Giant scrotal elephantiasis in a migrant from Niger.

We hereby describe the case of a giant scrotal elephantiasis due to infection by Wuchereria bancrofti, imported in Belgium. We briefly discuss diagnostic methods, their subtlety, and therapeutic possibilities.

Rosai-Dorfman disease involving the central nervous system: seven cases from one institute.

BACKGROUND: Rosai-Dorfman disease (RDD) is a rare, idiopathic, non-neoplastic histioproliferative disease. Central nervous system (CNS) manifestations are extremely rare. Its low incidence and unknown etiology restrict early diagnosis and optimal therapy. METHODS: In the 1995-2013 period, seven CNS-RDD patients with intracranial and/or spinal lesions were retrospectively analyzed, including the clinical data, laboratory and imaging results, treatment applied and outcome. All seven case samples were screened for the SLC29A3 gene mutation, and the literature was reviewed. RESULTS: Seven RDD patients (6 male/1 female, aged between 7 and 68) with CNS manifestations are reported. Five of the seven patients (71.4 %) had intracranial lesions (1 with skull erosion and 1 with multiple lesions mimicking meningiomas), and two (28.6 %) had spinal subdural lesions. The patients' symptoms included headaches, seizures, visual loss, epileptoid convulsions in the lower legs, fever, spastic paraparesis and paraplegia. An elevated erythrocyte sedimentation rate (ESR) was detected in five of the seven cases. The diagnosis was confirmed by immunohistochemical staining revealing that the characteristic histiocytes were positive for the S100 protein and CD68 and negative for CD1a. All patients were operated on: three recovered completely, two were partially rehabilitated, and two died. No SLC29A3 gene mutations were found in any of the seven samples. CONCLUSION: This short series suggests the following: (1) RDD should be included in the differential diagnosis of lesions mimicking intracranial/spinal meningiomas or inflammatory lesions, especially in children; (2) the definitive diagnosis is based on histopathology and immunocytochemistry; (3) surgical resection seems to be the most effective therapy; (4) the exact etiology and adjuvant therapy for relapsing/incompletely resected lesions remain to be established.

Genetic diversity of Echinococcus multilocularis specimens isolated from Belgian patients with alveolar echinococcosis using EmsB microsatellites analysis.

The genetic diversity of Echinococcus multilocularis (E. multilocularis) specimens isolated from patients with alveolar echinococcosis (AE), is a major field of investigation to correlate with sources of infection, clinical manifestations and prognosis of the disease. Molecular markers able to distinguish samples are commonly used worldwide, including the EmsB microsatellite. Here, we report the use of the EmsB microsatellite polymorphism data mining for the retrospective typing of Belgian specimens of E. multilocularis infecting humans. A total of 18 samples from 16 AE patients treated between 2006 and 2021 were analyzed through the EmsB polymorphism. Classification of specimens was performed through a dendrogram construction in order to compare the similarity among Belgian samples, some human referenced specimens on the EWET database (EmsB Website for the Echinococcus Typing) and previously published EmsB profiles from red foxes circulating in/near Belgium. According to a comparison with human European specimens previously genotyped in profiles, the 18 Belgian ones were classified into three EmsB profiles. Four specimens could not be assigned to an already known profile but some are near to EWET referenced samples. This study also highlights that some specimens share the same EmsB profile with profiles characterized in red foxes from north Belgium, the Netherlands, Luxembourg and French department near to the Belgian border. Furthermore, Belgian specimens present a genetic diversity and include one profile that don't share similarities with the ones referenced in the EWET database. However, at this geographical scale, there is no clear correlation between EmsB profiles and geographical location. Further studies including additional clinical samples and isolates from foxes and rodents of south Belgium are necessary to better understand the spatial and temporal circumstances of human infections but also a potential correlation between EmsB profiles and parasite virulence.

Mycobacterium avium complex and Cryptococcus neoformans co-infection in a patient with acquired immunodeficiency syndrome: a case report.

