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SCOPUS: ar.j, info:eu-repo/semantics/published

SCOPUS: ar.j, info:eu-repo/semantics/published

SCOPUS: ar.j, info:eu-repo/semantics/published

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OBJECT: The aim of this study was to compare the contribution of the tracers 11C-methionine (Met) and 18F-fluorodeoxy-glucose (FDG) in positron emission tomography (PET)-guided stereotactic brain biopsy. METHODS: Forty-five patients underwent combined Met-PET and FDG-PET studies associated with computerized tomography (CT)- or magnetic resonance (MR)-guided stereotactic biopsy. Each patient presented with a lesion that was in proximity to the cortical or subcortical gray matter. The Met-PET and FDG-PET scans were analyzed to determine which tracer offers the best information to guide at least one stereotactic biopsy trajectory. Histologically based diagnoses were rendered in all patients (39 tumors, six nontumorous lesions) and biopsies were performed in all tumors with the aid of PET guidance. When tumor FDG uptake was higher than that in the gray matter (18 tumors), FDG was used for target definition. When FDG uptake was absent or equivalent to that in the gray matter (21 tumors), Met was used for target definition. Parallel review of all histological and imaging data showed that all tumors had an area of abnormal Met uptake and 33 had abnormal FDG uptake. All six nontumorous lesions had no Met uptake and biopsies were performed using CT or MR guidance only. All tumor trajectories had an area of abnormal Met uptake; all nondiagnostic trajectories in tumors had no abnormal Met uptake. CONCLUSIONS: When FDG shows limitations in target selection, Met is a good alternative because of its high specificity in tumors. Moreover, in the context of a single-tracer procedure and regardless of FDG uptake, Met is a better choice for PET guidance in neurosurgical procedures., Comparative Study, Journal Article, SCOPUS: re.j, info:eu-repo/semantics/published

INTRODUCTION: Pleomorphic xanthoastrocytoma (PXA) is a rare brain glial tumour found in young patients. Most cases are reported as evolving low-grade neoplasms associated with a long survival after complete surgical resection. Some PXAs, however, can demonstrate secondary malignant transformation or progress with a short survival. Anaplastic histological features at first presentation or secondary meningeal dissemination have rarely been reported. CASE REPORT: We describe the case of a cerebral PXA in a 7-year-old girl presenting with anaplastic histological features and craniospinal meningeal dissemination that progressed rapidly with a poor outcome., Journal Article, SCOPUS: ar.j, info:eu-repo/semantics/published

We compared the contributions of the labeled tracers (11)C-methionine (Met) and (18)F-FDG for PET-guided stereotactic biopsy of brain gliomas. METHODS: In 32 patients with glioma, stereotactic Met PET and (18)F-FDG PET were integrated in the planning of stereotactic brain biopsy. PET images were analyzed to determine which tracer offered the best information for target definition. The stereotactic coregistration of PET images allowed accurate comparison of the level, distribution, and extent of uptake for both tracers according to tumor location and grade. RESULTS: A histologic diagnosis was obtained for all patients. All gliomas had an area of abnormal Met uptake, and 27 showed abnormal (18)F-FDG uptake. (18)F-FDG was used for target selection when its uptake was higher in tumor than in gray matter (14 gliomas). Seven were in the basal ganglia or brain stem. Met was used for target selection when there was no (18)F-FDG uptake or when (18)F-FDG uptake was equivalent to that in the gray matter (18 gliomas). Thirteen were in the cortex. Sixty-one of the 70 stereotactic trajectories obtained from the 32 patients were based on PET-defined targets and had an area of abnormal Met uptake. These 61 Met-positive trajectories always yielded a diagnosis of tumor. All nondiagnostic trajectories (n = 9) were obtained in areas with no increased uptake of Met. In all patients with increased uptake of both tracers, the focus of highest Met uptake corresponded to the focus of highest (18)F-FDG uptake. However, the extent of uptake of both tracers was variable. CONCLUSION: Distributions of highest Met and (18)F-FDG uptake are similar in brain gliomas. Because Met provides a more sensitive signal, it is the molecule of choice for single-tracer PET-guided neurosurgical procedures in gliomas., Clinical Trial, Comparative Study, Journal Article, Validation Studies, info:eu-repo/semantics/published

