries (BAP), far from the clot, were examined 7 days after SAH, in which an autologous blood clot was bilaterally placed around major cerebral arteries. 3. Compared with the sham-operated group, contractions in the clot removal groups at 48 and 72 h after SAH were reduced in MCP and enhanced in BAP. 4. These results suggest that divergent vascular contractility may occur according to the distance between artery and clot if the clot is removed later than 48 h after SAH.

To clarify the relation between neuronal protection against ischaemia and calcium/calmodulin-dependent protein kinase II (CaM kinase II) activity, we investigated temporal alterations of the kinase activity in the hippocampus after transient forebrain ischaemia under neuroprotective conditions, employing the gerbil bilateral carotid artery occlusion model. The hippocampal CA1 neuronal density at 2 hours after 5 minutes of forebrain ischaemia was 214.7 +/- 25.8/mm (mean +/- S.D.), and did not differ from the control significantly; however, it decreased to 11.7 +/- 4.2/mm at 7 days after the ischaemia. The neuronal density at 7 days after the ischaemia was 185.1 +/- 18.5 under the hypothermic conditions, 128.7 +/- 19.6 with the brief ischaemic pretreatment, 65.0 +/- 13.4 with administration of MK-801, and 20.5 +/- 4.2 with the repetitive hyperthermic pretreatment, respectively. The Ca2+/calmodulin-dependent activity of CaM kinase II in the hippocampal cytosolic fraction was decreased to 47.5% of the control value at 2 hours after the ischaemia, when CA1 neuronal death was not observed. In contrast, the activity was 98.8% of the control under the hypothermic conditions, 91.4% with the brief ischaemic pretreatment, 71.2% with administration of MK-801, and 47.9% with the repetitive hyperthermic pretreatment, respectively. These results indicated that the preservation of the Ca2+/calmodulin-dependent activity of cytosolic CaM kinase II after ischaemia parallelled the neuroprotective effect in the gerbil hippocampus. Thus, it is suggested that the preservation of the activity may be involved in the mechanism of neuronal protection against ischaemia.

Changes in cerebral hemodynamics and metabolism following cerebral revascularization were evaluated using positron emission tomography (PET). Ten patients who had received nonsurgical treatment for 3-6 months for minor completed stroke underwent superficial temporal artery to middle cerebral artery (STA-MCA) bypass surgery. All patients showed no extensive infarction on MR, and responsible vascular lesions were detected in the anterior circulation. A PET study of cerebral blood flow (CBF), oxygen extraction fraction (OEF), cerebral metabolic rate for oxygen (CMRO2), and cerebral metabolic rate for glucose (CMRGlu) measurements was performed before and 1.5 months after surgery using a steady state technique. Angiographically, anastomotic sites were patent in all patients. Seven patients showed neurological improvement after surgery and the others showed no improvement. The decreases in CBF, CMRO2 and CMRGlu recovered to some extent not only on the lesion side but also on the contralateral side after surgery. The increase in OEF values on the lesion side subsequently decreased after surgery. CMRO2 and CMRGlu showed parallel changes. It is concluded that the metabolic improvement afforded by the cerebral revascularization resulted in the neurological improvement, and that PET study is a powerful method for evaluating patients with cerebral occlusive diseases.

We report a 69-year-old woman who developed serious hydrocephalus after cervical laminoplasty for ossification of the posterior longitudinal ligament. The patient presented with approximately 50% spinal canal compromise pertaining to ossified lesion at C5 and C6 levels and subsequently underwent a C3-C7 open-door laminoplasty, followed by uneventful neurological recovery until 2 weeks postoperatively. Despite a favourable postoperative course, she presented with serious symptoms and signs of intracranial hypertension about 3 weeks after surgery. Computed tomography demonstrated the appearance of marked hydrocephalus, with no explainable cause. A ventriculoperitoneal shunt followed by removal of subdural fluid in the suboccipital fossa resulted in resolution of the clinical symptoms and of the hydrocephalus. It is important to be aware of the very rare occurrence of such intracranial neurological compromise after a cervical laminoplasty operation for long-standing ossification of the posterior longitudinal ligament.

