Junction between the great cerebral vein and the straight sinus: an anatomical, immunohistochemical, and ultrastructural study on 25 human brain cadaveric dissections.

The cerebral venous system is poorly understood, and best appreciated under macroscopic anatomical considerations. We present an anatomical and immunohistochemical studies to better define the morphological characteristics of the junction between the great cerebral vein and the straight sinus. Twenty-five cadaveric specimens from the anatomy laboratory of the University Victor Segalen of Bordeaux were studied. The observation of the venous junctions with the straight sinus was performed under an operating microscope. The smooth muscular actin immunohistochemical staining was performed for 18 veno-sinosal junctions. Five venous junctions were observed using an electron microscope. We observed 3 different anatomic aspects: type 1 was a junction with a small elevation in its floor and a posterior thickening (14 cases); type 2 was a junction with an outgrowth on the floor like a cornice (7 cases); and type 3 was a junction presenting a nodule. Microscopic study of type 1 and 2 junctions showed a positive coloration to orceine attesting the presence of elastic fibers. Immunohistochemistry revealed the presence of smooth muscular actin and S 100 protein attesting the presence of smooth muscular fibers and nervous fibers. We observed in the ultrastructural study, a morphological progression of the endothelium. The venous orifice of the great cerebral vein into the straight sinus could be anatomically assimilated as a true "sphincter." Its function in the regulation of the cerebral blood flow needs further exploration.

[Surgical management of synovial cyst of the lumbar spine: retrospective study of 52 patients]. / Prise en charge chirurgicale des kystes synoviaux lombaires: étude rétrospective concernant 52 patients.

PURPOSE OF THE STUDY: Lumbar synovial cysts are an uncommon cause of radiculopathy, low back pain and neurogenic claudication. We report a retrospective analysis of the clinical presentation, radiological studies, operative findings and outcome in 52 patients surgically treated for symptomatic lumbar synovial cysts. MATERIAL AND METHODS: Retrospective data from 52 consecutive patients treated from January 1996 to February 2006 were analyzed. We studied the clinical symptoms, diagnostic methods and radiological findings in all patients, reviewed the types of conservative therapy applied, the surgical findings and techniques, as well as the immediate and long-term results. Surgical outcomes were evaluated according to the Friedberg scale. RESULTS: There were 35 women and 17 men with an average age of 63.2 years (range 36-84 years). The most common symptoms were radiculopathy (65,4%) and neurogenic multiroot claudication (34,6%). Forty-seven patients had back pain and 22 paresthesia. Preoperative neurological examination demonstrated motor weakness (5.7%), sensory loss (7.6%). The radiological work-up consisted in CT-scan and/or MRI for all patients. The correct preoperative diagnosis was established in 44 patients. A total of 56 cysts were found. Five patients had bilateral cysts. The L4-L5 level was affected in 66%. Total resection of the synovial cyst was possible for 46 patients. No fusion was performed as a first line procedure. However, subsequent fusion was necessary in one patient who developed delayed symptomatic spondylolisthesis. Mean follow up period was 14 months ranging from six to 24 months. Three recurrences occurred during the follow-up period. Functional outcome was excellent in 61.6%, good in 34.6% and poor in 3.8%. CONCLUSION: Surgery should be proposed when synovial cysts fail to respond to conservative therapy. Recurrence and surgical complication rates are low. The usefulness of systematic fusion procedure is questionable.

[Value of relative cerebral blood volume measurement using perfusion MRI in glioma management]. / Intérêt de la mesure du volume sanguin régional cérébral relatif par IRM de perfusion dans la prise en charge des gliomes.

INTRODUCTION: Neoangiogenesis is a critical feature that can differentiate high-grade from low-grade glioma. Conventional MR imaging does not assess this histological feature accurately. The goal of this study was to evaluate the gain in relative cerebral blood volume measurement using perfusion MRI in the management of cerebral gliomas. MATERIALS AND METHODS: Between 1998 and 2001, 32 histologically proven glial tumors were assessed by perfusion MRI using echoplanar imaging (EPI) and gradient-echo techniques. Relative cerebral blood volume (rCBV) was measured in all patients and compared to histological data. RESULTS: rCBV values were significantly correlated to histological grading in all 32 patients (P<0.001). Mean rCBV values were 8.74 (+/-3.79) for glioblastomas, 7.37 (+/-2.83) for anaplastic gliomas and 0.84 (+/-0.61) for low-grade gliomas. Mean rCBV values were significantly different between low- and high-grade gliomas, making it possible to determine a threshold (2.5-3) that can separate these two types of lesion. In determining the histological grading, rCBV was shown to be significantly more accurate than conventional MRI (P<0.005). CONCLUSION: Perfusion MRI using the EPI technique reliably assesses tumoral neoangiogenesis in gliomas preoperatively. The specificity and sensitivity of this technique make this radiological modality a valuable tool in the assessment of cerebral gliomas.

