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Biomedical subjects

G Lot

Publications and source records attributed to G Lot.

At least 37 records · Page 2Linked to original sources
PubMed1999

Cerebral amyloid angiopathy (CAA) with presentation as a brain inflammatory pseudo-tumour.

Cerebral amyloid angiopathy (CAA) is frequent but often asymptomatic. It can induce lobar haemorrhage, rapidly progressive dementia or recurrent transient neurological symptoms, other presentations being less frequent. We report 3 patients in their sixties presenting with a space occupying lesion which was the first manifestation of CAA. They were operated with a diagnosis of cerebral tumour. In all three cases, macroscopy was similar, the lesions were superficial in the cerebral cortex and the preoperative diagnoses were glioblastoma, meningioma and cavernoma. Histologically, the lesions consisted of a large inflammatory granuloma with numerous lipophages and siderophages surrounding capillaries with prominent endothelial cells. Vessels in the near cortex and meninges and within the granuloma harboured heavy amyloid deposits immunolabelled by anti-P component, anti-protein beta A4 with a A40 predominance and anti-apolipoprotein E. Adjacent cerebral cortex showed reactive gliosis and rare senile plaques. Amyloidosis is rarely considered among diagnoses of space occupying lesions. In our three cases, CT scan and MRI changes were related to the presence of an inflammatory granuloma around foci of haemorrhage and amyloid laden vessels.

Aged↗
PubMed1998

Mucocele of the sphenoid sinus: a late complication of transsphenoidal pituitary surgery.

In an 18-month period, 3 cases of sphenoidal mucocele following pituitary surgery were diagnosed at our institution. Only 1 case of this late-onset disorder has yet been reported as a pitfall of the transsphenoidal route. Symptoms include recurrent headache and visual complications. Diagnosis was delayed because of misinterpretation of the magnetic resonance imaging findings, which actually showed the development of a sphenoid mucocele long before clinical symptoms occurred. These 3 cases suggest that attention should be focused not only on the sella turcica, but also on the sphenoid sinus, in analyzing the magnetic resonance imaging data. The treatment consists of endoscopic transnasal marsupialization, since the mucocele is lined by normal epithelium with an inflammatory reaction that will heal with drainage. At the time of surgery, prevention would require either endoscopic control of the mucosal remnants, in case of sinus exclusion, or leaving the sphenoid sinus air-filled under a sealed sella.

Adenoma↗
PubMed1998

Management of intracranial aneurysms by surgical and endovascular treatment--modalities and results from a series of 395 cases.

The selective occlusion of saccular intracranial aneurysms may be achieved by two techniques: microsurgical clipping and endovascular coiling. Each of them have particular indications which need to be defined. From September 1992 to June 1996, 395 consecutive patients with small or large aneurysms were treated either by surgery (n = 102) or by endovascular coiling (n = 293). Coiling was chosen each time the shape of the aneurysm seemed to be appropriate for this treatment: narrow neck and ratio neck diameter by sac diameter less than one third. Satisfying results with complete or subtotal obliteration and no recanalization on the following controls at 1, 6, 12, and 36 months were obtained in 92% before retreatment and in 98.8% after retreatment. Unsatisfying results were observed after surgery in seven cases and in 25 cases after embolization. After retreatment, it remains three post-surgical and two post-endovascular cases. Good and excellent clinical outcome was noted in 90% for small aneurysms and in 86.5% for large ones. Mortality is of 4.8% in the overall series. In a series in which were applied both types of treatment, surgery in 25% and endovascular techniques in 75%, good results in terms of efficiency and clinical results were achieved. These results are as good as the best series in which surgery was the only choice. Therefore with appropriate selection, endovascular treatment is a good alternative for treatment of the majority of saccular aneurysms.

Adult↗
PubMed1998

[Interruption of the lateral sinus in surgery of paraganglioma and acoustic neurinoma. Apropos of 2 complications].

The sigmoid sinus, one of the main structures of the venous cerebral circulation, may be interrupted by various pathological or surgical processes. Usually, interrupted circulation is compensated by collateral or contralateral venous circulation. No neurological deficit is observed. We report two neurological complications: cerebellar infarction and intracranial hypertension, secondary to lateral sinus interruption during removal of a paraganglioma and an acoustic neuroma. Attention is drawn on the importance of preoperative evaluation of the venous cerebral circulation to prevent such complications.

Cerebral Angiography↗
PubMed1997

[Cerebromeningeal hemorrhages in Rendu-Osler disease. 2 cases treated by embolization].

