Search PubMed⌕ Search

Biomedical subjects

M Sindou

Publications and source records attributed to M Sindou.

At least 181 records · Page 10Linked to original sources
PubMed1976

Experimental bypass for sagittal sinus repair. Preliminary report.

Bypasses of the sagittal sinus, 2.5 mm in diameter, were carried out in 25 dogs with venous (13 cases) and arterial (12 cases) autogenous grafts, by classical microtechniques. Animals were sacrificed 10 to 75 days after the operation, average 40 days. The patency rate was 54% in the venous autograft group; in all cases, thrombosis occurred early and was due to technical factors. The immediate postoperative patency rate was 100% in the arterial graft group, but this type of graft showed a tendency to progressive occlusion because of extensive fibrosis of the arterial wall; thus the patency rate was 75% at the time of autopsy. This preliminary work demonstrates the technical feasibility of bypass procedure which could be used for sagittal sinus repair.

Animals↗
PubMed1975

[Posterior osteosynthesis in the treatment of spinal cord tumors].

Prognosis of cancerous tumors of the spine depends above all on their neurological consequences. The authors have wondered whether osteosynthesis of the spine -- in addition to decompressive surgery -- can improve patient's survival and fonctional results. 23 patients, 20 with a metastatic tumor and 3 with a plasmocytoma were treated in this way. All of them had neurological deficits, 4 had isolated radicular symptoms, 1 a cauda equina syndrome and 18 a spinal cord compression (7 of which were complete). 20 of these patients suffered intractable pain of the spine. All the patients underwent decompressive surgical removal of tumor through laminectomy, associated with a bilateral posterior metallic osteosynthesis. The type of osteosynthesis consisted of two metallic plates placed along each articular column and screwed into the articular processes and the vertebral body through the pedicles of the adjacent normal vertebrae. Cobaltotherapy was added in 14 cases, hormonotherapy in one case and radioactive 131 1 in one another patient. Selective spinal angiography, performed in one case of thoracolumbar tumor was found useful in the location and avoidance of Adamkiedwicz's artery. With regard to the complication, there were two operative wound infections requiring reoperation. Our series -- in comparaison with others -- prove the effectiveness of the combined procedure. Patients without complete spinal deficit had a 20 months survival average. Patients with complete deficit had the same survival as in comparative group. But all the 20 patients suffering pain in the spine were substantially relieved. Such a combined procedure is indicated in cases of tumors involving the vertebrae, whether or not the epidural space is invaded especially when there are riskes of unstable fracture and only partial neurological deficits. The technique may be extended even to complete paraplegia because of its worth while antalgic effects. Thus this method -- by consolidating the spine -- relieving pain and consequently allowing kinesitherapy to be resumed earlier is able to improve the functionnal status and increase survival of the patients.

Adult↗
PubMedDate not supplied

Three transverse dipolar generators in the human cervical and lumbo-sacral dorsal horn: evidence from direct intraoperative recordings on the spinal cord surface.

In the context of the intraoperative study of spinal cord surface evoked potentials in patients operated upon for chronic pain and spasticity, we have undertaken an analysis of the dipolar dorso-ventral organization of surface spinal cord evoked potentials in man. Averaged evoked potentials to peripheral nerve electrical stimulations were obtained from the dorsal and ventral pial surface of the cervical and lumbo-sacral spinal cord (7 pairs from 5 patients), using a small silver ball macroelectrode, positioned during open neurosurgical approaches. We found that the dorsally recorded N13 and N24 waves reversed into ventral P13 and P24 waves respectively. A second negative potential, N2, and a late prolonged positivity, P, similarly reversed into a P2 and an N wave respectively. Our data add up to a collection of skin, oesophageal, epidural, pial and intramedullary recordings in man and animals to provide the evidence for a transverse dipolar organization of the human postsynaptic N13, N24 and N2 potentials, originating from deep layers of the cord dorsal horn, and for a similar organization of the P wave, which has been shown to correlate with presynaptic inhibition on primary afferent fibres.

Evoked Potentials, Somatosensory↗
PubMedDate not supplied

The human cervical and lumbo-sacral evoked electrospinogram. Data from intra-operative spinal cord surface recordings.