[Spinal cord compression by arachnoid cysts]. / Compression médullaire par kystes arachnoïdiens.

Spinal arachnoid cysts are considered to be rare entities, intradural locations are even less common. We report two cases of patients (two women aged 77- and 21-year-old) who presented spinal cord compression by intradural arachnoid cysts. For the second patient, repeated surgical procedures were necessary to improve the neurological status. After presenting the case reports, we expose the pathophysiological mechanisms and clinical features, and the surgical difficulties of treating this rare cause of spinal cord compression.

[Functional MR imaging and oligodendrogliomas]. / IRM fonctionnelle et oligodendrogliomes.

The localization of functional areas obtained from functional MRI (fMRI) is useful for patients suffering from tumors contiguous to eloquent brain areas. fRMI is an efficient tool in the strategy of treatment of low grade oligodendroglioamas in the rolandic area in intact or slightly impaired patients. It can be used preoperatively to assess motor functional areas. Indeed there is a good correlation for motor cortex lesions when using comparison between fMRI and intraoperative findings. Direct integration of fMRI data into neuronavigation enables to better visualize and preserve eloquent brain areas. One must be aware of fMRI limits. It is still often used with the control of direct cortical stimulations.

Multimodal anatomic, functional, and metabolic brain imaging for tumor resection.

OBJECTIVE: Improvement of neurosurgical techniques with a more detailed description of brain tumors and their functional environment. METHODS: We performed: (1) anatomical magnetic resonance imaging (MRI) for reference, (2) functional sequences dedicated to the adjacent cortical structures (sensorimotor, visual, language paradigms), and (3) thallium 201 cerebral tomoscintigraphy to visualize active tumor invasion. Data were transferred to a workstation for automatic registration. RESULTS: All data were combined into one synthetic image showing the foci of high proliferative activity, which have to be completely resected, and the peritumoral functional structures, which have to be spared in order to minimize postoperative sequelae. This trimodal image is entered into a surgical neuronavigation computer for preoperative planning in order to outline tumoral target and functional risk areas. All this information is displayed in the operative microscope (Zeiss MKM) optically linked to MR images. This multimodality technique diminishes operative time by reducing electrocorticography and improves the operative short-term outcome. CONCLUSION: Multimodal imaging is useful for optimization of neurosurgical tumor resection.

[Clinical application of functional MRI: a strategic tool for neurosurgery]. / Application clinique de l'IRM fonctionnelle: aide à la stratégie neurochirurgicale.

The purpose was to incorporate preoperative functional imaging data into anatomic data of operative microscope for neurosurgical procedures of patients suffering from lesions contiguous to eloquent brain areas. The day before surgery, patients bearing scalp markers underwent fMRI, just before anatomical contrast-enhanced MR images. FMRI data analysis were realised using a t test (p<0.0001). The resulting functional-anatomical images were downloaded onto a surgical neuronavigation computer in order to outline tumoral target and functional areas. At surgery, cortical stimulation has been used to confirm functional data. Functional image-guided surgery of lesions abutting functional cortex can be safely performed.

[Contribution of perfusion magnetic resonance imaging in a patient with cerebral ganglioglioma]. / Intérêt de l'imagerie par résonance magnétique de perfusion. A propos d'un cas de gangliogliome cérébral.

A 48-year-old woman was admitted to the Neurosurgery Department for a large frontal lobe tumor revealed by partial seizures. The patient was conscious and alert. Neurological examination was normal. MRI study showed a right frontal lobe tumor compounded of an anterior solid mass strongly enhanced after gadolinium injection and a posterior voluminous cyst with important mass effect. The cerebral blood volume (CBV) map showed no area of elevated CBV within the tumor consistent with a low-grade tumor. The patient was operated on with a presumed diagnosis of anaplastic oligodendroglioma. Postoperative course was uneventful. Histopathological examination was consistent with a benign ganglioglioma. The patient did not undergo an additional treatment. One year later, the patient was healthy and neurological and neuropsychological examination were normal. MRI study did not show any recurrence. This case emphazises the relevance of perfusion MR imaging in the preoperative workup of glioneuronal and glial tumors.

[Neuronavigation in third ventricle tumors]. / Tumeurs du troisième ventricule et neuronavigation.

The authors present the results of neuronavigation as a help to open neurosurgery for the tumors of the third ventricle. From January, 1995 to August, 1999, six image-guided surgical procedures were performed to remove third ventricle lesions : 4 colloïd cysts, 1 ependymoma, and 1 craniopharyngioma. The operative approach was transcortical in 5 cases, and transcallosal in 1 case. The use of neuronavigation allows a decrease of the surgical trauma during the surgical approach. The procedure secures the neurosurgeon in the choice and execution of his pathway to the target. It becomes however less accurate after opening the ventricle, because of the brainshift induced by the loss of cerebrospinal fluid becomes important. Nevertheless, neuronavigation is useful in the surgery of the third ventricle, especially if it is used with neuroendoscopy.

