Forty-one patients with brain abscesses treated during 1965-1983 were reviewed. Group 1 consisted of 25 patients with abscesses who were treated before the availability of computed tomography (CT) scan (1965-1976); Group 2 included 16 patients treated with the aid of CT (1976-1983). One case in Group 1 has been reported by Fukawa et al. The mortality rate of patients in Group 1 was 16%, but no deaths occurred in Group 2. The overall mortality was 9.8%. The mortality rate was correlated most directly with deteriorating preoperative level of consciousness due to delay in diagnosis. The recent reduction in the mortality rate could be due to early diagnosis and accurate localization of brain abscess by means of CT. Bacteriological studies indicated that abscesses containing anaerobic bacilli have increased lately. A few more patients were treated by excision than by aspiration. No significant differences in the results of the two groups were noted with respect to the method of surgery. Approximately three-fourths demonstrated no subsequent neurological deficit, and returned to their previous level of functioning. It is suggested, however, that aspiration has a lower postoperative long-term seizure incidence than excision. It may be concluded at present that the aspiration method is the best, because this method does less damage to the brain and postoperative resolution of the abscess can be monitored accurately by CT.

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Regional cerebral blood flow (rCBF) was measured by xenon-enhanced computerized tomography (CT) in 12 children with moyamoya disease (mean age 9 years) prior to surgical treatment. rCBF values in the cerebral regions were as follows; mean hemisphere 57±5.9 ml/100 g/min (mean±SEM), the frontal cortex 52±6.1, the temporal cortex 52±10.6, the occipital cortex 86± 9.6, the frontal white matter 13±1.6, the thalamus 151±18.1, the putamen 134±16.1, the caudate nucleus 148±15.7, and the internal capsule 50±5.4. According to the present data, cerebral circulation in children with moyamoya disease was characterized by the moderate to severe hypoperfusion in the frontal and temporal cortices, a subcortical ischemia, and a high flow in the central structures of the brain which involved the areas of basal moyamoya vessels. These characteristics were well demonstrated by a linear rCBF profile which passed coronally through the temporal lobes and thalamus on the rCBF map obtained by xenon-enhanced CT.

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Autopsy findings on a 16-year-old boy with moyamoya disease who was previously treated with external carotid-internal carotid (EC-IC) bypasses and encephalo-myo-synangiosis (EMS) are reported.
Five years after the surgery, he was involved in a traffic accident and the resulting head injury caused his death. In the autopsied brain, numerous vessels were observed in the subarachnoid space of the convexity, especially in the area corresponding to the EMS, where traumatic damages and hemorrhages were most drastic. In the histological study of the brain vessels, intimal thickening with elastofibrosis and tortuous internal elastic laminae in the arterial wall were generally observed, not only in the neighborhood of Willis' circle, but in the level of arterioles irrespective of the artificial bypass. Development of new intraluminal vessels, and recanalization were revealed in the terminal portion of the left internal carotid artery. These findings suggest that factors other than the blood flow, such as thrombo-emboli, may participate in the propagation of occlusive processes in moyamoya disease.

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Superficial temporal artery-middle cerebral artery anastomoses were performed for the treatment of cerebral ischemic diseases due to occlusion of the internal carotid artery, and in combination with ligation of the internal carotid artery for giant aneurysms. Bypass surgery was done on the same side as the occlusion. Twenty-nine anastomoses in 27 patients underwent radiological analysis.
Angiographical distribution of the intracranial blood flow through the anastomosed superficial temporal artery was analyzed from the lateral view of the postoperative films. The branches of the middle cerebral artery were divided into seven territories on the lateral projection of the angiogram according to Ring's method. In addition, visualization of the lenticulostriate artery was checked on the anteroposterior view film. The distribution area of the blood flow through the bypass was seen to be significantly wider in cases of double anastomosis than those of single anastomosis. Filling of the lenticulostriate artery was noted in cases of wider distribution. When the anastomosis was done to the suprasylvian cortical artery, the flow distribution was localized mainly in the suprasylvian frontotemporal area. On the other hand, when the infrasylvian cortical branch was revascularized, the distribution was inclined toward the infrasylvian temporal area. Thus, when one single branch of the superficial temporal artery was anastomosed to one cortical branch of the middle cerebral artery, the filling areas of the middle cerebral artery were localized on either side of the sylvian fissure, according to the site of the anastomosis. In cases where anastomoses were performed to both supra- and infrasylvian arterial branches of the middle cerebral artery, the distribution area of the bypass flow was markedly increased. It might, therefore, be better to make anastomoses to both supra- and infrasylvian cortical vessels using both branches of the superficial temporal artery, so that wider and more effective distribution of the intracranial bypass flow is obtained, and much more circulatory reserve of the brain is acquired.