INTRODUCTION: Opportunistic infections (OI) are common in patients with acquired immunodeficiency syndrome (AIDS). Cryptococcus neoformans and Mycobacterium avium complex (MAC) are frequently responsible of such infections. However, concurrent infection with these two pathogens is uncommon and underreported in the literature. CASE DESCRIPTION: We describe the case of a 28-year-old Caucasian Belgian patient with no travel history, who presented with low-grade fever, headache and wasting syndrome. He was diagnosed with human immunodeficiency virus (HIV) infection at AIDS stage, with a HIV viral load of 506,000 viral copies/mL and a CD4 + T-cells count of 10 cells/µL. Diagnosis of disseminated Cryptococcus neoformans infection was made by positive serum cryptococcal antigen and positive culture for Cryptococcus neoformans in blood and in cerebrospinal fluid. Diagnosis of disseminated Mycobacterium avium complex infection was made by positive culture on a biopsy of a mediastinal lymph node. With adequate anti-retroviral therapy (ART) and treatment of these OIs, the patient recovered well and had a good clinical evolution. DISCUSSION AND CONCLUSION: To our knowledge, this is the second case of coexistence of these two dangerous OIs reported in the post ART era. Clinicians should be aware that such co-infections still happen in high-income countries, in patients with severe immunodeficiency. Early detection and treatment of HIV is of paramount importance to prevent AIDS and its complications. We highlight the importance of thoroughly excluding all opportunistic infections in patients with newly diagnosed AIDS.Abbreviations: ABC: abacavir; AIDS: acquired immunodeficiency syndrome; AFB: acid-fast bacilli; ART: antiretroviral therapy; CM: cryptococcal meningitis; CrAg: cryptococcal antigen; CSF: cerebrospinal fluid; CT: computed tomography; EACS: European AIDS Clinical Society; FTC: emtricitabine; HIC: high-income countries; HIV: human immunodeficiency virus; HIV-VL: HIV-viral load; ICP: intracranial pressure; IRIS: immune reconstitution inflammatory syndrome; MAC: Mycobacterium avium complex; MRI: magnetic resonance imaging; MSM: man who has sex with men; NR: normal range; OD: omne in die = once daily; OI: opportunistic infection; RAL: raltegravir; TAF: tenofovir alafenamide fumarate.

Functional motor-cortex mapping using corticokinematic coherence.

We present a novel method, corticokinematic coherence (CKC), for functional mapping of the motor cortex by computing coherence between cortical magnetoencephalographic (MEG) signals and the kinematics of voluntary movements. Ten subjects performed self-paced flexion-extensions of the right-hand fingers at about 3 Hz, with a three-axis accelerometer attached to the index finger. Cross-correlogram and coherence spectra were computed between 306 MEG channels and the accelerometer signals. In all subjects, accelerometer and coherence spectra showed peaks around 3-5 Hz and 6-10 Hz, corresponding to the movement frequencies. The coherence was statistically significant (P<0.05) in all subjects, with sources at the hand area of the primary motor cortex contralateral to the movement. CKC appears to be a promising and robust method for reliable and convenient functional mapping of the human motor cortex.

Infective endocarditis caused by Neisseria mucosa on a prosthetic pulmonary valve with false positive serology for Coxiella burnetii - The first described case.

We present a case of infective endocarditis (IE) on a prosthetic pulmonary valve in a 36-year-old patient with tetralogy of Fallot (TOF). The patient underwent valve replacement surgery and active antibiotic treatment against Gram-negative cocci (Piperacillin Tazobactam then Ceftriaxone) for a total duration of 42 days with a favourable outcome. The causative agent was Neisseria mucosa which was identified on the infected valve by sequencing of 16S ribosomal RNA. To our knowledge, this is the first described case of a N. mucosa infective endocarditis on a pulmonary valve. Initially, serologies performed in clinical settings by immunofluorescence for Coxiella burnetii antibodies showed a major increase in phase I IgG titers at 1024 (normal values <16) corresponding with the diagnostic criteria for Q fever endocarditis. However, this diagnosis could not be confirmed by the National Reference Center, making it the first reported case of a false positive serology for C. burnetii during an infection due to Neisseria spp.

A rare case of invasive pulmonary aspergillosis presenting as organizing pneumonia due to Aspergillus niger in an immunocompetent host.

