This report describes the results of neuropathological examinations in 14 rabbit brains after 100 Gy of linac stereotactic irradiation. The tissue around the area of radiation necrosis was subjected to special examination. Fourteen rabbits were given a single dose of 100 Gy by a linear accelerator with a use of the 10 mm collimator. Animals were sacrificed serially after irradiation. Brains were removed and formalin treated paraffin sections were made. A11 sections were stained by H & E, GFAP and TUNEL (TdT-mediated dUTP-biotin nick end labeling method) stain. Pathological changes of vessels and neural tissue around the area of necrosis were examined. Three months after irradiation, TUNEL-positive oligodendrocytes were seen scattered in the white matter of the radiated field, and after 6 months, these changes extened around the radiating field, but vessels and neurons appeared to be intact. Two years after irradiation, massive necrosis had occured in the radiated area. Thickness and fibrinoid degeneration of the vessel walls were evident in the area around the necrosis. These vessel changes were recognized in the zone of the 40 Gy radiated region. TUNEL-positive oligodendrocytes were also observed around the necrosis, and were scattered in the white matter and corpus callosum over the region of vascular changes. These findings suggested the following : In the later period after irradiation, oligodendrocytes in the peripheral zone of necrosis are damaged by ischemia and edema, which are caused by vascular changes. TUNEL-positive oligodendrocytes which exsisted in the white matter and corpus callosum distal to the radiated area may exhibit development of serial damage of oligodendrocytes in those regions.

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We have not known Surgical indications for incidental Rathke's cleft cysts, because of our lack of knowledge about their natural history. In this study, we investigated whether symptomatic Rathke's cleft cysts have any characteristic features in magnetic resonance (MR) signal intensities, and analyzed their relation to clinical manifestations and to patterns of suprasellar expansion. MR signal intensities on T1-weighted (T1W) and T2-weighted (T2W) images were categorized into 3 types in 78 cases including our 9 cases ; type I, low signal intensity on T1W images and hyperintensity on T2W images in 25 cases ; type II, hyperintensity on both T1W and T2W images in 20 ; and type III, low Intensity on T2W images, in other 33. Patients of type I signal intensities presented with significantly high percentage of large cysts compressing the third ventricle than patients with other types. The patients of type I signal intensities also frequently had visual disturbance. Patients in type II showed significantly less percentage of large cysts. Anterior pituitary dysfunction was observed more often in patients of type II and III than patients of type I. We conclude that Rathke's cleft cysts with MR signal intensity like cerebrospinal fluid (CSF) are slowly growing, and are frequently diagnosed as large cysts associated with visual disturbance. The patients with other types of MR signal intensities may suffer pituitary dysfunction or other symptoms before the cysts compress the hypothalamic region. The assessment of MR signal intensities may contribute in predicting clinical progression in patients with Rathke's cleft cysts.

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We retrospectively studied 27 adult patients (male 9, female 18) with moyamoya disease, with and without vascular reconstructive surgery, with respect to angiographical finding, regional cerebral blood flow (rCBF) and long-term prognosis. Initial episodes involved intracranial hemorrhage in 20 cases (74%), ischemia in 6 cases and incidental detection in I case. Of 14 non-revascularization cases, 9 patients (64%) bled during 9 years follow-up. The recurrent bleeding rate in 10 cases of the hemorrhage type excluding aneurysm cases was calculated to be as high as 65% for 10 years. In the final outcome, 10 patients (71%) showed a poor prognosis including 5 who died due to rebleeding. The rCBF measured by ^<133>Xe SPECT in the bilateral middle cerebral artery territory of 6 patients revealed 41 ±15 ml/100 g/min at rest and 48±18 ml/100g/min after acetazolamide loading, indicating a percent increase of 20±22%. Thirteen cases were surgically treated on 22 hemispheric sides, by direct bypass (7 sides) and indirect bypass (15 sides) surgery. Postoperative angiogram demonstrated good neovascularization from the external carotid artery in 15 hemispheric sides (68%) ; all sides of direct procedure and half the sides of indirect procedure. Of these 15 sides, 14 sides (93%) showed reduction of moyamoya vessels fed b), the internal carotid artery. Only 1 patient (8%) among 13 cases undergoing revascularization bled during 5-year follow-up and the other 12 patients returned to their previous jobs. The rCBF measured in the area fed from the bypass circuit in 18 hemispheres of 11 patients was preoperatively. 48±9 ml/100g/min at rest and 53±15 ml/1OOg/min after acetazolamide loading, indicating a percent increase of 8±17%. Postoperative study revealed the resting and loading rCBF significantly increased by around 30% to 60±6 and 70±9 ml/100g/min, respectively, indicating a percent increase of 16±8%. Thus, vascular reconstructive surgery is recommended for adult patients with moyamoya disease, since the 10ng-term prognosis of non-surgical cases is poor due to recurrent bleeding and Surgery tends to inhibit recurrence of bleeding. The development of good collaterals from implanted external carotid artery can improve the cerebral blood flow and vascular reactivity at the bypass site leading to reduction of hemodynamic stress on basal moyamoya vessels. For this purpose, direct bypass surgery seems to be superior to indirect bypass surgery.