Brake pads used in automotive disk brakes are generally made of many components such as phenolic resin, aramid fiber, Cu powder, BaSO4, and cashew dust. Using a slider-on-disk-type wear tester, the friction and wear characteristics of the pad against the disk made of cast iron at high disk temperature (above 80°C) were studied with varying the content of the components. In particular, the relation between the sudden decrease in friction (fade) and the wear rate were closely studied. The experimental, result of the wear test was also analyzed, systematically by the multiple regression method and the effects of the components were clarified quantitatively. Presented at the 50th Annual Meeting in Chicago, Illinois May 14–19, 1995

This study in mongrel dogs was designed to observe the effects of ethanol on both endothelial cells of the basilar artery and brain function. By use of sterile surgical technique, a super-selective catheter was placed in the proximal portion of the basilar artery in the dogs. Five dogs received 3 ml of 25% ethanol and 5 dogs received 3 ml of 50% of ethanol through the catheter over 2 minutes. The remaining 5 dogs received 3 ml of saline as a control. Auditory brain stem response (ABR) was monitored for 2 hours after ethanol infusion, and then perfusion-fixation was performed from the heart with 4% paraformaldehyde. The basilar artery was observed with scanning electron microscopy after routine procedures. The endothelial cells were intact in the control group. The 50% group showed a higher level of injury to the endothelium as well as a higher degree of platelet adhesion and fibrin clot formation compared with the 25% group. The extensive endothelial-cell damage subsequently caused thrombus formation. The ABR disappeared immediately after ethanol infusion in both ethanol groups, and recovered gradually in the 25% group, but did not re-appear during the time course of 2 hours in the 50% group. The ethanol less than 25% in concentration near the endothelium is considered to be safe as a transcatheter embolic agent with the attention to the central toxicity.

Pre-radiosurgical embolization was carried out using cyanoacrylate in seven of 13 patients with cerebral arteriovenous malformations (AVMs) treated by stereotactic radiosurgery (SRS) with a linear accelerator (LINAC). The aim of embolization before SRS was the reduction of AVM volume and/or the elimination of vascular structures bearing an increased risk of haemorrhage. Staged-volume SRS was also performed in two patients because of residual irregular shaped nidus of AVMs even after the embolizations. Complete obliteration of the AVM nidus on angiogram was presented in five patients with embolizations (including one with staged-volume SRS) and in three of six patients with SRS alone, during follow-up periods after radiosurgery. No patients experienced haemorrhagic events after SRS. Although transient neurological symptoms were observed after embolizations in two patients, no permanent neurological deficits were presented in all patients with SRS. Pre-radiosurgical embolization may allow the effective influence on irradiation therapy in relatively large AVMs and promote more frequent obliteration in more small sized AVMs compared to those with SRS alone. However, further study must be needed to determine whether staged-volume SRS provides a high rate of AVM obliteration and its safeness.

An autologous blood clot was placed bilaterally around cerebral arteries in the basal subarachnoid space to mimic subarachoid haemorrhage (SAH). Cynomolgus monkeys were randomised into five groups: sham operated groups, clot removal group at 48, 72 or 96 h after. SAH and clot group. The proximal parts of the middle cerebral arteries were cut into rings for isometric tension measurements at 7 days after SAH. Potassium chloride, 5-hydroxytryptamine (5-HT), norepinephrine (NE), adenosine triphosphate (ATP), prostaglandin F(2alpha) (PGF(2alpha)) and haemoglobin all induced dosed-dependent contractions. There was a progressive attenution of the contractions in response to the agonists in the clot removal and the clot groups, which reached statistical significance at 48 h after SAH in the case of 5-HT, and at 72 h in the cases of NE, ATP and PGF(2alpha) as compared with the sham operated group. These pharmacological results suggest that clot removal should within the first two days after SAH to prevnt cerebral vasospasm.

In order to study how immune-inflammatory responses are involved in the pathogenesis of cerebral vasospasm after subarachnoid haemorrhage (SAH), the kinetics of expression of the intercellular adhesion molecule 1 (ICAM-1), a ligand for the leucocyte adhesion receptor, were studied on the cerebral arteries following SAH in rats. The SAH was induced by intracisternal injection of arterial blood. The rats were sacrificed at specified times: immediately after induction of SAH to seven days after SAH. Cryostat sections of the basilar artery (BA) were prepared and incubated with anti-rat ICAM-1 antibody. Morphometric analysis of the BA revealed a significant narrowing of the luminal diameter on Day 2 following SAH. While in the non-treated normal animals, no nor only weak expression of ICAM-1 was observed on the endothelial layer of the BA, there was greater expression of ICAM-1 on the endothelial layer of the BA in SAH rats, and the expression was observed also in the medial layer of the artery from Day 2 to Day 5 following SAH. The present results indicate that SAH really causes responses in the cellular immunity not only in the endothelial layer, but also in the medial layer of the artery as a target of immune damage, which is presumed to be one of the important steps in the development of cerebral vasospasm.

