Immunohistochemical studies using immunoperoxidase staining for glial fibrillary acidic protein (GFAP), S-100 protein, and factor VIII-related antigen (VIII-RAg) were performed on 10 hemangioblastomas of the central nervous system to determine the origin of stromal cells. No cytoplasmic immunoreactivity for anti-GFAP, anti-S-100 protein, or anti-VIII-RAg was detected in most stromal cells. A small number of GFAP-positive cells were found only in the periphery of the tumor; they were thought to be trapped astrocytes or stromal cells taking up GFAP. Most stromal cells had abundant, clear cytoplasm with some microfilaments and lipid vacuoles. Cylindrical cytoplasmic processes and intermediate junctions were observed in some stromal cells, but most cells did not possess any junctional device. No stromal cell possessed any feature clearly suggesting endothelial cells or pericytes. Our immunohistochemical and ultrastructural investigations did not support the theories of stromal cell origin from astrocytes or endothelial cells. We concluded that stromal cells can be regarded as an aberrant cell type of angiogenic mesenchymal derivation.
To investigate the value of direct measurement of the rate constants by performing 18F-labeled fluorodeoxyglucose (FDG) studies of glucose consumption in human gliomas in vivo, a kinetic method with 3- and 4-parameter rate constant models for FDG uptake was used to analyze data from dynamic scans obtained by positron emission tomography after injection of FDG into 14 patients with glioma. The results were compared with those obtained by the autoradiographic method using 3- and 4-parameter rate constant models. There were no significant differences in the glucose consumption calculated by the four different methods both in the gliomas and in the contralateral intact cortex. It was found that the rate constant k4* could be neglected in calculation of glucose consumption in gliomas as well as in the contralateral intact cortex. The rate constant k3*, an index of hexokinase function, was higher in malignant gliomas than in benign gliomas and was close to that in the contralateral cortex. This study indicates that the 3-parameter autoradiographic method, which is the most common one used in clinical practice, is reliable for the calculation of glucose consumption in human gliomas. Furthermore, direct measurement of the regional rate constants for FDG by the kinetic method was found to be useful for evaluation of the biochemical and physiological characteristics of human gliomas in vivo.
Twelve large or giant intracranial aneurysms were studied with magnetic resonance (MR) imaging, and the findings were compared with those from computed tomographic (CT) scanning. Characteristic MR features of such aneurysms are: round, extra-axial mass with hypointensity rim; signal void, paradoxical enhancement, or even-echo rephasing due to blood flow; and laminated, eccentric thrombus with increased signal intensity when fresh, perianeurysmal hemorrhage occurs in the acute or subacute stage after aneurysmal rupture. MR imaging, however, often fails to identify or characterize the area of calcification. For the diagnosis of large or giant intracranial aneurysms, MR imaging is apparently superior to CT scanning in differentiating aneurysms from tumors, delineating the blood flow and intraluminal thrombus, and detecting the exact size of the aneurysm. It may also provide useful information concerning the growth mechanisms of aneurysms with or without thrombus formation.
To evaluate the efficacy of vascular reconstructive surgery for childhood moyamoya disease, the cerebral blood flow (CBF) in 31 hemispheres of 16 patients was examined by single photon emission computed tomography (SPECT) using the 133Xe inhalation method. Results were divided into two groups; 17 hemispheres with superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis [A(+) group] and 14 hemispheres without anastomosis [A(-) group]. The mean hemispheric CBF (mCBF) and regional CBF (rCBF) in the frontal, temporal, occipital, and basal ganglia regions were calculated. Pre- and postoperative SPECT on the 10 hemispheres of the A(+) group showed an increase in mCBF in 6 hemispheres, the disappearance of the low perfusion area (LPA) in all 5 hemispheres where LPA was present before surgery, and an improvement in rCBF distribution (an increase in rCBF in the frontal and temporal lobes and a decrease in the basal ganglia). This suggests that vascular reconstruction is greatly effective in treating this disease. A comparison between the A(+) group and the A(-) group by postoperative SPECT, as well as the clinical outcomes and the postoperative findings of electroencephalography and angiography, revealed that the A(+) group was superior to the A(-) group in the frequency of LPA (12% and 43%, respectively) and rCBF in the frontal region where STA-MCA anastomosis was usually performed. These results indicate that STA-MCA anastomosis with indirect synangiosis is the most effective treatment of childhood moyamoya disease.
The clinical significance of traumatic subarachnoid hemorrhage (TSAH) was studied in 20 head-injured patients. They were classified into mild (9) and severe (11) groups by their initial Glasgow Coma Scale (GCS) scores. TSAH detected by computed tomography was localized in the Sylvian fissure in four of the nine mild group patients, but was also found in other basal subarachnoid cisterns in the other five. Except for one patient who developed delayed vasospasm and communicating hydrocephalus, all had favorable outcomes in this group. Massive TSAH was noted in the basal subarachnoid cisterns in 10 severe group patients and only one had a good outcome. Delayed intracerebral hematoma in the frontal or temporal lobe in the vicinity of the Sylvian fissure was found in two mild and two severe group patients with TSAH in the Sylvian fissures. Traumatic parenchymal lesions in the brainstem were minimal in one of the two autopsied patients and no evidence of diffuse axonal injury was found in both cases. Thus, TSAH in the Sylvian fissure is suggestive of focal brain contusion around the fissures. Massive TSAH in the basal subarachnoid cisterns is not necessarily associated with severe parenchymal injury of the brainstem.