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In order to make removal of subarachnoid clots safe and swift after aneurysmal early surgery, and thereby to prevent or alleviate cerebral vasospasms, a new irrigation system of the subarachnoid space using a plasminogen activator (urokinase, UK) was devised. After the previous report in 1983, 17 additional patients, amounting to 44 patients in total have been experienced. Furthermore, two basic studies are added. One is measurement of the uptake ratio of radioactive UK into an artificial thrombus formed in a Chandler's tube, and the other is an investigation of an optimal UK concentration, also by the Chandler's tube method. The ratio of radioactivity in the artificial thrombus versus that in the remaining fluid blood was found to attain to 11.03 in 90 minutes; it was 1.4 at the beginning. The thrombus lysing ratio in 6 hours was measured at various concentrations; 25, 30, 50, 100, 150, 300, and 600 IU/ml, respectively. The lysing ratios were found to reach a plateau at 150 IU/ml. The clot lysing effect of this method was studied in the recent patients, with two different ways of investigation. One was measurement of hemoglobin concentration in outlet fluid of the irrigation system by the cyanmethohemoglobin method, and the other was observation of subarachnoid clots by computed tomography (CT). Hemoglobin concentrations in outlet fluid were measured in three kinds of patients; one was 3 patients treated with the ordinary irrigation method (continuous subarachnoid irrigation with 48 IU/ml UK solution for 5-7 days in a dose of 2, 000 ml/day); another was one patient treated with a high concentration UK pooling method (pooling of 10 ml of 1, 200 IU/ml UK solution in the subarachnoid space for 6 hours with the interruption of the ordinary UK irrigation); and the other was one patient treated with physiological saline solution only. Hemoglobin concentrations in outlet fluid were found to be much higher in the patients treated with UK irrigation, especially in the patient treated with the high concentration UK pooling, than in the patient irrigated with physiological saline solution only. Sequential CT findings of 4 recent representative patients are shown. On CT, high densities in the perimesencephalic cistern were recognized to have disappeared within 7 days in the patients treated with UK irrigation, while they were still observed in the control patients. In one patient who was treated with UK irrigation combined with the high concentration UK pooling, high density in the insular cistern was found to have disappeared in 4 days.