This study was designed to examine the influence of total body hyperthermia (TBHT) using an extracorporeal circuit with a heat exchanger on the cerebral blood flow (CBF), intracranial pressure (ICP), brain tissue pH, cerebral autoregulation and blood-brain barrier (BBB) permeability in dogs. The rectal temperature of the dow was raised to 41.5 degrees C, maintained at 41.5-42.0 degrees C for 2 hours (HT period) and then reduced to normothermia by cooling. Regional CBF was measured by the hydrogen clearance method before heating, during the HT period and after cooling. ICP and brain tissue pH were monitored during the TBHT treatment. Autoregulation of the CBF during the HT period was assessed by measuring the regional CBF and the ICP in a state of induced hypo- or hypertension. The influence of TBHT on BBB permeability was examined using an immunohistochemical technique. The regional CBF increased from 38.1 +/- 6.5 (mean +/- SD) to 49.1 +/- 9.8 ml/100 g/min and the ICP from 10.3 +/- 4.2 to 16.8 +/- 3.4 mmHg when TBHT was raised. These returned to normal values after cooling. The regional CBF and the ICP changed in parallel with drug-induced changes of mean arterial blood pressure during the HT period. These changes suggest that autoregulation of the CBF is paralysed during the HT period. Brain tissue pH decreased rapidly when the rectal temperature exceeded 41.0 degrees C. The pH was 7.18 +/- 0.05 during the HT period and was relatively stable. The pH returned to a normal value after cooling. Immunopositive stain for albumin was not observed in heated brain tissue except for the normally leaky pineal gland and the choroid plexus, indicating preservation of BBB during TBHT. These results suggest that brain oedema may occur easily due to paralysed cerebral autoregulation when the arterial blood pressure fluctuates excessively, so arterial blood pressure must be controlled strictly during TBHT.

Four patients with prosthetic heart valves suffered intracranial hemorrhage (cerebral hemorrhage in one patient, cerebellar hemorrhage in one, and chronic subdural hematoma in two) during long-term oral anticoagulant drug therapy (warfarin). In all patients, warfarin was discontinued and its effect neutralized by vitamin K, then surgery was performed after the thrombotest value exceeded 50%. No uncontrollable bleeding occurred at surgery. Warfarin was discontinued until 3-7 days postoperatively. Intravenous heparin administration was used to prevent embolic complications and the dose was modified based on the activated clotting time measured at the bedside. One patient, who could not receive heparin administration because of massive bleeding, developed myocardial infarction due to coronary artery thromboembolism 2 days after operation and died 4 days later. The other patients received heparin administration and were alive and well at the most recent follow-up examinations. Heparin administration monitored by activated clotting time is a useful method to prevent embolic and bleeding complications in the surgical treatment of intracranial hemorrhage in patients with prosthetic heart valves receiving long-term anticoagulant therapy.

We report a case of bacterial aneurysm complicated by severe infectious endocarditis. A 34-year-old man developed idiopathic fever and general fatigue persisting for a month. He was admitted to our institution, and examinations revealed severe bacterial endocarditis with vegetation at the mitral valve and mitral incompetence. Right after admission, he suddenly developed acute cardiac infarction and cardiac arrest due to occlusion of the coronary artery by emboli from vegetation of the mitral valve. After achieving a good recovery, magnetic resonance (MR) imaging demonstrated an unruptured bacterial aneurysm at the distal branch of the left middle cerebral artery (MCA) supplying the left parietal lobe 5 days after admission, and T2* weighted images demonstrated multiple signal loss lesions, which were suspected of being thrombosed bacterial micro-aneurysms or micro-vasculitis. Although there was a risk of aneurysm rupture, we decided to proceed with mitral valve replacement by an artificial heart valve made of carbon, and repeatedly observed an unruptured bacterial aneurysm by serial MR imaging and angiography. Due to the preceding cardiac surgery, we were able to completely cure the severe infection and prevent new embolic showers. Under administration of antibiotics, the bacterial cerebral aneurysm did not increase over a period of 4 weeks, and finally the aneurysm disappeared about 6 weeks after admission. Although the timing of treatment of an unruptured bacterial aneurysm and cardiac surgery for infectious endocarditis associated with a bacterial cerebral aneurysm are controversial, we think that proceeding with cardiac surgery and observing the unruptured bacterial aneurysm by repeated MR imaging and angiography under administration of antibiotics was an appropriate strategy in this case.