Since computed tomography (CT)-guided stereotactic surgery is essentially blind surgery, it always involves the risk of injuring viable brain tissue and vessels, and it is difficult to obtain a sufficient amount of biopsy specimen from cystic or necrotic lesions. Moreover, the direct observation of the lesion would provide extremely valuable information. The authors have therefore developed a new subminiature rigid endoscope and an ultrasonic aspirator for use in stereotactic surgery, as well as a new micro manipulative system to attach the equipment to the stereotactic frame so that they can be accurately inserted into the optimum position from any direction. The new neuroendoscope includes a graded refractive index glass rod only 1.0 mm in diameter (Selfoc®, Nippon Sheet Glass Co., Osaka), which provides a focal depth from 1 mm to infinity, as well as an extremely bright and wide visual field with an angle of 70°. Furthermore, because the outer probe and endoscopic sheath share the outer rigid metal tube 4.5 mm in outer diameter, a large internal channel of 2.1 mm in diameter allows the introduction of various microinstruments such as an ultrasonic aspirator probe, laser probe, and biopsy forceps. When a miniaturized video camera is attached, the surgical procedures can be controlled using the video monitor and photographed. The new probe for the ultrasonic aspirator has been developed in various types suitable for fragmentation and aspiration of hematomas and brain tumors, so under endoscopic control even the harder coagulants and tumors can be removed. During removal of an intracerebral hematoma, intraoperative bleeding was prevented by the observation of microvessels in the wall of the hematoma cavity, which cannot be detected by CT or ultrasonography alone, and a cystic lesion of the thalamus was biopsied by inspecting the cystic inner cavity under the endoscope. Neuroendoscopic surgery is less invasive, safer and more accurate for the treatment of small, deep-seated tumors, hemangiomas, arteriovenous malformations, and other lesions.
A 29-year-old male was admitted with chronic headache on February 26, 1987, when there were no neurological deficits or physical abnormalities. Computed tomographic (CT) scans showed a mixeddensity mass with no evidence of calcification in the left lateral ventricle, which was irregularly enhanced by contrast medium. Under a diagnosis of an intraventricular glial tumor, surgery was performed via a left transcortical-transventricular approach on March 31. The highly vascular, nodular tumor, originated from the lateral wall of the left lateral ventricle near the foramen of Monro, was successfully removed. The postoperative course was uneventful and he was discharged 3 months after postoperative irradiation. Light microscopic examination revealed the tumor cells with the clear cytoplasm and perinuclear halos characteristic of an oligodendroglioma. However, electron microscopy showed neuronal elements identical with central neurocytoma as reported by Hassoun et al. in 1982. These included large numbers of dense-core or clear vesicles in the cell processes and synaptic structures.
A rare case of multiple traumatic aneurysms, arising from the distal anterior cerebral artery (ACA), associated with a diffuse axonal injury is presented. An 18-year-old male sustained a frontal impact injury in a traffic accident on February 19, 1988. He immediately lost consciousness and was transported to a local hospital where his Glasgow Coma Scale score was 6. A computed tomographic scan showed a traumatic subarachnoid hemorrhage extending from the corpus callosum to the left parietal lobe. With conservative treatment, he gradually regained consciousness and was referred to our hospital 12 days later. Skull x-rays revealed no fracture. A right common carotid angiogram revealed multiple aneurysmal dilatations on the right distal ACA. A left frontoparietal craniotomy was then performed to determine the nature of the aneurysmal dilatation, and to evacuate the intracerebral hematoma because his right hemiparesis persisted. Two aneurysmal dilatations on the distal ACA were tightly surrounded by clots and a hematoma extended from the corpus callosum to the parietal lobe. The ACA was trapped proximal and distal to the aneurysmal dilatations. The postoperative course was uneventful.
A 69-year-old female with bilateral giant internal carotid aneurysms at the cavernous portion was admitted with complaints of diplopia and radiating pain. The aneurysm on the left side was larger and symptomatic, and treated with the internal carotid artery ligation and the superficial temporal arterymiddle cerebral artery (STA-MCA) double bypasses. However, intraoperative somatosensory evoked potential (SEP) monitoring revealed the disappearance of N20 100 minutes after the carotid occlusion and rapid recovery of N20 following flow restoration. Therefore, a high-flow bypass using radial artery grafting was installed, and carotid ligation was performed again without any change in SEP. Postoperative angiograms demonstrated complete disappearance of the aneurysm and sufficient blood supply through a patent high-flow bypass. Although both STA-MCA double bypasses were occluded, no change in cerebral blood flow was detected by single photon emission computed tomography. Her neurological deficits improved, and she is being followed as an outpatient with a plan of second surgery for the remaining aneurysm.
The authors report on a surgical case of cavernous angioma in the pontomedullary region. A 60-year-old male exhibited a progressive neurological deficit consisting mainly of bulbar paresis and cerebellar signs, without ictal episodes, and computed tomographic scans showed growth of the lesion over 3 years. On preoperative assessment, a glial tumor was suspected to coexist with a cavernous angioma. The vascular malformation was totally excised successfully. This case also revealed an unusual familial occurrence.