Jean Guerin

Vestibular Schwannoma Surgery Outcomes: Our Multidisciplinary Experience in 400 Cases Over 17 Years

Objectives/Hypothesis The aim of the study was to evaluate the incidence of short‐ and intermediate‐term postoperative complications after vestibular schwannoma surgery.

Comparative evaluation of conventional and dynamic magnetic resonance imaging of the pituitary gland for the diagnosis of Cushing's disease.

The ability of MRI to detect pituitary ACTH‐secreting adenomas in patients with Cushings disease is limited. Owing to different dynamics of contrast enhancement between adenomas and normal pituitary tissue, it has been suggested that obtaining images within seconds after gadolinium (Gad) injection using dynamic procedures increases the sensitivity of MRI in the detection of pituitary microadenomas. The objective of this study was to compare the ability of conventional magnetic resonance imaging (CMRI) and dynamic MRI (DMRI) to detect ACTH‐secreting pituitary adenomas.

Fractionated radiation therapy in the treatment of intracranial meningiomas: Local control, functional efficacy, and tolerance in 91 patients☆

PURPOSE To evaluate efficacy and tolerance of external fractionated radiation therapy (RT) in the treatment of intracranial meningiomas. METHODS AND MATERIALS From January 1981 to September 1993, 91 patients with intracranial meningiomas were treated with fractionated RT. Indications were as follows: (a) incomplete surgical resection, 29 patients; (b) tumor recurrences without considering the amount of the second resection, if performed, 14 patients; (c) completely excised angioblastic, aggressive benign, and anaplastic tumors, 8 patients; (d) medically inoperable and basilar tumors where operation would involve considerable danger or permanent neurological damage, 44 patients. Most patients were irradiated with 6 to 9 MV photon beams. A three- to four-field technique with coned-down portals was used. Doses were calculated on the 95% isodose and were given 5 days a week for a median total dose of 52 Gy (1.80 Gy/fraction). RESULTS Median follow-up from radiation therapy was 40 months. Acute tolerance was excellent, but there were six late delayed injuries. Tumor recurrences occurred in six cases. Six patients died from their tumor or RT complications, 19 from nontumoral reasons. Three, 5- and 10-year survival rates were 82, 71, and 40%, respectively. The most significant prognostic factor was age: 5-year survival rate was 86% for patients less than 65 years and 37% for patients more than 65. However, there were no differences in recurrence-free survival rates between patients younger than 65 and the oldest ones. Of 60 symptomatic patients with neurological deficits, 43 had neurological improvement (72%), beginning in some cases within 15 to 20 days after starting RT. CONCLUSION These results reassess the role of fractionated RT in the treatment of meningiomas, and stress on its efficacy, especially on cranial nerves palsies, without severe toxicity in most cases.

Use of ketoconazole in the treatment of Cushing's disease and ectopic ACTH syndrome.

Ketoconazole, an imidazole derivative which Inhibits adrenal steroidogenesis, has been used with success for the metabolic control of Cushings disease. Few data are available about the use of ketoconazole in the management of the ectopic ACTH syndrome. We have used ketoconazole in eight patients: four patients with Cushings disease, two patients with overt and two with occult ectopic ACTH syndrome. Among patients with Cushings disease, reversible hypoadrenalism occurred once. All had full clinical and biochemical regression of the disease for more than 6 months with 400–1200 mg ketoconazole per day. Patients with ectopic ACTH syndrome received 1200 mg ketoconazole per day for at least 2 months. Partial biochemical regression was observed in two and a secondary escape to adrenal blockade in two others. These findings further indicate that ketoconazole is a valuable tool for the metabolic control of Cushings disease. On the contrary, in ectopic ACTH syndrome, this aim can be impossible to reach with ketoconazole although the reasons for its ineffectiveness remain to be determined.

Experimental Evaluation of a Collagen-coated Vicryl Mesh as a Dural Substitute

Dural substitutes must provide immediate restitution of a membranous covering for the brain without inducing any adverse reaction in the host or provoking adhesions to underlying nervous tissues. Ideally, the material should disappear completely and be replaced by tissues similar to the dura mater. In this study, parietal dural defects were created in 12 beagle dogs and closed with a vicryl mesh prosthesis made watertight by a film of bovine collagen. Clinical and biological tolerances were satisfactory. There was one case of early local infection. Gross and microscopic examinations performed between 7 days and 9 months after implantation showed degradation of the prosthetic mesh and connective tissue growth into the implant mimicking dura mater as early as 15 days after implantation. There was no attendant inflammatory reaction or cortical adhesions or other adverse reactions. The authors conclude that collagen-embedded vicryl mesh provides satisfactory biological function and compatibility when used as a substitute for dura mater in the dog.

Cerebral arterial fenestrations associated with intracranial saccular aneurysms

Fenestrations of cerebral arteries other than the anterior communicating artery are rare congenital anomalies, which may be associated with saccular aneurysms. In such cases, the aneurysms may be located at the fenestration itself or may involve other intracranial vessels. This kind of association is not infrequently the cause of angiographic diagnostic problems, as well as surgical difficulties, and consequently needs to be well known to physicians. Four recent cases of rare fenestrations of cerebral arteries associated with intracranial aneurysms are reported in this study and discussed together with a review of the literature.