We report 2 cases of hypoxic ischemic encephalopathy with atypical findings on computed tomographic (CT) and magnetic resonance (MR) imaging for the acute to subacute stage. Case 1: A 78-year-old man with larynx cancer suffered cardiac arrest after suffocation. Cardiopulmonary resuscitation, was performed; the patient then went into a deep coma and also developed severemyoclonus. CT scans on day 0 and day 3 after the arrest revealed no abnormalities MR imaging was performed on day 13 to evaluate cerebral anoxia; however, no abnormal findings were obtained. Since no abnormalities were detected both on CT and MR imaging, we expected that the prognosis would be good; however, the patients did not recover from coma and remains in a persistent vegetative state. Case 2: A 54-year-old man developed cardiac arrest after anaphylactic shock caused by insect bite. After cardiopulmonary resuscitation, the patient lapsed into a deep coma. CT scans performed on day 1 and 3 after the cardiac arrest revealed slight subarachnoid hemorrhage at the surface of the right cerebral cortex along the falx cerebri. MR images obtained on day 10 demonstrated slight hemorrhage at the surface of right cerebral cortex, but no abnormalities in basal ganglia, thalamus, cortex, and white matter. The transient damage of the blood brain barrier caused by hypoxia and ischemia was thought to induce the slight subarachnoid hemorrhage after cardiopulmonary resuscitation. The patient demonstrated early recovery and was almost completely recovered with slight agnosia. MR imaging to rule out hypoxic-ischemic encephalopathy may not have been timed appropriately in both the case, our radiological findings are usual as compare to the findings presented in other similar reports. The variations in the findings of CT and MR imaging in the case of hypoxic-ischemic encephalopathy should be clarified, and the prognosis and management of this condition should be planned on the basis of not only the neuroradiological images but also the neurological signs and symptoms.

We investigated the histological changes between arteries constricted by endothelin for 7 days and vasospastic arteries induced by the double injection of autologous blood. Group 1 was a sham-operated group. Group 2 animals received a continuous cisternal injection of endothelin-1 (1.7 x 10(-9) mol/7 days) by a miniosmotic pump implanted in the neck musculature for 7 days. Group 3 received double injections of cisternal blood administered 48 hours apart. Angiography showed severe constriction of the basilar artery, 34.6% and 43% in Groups 2 and 3, respectively, on Day 7. Histological study showed marked constriction of the basilar artery in both Group 2 and Group 3. Degenerative changes in endothelial cells and smooth muscle cells were observed in both Group 2 and Group 3. Immunohistochemical study demonstrated endothelin-1 in the endothelial cells in Group 2, but not in Group 1 or in Group 3. It is suggested that endothelin-1 may play an important role in the pathogenesis of cerebral vasospasm.

The authors studied the effect of the immunosuppressive drug cyclosporine (CS) on the development of cerebral vasospasm after subarachnoid hemorrhage (SAH) using a primate model of vasospasm. Eighteen monkeys were randomly divided into three groups: a sham-operated control group, an SAH group, and a CS-treated group. To induce SAH, the right side of the circle of Willis was dissected free of the arachnoid and an autologous blood clot was placed around the arteries. In the CS group, CS (5 mg/kg/day) was administered intramuscularly for 7 days after the induction of SAH. The vessel caliber was evaluated on angiograms before the induction of SAH (Day 0) and 7 days after SAH (Day 7). Histological changes and the deposition of IgG in the arterial wall were studied in the three groups. The combined values of the average reduction of the right cerebral arteries at Day 7 was significant (P less than 0.05) in the SAH group (-43.3%) and in the CS group (-31.3%) as compared with the Sham group (-0.7%); however, there was no significant difference between the values in the SAH and the CS groups. In the CS group, the average reduction in vessel caliber of the right middle and anterior cerebral arteries was significantly (P less than 0.05) less than in the SAH group; this did not prove true for the internal carotid artery, however. Although the deposition of IgG in the media and an inflammatory reaction were observed in the spastic arterial wall in both the SAH and CS groups, there was no definitive difference in these immune/inflammatory reactions between the two groups. It is suggested that CS may be helpful in reducing the severity of vasospasm, but may not have a major therapeutic effect, considering its systemic toxicity.