Invasive pulmonary aspergillosis associated with organizing pneumonia is increasingly described and mainly affects the immunocompromised individual. Most of Aspergillus invasive infections in both immunocompetent and immunocompromised patients are attributed to Aspergillus fumigatus. Herein we describe a clinical case of pulmonary Aspergillus niger infection presenting as an organizing pneumonia in an immunocompetent patient. A wedge resection and two successive cures of azoles (voriconazole 6 weeks then itraconazole 6 weeks) were necessary for the patient to be totally recovered. The association of OP and IPA is rare. The involvement of A. niger makes it even rarer, this is the reason why we decided to report on this case.

Incidence and Risk Factors of COVID-19-Associated Pulmonary Aspergillosis in Intensive Care Unit-A Monocentric Retrospective Observational Study.

Coronavirus disease 2019 (COVID-19)-associated pulmonary aspergillosis (CAPA) is an increasingly recognized complication of COVID-19 and is associated with significant over-mortality. We performed a retrospective monocentric study in patients admitted to the intensive care unit (ICU) for respiratory insufficiency due to COVID-19 from March to December 2020, in order to evaluate the incidence of CAPA and the associated risk factors. We also analysed the diagnostic approach used in our medical centre for CAPA diagnosis. We defined CAPA using recently proposed consensus definitions based on clinical, radiological and microbiological criteria. Probable cases of CAPA occurred in 9 out of 141 patients included in the analysis (6.4%). All cases were diagnosed during the second wave of the pandemic. We observed a significantly higher realization rate of bronchoalveolar lavage (BAL) (51.1% vs. 28.6%, p = 0.01) and Aspergillus testing (through galactomannan, culture, PCR) on BAL samples during the second wave (p < 0.0001). The testing for Aspergillus in patients meeting the clinical and radiological criteria of CAPA increased between the two waves (p < 0.0001). In conclusion, we reported a low but likely underestimated incidence of CAPA in our population. A greater awareness and more systematic testing for Aspergillus are necessary to assess the real incidence and characteristics of CAPA.

Selective image-guided venous sinus exposure for direct embolization of dural arteriovenous fistula: technical case report.

BACKGROUND: Transcranial approaches for transsinusal endovascular therapy of DAVF have been sporadically reported by large craniectomies. Large craniectomies carry nevertheless a risk of postembolization extradural hematoma, reduced by delaying the endovascular procedure. We report a 1-session technique of SIGC for percutaneous transvenous DAVF embolization. CASE DESCRIPTION: This 58-year-old woman developed a right-sided cerebellar hematoma in relation with a high-grade left transverse and sigmoid sinus DAVF. The DAVF was fed by branches from the left vertebral artery, left internal, and left external carotid arteries, draining into the transverse sinus with retrograde flow in cortical veins. Transvenous retrograde embolization was not feasible either through the left internal jugular vein because of thrombosis, or through the right one because of torcular septa. During the same anaesthetic session, a 5-cm-length selective craniectomy was shaped under magnetic resonance image guidance navigation according to the left transverse sinus with high-speed drill. Thereafter, back in the angiography room, the transverse sinus was taped and coiled resulting in a complete exclusion of the DAVF. CONCLUSION: Selective image-guided craniectomy is efficient and safe for direct percutaneous transvenous embolization of DAVF in a single anesthetic session. Leaving bone beside the sinus prevents a parenchymal traumatic puncture. This bone has nevertheless to be drilled to allow an adequate sharp puncture angle. Doing so, postoperative hematoma is prevented by the small bone opening, the natural adherence of the dura matter and the possibility of direct compression.

Physicians' preparedness for pre-exposure prophylaxis: results of an online survey in Belgium.