We have undertaken the analysis of the human 'evoked electrospinogram' during intra-dural surgical explorations in 20 patients. Averaged spinal cord surface evoked potentials to peripheral nerve electrical stimulation were obtained from various restricted loci on the pial surface of the cervical and lumbo-sacral spinal cord. The brachial plexus P9 potential and its lumbo-sacral counterpart P17 were recorded as ubiquitous initial far-field positivities. The pre-synaptic compound action potentials N11 and N21 dwelt on the ascending slope of N13 and N24 respectively. They were composed of 1-5 sharp peaks and collected from the dorsal and dorso-lateral positions mainly, on the cervical and lumbo-sacral cord respectively. They are thought to be generated in the proximal portion of the dorsal root, the dorsal funiculus and the afferent collaterals to the dorsal horn. Compound action potentials could also be gathered from the surface of the dorsal roots, the cervical N10 and lumbo-sacral N19 potentials. The large cervical N13 and lumbo-sacral N24 waves originate from a dorso-ventral post-synaptic dipole, generated in deep laminae of the dorsal horn during the activation of large diameter afferent fibers. These waves were maximal on the main entry cord segments of the stimulated nerves and fell off on the 1-4 more rostral and caudal segments. The N2 wave is the dorsal component of another post-synaptic dorso-ventral dipole generated in deep laminae of the dorsal horn but activated by medium diameter afferent fibers. The latest event was the N3 wave, also possibly part of a dorso-ventral post-synaptic dipole, and generated by cells in the dorsalmost and deep dorsal horn laminae during the activation of small diameter afferent fibers. The P wave was a prolonged positive deflection which carried the N2 and N3 waves. It is the manifestation of pre-synaptic inhibition on primary afferent fibers. A supra-segmental ascending spinal cord volley was also described, composed of a long succession of sharp and low voltage peaks.

Adult↗
PubMedDate not supplied

Functional imaging and neurophysiological assessment of spinal and brain therapeutic modulation in humans.

We summarize here our experience in the neurophysiological and neuroimaging assessment of spinal and brain neuromodulation for pain relief. Techniques reviewed include somatosensory evoked potentials (SEPs), nociceptive spinal (RIII) reflexes, and positron emission tomography (PET), which have been applied both to investigate the mechanisms and to optimize the application of neurostimulation procedures. SEPs are especially useful in the preoperative assessment of patients with neuropathic pain, as they allow the establishment of the functional state of the dorsal column system. Patients with strongly abnormal SEPs due to ganglionic or preganglionic pathology are not likely to benefit from spinal (SCS) or peripheral (TENS) neurostimulation, because ascending fibers disconnected from their soma will undergo rapid degeneration and not be excitable. In the postoperative period, nociceptive spinal reflexes yield objective data concerning the effects of neurostimulation on spinal circuitry. In our experience, the best clinical results are achieved in patients with preserved preoperative SEPs, in whom neurostimulation entails profound attenuation of nociceptive reflexes.PET-scan imaging techniques have recently been used to demonstrate changes in cerebral blood flow during new neuromodulation schemes such as motor cortex stimulation for pain control (MCS). PET studies highlight the thalamus as the key structure mediating functional MCS effects. Thalamic activation would trigger a cascade of synaptic events influencing activity in other pain-related structures including the anterior cingulate gyrus, insula, and upper brainstem. The combination of clinical electrophysiology and functional neuroimaging provides insight into the mechanisms of action of neuromodulation procedures, guides clinical decision, and contributes to optimize patient selection.

Central Nervous System Diseases↗
PubMedDate not supplied

[Spino-thalamic cordotomy in cancerous pain. Results of a series of 124 patients operated on by the direct posterior approach].

The authors -- about a series of 124 cancerous patients treated during the 12 last years with open spino-thalamic cordotomy for intractable pain -- have tried to evaluate effectiveness of the operation with regard to its levels in relation to the site of pain. Patients suffering median or bilateral perineo-pelvic pain, isolated or associated with algias in one or both legs (group I: 50%) underwent a bilateral C8-C6 cordotomy in one stage. Patients with the same perineo-pelvic cancers but suffering only unilateral pain (group II : 31,8%) and patients with painful cancers in the leg (group III : 3,2%), were operated on with a C7 controlateral cordotomy. Patients suffering widespread unilateral pain in the chest, isolated or associated with algias in the arm, for instance from lung or breast cancers (group IV : 15%) underwent a controlateral C2 cordotomy. There was 3,2% mortality and one paraplegia. A useful early effect(i.e. complete or partial relief) was obtained : in 85% cases (60% and 25%) for the 1st group, in only 51% (36% and 15%) for the 2nd, and in 87% (56% and 31%) for the 4th. Relief was complete in each of the 4 cases of the 3rd group. In the 2nd group 39% of patients were completely relieved of their initial unilateral pain, but complained of an early post-operative pain on the other side. This secondary pain was supposed existing prior to the operation, but masked because of its lesser intensity. The useful results at the time of death, after a 6 month mean survival (from 1 month to 4 years), were 63,75% in the 1st group, 33% in the 2nd, 100% in the 3rd and 72% in the 4th. The high rate of poor results with unilateral cervical cordotomy in the perineo-pelvic cancers with apparently unilateral pain, led us since then to systematically perform for them a bilateral cordotomy. Thus, our general management for pain of malignant origin is now as follows: C8-C6 bilateral cordotomy for all the perineo-pelvic cancers whatever uni- or bilateral the site of pain may be; C7 controlateral cordotomy for the painful cancers of the leg; and C2 controlateral cordotomy for hemithoracic and/or arm pain, when related to very extended lung or breast cancers. We prefer complete posterior rhizotomy for limited cancers of the thoracic wall, and selective posterior rhizotomy through the scope, from -- the brachial plexus roots down to T4 -- for pain as from the PANCOAST-TOBIAS syndromes, or in case of painful involvements of the upper limb roots. For cervico-facial cancers we generally use combined sections of the sensory cranial nerves in the posterior fossa and of the cervical posterior roots.