Plateau waves, as described by Lundberg (1960), can often be observed in patients with increased intracranial pressure (ICP) resulting from brain tumours, benign intracranial hypertension and other causes. The clinical significance of the waves, however, is still debated. In this study, the ICP was recorded continuously, the size of the ventricular system was evaluated using computerized tomography (CT), the cerebrospinal fluid (CSF) flow was studied using isotope cisternography, and the absorptive capacity of the CSF was determined by measuring the conductance to CSF outflow, in 94 patients with increased ICP. All patients who received continuous ICP monitorings had a basic ICP level of more than 200 mmHg, and these patients were assigned to two groups on the basis of the presence or absence of the plateau waves in the ICP recordings: group I comprising 17 patients without plateau waves but with a high ICP resulting from subarachnoid haemorrhage or hypertensive intracerebral haemorrhage, within 5 days after the start of bleeding; and group II consisting of 77 patients with both plateau waves and a high ICP resulting from brain tumours, meningitis carcinomatosa, benign intracranial hypertension, superior sagittal sinus thrombosis and communicating hydrocephalus. The isotope cisternography and conductance to CSF outflow studies showed that there was neither a delay in CSF circulation nor an impairment of CSF absorption in the group 1 patients and these patients showed no ventricular dilatation on CT, whereas there was a marked sluggishness in the CSF flow and a severe defect in the CSF absorption capacities of the group II patients irrespective of the presence or absence of ventricular dilatation on CT. The present observations indicate that patients with a plateau-wave phenomenon have a marked impairment of CSF absorption and CSF flow. We suggest that the phenomenon is an important sign indicating an impairment of CSF absorption capacities.

A 49-year-old male was admitted with a history of radiotherapy for a pituitary adenoma 9 years earlier. Three weeks prior to admission, he noticed visual loss in the left eye. Computed tomography (CT) scan revealed a sellar tumor. The patient underwent craniotomy and the tumor was partially resected. The histological diagnosis was benign pituitary adenoma. Two months after surgery, he began to complain of headache and left hemiparesis. CT scan at that time showed a large parasellar tumor extending into the right temporal lobe. A second craniotomy was performed and a firm tumor was partially removed. Under light microscopy, the tumor was composed of anaplastic spindle cells showing a fascicular pattern. Ultrastructurally, the tumor cells were spindle-shaped with elongated nuclei. The cytoplasm contained numerous distended rough endoplasmic reticula and free ribosomes, Golgi apparatus as well as glycogen granules. Some desmosome-like intercellular adherent were observed. Collagen fibers were scattered in the extracellular space. There was no apparent formation of a basement membrane. These findings suggested a close morphological similarity between tumor cells and fibroblasts, conforming to ultrastructural diagnostic criteria for fibrosarcoma. In spite of intensive treatment, such as a second radiotherapy and subsequent craniotomy, the patient died 9 months after admission. The clinical course and pathological findings of the post-irradiation pituitary fibrosarcoma are discussed.

The effects of increased intracranial pressure (ICP) during the appearance of plateau waves or Bwaves to the brainstem functions were investigated by evaluation of evoked potentials. The ICP and systemic blood pressure were continuously recorded in nine cases of intracranial hypertension. In the four cases demonstrating plateau waves in ICP recording, the latencies of the auditory brainstem evoked potentials (ABEP) measured during the appearance of plateau waves showed no significant differences compared to those measured during the interval phase between two plateau waves. In the five cases demonstrating B-waves in ICP recording, four cases showed significant (p < 0.05) prolongation of the V wave of ABEP and three showed significant (p

This paper measures a utility function for the latency time and the video quality in video download service, and newly proposes a service management scheme to maximize utility.

