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Biomedical subjects

M Gigaud

Publications and source records attributed to M Gigaud.

At least 19 recordsLinked to original sources
PubMed2006

[Decompressive craniectomy and intracranial hypertension].

Decompressive craniectomy was purposed for the treatment of refractory intracranial hypertension after head injury. This review discusses results obtained by this surgery in severe head trauma. Several studies have confirmed a reduction in intracranial pressure secondary to decompressive craniectomy. Mortality decreased and the proportion of good outcome of the survivors increased. These results have not been confirmed prospectively, and indications have to be clarified. The positive effects of decompressive craniectomy compared to barbiturate or hypocapnia in the "second tier therapy" in refractory intracranial hypertension could be interesting to evaluate.

Craniocerebral Trauma↗
PubMed2005

Immunodetection of SV40 large T antigen in human central nervous system tumours.

BACKGROUND/AIMS: DNA sequences from Simian virus 40 (SV40) have been previously isolated from various human tumours of the central nervous system (CNS). This study aimed to investigate a series of tumours of the CNS for the expression of the SV40 large T antigen (Tag), which is an oncogenic protein of the virus. METHODS: A French series of 82 CNS tumours was investigated for Tag expression using a monoclonal antibody and immunohistochemistry. A Tag positive hepatocellular carcinoma cell line from transgenic mice and a kidney biopsy from a patient infected by SV40 were used as positive controls. RESULTS: None of the tumours (20 ependymomas, 20 glioblastomas, 12 oligodendrogliomas, three plexus choroid adenomas, two plexus choroid carcinomas, 15 meningiomas, and 10 medulloblastomas) contained SV40 Tag positive cells. CONCLUSIONS: The lack of SV40 Tag in 82 CNS tumours of various types is at variance with previous studies from different countries, and suggests that the virus may not be an important factor in CNS tumorigenesis, at least in French cases.

Adolescent↗
PubMed2003

[Trigeminal neuralgia presenting as a deep recurrent desmoplastic neurotropic melanoma of a lentigo maligna].

INTRODUCTION: Neurotropic melanoma is a particular anatomopathological form corresponding to dermal proliferation of desmoplastic cells of neuroid differentiation. We report a new case of neurotropic melanoma revealed by facial neuralgia. CASE REPORT: A 64 year-old man presented in 1996 with a lentigo maligna on the right cheek treated by complete excision. After 2 years of medical supervision, a pigmented lesion recurred leading to new surgical treatment. The histological examination of the total lesion showed intra-epidermal atypical melanocyte proliferation without dermal invasion. In 1999, right trigeminal neuralgia occurred without associated cutaneous change. Cranial MRI revealed an infiltration of the right trigeminal nerve. Endo-buccal surgery disclosed a black swelling of the trigeminal nerve. Histological examination and immunohistochemistry revealed a desmoplastic melanoma. DISCUSSION: Neurotropic melanoma with nerve invasion by malignant cells presenting as a trigeminal neuralgia is rare. Our case report underlined the depth of the neurotropic melanoma and the initial existence of a lentigo maligna without associated "neurotropic" melanoma.

Cranial Nerve Neoplasms↗
PubMed2000

So-called malignant and extra-ventricular neurocytomas: reality or wrong diagnosis? A critical review about two overdiagnosed cases.

Central neurocytoma (CN) is described as a rare intra-ventricular benign neuronal tumor of the brain. Two primary tumors first diagnosed as malignant and extra-ventricular neurocytomas are reported here. Histologically, the tumor of the first patient, a forty-one-year-old man, consisted of monotonous cells with round nuclei, but no fibrillar background. The second tumor, in a nineteen-year-old girl, showed areas of moderately pleomorphic round cells, with numerous rosettes and ganglion cell differentiation, in an abundant fibrillary network. Both presented calcifications. Mitoses were more frequent in recurrences and spinal locations than in the primaries. All tumors stained strongly for synaptophysin, and GFAP was partly positive in the first case only. Patients received post-surgical radiotherapy and were still alive eight and six years, respectively, after initial surgery. The interpretation of atypical cases, such as ours is not easy: the diagnoses finally retained were oligodendroglioma in the first case and ganglioneuroblastoma in the second case. Furthermore, neurocytomas atypical either by their unusual topographical or histological presentation or by their poor prognosis, have been frequently entitled in this way on synaptophysin positivity. So, we were prompted to reassess the entity of CN, seventeen years after the first description, to re-appreciate the reality of anatomo-clinical variants and to discuss the value of synaptophysin positivity in these tumors. In conclusion, it seems preferable to individualize true classical CN, which has a favorable outcome, from so-called extra-ventricular, atypical and anaplastic, clinically malignant neurocytomas for which complementary treatment is required.

