Underlying mechanisms which lead to brain edema following ischemic insults have been subjects of much debate. In this study, experimental cerebral infarction was produced in dogs by injecting one or two silicone rubber cylinders through the cervical internal carotid artery. Twenty-four hours after embolization, animals were killed and morphometrical analyses in the capillary endothelial cell membranes in the cortex were done by freeze-fracture replica in addition to conventional ultra-thin section using the transmission electron microscope.
In ultra-thin sections of capillary endothelium in the ischemic cerebral cortex, surface infolding and increase in number of pinocytotic vesicles were recognized, but no findings of opening of tight junction were ascertained.
In freeze-fracture replicas of capillary endothelium of both normal and ischemic cerebral cortex, tight junction was presented as the network of ridges composed of about 100 Å particles on the protoplasmic face (PF) and grooves on the extracellular face (EF). In the ischemic cortex, arrangement of strands of these protein particles was not changed. In replica preparations, too, no definite findings of opening junction were certificated. Pinocytotic vesicles were seen as invaginations on the PF and as protrusions on the EF. In the ischemic cortex, the average number per square μm was increased. On the luminal front, it reached to 22.0 (on the PF) and 29.5 (on the EF) as compared to 7.2 and 9.0 in the normal cortex, respectively. The size of vesicles was also enlarged; 4, 990.7± 798 nm² (on the PF) and 4, 762.8±878 nm² (on the EF) as compared to 3, 567.7±570 nm² and 3, 404.5±573 nm² in the normal cortex, respectively.
These results indicate that transcellular transport by pinocytotic vesicles has an important role in increase of capillary permeability observed in an ischemic model.

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Experimental cerebral infarction was produced in dogs by injecting one or two silicone rubber cylinders through the cervical internal carotid artery (permanent group). In some dogs the rubber cylinder was removed by pulling out the monofilament suture thread after 6 hours of temporary embolization (temporary group). Twenty-four hours after embolization, the animals were killed.
In ultrathin section of capillary endothelium in the ischemic cerebral cortex of both groups, surface infolding and increase in number of pinocytotic vesicles were recognized, but no findings of opening of tight junctions were ascertained.
In replica preparations of both groups, no definite findings of opening junctions were certificated. Pinocytotic vesicles were seen as invaginations on the protoplasmic face and as protrusions on the extracellular face. The average number per square μm was increased. On the luminal front of protoplasmic face, it reached to 28±6 equally in both groups as compared to 7±1 in the normal cortex. The size of vesicles was also enlarged, 4, 713±868 nm² in permanent group and 3, 684±570 nm² in temporary group as compared to 3, 491±507 nm² in normal group.
The arteriole-venule in the ischemic cortex of temporary group also showed increased and enlarged pinocytotic vesicles, but no opening of tight junctions.
The results indicated that transcellular transport by pinocytotic vesicles plays an important role in the increase of capillary permeability observed in ischemic models of both groups. The vascular ultrasturctural differences between permanent and temporary groups were not statistically significant in either cortex.

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Electrocochleographic potentials from the internal auditory meatal portion of the cochlear nerve (IAM-EcoG) and brain-stem auditory evoked potentials (BAEP) from the vertex were simultaneously recorded during cerebellopontine angle (CPA) manipulations (retractions of the cerebellar hemisphere or the cochlear nerve) of dogs. The same BAEP changes as in human subjects were obtained from the animal models. IAM-EcoG showed graded deteriorations in accordance with BAEP changes. The results are as follows: 1) Prolongation of the I-V interpeak latency (IPL) of BAEP, the most common finding during CPA manipulations, is the reflection of prolongation of the I-II IPL, which is caused by conduction impairment or block of the nerve impulses between the extracranial portion of the cochlear nerve and the brain-stem. The operative manipulations act as stretch or compression injuries to the cochlear nerve in the CPA and bring about acute traumatic cranial nerve root lesion, a retrocochlear lesion. 2) The obliteration of all BAEP components including wave I cannot be caused by conduction block. This is caused by occlusion of the internal auditory artery (IAA). BAEP wave I and IAM-EcoG P₁-N₁ complex are important indicators for the cochlear blood flow during surgical interventions. 3) As possible causes of IAA obstructions, mechanical distortions of the relationship between the anterior inferior cerebellar artery (AICA) and IAA at their junctional portions, mechanical vasospasms of the AICA-IAA complex, and ensuing no-reflow phenomena are discussed. 4) The EcoG is expected to be a useful intraoperative, real-time monitor during CPA surgery which can detect rapid changes derived from cochlear insufficiency. This real timability can overcome the disadvantages of BAEP.