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The authors divided chronic subdural hematoma into 5 stages, from occurrence to disappearance, mainly according to computerized tomography (CT) findings. The origin was determined on the basis of the findings from the hematoma membrane and the contained fluid obtained at the surgery in each stage.
The initial stage (about 7-14 days after head injury) was characterized by the presence of communication between the subdural low density area and the subarachnoid space, shown by the CT scan. In this stage, a thin fibroblastic membrane was recognized beneath the dura mater. The contained fluid consisted of cerebrospinal fluid and a minimal amount of blood. The premature stage (about 15-30 days after head injury) was characterized by insufficient communication between the subdural low density area and the subarachnoid space in the CT scan. In this stage, the subdural membrane was thicker and consisted of fibroblastic cells, capillaries, and infiltrating cells. The contained fluid was rich in protein and showed increased plasmin activity. In the mature stage (about 30-60 days after head injury), CT change into iso- or high-density without mass sign was noted. In this stage, the subdural membrane consisted of fibroblastic cells, well-developed capillaries, and many infiltrating cells. Intramembranous bleeding was seen. Moreover, the contained fluid was very similar to fresh blood, and increased in fibrin degradation products. The progressive stage showed the typical chronic subdural hematoma with mass sign. The subdural membrane and the contained fluid were typical, as reported previously by other authors. In the resolving stage, the hematoma was relatively low in CT density and gradually disappearing. Mass sign was not found. In this stage, the subdural membrane became fibrous and consisted of well-developed collagen fibers.
From these findings, the authors postulated the following: The hematoma begins as a subdural fluid collection which is a mixture of a minimal amount of blood and cerebrospinal fluid. The fluid collection produces an active fibroblastic membrane beneath the dura mater (initial and premature stages). Immature capillaries in the membrane are made to bleed by physical factors, such as variation of the intracranial pressure. The intramembranous bleeding breaks the membrane to form the subdural hematoma without mass sign yet (mature stage). The subdural hematoma is expanded by repeated bleeding from the membrane (perhaps due to topical fibrinolysis, etc.) to form the typical chronic subdural hematoma (progressive stage). Finally, the membrane becomes fibrous and ceases to bleed (resolving stage).

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Morphological features of the autopsied specimens of 15 adult patients with supratentorial gliomas were analysed and the characteristics of recurrence of gliomas were searched for. The correlation between the computed tomography (CT) findings before death and the microscopic findings of a whole mount section of the brain was also analysed. The cases consisted of 2 grade II, 7 grade III and 6 grade IV astrocytomas.
The characteristic CT findings before death were regrowth of the tumor mass or the occurrence of a new enhanced lesion in 14 out of 15 patients. The enhanced lesion showing regrowth of the tumor was located in the same site as the previous tumor mass. The new enhanced lesion, resulting in a trans or subependymal tumor spread, was seen in the ventricular wall, and this was a characteristic feature of the recurrence of gliomas.
In morphological analysis, tumor regrowth and recurrent tumor cell infiltration into the brain parenchyma occurred in several patterns. One was the extending mode caused by regrowth of the residual tumor in spite of adjuvant therapy. CT scan correctly showed such tumor recurrence as an enhanced lesion, especially as a ring or nodular enhancement. In the second pattern, a spread of tumor cells occurred along the interfiber spaces to the brain stem, or to the contralateral cerebral hemisphere through the corpus callosum. CT scan could hardly show such a type of tumor cell infiltration. The third mode of tumor propagation was cerebrospinal fluid seeding, with intraventricular or subarachnoid tumor growth. The CT scan examined before death could display the tumor invasion of the intraventricular seeding in 3 out of 8 patients. Histologically, reinvasion of the tumor cells from the subarachnoid space to the brain parenchyma was along the Virchow-Robin spaces of penetrating blood vessels.
If tumor regrowth was accompanied by angiogenesis, CT scan could show the recurrence as an enhanced lesion. Marked angiogenesis occurred in the margin of the residual tumor with central necrosis due to adjuvant therapy.

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There are only a few reports on the surgical results in cases of very large pituitary adenomas. Several authors have indicated that the operative mortality in cases of giant pituitary adenoma is considerably higher than that in cases of usual pituitary adenoma. Therefore, surgical indication and approach for very large pituitary adenomas are controversial. In order to determine the surgical indication and approach for very large pituitary adenomas the authors examined 35 cases of very large pituitary adenoma with suprasellar extension higher than that of type B according to the classification by Wilson, or with intracranial tumor lobules extending extrasellarly in more than two directions. Surgical results were divided into three groups as follows: 1) cases from pre-computed tomography (CT) era, 2) cases operated on by transcranial approach in post-CT era, and 3) cases operated on by transsphenoidal approach in post-CT era. Several characteristic features were obtained as listed below: 1) Spontaneous intratumoral hemorrhage is apt to occur more frequently in the very large adenoma cases than in ordinary cases. Therefore, surgical treatment of the very large adenoma cases should be performed very carefully. 2) Intratumoral hemorrhage and swelling of the residual tumor in cases with marked posterior extension are the crucial cause of postoperative death. However, radical removal often aggravates preoperative dysfunction of the hypothalamohypophyseal system, and progressive disorders of the hypothalamo-hypophyseal system can be another cause of death. Therefore, intracapsular decompression is advised. 3) Transsphenoidal intracapsular removal shows less mortality and morbidity than the transcranial approach in cases with postero-superior extension. A combined supra-infrasellar approach seems to be indicated for tumors with prominent parasellar or frontal extension. 4) Postoperative radiation therapy is very effective for reducing residual tumors in size and for prevention of their recurrence.