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Resting energy expenditure (REE), basal energy expenditure (BEE), urinary nitrogen (UN), nitrogen balance (NB), albumin (Alb), transferrin (T), prealbumin (P), and retinol binding protein (RBP) were determined in 31 subarachnoid hemorrhage (SAH) patients. The patients were divided into 2 groups according to the Hunt & Kosnik classification; 14 patients with grades I-II, and 17 patients with grades III-V. The patients received intravenous alimentation consisting of 1,320-1,640 kcal/day and 7.9-9.4 g nitrogen/day. The mean values of REE/BEE in the patients with grades I-II on Day 4, Day 10, and at discharge were 1.3, 1.5, 1.4, UN (g/day) were 9.5, 10.0, 7.0, NB (g/day) were -1.1, -2.6, 2.2, Alb (g/dl) were 3.4, 3.9, 3.8, T (mg/dl) were 192, 235, 249, P (mg/dl) were 16.5, 24.1, 23.9, and RBP (mg/dl) were 2.2, 3.8, 3.9, respectively. The mean values or REE/BEE in the patients with grades III-V on Day 4, Day 10, and at discharge were 1.7, 1.9, 1.5, UN (g/day) were 13.5, 15.1, 7.8, NB (g/day) were -4.9, -6.0, 2.5, Alb (g/dl) were 3.4, 3.5, 3.8, T (mg/dl) were 208, 214, 242, P (mg/dl) were 19.0, 21.9, 25.5, and RBP (mg/dl) were 2.8, 3.5, 4.1, respectively. There were significant differences in REE/BEE and NB between the 2 groups on Days 4 and 10, but no significant differences in P, T, or RBP. The nitrogen balance was always negative at an acute stage. T, P, and RBP were significantly decreased on Day 4 in both groups. In creased metabolic expenditure and increased catabolism, especially in patients with a severe clinical grade, and decreased anabolism should be taken into consideration when caring for SAH patients in the stage of vasospasm.

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The case described here was a 59-year-old man visiting our hospital because of persistet fever since April 1993 and a sudden onset of visual field defect and impaired consciousness on June 19. Cardiac examination revealed mitral valve insufficiency, and cerebral CT scanning detected intracerebral hemorrhage in the right occipital lobe. Hematoma was removed on June 22, and pathological features in inflammtion were observed in blood vessels surrounding the hematoma. He developed subarachnoid hemorrhage on July 2 during the postoperative observation period. Aneurysm detected by cerebral angiography in the transitional area from left M1 and M2, which had appeared normal at the time of admission, was clipped on July 3. He was again brought to the hospital on October 28 because of subarachnoid hemorrhage. At the second admission, the area between right M1 and M3 was narrowed and had a head-like lesion although this area had been determined normal during the previous hospitalization on angiography. He deceased by re-homorrhage on November 11. Although systemic inflammatory signs were observed throughout the entire course, arterial blood cultures were negative. Spindle-shaped aneurysm was detected in the right M3 on autopsy, and inflammation of the intima and invasion of destroyed intravascular blood cells into the internal membrane were pathologically observed. From the history of heart disease, systemic inflammatory findings, rapid formation of aneurysm, pathological features of vascular inflammation, it is inferred that he had intracranial hemorrhage caused by becterial angitis and bacterial aneurysm.