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Twenty patients with severe head injury were treated under hypothermia with barbiturate and hyperventilation. Indications for hypothermia were 1: younger aged acute head injuries, 2: Glasgow Coma Scale 3 to 5 without severe cardio-pulmonary complications, 3: presence of spontaneous respiration. Hematomas with surgical indications were evacuated before the procedure. Surface cooling was applied with accurate cardio-pulmonary monitoring. Steroid, large dosis of thiopental and hypertonic diuretics were used routinely. Dopamine was administered when the blood pressure was low to maintain the cerebral perfusion pressure of normo-thermia. The average duration of hypothermia at 30°C was 6.6 days. In 7 cases with primary brain stem injury, 3 died and 4 recovered with mild to moderate disability. In 13 cases with secondary brain stem injury, 2 died and 3 showed excellent recovery without any defects. Eight cases recovered with mild to moderate disability. The overall mortality rate was 25% and none remained in a persistent vegetative state. When compared with other series of severe head injury treated with barbiturate and hyperventilation, the mortality and morbidity rates were improved by application of hypothermia.

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Cerebral vascular malformation (CVM) and hemangioblastoma were verified pathologically in 14 of the 17 operated cases with lobar (15 cases) or cerebellar (2 cases) hematoma with no abnormal vessels or tumor blush on angiograms during the past eight years. Six of the 9 CVM cases and 2 of the 5 hemangioblastoma cases were over 60 years in age. Eight of the 14 cases had definite hypertension before and after surgery. The symptoms developed suddenly without preceding apoplectic histories in all cases. Computerized tomography scan disclosed oval shaped hematoma in 11 cases, but no definite enhanced mass within or around the hematoma in any case. The operation was undertaken under a surgical microscope for searching abnormal vessels or tumor mass around the hematoma. Histologically, eight were small arteriovenous malformations and one was a large cavernous angioma. Five hemangioblastomas were diagnosed as transitional type according to Silver and Hennigar's classification.
The authors' operative technique is described herein and the significance of the hemorrhage from the angiographically occult CVM and hemangioblastoma is discussed.

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The result of surgical treatment in 108 elderly cases aged over 60 years with ruptured cerebral aneurysms were analysed and were compared with that in 347 younger cases aged under 60 years. Operation using microsurgical techniques was carried out basically in cases where they were able to make a daily living without complaints and if they did not show severe complications. In some cases with Hunt and Kosnik's grade IV and V operation was carried out, but only when large intracerebral hematoma was present. Fifty-eight cases of the elderly group and 174 cases of the younger group were operated on more than 2 weeks after the bleeding. Surgical mortality and morbidity rates were 7% and 3% in the elderly group, and 1% and 4% in the younger group, respectively. Three out of 4 expired cases in the elderly group had died of an incidental disease unrelated to operative procedures. Social recovery rate in survivors was calculated by dividing the number of cases who had returned to work by the total number of survivors. This rate was 85% in the older and 88% in the younger groups. The operative result was not affected by patient's age or the location of the aneurysms, but was affected by the level of consciousness in delayed operation. Fifty cases of the elderly group and 173 cases of the younger group were operated on within 2 weeks after the bleeding. The mortality rate in cases of grade I plus II, III, N and V was 0%, 13%, 54% and 100% in the elderly group, and 1%, 9%, 26% and 57% in the younger group, respectively. The morbidity rate in cases of grade I plus II and III was 21% and 13% in the elderly group, and 9% and 6% in the younger group, respectively. Social recovery rate in survivors was 71% in the elderly group and 88% in the younger group. The following conclusions were obtained. Direct operation should be the choice of treatment in elderly patients same as in younger cases, if they were admitted more than 2 weeks after the bleeding. If they had been admitted less than 2 weeks after the hemorrhage, the operation should be carried out as soon as possible in elderly patients of grade I through III, but should not be performed in cases of grade V, even though a large intracerebral hematoma was present. In cases of grade IV, operation should be indicated, if the patients were admitted less than 24 hours after the bleeding and had a relatively small intracerebral hematoma.

