The recurrence of meningiomas in 89 cases which were operated on and followed up are discussed in this paper. The recurrence rate of meningiomas was 22% in all cases, 13% in cases of complete removal (Simpson's grades I & II) and 55% in cases of incomplete removal (Simpson's grades III, IV & V). The most probable cause affecting the recurrence was the operative method in which the tumors were completely or incompletely removed.
The recurrence rate of meningiomas in each histological subtypes after complete removal was as follows: 33% in fibroblastic, 13% in meningotheliomatous, and none in angioblastic and atypical types. When they were diagnosed at the first operation, there were no significant differences in the histological subtypes among the recurrent and non-recurrent meningiomas, and those which became malignant after repeated operation.
While most recurrent meningiomas did not change their basic morphological types, 25% in the recurrent tumors, or 5.6% in the total series, showed malignant transformation. The averag. interval of time between the first and the second operation was 31 months, and the intervals became shorter with consecutive operations. The intervals between the first and the second operations of tumors with no malignancy ranged from 5 to 13 years.
Histological features in malignant transformation of tumors were: 1) the lack of normal arrangements of tumor cell, 2) increased mitotic rate, 3) focal necrosis, and 4) cortical and bone invasion.
One case was initially diagnosed as fibroblastic meningioma but finally as sarcoma.

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We are reporting the results of internal irradiation using P-32 chromic phosphate and Au-198 colloid for cystic craniopharyngiomas.
The irradiation schedules were made by a newly developed dosimetric formula, by which the radiation dose can be calculated at the cyst wall and at the point far from the radioactive source as well as simultaneously. Using this formula, untoward effects of irradiation on surrounding brain tissues can be eliminated, especially in cases in which the cyst wall is thin and can be penetrated by beta emission.
Eight cysts out of 6 cases with craniopharyngioma were treated in this series by injection of radioactive phosphate or gold into the cyst through Ommaya reservoir and tube which had been placed beforehand at the time of craniotomy. All cysts were effectively treated to eliminate fluid retention or the collapse of the cyst for 3 to 33 months, which had been confirmed by follow-up conray cystography and computerized tomography. The effectiveness of irradiation was also shown histologically with a collapsed cyst removed at the second craniotomy. The side effect of irradiation, oculomotor palsy, was found only in a case with small cyst (5.0 ml of volume) at supra and intrasellar region 10 days after the injection of 5 me of P-32 chromic phosphate. The thickness of the cyst wall was less than 0.5 mm and the oculomotor nerves were thought to be adherent to the cyst wall by retrospective analysis.
From these experiences, it was concluded that not only the amount of wall dose but also the thickness of cyst wall and the localization of the cyst were important factors for planning internal irradiation. Sufficient and safer doses to the cyst wall, which kills the tumor cells in the wall without side effects, would be between 9, 000 to 30, 000 rad for cystic craniopharyngiomas.
Regarding the indications of internal irradiation, we are setting up some criteria to choose this method of treatment for cystic craniopharyngiomas. Large cysts of more than 10 ml and which are thought to be difficult to remove radically, would be the first choice of this treatment. Another indication will be cases with recurrent cyst resisting to the previous treatments or cases with multiple cysts.
In conclusion, internal irradiation is effective not only for cystic craniopharyngiomas but also is applicable to cystic intracranial tumors other than craniopharyngioma if the dosimetry is done accurately.

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The laser system has been applied in various fields of medicine, due to its unique characteristics, both experimentally and clinically, in recent years. High-powered carbon dioxide laser beam especially has shown several advantages in the resection of tumors. We employed carbon dioxide laser (maximum output: 60 W) in the operation of 9 cases of brain tumors and clinical results of this laser surgery has been excellent. Blood loss during operation was reduced to minimum and simplification of surgical procedures shortened the time of operation.
Carbon dioxide laser beam has the following surgical usefulness:
1) It enables non-contact surgery as a “light knife”.
2) It enables vaporization of tissue by focussed beam irradiation (laser vaporization and laser cutting).
3) It enables thermocoagulation by unfocuseed beam irradiation (laser coagulation and laser hemostasis).
Carbon dioxide laser, thus has proven to be suitable not only for cutting but also for coagulation. Since cutting and hemostasis are obtained at the same time, bloodless excision of tumor tissue is possible. Carbon dioxide laser also offers a new technique in removing highly vascularized brain tumors.