A 38-year-old man presented with progressive cervical myelopathy due to atlas hypoplasia associated with non-traumatic retro-odontoid mass. The neuroimaging findings suggested hypertrophy of the transverse ligament of the atlas. No histological confirmation of the retro-odontoid mass was obtained. Clinical manifestations improved after posterior decompression. Decompressive laminectomy of the atlas with or without fusion can achieve a good outcome in such cases.

Total removal of spheno-orbital fibrous dysplasia was achieved through intraoperative CT-assisted surgery via a burr hole. A 32-year-old man had persistent headache. Radiological studies demonstrated a small osteolytic lesion in the sphenoidal bone underneath the superior orbital fissure. Intraoperative serial CT scans showed the depth and width of the tumor within the complicated structure of the skull base. The lesion was successfully removed by CT-guided minimally invasive surgery.

A chordoid glioma in the third ventricle was studied immunohistochemically and ultrastructurally. In this report, special attention is paid to the histogenesis in relation to the pathological appearance and unique anatomic location of this tumor. Light microscopic and immunohistochemical findings were similar to those reported previously. Ultrastructurally, microvilli were frequently seen, but three types of abnormal cilia were rarely observed. Basement membrane around the tumor cells and microvessels was extensive. Poorly to moderately developed intermediate (adherent) junctions were frequently seen. Resemblance of these ultrastructural features of the tumor to embryonic tanycytes suggests the tanycytic differentiation of chordoid glioma. Neuroradiologically, all of the previously reported cases of chordoid gliomas seem to arise in the anterior part of the third ventricular floor. This region includes the lamina terminalis, infundibular recess and median eminence, which corresponds to a tanycyte-rich area. These findings suggest a tanycytic origin of chordoid glioma.

Oxidation and/or free radical reactions after subarachnoid hemorrhage (SAH) may be involved in the development of chronic cerebral vasospasm. The inhibition of these reactions is thought to be one of the therapeutic strategies for prevention of cerebral vasospasm. We investigated the effect of Ebselen, a synthetic seleno-organic compound, which exhibits anti-oxidation by glutathione peroxidaselike activity to inhibit free radical reactions by lipid peroxidation on the development of chronic cerebral vasospasm in a primate model.Seventeen monkeys were used. SAH was produced by introduction of a blood clot around the right middle cerebral artery and the right side of the circle of Willis in all animals. The monkeys were randomly divided into three groups according to Ebselen dosage: 1) no dosage or non-treated group; 2) high-dose Ebselen group; and 3) low-dose Ebselen group. The drug was administered at 10 mg/Kg in the high-dose group and 5 mg/Kg in the low-dose group twice a day in each group for 7 days after SAH. The vessel diameter was evaluated on angiograms before the induction of SAH and at Day 7 following SAH.In the untreated group, the angiograms showed significant (p0.05) reductions of the mean vessel caliber of the right internal carotid (ICA) (38 +/- 10% reduction) and the middle cerebral artery (MCA) (56 +/- 9.7%) compared with the baseline value before SAH. In the high-dose Ebselen-treated group, the mean percent reduction in vessel caliber of the right ICA (16 +/- 11%) and MCA (28 +/- 9.5%) on Day 7 angiograms were significantly (p0.05) lower than those in the nontreated group, whereas the mean percent reduction of these vessels in the low-dose Ebselen-treated group showed no significant difference compared with the untreated group.Chronic cerebral vasospasm was inhibited in the animals in which a relatively large amount of Ebselen was administered for 7 days after SAH. The results suggest that the oxidation or free radical reaction by lipid peroxidation after SAH might be involved in the pathogenesis of vasospasm, and that inhibition of these reactions by drugs, such as Ebselen, may have a promising effect for prevention of vasospasm.

This is a report on a patient with traumatic carotid-cavernous sinus fistula (CCF). She gradually noticed noise in her head and suffered from partial ophthalmoplegia. Angiography demonstrated a left high flow CCF. She underwent a direct surgical treatment with a detachable balloon because an endovascular balloon embolisation for the CCF had been unsuccessful. Immediate disappearance of the bruits after surgery was noted and the patient recovered progressively her ophthalmoplegia. Follow angiograms 3 months after surgery revealed the disappearance of the fistula and an appearance of a false aneurysm. She is asymptomatic and periodically monitored in the outpatient clinic.