Background Physicians have a crucial role in the implementation and scale up of pre-exposure prophylaxis (PrEP). The objective of this study is to examine Belgian physicians' PrEP knowledge, concerns, acceptance and their willingness to prescribe PrEP. METHODS: A cross-sectional online survey was conducted between March and June 2016. Dissemination targeted Belgian primary care physicians (PCPs) and HIV specialists. Sociodemographic characteristics, experience with HIV and PrEP, self-assessed PrEP knowledge, concerns about PrEP, and PrEP acceptance were stratified according to professional background. Associations with willingness to prescribe PrEP were examined using univariable and multivariable binary logistic regression analyses. RESULTS: In total, 333 completed surveys were included in the analysis. Sixty-two physicians (18.6%) scored their knowledge of PrEP to be good, 263 (79.0%) had an accepting attitude towards PrEP and 198 (59.5%) were willing to prescribe PrEP if approved in Belgium. HIV specialists consistently reported having better knowledge of PrEP, less concerns and a more accepting attitude towards PrEP than PCPs. In multivariable logistic regression analysis, higher PrEP knowledge (OR 2.4; 95%CI: 1.0-5.7) and higher PrEP acceptance (OR: 3.8; 95%CI: 2.1-6.8) remained significantly associated with the willingness to prescribe PrEP. CONCLUSIONS: HIV specialists are better prepared to provide PrEP than PCPs in Belgium. Interventions to improve PrEP knowledge and acceptance among all providers are needed. The role of PCPs could be very important in optimising the rollout of PrEP, but additional training and guidelines will be needed.

Results of positron emission tomography guidance and reassessment of the utility of and indications for stereotactic biopsy in children with infiltrative brainstem tumors.

OBJECT: Most intrinsic infiltrative brainstem lesions diagnosed in children are gliomas, and these carry a very bad prognosis. Although the utility and risk of stereotactically guided biopsy procedures in intrinsic infiltrative brainstem lesions have been widely questioned, the neuroimaging diagnosis may be inaccurate in approximately 25% of cases, and the consequences of empirical therapy should not be underestimated. Stereotactic biopsy sampling is still performed in many centers, but the reported diagnostic yield ranges from 83 to 96%. The authors integrated positron emission tomography (PET) images into the planning for stereotactic biopsy procedures to direct the biopsy needle's trajectory to hypermetabolic foci of intrinsic infiltrative brainstem lesions. Their aim was to assess the benefit of the technique in terms of target selection and diagnostic yield. METHODS: Twenty children with newly diagnosed intrinsic infiltrative brainstem lesions underwent a PET-guided stereotactic biopsy procedure. The PET tracer was(18)F-2-fluoro-2-deoxy-D-glucose (FDG) in six cases, (11)C-methionine in eight, and both agents were used in six. A single biopsy target was selected in the area of highest PET tracer uptake in all cases. The PET data were compared with diagnoses and outcome. RESULTS: Use of PET guidance improved target selection and provided tumor diagnosis in all trajectories and in all children (high-grade glioma was diagnosed in 10, low-grade glioma in five, and nonglial tumor in five). The PET-guided trajectories provided a higher diagnostic yield than those guided by magnetic resonance imaging alone, which allowed the sampling to be reduced to a single trajectory. The PET data might also carry a prognostic value that could be useful for oncological management. CONCLUSIONS: These data support the suggestion that PET guidance improves the diagnostic yield of stereotactic biopsy sampling, allows the practitioner to reduce the number of sampling procedures, and might lead to a reassessment of the utility of and indications for stereotactic biopsy in children with intrinsic infiltrative brainstem lesions.

Motor Cortex Stimulation in Patients Suffering from Chronic Neuropathic Pain: Summary of Expert Meeting and Premeeting Questionnaire, Combined with Literature Review.

BACKGROUND: Motor cortex stimulation (MCS) was introduced in the early 1990s by Tsubokawa and his group for patients diagnosed with drug-resistant, central neuropathic pain. Inconsistencies concerning the details of this therapy and its outcomes and poor methodology of most clinical essays divide the neuromodulation society worldwide into "believers" and "nonbelievers." A European expert meeting was organized in Brussels, Belgium by the Benelux Neuromodulation Society in order to develop uniform MCS protocols in the preoperative, intraoperative, and postoperative courses. METHODS: An expert meeting was organized, and a questionnaire was sent out to all the invited participants before this expert meeting. An extensive literature research was conducted in order to enrich the results. RESULTS: Topics that were addressed during the expert meeting were 1) inclusion and exclusion criteria, 2) targeting and methods of stimulation, 3) effects of MCS, and 4) results from the questionnaire. CONCLUSIONS: Substantial commonalities but also important methodologic divergencies emerged from the discussion of MCS experts from 7 European Centers. From this meeting and questionnaire, all participants concluded that there is a need for more homogenous standardized protocols for MCS regarding patient selection, implantation procedure, stimulation parameters, and follow-up-course.