[Polytraumatized burnt patients]. / Le brûlé polyagressé.

In peace time, burn injury combined with traumatic, chemical or radioactive casualties, is rarely encountered and often unrecognised; during disasters, burn injury is unlikely the only trauma. The authors try to bring out the great physiopathologic, diagnostic and therapeutic principles of changes due to combined lesions on burn injury and vice-versa.

[Multiple trauma and burns]. / Le brûlé polyagressé.

In peace time, burn injury combined with traumatic, chemical or radioactive casualties is rarely encountered and often unrecognized; during disasters, burn injury is unlikely the only trauma. The authors try to bring out the main pathophysiological, diagnostic and therapeutic characteristics of changes induced by combined lesions on burn injury and vice-versa.

Surgical treatment of large vestibular schwannomas (stages III and IV).

OBJECTIVE: Study the results of surgical treatment of large vestibular schwannomas. MATERIAL AND METHODS: Between January 1995 and December 2005, 87 stage III and IV unilateral vestibular schwannomas (Koos classification) were operated. RESULTS: The approach used was for the most part translabyrinthine. Nine patients were operated in two phases. Tumor exeresis was total in 79% of the cases, nearly total in 17%, and subtotal in 3.6%. Good facial function was preserved in 63% of the patients. Mortality was zero. Tumor control after a mean follow-up of 45 months was 86%. CONCLUSIONS: Surgery for large vestibular schwannomas should have a 0% mortality rate and low morbidity. Otoneurosurgical collaboration, with a preference for the translabyrinthine approach, with surgery undertaken in several phases if need be, provides maximum safety and good functional results as well as an acceptable residual tumor rate.

[Advances in adults' gliomas biology, imaging and treatment]. / Actualités dans la biologie, l'imagerie et le traitement des gliomes de l'adulte.

A better understanding of gliomas biology is now leading to a combined histo-molecular classification of these tumors. In anaplastic gliomas ongoing studies depend on 1p/19q codeletion status and in glioblastomas on MGMT methylation status. Advanced brain tumor imaging elicits a better identification of gliomas evolutive potential of. In low-grade gliomas, the importance of maximal resection and the role of chemotherapy are being increasingly recognized. In anaplastic gliomas, phase III studies have clarified the respective roles of chemotherapy and radiotherapy. In glioblastomas concomitant chemoradiotherapy is the standard. Most targeted therapies, namely anti-EGFR therapies have failed to demonstrate efficacy but anti-angiogenics are promising. The aim of this review is to discuss the main advances in adults' gliomas biology, imaging and treatment.

[Recurrent giant cystic vestibular schwannomas: role of cystoperitoneal shunt]. / Schwannomes vestibulaires kystiques géants: intérêt du drainage kystopéritonéal.

INTRODUCTION: Surgical removal of giant cystic vestibular schwannomas is difficult because of adherences between the cyst membrane, brainstem, and the VII-VIII nerve complex. The recurrence of the cyst is frequent and requires reoperation. The aim of this study was to analyze the role of the palliative cystoperitoneal shunt in giant cystic vestibular schwannomas. MATERIALS AND METHODS: Eighty-eight patients with a diagnosis of stage III or IV vestibular schwannoma were managed surgically from January 2000 to December 2005 in our department. Six schwannomas were deemed to be cystic according to the following criteria: a voluminous cystic component with mass effect causing symptoms as well as radiological and intraoperative identification of cystic elements. RESULTS: Complete tumor removal was achieved in two patients. After a follow-up of 5 and 7 years, these patients were asymptomatic. In four cases, we performed cyst drainage. For three patients, we implanted a permanent cystoperitoneal shunt. These patients were asymptomatic with a mean follow-up of 19.7 months. CONCLUSIONS: The cystoperitoneal shunt with no valve is a valid palliative surgical solution to remove brain stem compression. Neuronavigation allows proper positioning of the drain and secures the procedure.

[Extradural spinal meningioma: case report]. / Méningiome rachidien extradural. A propos d'un cas et revue de la littérature.

OBJECTIVES: We report a case of purely extradural spinal meningioma and discuss the potential pitfalls in differential diagnosis. BACKGROUND: Spinal meningiomas account for 20-30% of all spinal neoplasms. Epidural meningiomas are infrequent intraspinal tumors that can be easily confused with malignant neoplasms or spinal schwannomas. CASE: A 62-year-old man with a previous history of malignant disease presented with back pain and weakness of the lower limbs. Magnetic resonance imaging revealed a well-enhanced T4 intraspinal lesion. The intraoperative histological examination showed a meningioma (confirmed by postoperative examination). Opening the dura mater confirmed the purely epidural location of the lesion. The postoperative course was uneventful with no recurrence 12 months after surgery. CONCLUSION: Purely extradural spinal meningiomas can mimic metastatic tumors or schwannomas. Intraoperative histology is mandatory for optimal surgical decision making.