OBJECTIVE: To study how neuronal cells are affected by development of chronic cerebral vasospasm after subarachnoid hemorrhage (SAH), the changes in neuronal metabolites during development of vasospasm were evaluated by in vivo localized proton magnetic resonance spectroscopy (MRS) in primates. METHODS: SAH was produced by introduction of a blood clot around the right middle cerebral artery and the right side of the circle of Willis. MRS experiments were performed before SAH and on Days 7 and 14 after SAH. Multislice magnetic resonance images were obtained to locate the volume of interest (1.0 cm 3 ) in the bilateral parietal regions. The peak areas for choline compounds, the sum of creatine and phosphocreatine, and N-acetyl-aspartate were calculated. RESULTS: Angiograms revealed approximately 50% reduction of vessel caliber for the right main cerebral arteries on Day 7. Magnetic resonance imaging revealed no apparent cerebral infarction, even in the spasm-side hemisphere. MRS revealed a significant (P < 0.05) reduction of the N-acetyl-aspartate/creatine and phosphocreatine ratio on Days 7 and 14 and a significant increase in the choline/creatine and phosphocreatine ratio on Day 7, in the spasm-side parietal region. In the sham-operated animals, there were no significant changes in these ratios in the bilateral parietal region on Days 7 and 14 after the operation. CONCLUSION: The results suggested that the development of cerebral vasospasm after SAH caused ischemic injury in a subpopulation of neuronal cells, even when no apparent cerebral infarction was shown. Proton MRS may be useful to evaluate how neuronal cells are affected by the ischemic insult during development of vasospasm in clinical situations.

To determine the postganglionic targets of NOS-containing preganglionic neurons, we studied the association of NADPH-diaphorase positive preganglionic fibers and retrogradely labeled postganglionic neurons in the superior cervical ganglion (SCG) in rats. Wheat germ agglutinin-horseradish peroxidase solution was applied to the anterior chamber of the eye, middle cerebral artery, subcutaneous layer of the facial skin, or submucosal layer of the inside of the lip. Two days after tracer application, the rats were perfused with fixative solution. Serial sections of the SCG were stained histochemically for NADPH-diaphorase followed by diaminobenzidine reaction. More than 80% of the labeled postganglionic neurons innervating the structures in the subcutaneous or submucosal layer showed close association with NADPH-diaphorase positive preganglionic nerve terminals; approximately one-third of these labeled neurons were encircled by dense baskets of pericellular terminals. On the other hand, most of the postganglionic neurons innervating the iris (69%) or the cerebral artery (90%) did not show a distinct association with NADPH-diaphorase positive terminals. These results suggest that one of the principal roles of the NOS-containing preganglionic neurons may be in controlling the postganglionic neurons which innervate the structures in the subcutaneous or submucosal layer.

BACKGROUND Cerebrospinal fluid (CSF) otorhinorrhea is one of the most common postoperative complications following the suboccipital approach to the cerebellopontine angle and the internal auditory canal. Accurate preoperative detection of the site of CSF leakage is important because inaccuracy may require a more extensive exploratory surgical procedure in the repair operation. There are few reports on evaluation of magnetic resonance (MR) imaging in diagnosing CSF leakage. CASE DESCRIPTION MR imaging of two cases of postoperative CSF rhinorrhea is reported. A 53-year-old woman and a 29-year-old man underwent suboccipital operations for microvascular decompression of the facial nerve in hemifacial spasm and for removal of an acoustic schwannoma, respectively. In both cases, MR findings were useful in preoperatively delineating the site of the CSF leakage, which was confirmed during the repair operation. CONCLUSION MR imaging may be useful in identifying the site of CSF leakage following the suboccipital approach to the cerebellopontine angle.