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Scientific paper oral 04-O-547 ASNR, info:eu-repo/semantics/nonPublished

SCOPUS: ar.j, info:eu-repo/semantics/published

Physical functioning is improved after liver transplantation but studies comparing liver transplant recipients with normal healthy people are lacking. How liver (and other organ) transplant recipients tolerate strenuous physical activities is unknown. There are no data on the tolerance of transplant patients at high altitude. Six liver transplant subjects were selected to participate in a trek up Mount Kilimanjaro 5895m, Tanzania. Physical performance and susceptibility to acute mountain sickness were prospectively compared with fifteen control subjects with similar profiles and matched for age and body mass index. The Borg-scale (a rating of perceived exertion) and cardiopulmonary parameters at rest were prospectively compared with six control subjects also matched for gender and VO2max. Immunosuppression in transplant subjects was based on tacrolimus. No difference was seen in physical performance, Borg-scales and acute mountain sickness scores between transplant and control subjects. Eight-three percent of transplant subjects and 84.6% of control subjects reached the summit (p = 0.7). Oxygen saturation decreased whereas arterial blood pressure and heart rate increased with altitude in both groups. The only difference was the development of arterial hypertension in transplant subjects at 3950 m (p = 0.036). Selected and well-prepared liver transplant recipients can perform strenuous physical activities and tolerate exposure to high altitude similar to normal healthy people., SCOPUS: ar.j, FLWIN, info:eu-repo/semantics/published

Because brain tumors can be histologically heterogeneous, stereotactic brain biopsies (SBB) may lead to inaccurate diagnosis or grading. Positron emission tomography (PET) has been used in pediatric neuro-oncology to help in the understanding and management of brain neoplasms. We combined PET and magnetic resonance (MR) imaging in the planning of SBB in 9 children (5 males and 4 females, aged 2-14 years) with infiltrative, ill-defined brain lesions. Tracers used for PET were (18)F-2-fluoro-2-deoxy-D-glucose in 4 cases, (11)C-methionine in 2 cases and both tracers in 3 cases. Biopsy targets were selected in hypermetabolic areas. PET-guided SBB provided accurate histological diagnosis in all patients and allowed a reduction of the number of trajectories in lesions located in functional areas. It also helped in better understanding and management of complex cases. This preliminary series suggests that combining PET and MR imaging in the planning of SBB in children (1) improves the diagnostic yield of SBB in infiltrative, ill-defined brain lesions, (2) makes it possible to reduce the sampling in high-risk/functional areas and (3) improves the quality of therapeutic management of pediatric brain tumors., Journal Article, Review, info:eu-repo/semantics/published

SCOPUS: ar.j, info:eu-repo/semantics/published

Opened on November 1st, 2001, the Department of Neurosurgery has progressively grown to become worldwide renown in a few years. All the pathologies are covered, from lumbar disc hernia to intracranial tumors and vascular malformations. But the originality stays into the exceptional environment by the concentration of logistic resources and the ability of clinician and researchers who daily collaborate with the neurosurgical team. The Department of Neurosurgery has a strong reputation in several fields like intraspinal cord tumors or Pet-guided Neurosurgery in stereotactic biopsies, neuronavigation and Gamma Knife and, generally speaking, in the original approach of the treatment and follow-up of brain tumors. Neurodegenerative diseases also benefit of modern approaches trough the Gamma Knife, deep brain stimulation or fetal cell grafting into the brain in Parkinson and soon in Huntington diseases. Last but not least, the arrival for the 25th anniversary of Erasme Hospital of an interventional MRI will allow to follow in real-time the resection of brain tumors with an obvious benefit for the surgical performances and the quality of life of the patients. It will also open a new window for neurosurgical research through combination with functional MRI and Pet-Scan, reinforcing the reputation of Erasme Neurosurgical Department who has been distinguished in 1997 by the World Health Organisation as "WHO Collaborating Center for Research and Training in Neurosurgery" and nominated again in 2002 for a new 4-year period, which is unique in the Neurosurgical World., English Abstract, Journal Article, Review, info:eu-repo/semantics/published