Cordotomy↗
PubMedDate not supplied

Polyglucosan bodies and temporal lobe epilepsy: an incidental finding or more?

This study reports on histological findings in the temporal lobe of a 36-year-old woman who underwent a right temporal lobectomy for pharmaco-resistant complex partial seizures. Since surgery, the patient has remained seizure-free. The patient had an established diagnosis of right temporal lobe epilepsy, based on video EEG recordings of seizures, MRI hippocampal atrophy, focal interictal hypometabolism on fluoro-desoxyglucose, hypofixation of Cl1-flumazenil in PET studies, and ictal intracerebral recordings. Biopsies were studied under light- and electron microscopy. Histology showed diffuse distribution of a large number of polyglucosan bodies (PBs) in the whole right temporal lobe white matter. PBs were mostly confined to the perivascular areas and in subpial zones rarely and were observed in the most superficial cortical layers. There was some neuronal loss, especially in opercular zone T , but no other histological lesion was found. Ultrastructurally, PBs were made of filamentous and amorphous material, and were found both in intra-astrocytic processes and in axons. The presence of numerous PBs in the temporal lobe of patients with refractory temporal lobe epilepsy has been reported in 3 patients in the literature. It raises the questions whether this histological abnormality could be related to the epileptogenic process as a cause or as a consequence.

Adult↗
PubMedDate not supplied

[Pan-spinal ependymoma. Apropos of 2 cases with complete exeresis].

Authors performed in two patients a macroscopically complete exeresis of a panspinal ependymoma. The first case concerns a 27 years old woman, submitted to surgery in 1971, soon after a delivery, who exhibited a tumor in all points identical to the one described by G. Horrax an D. Henderson (1939). The second case concerns a male subject submitted to surgery in May 1973 because of a lesion extending from C2 to L2 and corresponding to a dorsal fleshy ependymoma, surrounded by two voluminous pseudosyringomyelic cysts, with respectively cervical and dorsal-lumbar localization. Such cases rare, with sometimes difficult clinical and roentgenologic diagnosis, raise before all problems of surgical tactics. We are dealing here with benign ependymomas, few favourable to roentgentherapy. Their management is surgical, i.e. complete exeresis. The few common extent of some of these tumors to the totality of the spinal cord does not modify in any manner such a principle. The same may be said of some etiologic circumstances, such as pregnancy, that often enough constitute a postponing of diagnosis and mangement detrimental for the patient. Only, the march of the surgical procedure may be object of discussion. The here reported experience lets appear that, when necessary, complete exeresis may be performed in one session under the same conditions and with the same spinal risks than for a less extensive analogous tumor. At long term the problem of spasticity of lower extremities has to be considered. However, in spite of extensive laminectomy, no major deformity of the vertebral column is to be noted.

Adult↗
PubMedDate not supplied

[Experimental intracranial venous microsurgery. Bypass of the sagittal sinus for arterial or venous repair and preoperative measurement of the cerebral impedance in the dog].

By-passes of the sagittal sinus-which is 2,5 mm in diameter-were carried out with autogenous arterial or venous grafts, in 34 dogs, using the classical microtechniques (operative microscope, micro-instruments, micro-sutures...). Controls were done both 1 degree by angiography (direct sinography was the only convenient procedure to visualize the sinus and the by-pass) during survival, and 2 degrees by anatomical and histological examination after sacrifying the animals, on an average the 40th post-operative day (from the 10th to the 75th day). The early patency rate (within the first post-operative month) was 76 p. 100. All cases of early thromboses, which affected especially venous autografts, were related to technical insufficiencies. The late patency rate (after a one month follow-up) was only 64 p. 100, because of the secondary occlusion of some arterial autografts. All these late thromboses were related to an extensive fibrosis of the arterial wall.

Animals↗