Clot removal at early surgery has been reported to be clinically effective for the prevention of cerebral vasospasm following subarachnoid hemorrhage (SAH) due to rupture of an intracranial aneurysm. We examined the most efficacious timing of mechanical clot removal on pharmacological responses in a monkey SAH model. Cynomolgus monkeys (Macaca fascicularis) were randomized into five groups: sham-operated, clot removal in which the clot was removed 48, 72, or 96 h after SAH, and clot groups. An autologous blood clot was placed around the bilateral major cerebral arteries after craniectomy to mimic the hemorrhage. Seven days after the SAH, proximal and successively distal parts of the middle cerebral arteries were cut into rings for isometric tension measurement. The contractile responses to potassium chloride, 5-hydroxytryptamine, norepinephrine, adenosine triphosphate, prostaglandin F20, and hemoglobin were greater in the proximal parts than in the distal parts in each group. Compared with the sham-operated group, the responses of the clot-removal and clot groups to the drugs were progressively attenuated. The maximum responses to 5-hydroxytryptamine in the proximal parts and to adenosine triphosphate in the distal parts started to decrease, significantly, in the clot-removal group 48 h after SAH, while most of the responses to the other agonists began to decrease in the clot-removal groups later than 72 h after SAH. These results suggest that the attenuation of cerebrovascular contractile responses 7 days after SAH is pharmacologically inevitable, even if the clot is removed as early as 48 h after the SAH. Clot removal may thus be recommended within 48h after SAH to ameliorate the severity of cerebral vasospasm following SAH.

The purpose of this study was to assess the incidence of unruptured asymptomatic cerebral aneurysms detected by magnetic resonance angiography (MRA). Three thousand patients without major neurological deficit had undergone MRA. MRA was obtained using three-dimensional time-of-flight method. Among the 3000 patients examined, 80 unruptured asymptomatic aneurysms were discovered in 68 patients (2.3%). Twenty-six were located on the internal carotid artery, 28 on the middle cerebral artery, 17 on the anterior communicating artery, 1 on the posterior cerebral artery and 8 on the vertebro-basilar artery. Thirty-seven patients underwent surgery. Mortality was zero and morbidity was 5%. Three patients who declined surgery died of subarachnoid haemorrhage in the ensuing 2.5 years.

BACKGROUND Mannitol has been used in routine neurosurgical practice for the control of increased intracranial pressure. The effect of mannitol on focal cerebral ischemia was evaluated by somatosensory-evoked potentials (SEP) and magnetic resonance imaging (MRI). METHODS The left middle cerebral artery (MCA) was exposed via the superomedial transorbital approach and occluded proximal to the origin of the perforating arteries. Ten cats received mannitol (0.5 g/kg IV) immediately, 6, 12, and 18 hours after MCA occlusion. The other 10 cats received saline solution and served as control. The animals were initially prepared to measure SEP before and 15, 30, and 60 minutes after MCA occlusion. Following SEP measurement, all cats were prepared for MRI. Sequential MRI of both intravoxel incoherent motion (IVIM) and T 2 -weighted spin echo techniques were obtained at 2, 4, 6, and 24 hours after MCA occlusion. The animals were sacrificed after the last MRls for histologic study. RESULTS The SEP amplitude decreased to about 10% at 15 minutes after MCA occlusion and then gradually recovered to 38% at 60 minutes in the mannitol group, and 21% in the control group. In MRI study, IVIM imaging demonstrated ischemic cerebral injury as a sharply demarcated area at 2 hours after MCA occlusion, while T- 2 weighted imaging failed to show clear evidence of injury until 2-6 hours. High-signal intensity areas on both IVIM and T 2 -weighted images were smaller in the mannitol group than those in the control group. Histologic study demonstrated that infarction size was 36.9% ± 7.7% of the left hemisphere in the mannitol group and 57.3% ± 5.3% in the control group (p < 0.05). CONCLUSIONS Mannitol is effective for acute cerebral ischemia, and SEP and MRI are useful for monitoring it.

The results of surgical management of ossification of the posterior longitudinal ligament (OPLL) of the cervical spine consisting of either anterior or posterior surgical decompression of the spinal cord and/or nerve roots were evaluated in 75 patients. The OPLL was continuous (COPLL) in 37 patients, segmental (SOPLL) in 29, mixed COPLL and SOPLL (MOPLL) in five, and circumscribed disk type (DOPLL) in four. Fourteen of the patients with COPLL, 27 with SOPLL, three with MOPLL, and all four with DOPLL were treated via the anterior approach with vertebrectomy and discectomy with anterior fusion. The remaining patients were treated by posterior laminoplasty or laminectomy. The overall mean improvement in the neurosurgical cervical spine scale (NCSS) score after surgery was 78.0% in those treated with anterior decompression and 46.1% in those treated with posterior decompression. The NCSS score in the latter group decreased during the follow-up period, from 10.4 to 9.7 points, whereas that in the anterior decompression group increased, from 12.9 to 13.0.