Adolescent↗
PubMed1999

Posterior extradural migration of extruded thoracic and lumbar disc fragments: role of MRI.

We report three patients with a sequestrated disc fragment posterior to the thecal sac. The affected disc was lumbar in two cases and thoracic in the third. Disc fragment migration is usually limited to the anterior extra dural space. Migration of a disc fragment behind the dural sac is seldom encountered. MRI appears to be the method of choice to make this diagnosis. The disc fragments gave low signal on T1- and slightly high signal on T2-weighted images and showed rim contrast enhancement. The differential diagnosis includes abscess, metastatic tumour and haematoma.

Diagnosis, Differential↗
PubMed1998

Spinal cord abscess in a heroin addict: case report.

Spinal cord abscesses are extremely rare, even in intravenous drug abusers. They usually have a poor prognosis unless diagnosed and treated promptly. MRI is the best imaging modality for diagnosis and follow-up. We report a 42-year-old man, an active intravenous drug user, HIV negative, who developed subacute tetraplegia from an intramedullary abscess caused by Staphylococcus aureus. Immediate decompressive surgery and antibiotic treatment led to progressive recovery.

Abscess↗
PubMed1996

The treatment of neuroblastoma with intraspinal extension with chemotherapy followed by surgical removal of residual disease. A prospective study of 42 patients--results of the NBL 90 Study of the French Society of Pediatric Oncology.

BACKGROUND: Neuroblastoma is the most common malignant cause of spinal compression in the pediatric population. More than 30% of patients who are impaired prior to treatment remain impaired after the completion of therapy. Those who do not improve after decompressive laminectomy may go on to develop severe delayed spinal deformities. METHODS: To decrease the long term sequelae of routine neurosurgical intervention for all intraspinal extensions of neuroblastoma, the French NBL 90 Study was formulated to use chemotherapy as a first-line treatment for all nonmetastatic neuroblastomas with intraspinal extension. Neurosurgical decompression and excision was recommended only for patients demonstrating rapid neurologic deterioration. RESULTS: The overall survival of the 42 patients registered was 97%. Initial neurologic impairment was present in 27 patients (64%), including 11 with paraplegia. Thirty-two patients received chemotherapy as first-line treatment. Complete regression of the intraspinal component was observed in 13 patients and partial regression of greater than 50% of the initial volume in 5 patients. Of 19 evaluable patients presenting with a neurologic deficit and treated with primary chemotherapy, recovery was completed in 11 and partial in 3. Four patients failed to recover from long-standing pretreatment paraplegia. Only one patient worsened during therapy, and recovered completely after emergent neurosurgical intervention. Seven patients underwent initial neurosurgical procedures; six had a neurologic deficit and five recovered completely, including all three who presented with acute onset of paraplegia. Three patients had extraspinal surgery as exclusive treatment. Six patients (15%) suffered severe neurologic sequelae. Only one of the patients who underwent surgery required spinal stabilization for progressive deformity, but follow-up is limited. CONCLUSIONS: By treating patients with dumbbell neuroblastoma initially with chemotherapy, the authors were able to reduce the size of the intraspinal mass in 58% of patients, improve partial neurologic deficits in 92%, and avoid neurosurgical decompression in 60%. Neurologic deficits also improved in 83% of patients requiring emergent neurosurgical intervention.

Adolescent↗
PubMed1992

Experimental focal cerebral ischaemia assessed with IVIM*-MRI in the acute phase at 0.5 tesla.

Intravoxel incoherent motion (IVIM*)-MRI has been performed on a clinical system at 0.5 tesla with a b gradient factor of 100 s/mm2, in a feline focal model of cerebral ischaemia. Images were obtained in 26 cats from less than 1 hour and up to 7-12 hours after stroke. The apparent diffusion coefficient (ADC) was decreased at the site of injury when compared to the contralateral normal side, by 30% in the first, 33% in 1-2 h and 27% in 2-4 h; it increased at 7-12 h, when vasogenic oedema occurred. IVIM*-MRI demonstrated early changes, due to cytotoxic oedema, during the acute phase of cerebral ischaemia to which conventional T2-weighted spin-echo imaging was not sensitive.

