Meningioma of the third ventricle. Computed tomography and magnetic resonance imaging.

Meningiomas of the third ventricle are rare intracranial neoplasms. We reported such a case in a 42 years old man without clinical evidence of increased intracranial pressure. Computed tomography (CT) and magnetic resonance imaging (MRI) demonstrated the tumour sitting in the superior and anterior part of the third ventricle, bulging into the lateral ventricles. CT was more effective than MRI in the demonstration of calcifications whereas MRI proved to be superior in delineation of the tumour and its relation with surrounding structures.

Infarct of the anterior limb of the right internal capsule causing left motor neglect: case report and cerebral blood flow study.

A sixty-nine year old hypertensive man had left motor neglect following an infarct of the anterior limb of the right internal capsule. He also had left auditory extinction on verbal dichotic listening and a sligh constructional apraxia. Regional cerebral blood flow (CBF) was measured at rest with Xenon 133 inhalation and was found to be slightly decreased in a diffuse fashion. Motor activation of the right hand resulted in an increase of CBF in the contralateral superior rolandic area, whereas no such increase was found during motor activation of the left hand. This lack of cortical CBF increase on contralateral motor activation is interpreted as a consequence of the failure of some corticosubcortical connexions involved in motor arousal. The specifically dynamic appearance of regional CBF abnormalities, i.e. during selective activation as opposed to rest measurements, is consistent with the functional character of neglect.

[Contribution of microradiography in search of calcifications of valvular bioprostheses]. / Apport de la microradiographie dans la recherche des calcifications des bioprothèses valvulaires.

Implantation of a valvular bioprosthesis is one of the best treatments for valvular disease, particularly in children. Unfortunately, their use is limited as calcifications develop over time. Prevention of these calcifications is still an unresolved problem that is under study by Professor Carpentier and coworkers. These investigators have developed an experimental model in which accelerated development of calcifications occurs: fragments of porcine valves implanted under the skin of rats become calcified in a few days. Prior to implantation, the fragments are pretreated in an attempt to delay or prevent the development of calcifications. Two, four, six and eight months after implantation, the fragments are removed and calcifications are looked for using microradiography. Two hundred fragments have been studied. The material and technique used in our study are described. Results are semi-quantitative, based on the volume of calcifications. We conclude that microradiography is faster and more reliable than histology (the only technique used up till now) as it allows to study the entire fragments.

[Spinal biphotonic absorptiometry]. / L'absorptiométrie biphotonique rachidienne.

Spinal biphotonic absorptiometry allows a quantitative investigation of bone mineralisation. The study of a control and an osteoporotic population allowed the definition of the fracture threshold independent of age and the curve of the variation in the mineral content with aging. A good correlation was observed with computed tomography. The criteria of definition of a population at risk for the purposes of a longitudinal study are proposed. Biphotonic absorptiometry is an excellent examination for the detection of demineralisation and for the monitoring of treated subjects.