BACKGROUND: Treatment for cerebral vascular malformations in patients with hereditary hemorrhagic telangiectasia, also called Osler-Weber Rendu disease, has been greatly improved with advances in interventional neuroradiology. CASE REPORTS: Two patients with Osler-Weber Rendu disease experienced intracranial hemorrhage. In the first case, the disease was diagnosed at the age of 60 years in a man with recurrent epistaxis and numerous angiomas on the face and trunk as well as in the buccal cavity. The first neurological signs appeared seven years later and brain MRI revealed a 2-3 cm temporo-occipital arteriovenous malformation. Six months later sudden onset headache following exertion led to a CT-scan which showed tetraventricular hemorrhage. The second case was a 63-year-old man referred to neurosurgery for cerebromeningeal hemorrhage. Clinical examination and history taking found several small skin angiomas and a family and personal history of epistaxis. CT-scan revealed a dural fistula in the posterior fossa. Good clinical outcome was obtained in both cases by endovascular embolisation. DISCUSSION: Intracranial hemorrhage is observed in 2 to 3% of patients with Osler-Weber Rendu disease. Telangiectasia is not a pathognomonic sign and non-specific vascular malformations may be observed, particularly arteriovenous malformations or arterial aneurysms. Most can be reached by endovascular catheterism. Most of these usually unique malformations can be successfully treated by first-line embolisation.

Cerebral Hemorrhage↗
PubMed1997

Meningioma of the foramen magnum: a series of 40 cases.

BACKGROUND: Surgical treatment of foramen magnum meningiomas (FM meningiomas) has been improved by the recently developed posterolateral and anterolateral approaches. The choice of these approaches and the extent of bone resection, however, need to be defined according to the tumor location. METHODS: Over a short period (1980-1993), 40 cases of FM meningiomas were treated either by the posterolateral (N = 31), the anterolateral (N = 5), or the midline posterior approaches (N = 4). The choice of surgical technique (surgical approach, extent of bone drilling, and dural opening) was made according to the tumor location, which is defined by three parameters: the horizontal plane (anterior N = 18, lateral N = 21, and posterior N = 1); the vertebral artery (above N = 4, below N = 20, and on both sides N = 16); the dura mater (intradural N = 24, extradural N = 2, and intraextradural N = 4). RESULTS: Intradural anterior and lateral FM meningiomas were operated by the posterolateral approach. The bone drilling was limited either to the occipital condyle or to the lateral mass of the atlas, depending on whether the tumor location is above or below the vertebral artery, respectively. Intradural posterior meningiomas were treated by the midline posterior approach. FM meningiomas with an extradural component were resected by the anterolateral approach alone or combined with a midline posterior approach. The rate of complete resection was 94% for intradural FM meningiomas and 50% for the extradural ones. FM meningiomas with an extradural component generally have aggressive features invading the adjacent bone and soft tissues; this explains the difficulty of performing a complete resection. The clinical condition improved in 90%, worsened in 7.5%, and did not change in 2.5%. The worsened group consisted of three deaths (one case of air embolism, one case of pulmonary embolism, and one case with preoperative coma and tetraplegia). Similar results were obtained in both anterior and lateral locations. CONCLUSION: FM meningiomas can be completely and safely removed in most cases, using an appropriate surgical technique. The technique must be chosen after precise and correct analysis of the tumor location. The lateral approaches are very effective in the treatment of lateral and anterior FM meningiomas.

Adolescent↗
PubMed1997

Cervical neuromas with extradural components: surgical management in a series of 57 patients.