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Previously, Sugita and Kageyama proposed that optic gliomas in childhood could be classified into two groups, namely infant type and child type. Infant type tumors, which were often seen in infants or younger children, were usually large in size and severely invaded the hypothalamus in the early stage of their courses. Thus, their prognosis was very poor. Histologically, this infant type was considered to be immature astrocytoma. On the other hand, child type tumors, which affected usually older children, were relatively localized to the optic pathway and rather self-limited in growth. Histologically, they belonged to mature astrocytoma.
In the present study, 11 cases of verified optic glioma (4 infant type and 7 child type) were studied. The association with neurofibromatosis was recognized in 2 cases. Three out of 4 infant type cases died shortly after surgery mainly due to hypothalamic dysfunction. All of the other 8 cases (1 infant type and 7 child type) have survived and were followed-up. Only one survivor of the infant type was alive 10 years after the onset but severely disabled. Two out of 7 child type cases were cases of unilateral optic nerve glioma. In both, the tumors were resected totally and have shown no signs of recurrence. Five cases of child type tumor with chiasmal involvement, who underwent partial removal or biopsy alone, were closely studied. The follow-up period of each case ranged from 8 to 12 years. In 10 eyes of these 5 cases, 7 had useful visual acuity (0.02 or better) before surgery. At the time of present study, 5 of these 7 eyes (71 %) had been either unchanged or improved in each visual acuity. All of these 5 cases were leading a mainly normal student life taking various educational courses. None of the 3 patients who were followed-up by computerized tomography scan for a period of 4 years showed any evidence of enlargement of tumors.
These results support the previous notion that optic gliomas of child type had a rather benign course and good prognosis.

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Two cases of chronic epidural hematoma are reported. Case 1, a 15-year-old female, was admitted with complaints of mild headache and hyposmia, and with computerized tomography (CT) findings of suspected epidural mass. Thirty-six days before admission, she fell from a motorcycle. Surgery revealed that the mass was an epidural hematoma with calcification. Case 2, a 17-year-old male, was admitted as the CT scan revealed an epidural mass. Thirty-one days before admission, he was involved in a traffic accident. Neurological examination revealed mild left motor weakness. Surgery confirmed that the mass was an epidural hematoma. Many atypical epidural hematoma have been reported. Some cases were reported as chronic epidural hematoma, and the others were reported as delayed epidural hematoma. However, the difference between the chronic epidural hematoma and the delayed epidural hematoma is not clear. In this paper, the chronic epidural hematoma and the delayed epidural hematoma are determined as follows. 1) Chronic epidural hematoma: Time interval between injury and operation is 14 days or more. Chronically increased intracranial pressure (ICP) is the main sign in these cases. In some cases, no symptoms or signs are observed. The hematoma is accompanied by a membrane or calcification. 2) Delayed epidural hematoma: Time interval between injury and operation is within 14 days. The chief complaint is the progressive ICP elevation sign.

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Two patients with ganglioglioma are reported. Case 1, a 10-year-old boy, was admitted with a 5-year history of seizures. Plain skull films and tomograms showed a thinned calvarium adjacent to an amorphous calcification in the frontal region. A computerized tomography (CT) scan revealed a calcified mass, and cerebral angiography revealed an avascular lesion in the left superior frontal lobe. Total removal of the tumor was performed successfully, followed by postoperative radiation therapy of 5, 500 rad. The tumor was verified histologically as a ganglioglioma. Clinical follow-up over a 3-year period has been uneventful. Case 2, an 18-year-old young man, was admitted with a 1-month history of headaches and double vision. Neurological examination revealed papilledema, left abducens paralysis and hemiparesis. Urinary vanillylmandelic acid was slightly increased (16.9 mg/day). A CT scan revealed a large contrast-enhanced lesion with a surrounding cyst, and cerebral angiography revealed an avascular space-occupying lesion in the right temporal lobe. After the cystic neoplasm was removed successfully, radiation therapy of 6, 000 rad was given. On histological examination, it was verified as a ganglioglioma. He remained well at follow-up examination 2 years later. The 15 cases of ganglioglioma reported in literature since the introduction of CT, including the present cases, are discussed with regard to the neuroradiological manifestations.