Animals↗
PubMed1989

Curability of third ventricular region tumours. A multidisciplinary approach to evaluate the places of operative, radiation and chemotherapy.

Between 1976 and 1988, 17 patients suffering from tumours located in the third ventricular region were entered into a retrospective study. There were 11 males and 6 females aged from 2 to 30. These tumours were located in the pineal area (n = 12), in the floor of the third ventricle (n = 3), in the roof of the third ventricle (n = 1) and multiple midline tumours (n = 1). A ventriculoperitoneal shunt was performed in 13 patients. In 8 patients the tumour was operated upon directly. 2 patients did not undergo surgery. A histological examination was performed in 13 cases with identification of 9 germinomas, 2 pinealoblastomas and one astrocytoma. In one case the plasma and cerebro-spinal-fluid level of tumour markers (human béta chorionic gonadotrophin & alpha feto protein) were elevated. All patients received 45 to 60 grays by cobalt megavoltage irradiation on the tumoural volume, 8 of them receiving additional whole brain and spinal irradiation ranging from 30 to 36 grays. One patient had chemotherapy in addition to radiotherapy. The 5 years survival rate was 74% and the mean follow-up period was 5 years. Five deaths occurred: 1 during irradiation, 3 following a relapse and 1 unexplained death later on. There were no neurological sequelae related to irradiation but 7 patients (37%) had pituitary insufficiency. The irradiation dose level required to obtain local control, the methods of spinal prophylactic treatment and the role of chemotherapy are discussed.

Adolescent↗
PubMed1985

[Use of barbiturates in posttraumatic comas at the mesencephalic level. Apropos of 38 cases].

Thirty-eight patients with brain injury and mesencephalic coma, or a Glasgow score of less than 5, were treated routinely with Thiopental administered by electric syringe for a mean duration of 4 days. Follow up review criteria were based on clinical computed tomography and electroencephalographic data, as well as results of monitoring of intracranial pressure and assay of blood barbiturate levels. Global results indicated a mortality of 55.3% and reintegration of 34.2% of the patients. Results as a function of the different parameters of surveillance are discussed.

Adult↗
PubMed1980

[Transtentorial central impaction in traumatic cranio-cerebral pathology (author's transl)].

On the basis of a series of 255 severe head injuries, the authors present a clinical, radiological and anatomical study of central transtentorial impaction. Anatomical examination reveals the frequency of central impaction which affects from above downwards and in succession all of the axial structures in their median part. Clinically, these lesions fall into three categories in terms of signs: homogeneous and corresponding to the anatomical lesions. Scanner findings confirm the anatomoclinical data and provide important information in the assessment of prognosis.

Brain↗
PubMed1978

[Levels of axial lesion in severe head injuries (author's transl)].

Over the past few years considerable amount of clinical syndromes describing brain stem levels of lesion were reported. This work was undertaken to establish, if possible, a simplification of criterions of axial lesions in head injuries. 125 patients with severe head injuries were strictly selected. Statistical analysis of careful examination of clinical pattern was performed and correlated, when possible, with anatomical lesions. Only four homogeneous groups were isolated:--group I represents the cortico-sub-cortical level,--group II représents the diencéphalie level,--group III represents the upper brain stem level with two subdivisions dependent upon the mechanism of herniation : central or uncus,--group IV represents the lower brain stem level.

Brain Stem↗
PubMedDate not supplied

Internal capsule: normal anatomy and ischemic changes demonstrated by computed tomography.

The purpose of this study was two-fold: (1) to attempt to localize the different parts of the internal capsule on computed tomography (CT) axial sections and (2) to correlate clinical data and CT appearance of 25 cases of ischemic capsular lesions. Twenty-three of the ischemic lesions produced a pure motor hemiplegia. The internal capsule was studied on routine CT axial sections parallel to the canthomeatal line with 8 mm collimation before and after intravenous contrast medium injection. Absorption values of the white matter at the level of the anterior limb of the internal capsule were found to be a little higher (mean, 32 Hounsfield units [H]) when compared with the posterior limb (mean, 28 H). Lesions were classified according to the topography of the internal capsule: anterior limb (three), genu (one), posterior limb (seven), and putaminocapsulocaudate (14). CT appears to be the most sensitive and reliable method to investigate small deep cerebral infarcts since isotope scans were positive in only two of 13 cases, while angiography was positive in eight of 17 cases.

Adolescent↗