OBJECTIVE: Cervical neuromas with extradural components (intraextradural or strictly extradural forms) are rare. Their resection raises the problems of nerve root preservation, vertebral artery (VA) control, and spinal stability. METHODS: A series of 57 patients with neuromas (29 neurofibromas, 23 schwannomas, 4 neurofibrosarcomas, and 1 plexiform neurofibroma) was treated during the period of 1980 to 1995, using one of the lateral approaches (antero- or posterolateral approach). The VA was always controlled before resection of the tumor. In cases of intraextradural forms, the intradural component was removed by a complementary laminectomy (three patients) in the early period and then by an oblique corpectomy through the same lateral approach (five patients) in the late period. A laminectomy had been performed in 15 other patients (11 patients with intraextradural neuromas) before they were referred to us. These patients included seven with recurrent neuromas, occurring after an average period of 4.1 years (1-9 yr). RESULTS: Complete resection was achieved in all except two patients, in whom the nerve root reacted positively to intraoperative stimulation and could not be separated from the tumor. One of the patients was subsequently operated on after 2 years. Another recurrence was observed in another patient at 1 year. The four patients with sarcomas died from recurrence within 2 years. The rate of root preservation included an average of 28%, including 43.5% for schwannomas, 18% for neurofibromas, 44% for lower cervical neuromas (C4-C8), and 4.5% for upper cervical neuromas (C1-C3). Worsening of preoperative neurological deficits was observed in only two patients. The VA was always preserved, except in one patient with a sarcoma that was preoperatively occluded. No instability was observed in any of the patients. CONCLUSION: Complete resection with good neurological results can be achieved in most patients harboring cervical neuromas each with an extradural component by using a lateral approach and VA control. If the root cannot be separated from the tumor, especially in patients with neurofibromas, intraoperative stimulation can help decide whether the root may be divided without incurring postoperative deficit. The lateral approach permits the resection of the extradural as well as the intradural component by a complementary oblique corpectomy. There was no morbidity in relation to VA control as well as no postoperative instability.

Adult↗
PubMed1997

[Malignant tumors of the ethmoid sinuses. A homogeneous series of 41 cases operated on by mixed approaches].

A series of 41 malignant tumors including 31 adenocarcinomas invading the ethmoid sinuses were treated by a combined transcranial-transfacial approach. Management, by the same team, of these consecutive cases permitted to analyze the technical problems and the carcinologic results. Chemotherapy was given to 21 patients pre-operative followed by surgical resection by a combined transbasal and paralateronasal routes and then, by a post-operative radiotherapy. Post-operative complications were more frequent (52%) in case of reconstruction of the anterior skull base and especially with madroporic corals. In the other cases where the double dural closure was only packed with abdominal subcutaneous fat, the rate of post-operative problems was only 20%. Noticeably, infection at the cranial base was observed in 6 cases (4 cases needing a reoperation) with bone reconstruction and in none without reconstruction. Actuarial survival rate was 84% at 1 year, 53% at 3 years and 36% at 5 years whatever the pathology (whole series or subgroup of adenocarcinomas). Mortality is related to incidental problems (3 cases), another malignant primary disease (3 cases), metastasis (8 cases) and local recurrence (4 cases). A longer survival was observed in the group of patients without skull base invasion (survival rate 100%, 83%, 50% at 1, 3 and 5 years respectively).

Combined Modality Therapy↗
PubMed1996

[Therapeutic management of craniocervical chordoma].

Chordomas are rare neoplasms of notochordal origin that arise along the vertebral axis. In the cervicofacial area, they show a marked proclivity for the sphenooccipital region. These slow-growing and infiltrating tumors are often discovered because of neglected symptoms related to the ENT field such as nasal obstruction, snoring, dyspnea or dysphagia in the case of anterior development, serous otitis media, cervical pain, or even palsy of the X, XI, or XII cranial nerves when the tumor develops toward the foramen jugulare or the foramen magnum. Prognosis is usually poor because of local malignancy, proximity to critical central nervous system structures, and volume of the tumor. Surgery is the preferred treatment for these extradural tumors, but most authors recommend postoperative irradiation because of surgical spillage or residual tumor. However, conventional irradiation is limited by the sensitivity of surrounding structures, which results in a poor rate of local control. We present 9 cases of histologically proven diagnosis of chordoma treated from 1984 to 1994 at our institution. Prognosis and therapeutic modalities are discussed. Therapeutic improvement might be brought the protontherapie, which ensures a better local control, and therefore may transform the prognosis of the disease.

Adolescent↗
PubMed1995

The juxtacondylar approach to the jugular foramen (without petrous bone drilling).

BACKGROUND: Surgical access to the jugular foramen is generally realized through the infratemporal approach, requires petrous bone drilling with facial nerve exposure and sometimes transposition. This is a rather complex and time-consuming technique that exposes the patient to complications such as deafness and facial nerve palsy. METHODS: The juxtacondylar approach we propose in this paper needs only a partial mastoidectomy and exposure of the distal cervical segment of the vertebral artery (above C2). The transverse process of the atlas is completely removed so as to permit progress upward along the lateral mass of the atlas and the occipital condyle. The vertebral artery rarely has to be transposed. RESULTS: The main indication for the juxtacondylar approach is neurinoma and meningioma of the jugular foramen. For tumors like paraganglioma extending into the petrous bone, the juxtacondylar approach can be combined with an infratemporal approach. The juxtacondylar approach has been used in seven cases including three neurinomas, three paragangliomas and one meningioma. Exposure was quite satisfactory on both intra- and extradural parts in all cases. CONCLUSIONS: The juxtacondylar approach is a different way to expose the jugular foramen region. Compared to the standard infratemporal approach, it is a complementary rather than an alternative technique; the exposure is rather on the posteroinferior side for the juxtacondylar approach and on the anterosuperior side for the infratemporal approach.

