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Biomedical subjects

O Missir

Publications and source records attributed to O Missir.

31 records · Page 2Linked to original sources

[Complementarity of x-ray computed tomography of staged stereotaxic biopsies and of stereo-electroencephalography in the spatial definition of intracranial lesions].

This study concerns 180 patients (132 M; 48 F) (age: 2 to 69 years; m: 33 years) who underwent stereotactic procedures according to the methodology of Talairach and Szikla. Such procedures (stereotactic and stereoscopic angiography in all cases, and ventriculography in 81%) should permit a correct spatial definition of intracranial lesions. The informations provided by the angiography (normal in 7%) and by the ventriculography (normal in 11%) are complementary to those yielded by the TDM and permit an easier and safe stereotactic approach to the lesions. In 43% of patients the lesions were deep-seated (basal ganglia: 24; sellar region: 19; thalamo-peduncular: 13; brain stem: 6, etc.). The histological examination showed: low-grade gliomas in 43%; glioblastomas in 21%; non tumoral lesions in 17%. A precise diagnosis couldn't be obtained in 3.8%. The data provided by the stereo-EEG (in 11 patients suffering also of severe drug-resistant partial epilepsy) did not permit, alone, an histological diagnosis, excepted when electrodes explored a solid tumor. Two patients had a neurological impairment, and two died (one for extracerebral reasons). The authors consider that the TDM data and the informations given by the stereotactic procedures are complementary for obtaining valuable informations on the spatial organization of intracranial lesions and choosing the best treatment.

Adolescent↗

[Value and technic of translating the data from x-ray computed tomography into the stereotaxic coordinates of the Talairach system].

The neuroradiological stereotactic examinations provide indispensable information to localize many intracranial lesions: the data obtained by the CT-Scan are complementary of the stereotactic ones. The transfer of the routine CT-Scan transverse axial slices into the Talairach stereotactic system needs a precise definition of the inclination of the plan of the slices and a correct evaluation of the mean magnification factor. The inclination of the slices is appreciated using the bony, vascular and ventricular landmarks clearly identified on the CT-Scan and stereoscopic stereotactic images. We compared the spatial "reconstructed" CT-Scan data with the histopathological findings obtained by serial stereotactic biopsies in 48 tumor patients. The error varied from 1.5 to 4.6% (m: 2.7 +/- 1.2) on the sagittal plane; from 1.3 to 10% (m: 5.8 +/- 3.4) on the transversal plane; from 2.5 to 4.3% (m: 3.5 +/- 0.7) on the axial plane. The mean global error was 3.7% +/- 2.3. The CT-Scan directly performed under stereotactic conditions (acrylic frame) seems to be the more useful procedure. Nevertheless considering the good precision obtained with our methodology applied to the Talairach's system, we consider it suitable when: a) the gantry of the CT-Scan apparatus is too narrow for the acrylic frame; b) the exploitation of previous CT-Scan examinations is necessary; c) patient refuses the discomfort of the acrylic frame.

Brain Diseases↗

Correlation between stereo-EEG, CT-scan and stereotactic biopsy data in epileptic patients with low-grade gliomas.

Stereo-EEG activity, which was recorded precisely from the same location as stereotactic biopsies, was studied on 11 patients with low-grade glioma and severe partial epilepsy. The volume of the lesions varied from 6 to 72 cm3 (mean 23 cm3). A very depressed activity was recorded in all the 25 specimens of solid tumor and in more than half of infiltrated white matter. The background activity was still conserved in all 'normal' fragments, while it is never found in solid tumor; sometimes it could be found in the infiltrating tumors of white or gray matter. High voltage theta and delta activity was recorded in neither 'normal' nor solid tumors. We emphasize the importance of considering the stage of evolution when we evaluate the significance of the stereo-EEG activity.

Adolescent↗

[Current significance of stereotactic exploration in the diagnosis and therapy of space-occupying cerebral processes].

To reach good functional results in patients with spaceoccupying processes--especially with those localized in the dominant hemisphere operative treatment should be planned individually, which is impossible if all diagnostic assessments are followed by the same surgical procedure. The choice of appropriate method of therapy in case of brain tumor depends on various factors, such as the histological nature, extent and volume, relationship to the brain structures and vessels, and spatial form of the growth. The synthesis of all neuroradiological information from stereotactic exploration, together with the histological findings from stereotactic serial biopsies yields a three-dimensional representation of the brain with the tumor. This method seems to offer the optimal basis for the choice of appropriate treatment--especially for gliomas--between surgery, radiotherapy (external or/and interstitial), endocavitary radiation therapy or drainage.

Adolescent↗

[Contribution of iodinated cisternography to craniocerebral computed tomography].

Computerized tomography is usually adequate to explore supratentorial lesions of the skull and brain. However, it is often inadequate for a detailed analysis of lesions of the base of the skull and their anatomical rapports. Opacification of the subarachnoid spaces by means of a contrast medium (computerized cisternography) has proved extremely useful in such cases. The contrast media utilized are tri-iodized, water-soluble compounds which are well tolerated. The technique and anatomical data of the method are described, and its applications in different fields of tumoral and non-tumoral pathology are discussed.

Arachnoid↗

[Reliability of a simplified method of localization of CT images. Correlation with stereotaxic results in 30 cases].

A simplified method of localization of cerebral lesions by reference to CT Scan images was compared systematically in 30 cases, with localization obtained under stereotaxic conditions. The comparison was made in reference to the pineal gland and certain ventricular landmarks. The uncertainty of the method in an angular plane is less than or equal to 2,5 degrees; it is less than or equal to 3 mm in a linear plane in more than 90% of the cases.

Brain↗

[Closed injuries to the extracranial carotid artery].

A series of 26 cases of injury to the extracranial carotid artery included 3 patients with false aneurysms, 21 dissecting aneurysms, and 3 aneurysms following direct trauma. Clinical and angiographic findings, and clinical course in the 26 patients are described, together with changes observed on angiography in the 11 cases where this was repeated. Prognosis in this series appeared to be better than that usually described.

Aneurysm↗

[Contribution of radiography and gammagraphy to the monitoring of the development of psychoses].

The authors emphasize the frequency of intracranial tumors in psychiatric patients. They make a distinction between the rare cases of psychiatric patients with intracranial tumors and the even most-frequent cases of tumors that express themselves through psychiatric disorders. According to the authors, the most important detection-tests are the brain scan and, more recently, the EMI scan or tomodensitometer.

Adult↗

[Point of view of the radioneurologist].

Since the 1970s, neuroradiology has benefited from significant advances and has become less and less invasive. SALT group (Saint-Anne-Lariboisière-Tenon), created in 1986, treats and follows patients presenting with arteriovenous malformation with surgery, embolization and/or radiosurgery. Treatment failures and complications are analyzed in order to better define indications and improve techniques of treatment which benefit from advances in equipment and software, as well as in radiobiology and genetics.

Embolization, Therapeutic↗