Integrated positron emission tomography and magnetic resonance imaging-guided resection of brain tumors: a report of 103 consecutive procedures.

OBJECT: The aim of this study was to evaluate the integration of positron emission tomography (PET) scanning data into the image-guided resection of brain tumors. METHODS: Positron emission tomography scans obtained using fluorine-18 fluorodeoxyglucose (FDG) and L-[methyl-11C]methionine (MET) were combined with magnetic resonance (MR) images in the navigational planning of 103 resections of brain tumors (63 low-grade gliomas [LGGs] and 40 high-grade gliomas [HGGs]). These procedures were performed in 91 patients (57 males and 34 females) in whom tumor boundaries could not be accurately identified on MR images for navigation-based resection. The level and distribution of PET tracer uptake in the tumor were analyzed to define the lesion contours, which in turn yielded a PET volume. The PET scanning-demonstrated lesion volume was subsequently projected onto MR images and compared with MR imaging data (MR volume) to define a final target volume for navigation-based resection-the tumor contours were displayed in the microscope's eyepiece. Maximal tumor resection was accomplished in each case, with the intention of removing the entire area of abnormal metabolic activity visualized during surgical planning. Early postoperative MR imaging and PET scanning studies were performed to assess the quality of tumor resection. Both pre- and postoperative analyses of MR and PET images revealed whether integrating PET data into the navigational planning contributed to improved tumor volume definition and tumor resection. Metabolic information on tumor heterogeneity or extent was useful in planning the surgery. In 83 (80%) of 103 procedures, PET studies contributed to defining a final target volume different from that obtained with MR imaging alone. Furthermore, FDG-PET scanning, which was performed in a majority of HGG cases, showed that PET volume was less extended than the MR volume in 16 of 21 cases and contributed to targeting the resection to the hypermetabolic (anaplastic) area in 11 (69%) of 16 cases. Performed in 59 LGG cases and 23 HGG cases, MET-PET demonstrated that the PET volume did not match the MR volume and improved the tumor volume definition in 52 (88%) of 59 and 18 (78%) of 23, respectively. Total resection of the area of increased PET tracer uptake was achieved in 54 (52%) of 103 procedures. CONCLUSIONS: Imaging guidance with PET scanning provided independent and complementary information that helped to assess tumor extent and plan tumor resection better than with MR imaging guidance alone. The PET scanning guidance could help increase the amount of tumor removed and target image-guided resection to tumor portions that represent the highest evolving potential.

Comparison of functional MR imaging guidance to electrical cortical mapping for targeting selective motor cortex areas in neuropathic pain: a study based on intraoperative stereotactic navigation.

PURPOSE: To assess the concordance between data from functional MR imaging (fMRI) guidance and the intraoperative electrical cortical mapping (iCM) in targeting selective motor cortex areas in refractory neuropathic pain. METHODS: Twenty-one patients (11 women and 10 men; mean age, 55.6 years) with refractory central (ischemic, 8 cases) and neuropathic pain (trigeminal neuropathy, 6 cases; syrinx/amputation/plexus trauma, 7 cases) underwent surgery for the implantation of an epidural electrode for chronic motor cortex stimulation (MCS) with general anesthesia and a frameless neuronavigation system used for the image-guided targeting procedure. All patients were studied by preoperative fMRI and epidural iCM with somatosensory evoked potentials and motor cortex stimulodetection. fMRI investigated systematically motor tasks of both hands and that related to the somatic area (foot or tongue) affected by pain. fMRI data were analyzed with the Statistical Parametric Mapping99 software (initial analysis threshold [AT] corresponding to P < .001), registered in the neuronavigation system and correlated intraoperatively with iCM. Matching of fMRI and iCM was specifically examined, focusing the study on hand mapping. RESULTS: Concordance between contours of fMRI activation area and iCM in precentral gyrus (mean distance, 3.8 mm) was found in 20/21 patients (95%). Because precision of iCM was suboptimal in 7 patients, concordance for more restrictive values of the AT (P < .0001) was found in only 13 of these 20 patients. Concordance was not found in one patient, as result of image distortion and residual motion artifact. CONCLUSIONS: In this study, fMRI guidance provides information that matches those of an independent functional method. These data illustrate the functional accuracy of fMRI guidance for the operative targeting of selective motor cortex areas in neuropathic pain.