Adult↗
PubMed1995

Radiation therapy with or without surgery in the management of low-grade brain astrocytomas. A retrospective study of 120 patients.

From 1977 to 1988, 120 consecutive patients with a diagnosis of low-grade astrocytoma were referred to our department for radiotherapy. Fourty-one patients (group 1) underwent surgery and post operative external radiation therapy (2 gross total resections and 39 subtotal resections). Sixty-nine patients underwent exclusive external radiotherapy (group 2). In ten patients, the irradiation was delivered by stereotactic implantation of iridium-192 wires into the tumor with or without external irradiation (group 3). Ten had pilocytic astrocytomas (mean age, 24 years) and twenty had microcystic astrocytomas (mean age, 35.4 years). The 5- and 10-year survival rates were 55.6% and 44.4%, respectively and 55% and 48%. Ninety astrocytomas were classified as "ordinary" astrocytoma (mean age, 36.8 years). The 5- and 10-year overall survival rates were 51% and 20.5%, respectively. The same probabilities at 5 and 10 years were 65% and 37% respectively, for group 1, 38.8% and 12.7% for group 2 and, 78.8 and 22.5% for group 3. In multivariate analysis, two prognostic factors had a significant impact on overall survival: IK score (IK < 90 vs IK > or = 90, p = 0.0001), surgical resection (surgical resection and post operative radiotherapy vs radiation therapy alone, p = 0.012). However, the patients who underwent surgical resection were those in the best condition, having tumors that were easily accessible and less invasive.

Adolescent↗
PubMed1995

Anterolateral and posterolateral approaches to the foramen magnum: technical description and experience from 97 cases.

Over a 12-year period (1981-1993), 97 lesions located in the foramen magnum area were treated using either the posterolateral or the anterolateral approach. The former is a lateral extent of the midline posterior approach; the latter is the technique of exposure of the cervical vertebral artery applied at the C-1 to C-2 level. The choice between the two types of lateral approaches was made following three modes of localization: anteroposterior attachment, relation to the dura, and relation to the vertebral artery. Both techniques are described in detail, with special attention paid to the bone and dural openings, which vary according to the localization.The treated lesions include 91 tumors, 4 craniocervical junction malformations, 1 synovial cyst, and 1 abcess. A complete resection was realized in 95% of the tumoral cases, with a very limited morbidity and mortality (3%).

Journal Article↗
PubMed1995

Neurinomas of the first two cervical nerve roots: a series of 42 cases.

A group of 42 patients with C-1 and C-2 neurinomas treated during the 10-year period 1982 to 1992 has been collected, including 25 cases from 20 French neurosurgical departments and 17 personal cases from the Neurosurgical Department of the Lariboisière University Hospital, Paris. Analysis of this series reveals some interesting findings relating to multiplicity of tumors, extradural extension, and neurofibromatosis. There were seven patients with multiple lesions (bilateral C-2 neurinomas in six cases and two neurinomas at C-2 and one at C-1 in one case). In the 35 other cases, 16 lesions were entirely extradural and 19 had an hourglass configuration. Thirteen patients presented signs of neurofibromatosis. One lesion had a melanotic form and another was a radiation-induced schwannoma. Surgical results were excellent in most cases with no immediate postoperative death. Best results in terms of complete removal and neurological condition were achieved with posterolateral or anterolateral surgical approaches (17 cases) as compared with the standard midline posterior route (25 cases).

Adolescent↗
PubMed1994

Superolateral approach to orbital tumors.