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A rare case of nontraumatic cerebrospinal fluid (CSF) rhinorrhea is reported. A 54-year-old man with spontaneously occurring CSF rhinorrhea was admitted to our institution. A bone-window CT scan showed bilateral extension of the sphenoid sinus into the greater wings. Multiple bony defects were revealed in the anteromedial portion of the right middle cranial fossa. A CT cisternogram clearly demonstrated efflux of the contrast medium from the middle cranial fossa into the sphenoid sinus. The bony defects were successfully repaired, and the rhinorrhea resolved completely. The patient was discharged in satisfactory condition. Nontraumatic CSF rhinorrhea associated with bony defects_ in the middle cranial fossa is rare, and to the authors' knowledge only 18 cases have been reported in the literature. The features and etiology are reviewed, using the measurement of the size of the sphenoid sinus (16 Japanese subjects).

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We report a rare case of intraorbital arteriovenous malformation (AVM) in a 62-year-old man who came to our hospital because of a cerebral infarction. Right carotid angiography incidentally showed the nidus of the AVM in the right retro-orbital region, which was fed by the ophthalmic artery and drained by the superior ophthalmic vein. The patient showed no sign of neuro-ophthalmic disturbance. He was subsequently observed without being given any specific treatment. Thirteen cases of intraorbital AVM have been reported. Many cases of intraorbital AVM have shown unilateral proptosis but rarely have caused progressive visual or functional disturbance of the eyes. Most of the feeders and drainers were ophthalmic arteries and ophthalmic veins. These facts suggest the cautious use of surgery or embolization against intraorbital AVM.

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Olfactory neuroblastma is a rare kind of malignant tumor originating in the olfactory epithelium of the nasal cavity. We report here a clinical case of olfactory neuroblastoma. A 52-year-old man presented with headache and vomiting. CT scan and MRI showed a large tumor in the right ethmoid sinus extending into the frontal base. The tumor was resected subtotally, and radiation therapy at a dose of 60 Gy was undertaken. However, a follow-up MRI two years after surgery showed metastasis to the left cervical lymph nodes. The patient was treated with radiation and chemotherapy, which resulted in a reduction in the size of the metastasized tumor.

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A 9-year-old girl experienced mutism after gross total removal of a cerebellar medulloblastoma. Immediately after surgery, the patient could not speak but could obey verbal commands. On the 35th postoperative day, she began to speak simple words with dysarthria. By the 72nd postoperative clay, she had almost completely recovered speech. Brain single photon emission computed tomography (SPECT) scanning was performed on the 4lst and 56th postoperative days. The first scan showed reduction of ^<123>I-IMP uptake in the bilateral cerebellar hemispheres, right thalamus, and basal ganglia. The second showed that ^<123>I-IMP uptake had been recovered in these regions. This suggests that mutism may occur in association with crossed cerebello-cerebral diaschisis (CCCD). Transient insult to the bilateral cerebellar hemispheres or dentate nuclei may cause CCCD and result in dysfunction of the thalamus and supplementary motor area through the dentatethalamocortical pathway.

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A case of recurrent trigeminal neuralgia due to granulomatous change in a prosthesis (Teflon felt) for microvascullar decompression (MVD) is reported. A 40-year-old woman experiencing right trigeminal neuralgia presented at our institution. A Teflon felt prosthesis was inserted between the caudal loops of the duplicated Superior cerbellar arteries (SCAs) and the pons for MVD. The symptoms of neuralgia resolved immediately after surgery. Two months after Surgery, the trigeminal neuralgia recurred and was controlled by carbamazepine (CBZ) administration. Three years thereafter, the pain suddenly became severe and was no longer controllable with CBZ. Radiographic images showed typical findings of granuloma in the right prepontine cistern. The granuloma size subsequently increased, and a second surgery was performed. The root entry zone of the trigeminal nerve and SCAs, where the Teflon felt was inserted at the time of the first surgery, were completely covered by a soft, white, granulomatous mass and the prosthesis adhered to the nerve and SCAs. Most of the prosthesis was removed, and the SCAS were attached to the interior surface of the cerbellar tentorium. The pain resolved soon after the second surgery, although slight hypesthesia of the light cheek remained. The patient's postoperative status has been uneventful during 10 months of follow-up. Histological examination revealed that the mass was a granuloma. In this patient, the CT findings were characterized by all abnormally long duration of marked enhancement and increased size of the lesion, which were compatible with a diagnosis of granuloma. It should be borne in mind that granulomatous changes in prostheses may result in early recurrence of trigeminal neuralgia. Therefore patients with early recurrence should be followed up with CT scanning, since the results of surgical removal of the prosthesis and granuloma are good.

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