Persistent hydrocephalus after early surgical management of posterior fossa tumors in children: is routine preoperative endoscopic third ventriculostomy justified?

OBJECT: The authors evaluate the incidence of persistent hydrocephalus after early surgical management of pediatric posterior fossa tumors and the indicators for routine preoperative endoscopic third ventriculostomy (ETV). METHODS: Between 1989 and 2004, 160 children with a posterior fossa tumor were treated at Erasme Hospital in Brussels, Belgium. Hydrocephalus was present at admission in 114 of the patients. Thirty-one patients had severe hydrocephalus (Evans index [EI] > 0.4). Twenty-four of these and the 83 patients with mild hydrocephalus (EI between 0.3 and 0.4) were treated with early posterior fossa surgery (Group 1; 107 patients). In this group, 93 patients underwent a total or subtotal tumor resection associated with external ventricular drainage (Group 1A), and 14 underwent a stereotactic biopsy associated with an ETV (Group 1B). The 53 remaining patients underwent elective posterior fossa surgery (Group 2). Early tumor resection (Group 1A) resolved hydrocephalus in 85 (91%) of 93 patients, whereas an ETV resolved intracranial hypertension in 11 patients (Group 1B). In Group 1, persistent hydrocephalus affected 11 (10%) of 107 patients, seven of whom had symptoms and were treated (three with shunts and four with ETVs). Persistent hydrocephalus was more frequent in children with severe preoperative hydrocephalus (p = 0.002) and with medulloblastomas (p = 0.0154). A total of 22 technically successful ETV procedures were performed. The ETV success rate for controlling hydrocephalus was 81% (18 of 22) and the rate of severe complications was 9% (two of 22). CONCLUSIONS: An ETV is an efficient procedure for controlling hydrocephalus associated with posterior fossa tumor. The authors confirm that a routine postoperative ETV is indicated for treating persistent hydrocephalus. For preventing it, however, they recommend early posterior fossa surgery whenever possible. The low rate of persistent hydrocephalus does not justify adopting routine preoperative ETVs.

Comparison of 18F-FDG and 11C-methionine for PET-guided stereotactic brain biopsy of gliomas.

UNLABELLED: 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.

Fluorodeoxyglucose and methionine uptake in Lhermitte-Duclos disease: case report.

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.

Synovial cysts of the lumbar spine: surgery-related results and outcome.

OBJECT: The authors conducted a study to determine the surgery-related results and outcomes in patients with synovial cysts of the lumbar spine. They emphasize several specific characteristics useful in clinical management. METHODS: Forty-six consecutive patients with 54 lumbar synovial cysts underwent surgery between 1990 and 2001. A retrospective analysis of the clinical presentation and follow-up data, radiological findings, and surgical techniques was performed. Clinical presentation was dominated by acute or subacute sciatic pain. No specific symptom allowed differentiation of synovial cyst from a lumbar disc herniation. Computerized tomography scanning aided in establishing the correct diagnosis in 19 of 30 cases and magnetic resonance (MR) imaging did so in all cases. Three of the 46 patients presented with bilateral lumbar synovial cysts. The L4-5 level was affected in 61%, and radiological signs of disc degeneration/spondylosis were observed in 54% of the patients. Immediate symptom relief without local recurrence was obtained by complete microsurgical excision in which bipolar coagulation was used to remove the synovial membrane and in which the interapophysial joint was preserved. During the 1st postoperative year, a newly formed symptomatic synovial cyst developed on the contralateral side or at a superior vertebral level in five patients. They underwent surgery; results were good and there was no recurrence. CONCLUSIONS: The findings in this series suggest that synovial cysts can occur at multiple lumbar sites within a short period of time and could be predisposed to developing in certain individuals, predominantly in women older than 40 years of age. Postoperative follow up is recommended and MR imaging mandatory in cases of recurrent sciatica.

Combined use of 18F-fluorodeoxyglucose and 11C-methionine in 45 positron emission tomography-guided stereotactic brain biopsies.

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.

The integration of metabolic imaging in stereotactic procedures including radiosurgery: a review.

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.