OBJECT: The authors review their experience with the clinical development and routine use of positron emission tomography (PET) during stereotactic procedures, including the use of PET-guided gamma knife radiosurgery (GKS). METHODS: Techniques have been developed for the routine use of stereotactic PET, and accumulated experience using PET-guided stereotactic procedures over the past 10 years includes more than 150 stereotactic biopsies, 43 neuronavigation procedures, and 34 cases treated with GKS. Positron emission tomography-guided GKS was performed in 24 patients with primary brain tumors (four pilocytic astrocytomas, five low-grade astrocytomas or oligodendrogliomas, seven anaplastic astrocytomas or ependymomas, five glioblastomas, and three neurocytomas), five patients with metastases (single or multiple lesions), and five patients with pituitary adenomas. CONCLUSIONS: Data obtained with PET scanning can be integrated with GKS treatment planning, enabling access to metabolic information with high spatial accuracy. Positron emission tomography data can be successfully combined with magnetic resonance imaging data to provide specific information for defining the target volume for the radiosurgical treatment in patients with recurrent brain tumors, such as glioma, metastasis, and pituitary adenoma. This approach is particularly useful for optimizing target selection for infiltrating or ill-defined brain lesions. The use of PET scanning contributed data in 31 cases (93%) and information that was specifically utilized to adapt the target volume in 25 cases (74%). It would seem that the integration of PET data into GKS treatment planning may represent an important step toward further developments in radiosurgery: this approach provides additional information that may open new perspectives for the optimization of the treatment of brain tumors., Journal Article, Research Support, Non-U.S. Gov't, Review, info:eu-repo/semantics/published

OBJECTIVE AND IMPORTANCE: Lhermitte-Duclos disease (LDD) represents a focally indolent dysplastic growth of the cerebellar cortex. The 106 cases reported previously in the literature show an extremely slow evolution, and the operative indications and techniques for this disease entity are still controversial. The authors present the first case of LDD studied with positron emission tomography using the labeled tracers [(18)F]2-fluoro-2-deoxy-d-glucose ([(18)F]FDG) and (11)C-labeled methionine ([(11)C]Met) to study the glucose and protein metabolism of the lesion. CLINICAL PRESENTATION: A 40-year-old woman suddenly became unconscious then completely recovered 5 minutes later. Magnetic resonance imaging of her brain showed a well-delineated 10 x 5-cm abnormal area with enlarged cerebellar folia, which led to the diagnosis of LDD. TECHNIQUE: On positron emission tomographic scans, [(18)F]FDG and [(11)C]Met uptake in the normal cerebral and cerebellar cortex appeared higher than normal, reaching levels found in patients with primary malignant brain tumors. Moreover, the uptake of both tracers was heterogeneous, in contrast to the homogeneous uptake visualized on magnetic resonance imaging scans. The areas of greatest [(11)C]Met and [(18)F]FDG uptake were discordant. Some areas of greater than normal [(18)F]FDG uptake corresponded to areas of moderate or low [(11)C]Met uptake. Because of the important mass effect in the posterior fossa, total surgical resection was performed. A histological examination confirmed the diagnosis of LDD. CONCLUSION: This first reported metabolic study of LDD supports the view that LDD is an active and evolving disease. These data should prompt reevaluation of the indications for surgery in patients with this disease as well as the timing of surgery., Case Reports, Journal Article, info:eu-repo/semantics/published

SCOPUS: ar.j, info:eu-repo/semantics/published

A 36 year old woman who ruptured a basilar artery aneurysm at 38 weeks gestation in her second pregnancy was managed successfully by endovascular embolisation 36 hours after an emergency Caesarean section. The timing of treatment along with the obstetric, neurosurgical and anaesthetic aspects of this complex problem are discussed along with a review of the current literature on the subject., Case Reports, Journal Article, info:eu-repo/semantics/published