Fractionated radiation therapy in the treatment of stage iii and iv cerebello-pontine angle neurinomas: Preliminary results in 20 cases

From January 1986 to March 1989, 20 patients with stage III and IV cerebello-pontine angle neurinomas were treated with external fractionated radiation therapy; seven patients had phacomatosis. Indications for radiation therapy were as follows: (a) poor general condition or old age contraindicating surgery, 10 patients; (b) hearing preservation in bilateral neurinomas after contralateral tumor removal, 5 patients; (c) partial resection or high risk of recurrence after subsequent surgery for relapse, 4 patients; (d) non-surgical relapse, 1 patient. Most patients were irradiated with a 9 MV linear accelerator. A 3 to 4-field technique with 5 x 5 cm portals was used. Doses were calculated on a 95% isodose and were given 5 days a week for a mean total dose of 5140 cGy (180 cGy/fraction). Median follow-up from radiation therapy was 30 months (7 to 46); 4 patients died, 2 with progressive disease. Two patients underwent total tumor removal after radiation therapy (1 stable and 1 growing tumor). On the whole, 14 tumors remained stable, 3 decreased in size, and 3 progressed. CT scan or NMR tumor changes consistent with partial tumor necrosis appeared in four cases. Hearing preservation was obtained in 3/5 hearing patients with phacomatosis. When surgery is not indicated or incomplete, fractionated radiation therapy appears to be an effective and well-tolerated treatment for stage III and IV neurinomas. Hearing can be preserved.

Morphologic and histologic study of the ligamentum flavum in the thoraco-lumbar region

The ligamentum flavum, of which there are only a few studies in the literature, has several features discussed in this work. On the macroscopic level, it has a metameric arrangement it has two layers, superficial and deep, whose fibers are oppposite, and it has close relations with the tendons of attachment of some spinal erector muscles. On the microscopic level, its structure is unique for a ligament, because of a predominance of elastic fibers, because of its intrinsic innervation at each level of the spine, and because this innervation grows poorer with increasing degeneration. The ligamentum flavum constitutes an active ligament, with an essential biomechanical role. Its injury is probably not without consequences, and therefore there are many technical problems about the surgical interlaminar approach.

Effects of prolactin on intracellular calcium concentration and cell proliferation in human glioma cells

Prolactin (PRL) has several physiological effects on peripheral tissues and the brain. This hormone acts via its membrane receptor (PRL‐R) to induce cell differentiation or proliferation. Using reverse transcription–polymerase chain reaction (RT‐PCR) combined with Southern blot analysis, we detected PRL‐R transcripts in a human glioma cell line (U87‐MG) and in primary cultured human glioblastoma cells. These transcripts were deleted or not in their extracellular domains. We examined the effects of PRL on intracellular free Ca2+ concentration ([Ca2+]i) in these cells in order to improve our understanding of the PRL transduction mechanism, which is still poorly documented. [Ca2+]i was measured by microspectrofluorimetry using indo‐1 as the Ca2+ fluorescent probe. Spatiotemporal aspects of PRL‐induced Ca2+ signals were investigated using high‐speed fluo‐3 confocal imaging. We found that physiological concentrations (0.4–4 nM) of PRL‐stimulated Ca2+ entry and intracellular Ca2+ mobilization via a tyrosine kinase–dependent mechanism. The two types of Ca2+ responses observed were distinguishable by their kinetics: one showing a slow (type I) and the other a fast (type II) increase in [Ca2+]i. The amplitude of PRL‐induced Ca2+ increases may be sufficient to provoke several physiological responses, such as stimulating proliferation. Furthermore, PRL induced a dose‐dependent increase in [3H]thymidine incorporation levels and in cellular growth and survival, detected by the MTT method. These data indicate that PRL induced mitogenesis of human glioma cells. GLIA 38:200–214, 2002.

Radiothérapie fractionnée des méningiomes intracrâniens : 15 ans d'expérience au centre hospitalier universitaire de Bordeaux

PURPOSE: To evaluate the long-term results of external fractionated radiation therapy (RT) in the treatment of intracranial meningiomas. PATIENTS AND METHODS: From January 1981 to December 1996, 156 patients with intracranial meningiomas were treated with external fractionated RT. Median age was 57. Indications for radiation therapy were as follows: (1) completely excised histologically aggressive tumors (12 patients); (2) incomplete surgical resection (37 patients); (3) medically inoperable or basilar tumors where operation would involve considerable danger or permanent neurological damage (77 patients); and, (4) tumor recurrences (30 patients). Most patients were irradiated with 6 to 9 MV photon beams. A three to four-field technique with coned-down portals was used. Since 1993, 71 patients had a three dimensional dosimetry. Doses were calculated on the 95% or 98% isodoses, all fields were treated every day, five days a week, for a median total dose of 50 Gy (1.8 Gy/Fraction). RESULTS: Median follow-up from radiation therapy was 40 months. Acute tolerance was excellent; an early clinical improvement during radiation therapy was noted in 19 patients (17.8%). Clinical improvement or stabilization was observed in 130 patients (83.4%). Radiologically, local control was obtained in 124 cases (79.4%) and tumor recurrences occurred in 21 cases (ten progressions in the treated volume, five borderline, six new locations). Overall and cause specific-survival rates were 75% and 89% at five years, and 45 and 76% at 10 years, respectively. CONCLUSION: These results reassess the role of fractionated RT in the treatment of intracranial meningiomas. Long-term tolerance is excellent for a majority of patients. The study of recurrences confirms the importance of the definition of the target volume, and asks questions about total given doses.