The conventional lateral approach to the orbit (Krönlein) does not allow a satisfactory view of the superior part of the orbit and the operative field is rather narrow. Therefore, large tumors which have developed not only laterally but also superiorly are usually approached transcranially. The craniotomy and exposure of the dura may be avoided when the tumor does not extend too far posteriorly and medially, by turning a larger orbital bone flap than the Krönlein's one. This technique was described by Nakamura as "type I orbitotomy" and can be referred to as a superolateral approach. After a bicoronal skin incision, a free orbital bone flap is cut. It includes the lateral orbital rim, a large external part of the superior orbital rim, and the lateral orbital wall. From 1985 to 1990 this approach was performed on 23 patients presenting with lacrimal gland tumors in 14 cases (11 pleomorphic adenomas, 2 adenoid cystic carcinomas, 1 adenocarcinoma), schwannomas in 2 cases, dermoid cyst in 1 case, hydatic cyst in 1 case, cavernous hemangiomas in 2 cases, inflammatory pseudotumor in 1 case, and mucoceles in 2 cases. This superolateral approach provides a wider exposure to the superolateral orbit than the classical Krönlein's approach and avoids the drawbacks of a craniotomy. A direct incision through the eyebrow can be used for bald people or for patients in poor condition.

Follow-Up Studies↗
PubMed1994

Oblique transcorporeal drilling to treat anterior compression of the spinal cord at the cervical level.

Oblique transcorporeal drilling is a new surgical technique in which the transverse foramina with the vertebral artery and lateral aspects of the bodies of the cervical vertebrae are exposed; it allows to drill out obliquely from the antero-lateral to the opposite postero-lateral corner, half of one or several cervical vertebral bodies. The technique is shortly described and its indications are discussed. It can mainly be applied to release osteophytic compression and to remove anteriorly developed tumors. The advantages are to work in a wide field with all important structures kept medially and protected and to keep a sufficient portion of the vertebral bodies to preserve the spine stability. This technique has been used in 39 cases with spondylosis in 27 cases, tumor in 11 cases and kyphosis in 2 cases including one with neurofibroma. Results in term of decompression were excellent in all cases. Mortality was none and morbidity was limited to a transient Horner's syndrome in almost all cases and to a CSF leak in three cases. This technique is therefore alternative to the anterior transcorporeal approach. In our experience, the oblique transcorporeal drilling provides a wider and safer access to lesions located anterior to the spinal cord.

Adult↗
PubMed1994

Glycoprotein hormone alpha-subunit secretion in prolactinomas and in non-functioning adenomas: relation with the tumour size.

OBJECTIVE: Free glycoprotein hormone alpha-subunit plasma levels have been reported to be increased in glycoprotein hormone-secreting adenomas and in acromegaly, but rarely in prolactinomas and in only two cases of Cushing's disease. The prevalence of elevated plasma alpha-subunit levels in patients with non-functioning adenomas is still unclear. In addition, no previous work has described plasma alpha-subunit levels in a comprehensive series of adenomas characterized by in-vivo secretion and/or immunocytochemistry. PATIENTS: Thirty-seven patients with definite prolactinomas and 48 with non-functioning tumours characterized by immunocytochemistry were studied, from a series of 145 consecutive patients including 33 acromegalics, 18 patients with glycoprotein hormone-secreting adenomas and 9 with Cushing's disease. MEASUREMENTS: Plasma free alpha-subunit was measured by radioimmunoassay in all patients and in a large sample of normal subjects to establish normal ranges according to sex, age and menstrual status. Tumour volume index was the product in cm3 of length, width and height of the adenoma as assessed by computerized tomography or magnetic resonance imaging. RESULTS: Twelve of the 37 (32%) patients with prolactinomas had increased plasma alpha-subunit levels; their tumours were significantly larger with significantly higher plasma PRL levels than those of patients without increased plasma alpha-subunit levels (P < 0.02). All prolactinomas above 50 cm3 were associated with alpha-subunit secretion, whereas only 6 of 29 smaller tumours were similarly associated. Twelve of the 48 'non-functioning' adenomas actually secreted alpha-subunit in vivo: 8 gonadotrophin-secreting, 2 'pure' alpha-secreting, one with negative immunocytochemistry and one necrotic adenoma. Their volumes were significantly higher than those of adenomas without increased plasma alpha-subunit levels (P < 0.04). Plasma alpha-subunit levels were increased in the 6 patients with TSH-secreting adenomas, 8 of 12 with FSH-secreting adenomas, 11 of 33 acromegalics and none of those with Cushing's disease. CONCLUSION: Plasma free alpha-subunit levels were increased in 49 of 145 patients (34%). For prolactinomas and 'non-functioning' adenomas, alpha-subunit hypersecretion was seen more often with larger tumours. Half of the cases with increased free alpha-subunit in this series were patients harbouring an adenoma which did not stain for an intact glycoprotein hormone.

Adenoma↗