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For the purpose of a clear demonstration of the skull base structures by computed tomography (CT), we first investigated a model human skull (embedded into 2% agar gel containing 0.1% iodine) by examining it with EMI-CT1010 with the scanning plane at +25° to -90° to Reid's base line. The overlapping slice and magnification method was used at the same time for examining the optic canal, sella turcica and internal auditory meatus.
In the model study the optic canal was best viewed with the scanning plane at -10° to Reid's base line, the sella turcica and the anterior part of the posterior fossa were at -20°, the anterior half of the middle fossa was at -30°, the anterior skull base and the internal auditory meatus were at -40°.
Clinically, 10 cases (sphenoidal ridge meningioma, craniopharyngioma, recurrence of sphenoidal ridge meningioma, hematoma in the cerebellum, cerebellar astrocytoma, orbital tumor, pituitary adenoma, recurrence of tuberculum sellae meningioma, acoustic neurinoma and C-P angle meningioma) were examined by CT with the scanning plane at +25° to Reid's base line (ordinary section) and the plane at -10° to -40° (reverse section) used in the model study.
With reverse sections, the size and extent of lesions and their relationship to the base of the skull were delineated better than in those with ordinary sections. The two-plane CT examinations (ordinary section and reverse section) were helpful for three-dimensional evaluation of lesions and in determining the best method for surgery or radiotherapy.
From a technical point of view, it is emphasized that a reverse section can be done by head scanners with no difficulty in patient positioning. Reverse section produces an insignificant amount of artifacts caused by body movement, air in the paranasal sinuses and tooth fillings.

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Thirty-one patients with brain tumor were studied by CT delayed scan performed 60 and 120 minutes after intravenous administration of contrast medium. Dynamics of contrast enhancement (CE) in the lesion were analyzed quantitatively and qualitatively by calculating the tissue-blood ratio (TBR) at each scan. Since the individual blood contrast medium concentration had a wide range of values in spite of a settled dose given by body weight, it was necessary to calculate the TBR to analyze the intensity of CE qualitatively. Dynamics of CE are shown as relative TBR (R-TBR) which represents the ratio of TBR 60 minutes (TBR₁) and 120 minutes (TBR₂) after intravenous administration of contrast medium to the initial TBR (TBR₀). The higher R-TBR means the higher retention of contrast medium in the tumors. R-TBR₂ (TBR₂/TBR₀) was found to be very useful for differential diagnosis of brain tumors.
The R-TBR₂ could be classified into three types : less than 1.5 (type 1); 1.5 to 3.0 (type II) ; and more than 3.0 (type III). In the glioma group, 7 of 8 astrocytomas, grade 3 and 4, were type III ; and all of 3 astrocytomas grade 2, were type II . All of 7 meningiomas were type I. In 5 pituitary adenomas, 4 were type II and 1 was type I. In 4 neurinomas, 3 were type III, and 1 was type II . In 4 metastatic tumors, 2 were type II, and 2 were type III. By this method meningioma, pituitary adenoma and neurinoma may be differentiated from each other. We can also presume the degree of malignancy and its distribution in glioma. The possibility of differential tumor diagnosis and mechanism about various types of dynamics of CE are discussed.

