Positron emission tomography (PET) study in patients with meningiomas

Regional hemocirculation and metabolism were evaluated in five patients with meningiomas using positron emission tomography (PET). Histological diagnoses were: two cases of meningotheliomatous type, one hemangiopericytic type, one fibroblastic type, and one transitional type. Regional cerebral blood flow (rCBF), blood volume (rCBV), oxygen extraction fraction (rOEF), and metabolic rates of oxygen (rCMRO2) and glucose (rCMRG1) were measured with 15O2, C15O. 15O2, and 18F-fluorodeoxyglucose tracers. For the quantitative analysis, regions of interest were delineated on tumors, the peritumoral region, and the contralateral gray matter in comparison with age-corresponding 5 malignant gliomas and 5 normal volunteers. Tumor hemocirculatory parameters (rCBF: 57.2 +/- 22.6 ml/100 ml/min, rCBV: 7.95 +/- 3.27 ml/100 ml, mean + SD, n = 5) were markedly higher than those of the contralateral gray matter (p less than 0.05 by a Student-t test). The high values were consistent with angiographic findings of tumor staining and with abundant tumor vessels demonstrated by pathological examination. rCMRO2 was 2.15 +/- 0.80 ml/100 ml/min, which were comparable to those of the contralateral gray matter. Tumor rCMRG1 showed 4.76 +/- 2.37 mg/100 ml/min; the values of two cases were similar to the respective gray matter. The raised metabolic rate (rCMRO2/rCMRG1) therefore suggests rather aerobic glycolysis as compared with gliomas. Low rOEF (0.26 +/- 0.16) reveals an excessive blood flow beyond oxygen demand of the tumor. In the peritumoral regions, rCBF and metabolism fell slightly but rOEF reached a level similar to the contralateral gray matter, possibly due to hemocirculatory stasis caused by intracranial hypertension; in contrast, an unmatched reduction of rCBF and rCMRO2 implies tumor cells infiltration in gliomas.(ABSTRACT TRUNCATED AT 250 WORDS)     

Stimulus train-induced bursting in hippocampal slices: difference between CA1 and CA2/3 subfields

We studied the relationship between CA2/3 and CA1 subfields in the generation of stimulus train-induced bursting using in vitro hippocampal slices. Repeated stimulation to the stratum radiatum induced three types of epileptiform activities: afterdischarge bursts, spontaneous bursts and single stimulus-triggered bursts. In the intact slices, spontaneous bursts in CA3 preceded those in CA1, whereas afterdischarge bursts in CA3 followed those in CA1 when it was possible to distinguish differences in the burst onset. After transection between CA2/3 and CA1, neither spontaneous nor triggered bursts could be induced or maintained in isolated CA1, where only small afterdischarge bursts with a higher bursting frequency were observed. It was difficult to induce afterdischarge bursts by the tetani to the mossy fibers. Some of the mechanisms underlying the generation of these stimulus train-induced bursts are discussed.     

An operated case of clivus chondroma (author's transl)]

A case of clivus chondroma was presented in detail with a review of twenty-four cases reported in Japan. A twenty-eight-year-old house wife was admitted to hospital with complaints of muscle weakness and numbness on the right side of the body. Neurological examination revealed the right hemiparesis and hemihypesthesia. Cranial nerve palsies were also disclosed on the right Vth and the left IXth, Xth and XIth nerves. Craniograms showed a ring-like calcified shadow localized in the clival region without definite bone destruction. Roentgenograms disclosed many well-demarcated radioluscent areas in the phalanges of both hands and feet. The marked separation between the basilar artery and the clivus was demonstrated on vertebal angiograms and pneumoventriculograms. CT scan showed an irregularly shaped low density area localized on the clivus, which turned out to be enhanced following contrast infusion. The tumor was partially removed by the subtemporal approach, and was histologically chondroma. The patient was discharged, gaining adequate muscle strength after operations.