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This report describes a case of brain tumor with multiple cerebral aneurysms. A 73-year-old female complained of double vision and head heaviness. Bilateral visual disturbance, right homonymous hemianopsia, left abducens palsy and upward gaze disturbance were observed. Three lesions were noted on computerized tomography (CT). One lesion was located in the left middle fossa adjacent to the cavernous sinus, which had heterogeneous contents with partial enhancement and peripheral calcification. Two other lesions had round homogeneous high density, one of which located suprasellarly showing marked enhancement, and the other located in the left occipital region with slight enhancement. Angiographically, the middle fossa lesion was revealed to be a partially thrombosed giant aneurysm (17×11×26 mm) and the suprasellar lesion a basilar top aneurysm (21×15×18 mm). The occipital lesion was radiologically considered to be meningioma. No surgery was attempted. In combined cases of brain tumor and aneurysm, the giant aneurysm is rare (3.7%), and multiple aneurysms are rather common (11.0-14.0%). There are several pathogenetic theories about aneurysms in the cases of brain tumor. In this case the aneurysms may be considered to coexist incidentally with the tumor, but the congenital factors can not be denied because of the multiplicity of the aneurysm.

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A 38-year-old female was admitted, because of a dull headache and a slowly growing, hard, fixed mass in the vertex area. Severe papilledema was noted. Plain roentgenograms of the skull showed thickening of the outer table and diploe at the vertex. Selective external carotid angiography demonstrated enlarging branches of both the superficial temporal artery and middle meningeal artery entering the region of the thickened skull and forming a homogeneous tumor stain. The superior sagittal sinus was obscured beneath the thickened skull. Computerized tomography revealed no intracranial mass lesion. Chest X-ray film showed multiple coin lesions in both the lung fields. During the operation, an intraosseous meningioma was found as well as isolated small intradural tumors. The superior sagittal sinus was grossly collapsed without any tumor masses. These tumors were totally removed (grade 1 removal after Simpson). The postoperative course was uneventful. An open biopsy of one of the lung tumors was performed. The skull, falx and lung tumors were identical in histological appearance and showed typical features of meningotheliomatous meningioma.
Without histologically malignant features, meningioma rarely metastasizes. Only 10 cases of metastatic meningioma without craniotomy were reported in the literature from 1941 to 1983. In the present case the lung metastasis seems most likely hematogenous. The route by which the small falx tumors were seeded is not clear.

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Seven cases of aneurysms with azygos anterior cerebral artery are reported. Two were males and 5 were females. The ages of the patients on admission ranged from 47 to 61, the average being 56 years. Two cases out of 7 also had middle cerebral artery aneurysms and one had two aneurysms of the azygos anterior cerebral artery. Preoperative clinical features were complicated: moderate to severe psychic changes (5 out of 7), urinary incontinence without disturbance of consciousness (3 out of 5), hemiparesis (1 out of 7), and paraplegia with one upper limb paresis (2 out of 7). Aneurysms were found to arise near the genu of the corpus callosum in six cases; in four cases, they were located on the distal portion of the azygos anterior cerebral artery at its junction with two pericallosal arteries. In one, the aneurysm was on the middle portion of the azygos anterior cerebral artery at its junction with the frontopolar artery. In another case, the aneurysm was on the pericallosal artery at its junction with the callosomarginal artery after the azygos artery had branched. In another one, the aneurysm was on the proximal portion and radiologically simulated the anterior communicating artery aneurysm because the azygos anterior cerebral artery was short in length, about 10 mm. One was accompanied by the hydrocephalus. All aneurysms were clipped. A lumbo-peritoneal shunt was done in one case with hydrocephalus. Follow-up results after the operation revealed that four had full working capacity, two were partially disabled and one was totally disabled.
The distal anterior cerebral artery aneurysms are frequently associated with the azygos anterior cerebral artery, of which the common trunk irrigates both cerebral hemispheres. Its clinical features are complicated. One must keep in mind this anomaly during the radiological examination of such patients and should take particular care during the operation to avoid injury of this common trunk.

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