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We report a cavernous haemangioma in the left cavernous sinus. This lesions very rarely occurs in this site and is difficult to diagnose correctly preoperatively. CT, angiography and MRI permit differentiation of the cavernous haemangioma from other tumours in this region and thereby contribute to a better surgical approach. The radiological features of cavernous haemangioma reported in the literature are summarised., Case Reports, Journal Article, Review, info:eu-repo/semantics/published

OBJECT: Twelve patients (seven female, and five male, mean age 55.6 years) suffering from refractory central (ischemic/traumatic [eight cases]) and neuropathic pain (trigeminal neuropathy [four cases]) underwent surgery for the implantation of an epidural motor cortex stimulation (MCS) device in which the authors used a frameless neuronavigation system, the Zeiss-MKM microscope. METHODS: The authors assessed the spatial accuracy of the neuronavigation system and its potential contribution to improve the quality of targeting pain. In these patients, the positions of the central sulcus, defined by stereotactic magnetic resonance MR imaging, intraoperative somatosensory evoked potentials (SSEPs) and subdural visual verification, were correlated into the stereotactic neuronavigation planning procedure. The mean spatial accuracy of distance between (MR) imaging-defined and actual central sulcus was 2.4 mm (range 5-10 mm). The intraoperative SSEPdefined central sulcus was close to that defined by MR imaging (mean distance 6.4 mm). Although very precise, intraoperative SSEP recordings were impaired by artifacts and wave attenuation in six of the 12 patients. Stereotactic correlations between anatomical and functional data in the navigation system corrected final targeting in 10 of 12 cases. Pain relief was obtained in eight patients. Indeed, inappropriate targeting probably explains the reported variable success rate of MCS and certainly underestimates the actual efficacy. CONCLUSIONS: Since intraoperative SSEP monitoring has, for many years, been considered the standard procedure to approach motor target, the development of an accurate stereotactic image guidance system could help to increase the efficacy of MCS on the alleviation of pain. The excellent spatial accuracy provided by the Zeiss-MKM navigation system allows precise data correlations that represent a remarkable means to validate functional MR imaging as an alternative to SSEP. The authors believe that developi, SCOPUS: ar.j, info:eu-repo/semantics/published

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OBJECT: In the management of brainstem lesions, the place of stereotactic biopsy sampling remains debatable. The authors compared the results of magnetic resonance (MR) imaging, positron emission tomography (PET) scanning, and histological studies obtained in 30 patients who underwent MR imaging- and PET-guided stereotactic biopsy procedures for a brainstem mass lesion. METHODS: Between July 1991 and December 1998, 30 patients harboring brainstem mass lesions underwent a stereotactic procedure in which combined MR imaging and PET scanning guidance were used. Positron emission tomography scanning was performed using [18F]fluorodeoxyglucose in 16 patients, methionine in two patients, and both tracers in 12 patients. Definite diagnosis was established on histological examination of the biopsy samples. Interpretation of MR imaging findings only or PET findings only was in agreement with the histological diagnosis in 63% and 73% of cases, respectively. Magnetic resonance imaging and PET findings were concordant in 19 of the 30 cases; in those cases, imaging data correlated with histological findings in 79%. Treatment based on information derived from MR imaging was concordant with therapy based on histological findings in only 17 patients (57%). Combining MR imaging and PET scanning data, the concordance between the neuroimaging-based treatment and treatments based on histological findings increased to 19 patients (63%). In seven patients who underwent biopsy procedures with one PET-defined and one MR imaging-defined trajectory, at histological examination the PET-guided samples were more representative of the tumor's nature and grade than the MR imaging-guided samples in four cases (57%). In 18 patients PET scanning was used to define a biopsy target and provided a diagnostic yield in 100% of the cases. CONCLUSIONS: Although the use of combined PET and MR imaging improves radiological interpretation of a mass lesion in the brainstem, it does not accurately replace histo, Comparative Study, Journal Article, info:eu-repo/semantics/published

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SCOPUS: cp.j, info:eu-repo/semantics/published