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An autopsy case of primary melanoma of the central nervous system is reported.
An 11-year-old female was admitted complaining of headache and nuchal pain. At 2 months of age, a ventriculo-peritoneal (V-P) shunt had been performed after a diagnosis of communicating hydrocephalus. She had grown without any neurological deficits thereafter. On admission she was neurologically free except for a decreased patellar tendon reflex on the left side. Cerebrospinal fluid obtained by lumbar puncture was bloody. A computerized tomography scan showed a contrast positive mass in the left temporal base and diffuse enhancement of the subarachnoid space. The tumor was partially removed and diagnosed as a malignant melanoma. The patient developed various symptoms due to involvement of cranial nerves and the spinal cord. She died 2 months after a subarachnoid hemorrhage. Necropsy revealed diffuse leptomeningeal dissemination of the tumor in the central nervous system and peritoneal metastasis via a shunt tube.
The authors suggest that peritoneal dissemination of melanomas in the central nervous system via V-P shunt system is not a rare occurrence; they make treatment more difficult.

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Extracranial metastases of pineal tumors are extremely rare. Only 26 cases are reported in the literature. Another such case is reported and the relevant literature is reviewed. An 8-year-old boy with human chorionic gonadotropin (HCG) producing pineal tumor was treated by ventriculoperitoneal shunt and irradiation. After a 2-month period, re-elevated serum HCG level, bloody sputum, and multiple pulmonary lesions on X-ray developed. Multiple pulmonary metastases of the pineal tumor were suspected. They were diagnosed because abnormal tumor cells were obtained from the left lung by needle biopsy, and the size of the pulmonary lesions corresponded well to the serum HCG level after chemotherapy.

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A 46-year-old female was admitted to the Department of Neurosurgery in July 1983 for a giant hard tumor on the skull and dyspnea. In 1942 a swelling on the forehead had occurred and attained approximately the size of an egg in 1953. Her left eyeball was slanted down and to the side, and left visual acuity was lost. Another neoplasm filled her nasal cavity in 1983. She complained of dyspnea and dysphagia. The nasopharyngeal tumor was removed at that time. She could respirate and swallow well after the operation. Histological findings disclosed juvenile nasopharyngeal angiofibroma. Then, a stony hard tumor was partially removed and cranioplasty was done. Her facial appearance was improved. Histological examination showed mature spongy osteoma.

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Surgery for carotid body tumors has been said to have many difficulties. In this paper a case of a big carotid body tumor managed with preoperative catheter embolization is reported.
A 22-year-old male was referred in May, 1983, complaining of a right neck mass measuring 6×4 cm, of two years duration. Before admission he had been operated on twice in another hospital, but removal of the tumor had been impossible because of excessive bleeding. Angiography revealed a highly vascular tumor at the carotid bifurcation, fed by branches of the external carotid artery, namely the superior thyroid, lingual, occipital, and ascending pharyngeal arteries.
Selective catheter embolization of these feeders was performed using Ivalon® powder, and during this procedure temporary occlusion of the internal carotid artery with a balloon catheter was employed in an attempt to avoid cerebral emboli. After the embolization the tumor stain disappeared almost entirely, and the size of the tumor was reduced. In the operation the tumor was easily excised without giving any injuries to the surrounding nerves or the carotid arteries. The total bleeding volume was less than 250 cc and blood transfusion was not necessary.
Preoperative catheter embolization for carotid tumors is advisable, especially for a big tumor.

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