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The effect of intravenous infusion of 10% glycerol on polymorphic delta waves of EEG was investigated in 13 patients (15 studies) with brain tumors in cerebral hemisphere. The delta waves were analyzed by two-dimensional EEG topography and power spectrum of delta waves (P(delta)) over the tumor, adjacent, and distant regions in the same hemisphere to the tumor, and ipsi- and contralateral hemispheres to the tumor. The data focus of EEG topography was well corresponded to the tumor and surrounding brain edema which visualized by x-ray CT-scan. In the patient with brain tumors with marked brain edema (group A, 11 studies), EEG topography showed marked reduction of delta focus within 20 minutes from the end of intravenous infusion of glycerol, and returned to preinfusion distribution within 60 minutes. In patients with absent to minimum brain edema (group B, 4 studies), delta focus showed the tendency to enlarge and returned to preinfusion state at 60 minutes after the end of glycerol infusion. In patients of group A, P(delta) of ipsilateral hemisphere to tumor decreased at the end of glycerol infusion, and showing maximal reduction ratio (30%, p less than 0.01) at 20 minutes, re-increased there-after. In group B, P(delta) of ipsilateral hemisphere showed no definite changes after the glycerol infusion. P(delta) of contralateral hemispheres in patients of both group A and B, showed similar reduction ratio and time course to those of ipsilateral hemisphere of group A.(ABSTRACT TRUNCATED AT 250 WORDS)

A case of asymptomatic syringomyelia associated with tentorial meningioma is reported. A 53-year-old female was admitted to our hospital with the complaints of headache, decrease of bilateral visual acuity and gait disturbance. Neurological examination revealed no abnormality except for bilateral papilledema and left cerebellar sign. Motor and sensory systems were also intact. CT and MRI scans showed a left tentorial mass lesion, cervical syringomyelia and left tonsillar herniation. A relationship between the fourth ventricle and syringomyelia was not clearly identified. The tumor was totally removed and a histological diagnosis of fibroblastic meningioma was made. Postoperative radiological examination showed a diminishing of syringomyelia with the improved tonsillar herniation. Association of syringomyelia with brain tumor was reviewed, and its pathogenesis was discussed.

Three cases of trigeminal neurinoma originating from the Gasserian ganglion were reported. The findings observed on plain roentgenograms, cerebral angiograms and pneumoencephalograms were described in detail. Neuroradiologic examinations used routinely our department for the diagnosis of the skull base tumors were as follows; (1) plain skull examinations, including lateral, straight posterior-anterior, anterior-posterior half axial (Towne), axial, Stenvers, optic canal as well as tomograms in frontal, sagittal and axial projections; (2) angiographies by transfemoral catheter technique including selective internal carotid, external carotid and vertebral angiograms, and orbital-cavernous sinus venography via frontal and femoral veins; (3) pneumoencephalography with tomography. Bone destruction of the middle fossa including foramen ovale, foraman spinosum and lateral aspect of the sella was seen in all cases. Superior orbital fissure, optic canal and anterior surface of the petrous bone were also eroded depending upon the extent of tumors. Sharply circumscribed erosion of the petrous apex was seen in one of 3 cases, indicating the tumor extention into the posterior fossa. A soft tissue mass in the sphenoid sinus and ethmoidal air cells was recognized in all cases. Selective internal and external carotid angiograms demonstrated tumor vessels in 2 of 3 cases. Orbital-cavernous sinus venography was helpful for the interpretation of the lesion extending to the cavernous sinus and its neighboring structures. Conventional gas encephalography showed elevation of the temporal horn, and the concave arch formed by the supracornual cleft and lateral cleft was directed basally and medially in all of the cases. Tomography was also useful in the more detailed analysis of temporal horn. It should be stressed that the plain skull features are most important for deciding which contrast examination should be performed further.