SCOPUS: ar.j, info:eu-repo/semantics/published

info:eu-repo/semantics/published

An implantable device (ADCON-L), which acts as a resorbable barrier to epidural fibrosis following lumbar discectomy, has been shown to minimize the formation of peridural fibrotic scar and to improve the post-operative outcome, in two large controlled and multi-center clinical trials. In this prospective study, 100 patients were treated with the device during their first-time lumbo-sacral discectomy surgeries and monitored for 12 months. During this time interval, four of these patients required re-operation. In these cases, epidural scar and ease of dissection were systematically evaluated and recorded. At the time of re-operation, in all four patients, absent or minimal soft scar tissue was found where ADCON-L had been placed, no adhesions to the involved root were observed, and the dissection was easier than expected; the healing of the surgical wound was excellent ,and no residual implant material was found. These observations indicate that the use of ADCON-L at the time of the first lumbar disc surgery minimizes the hazards and difficulty that can be encountered in a subsequent revision surgery due to the presence of epidural fibrosis, and may therefore improve the chances of satisfactory outcome following re-operation., Case Reports, Journal Article, Research Support, Non-U.S. Gov't, info:eu-repo/semantics/published

Angiolipomas (ALs) are hamartomas composed of abnormally differentiated vessels and mature adipose tissue. Although they are most commonly found in peripheral tissues, ALs sometimes grow in the spinal epidural space. Intracranial ALs (ICALs) are rare: only seven cases have been reported in the literature. The authors describe the case of a 70-year-old woman who presented with ocular symptoms from a clinically and radiologically progressing parasellar ICAL. The radiological as well as the microsurgical findings are illustrated and compared with the seven previously published cases. The most frequent location of ALs is the skull base, especially the parasellar region. Other ICALs were diagnosed as components of cerebral arteriovenous malformations and were not symptomatic by themselves. Neuroradiological studies of ICALs usually demonstrate the characteristics of both adipose and vascular tissues. However, a review of the literature shows that the diagnosis had not been suspected preoperatively in any of the cases. Operative descriptions emphasize that most neurosurgeons were caught off guard by the profuse bleeding and the unusual relationship of this unexpected lesion to the cavernous sinus, so that removal was rarely complete. The authors conclude that preoperative diagnosis of ICALs is achievable based on magnetic resonance analysis, which should help optimize the microsurgical management of these lesions., SCOPUS: ar.j, info:eu-repo/semantics/published

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SCOPUS: ar.j, info:eu-repo/semantics/published

We report a 25-year old immunocompetent woman with a high grade primary non-Hodgkin's lymphoma of the central nervous system (PNHL-CNS) in whom the administration of dexamethasone alone during three months produced a complete clinical and radiological response lasting over four years. If complete remission of PNHL-CNS induced by glucocorticoids are well known, the opportunity to observe glucocorticoid-induced remission for a long period of time without radio- and chemotherapy is rare. Only nine other cases of PNHL-CNS with complete remission induced by glucocorticoids lasting from 6 to 60 months, were found in the literature and are summarized here. Duration of glucocorticoids therapeutic effect in PNHL-CNS is probably underestimated. Glucocorticoids cannot be recommended as sole initial treatment for PNHL-CNS. However, we suggest standard therapies to be delayed in those patients responding completely to glucocorticoids where radio- and chemotherapy should be contraindicated (kidney, liver, bone marrow failure, pregnancy)., Case Reports, Journal Article, info:eu-repo/semantics/published

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SCOPUS: ar.j, info:eu-repo/semantics/published

SCOPUS: le.j, info:eu-repo/semantics/published

Central nervous system vasculitis is an exceptional extraintestinal manifestation of Crohn's disease. Reported here are 2 cases, highlighting the difficulty of differential diagnosis with multiple sclerosis and stressing the importance of early immunosuppressive therapy., SCOPUS: ar.j, FLWIN, info:eu-repo/semantics/published

in :Acta neurologica Belgica, 1997/2, p. 136, info:eu-repo/semantics/nonPublished