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Between December 1977 and September 1978, 85 cases of head injuries were admitted to the Toritsu Fuchu General Hospital. Among these 10 cases were noted to have intracerebral hematoma by CT scanning. Seven cases out of the 10 showed intracerebral hematoma with the initial CT scan which was performed 14 hours to 4 days after the trauma. One of these showed delayed occurrence of another intracerebral hematoma 5 days after the trauma which was later confirmed to be contusional hemorrhage by post-mortem examination.
In 3 out of the 10 the initial CT scan had not shown intracerebral hematoma. However, secondary CT scan performed 7.5 to 30 hours after the trauma disclosed intracerebral high density area. In one case, tertiary CT scan performed 4 days later disclosed another high density area. Operation was carried out in 2 cases. Solid hematoma surrounded by contusion was found and evacuated in one and contusional hemorrhage was found in another.
Details of these 4 cases showing delayed occurrence of traumatic intracerebral hematoma are presented with CT scan pictures. Included is a case, treated at another hospital, of delayed traumatic intracerebral hematoma which appeared on the secondary CT taken 3 hours after the trauma. Solid hematoma was found and evacuated at operation.
At least 7 cases of delayed traumatic intracerebral hematoma shown by CT scan have been reported in the literature. Most of these authors considered this as manifestation of delayed traumatic apoplexy or “Spät-Apoplexie”.
However, it may be reasonably postulated based on our cases that almost all traumatic intracerebral hematomas occur in delayed fashion from a few hours to days after trauma. They can be adequately divided into three types: namely, early-onset type; intermediate type; and delayed-onset type. Early-onset type is formed within several hours after trauma and is mostly composed of solid hematoma. Delayed-onset type is formed probably later than 12 hours and is aptly named contusional hemorrhage. This classification might be useful in interpreting CT pictures and choosing most the appropriate treatment for such patients.

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Investigations was performed on effective and safe methods of the intraventricular and intrathecal administration of antibiotics.
When antibiotics are administered intrathecally or intraventricularly, the main side effects are brainstem symptoms such as clouding of the consciousness, respiratory and circulatory disorders, and decerebration.
In order to investigate the relation between the appearance of these brainstem symptoms and the concentration of the antibiotics in the basal cistern, different concentrations of various antibiotics including sulbenicillin (SBPC), gentamicin (GM) and cephaloridin (CER) were injected into the cisterna magna of rabbits and the respiratory rate, blood pressure, pulse rate, electroencephalograms, neurological findings and histological findings in the brain were observed.
Five of six rabbits to which SBPC was injected into the cisterna magna showed tonic convulsions. The lowest concentration of SBPC injected among the five rabbits was 1, 500 mcg/ml. There was noted nystagmus, dilated pupil or upward conjugate deviation together with the tonic convulsions.
Among the three rabbits to which CER was given, one was found to have a conjugate deviation and tremor at concentrations of 3, 000 mcg/ml or more.
However, there were no neurological changes in the three rabbits to which GM was given, even at concentrations of 50, 000 mcg/ml.
In all of the cases with neurological changes, there were noted increased blood pressure and changes in the electroencephalograms, but there were no fixed trends for the respiratory and pulse rates.
Among 24 rabbits to which was given various antibiotics of 50-800 mcg/ml in concentration in the cisterna magna for seven consecutive days, there were histological changes in the seven rabbits. These changes consisted of congestion of the choroid plexus in seven, subarachnoidal hemorrhages in three and localized meningial thickening in four.
The conclusion in regard to the safe dosage when administering antibiotics in the c.s.f. cavity is 50 mg or less for CER, CET and SBPC, and 12 mg or less for GM.

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A 63-year-old man was admitted to our clinic due to progressive visual impairment. He had a history of cerebrovascular disease about one year before admission, which had almost recovered in 5 months. Visual inpairment was noted 3 months before admission. On admission, visual acuity was 2 feet F.C. on the left and 20/100 on the right. There was bitemporal hemianopsia with bilateral centrocecal scotomas. Pneumoencephalogram revealed empty sella and dilatation of the third ventricle. Unifrontal craniotomy was performed. The anterior part of intrasellar space was empty. There was no adhesion around the chiasma and optic nerves. The chiasma and optic nerves were slightly flattened and stretched downward. The lower part of the lamina terminalis was opened about 3 mm in diameter. Then chiasmapexy was performed using the temporal muscle and arona adhesive. Postoperatively, visual acuity improved: 20/200 on the left and 20/50 on the right. Ten months after the operation, visual acuity was 20/200 on the left and 20/30 on the right. Combination of chiasmapexy and opening of the lamina terminalis seemed to have been effective for visual disturbance in empty sella syndrome.

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