Showing papers by "James T. Rutka published in 2003"

Complications of invasive subdural grid monitoring in children with epilepsy.

Abstract: Object. This study was performed to evaluate the complications of invasive subdural grid monitoring during epilepsy surgery in children. Methods. The authors retrospectively reviewed the records of 35 consecutive children with intractable localization-related epilepsy who underwent invasive video electroencephalography (EEG) with subdural grid electrodes at The Hospital for Sick Children between 1996 and 2001. After subdural grid monitoring and identification of the epileptic regions, cortical excisions and/or multiple subpial transections (MSTs) were performed. Complications after these procedures were then categorized as either surgical or neurological. There were 17 male and 18 female patients whose mean age was 11.7 years. The duration of epilepsy before surgery ranged from 2 to 17 years (mean 8.3 years). Fifteen children (43%) had previously undergone surgical procedures for epilepsy. The number of electrodes on the grids ranged from 40 to 117 (mean 95). During invasive video EEG, cerebrospinal fluid...

Expression of fascin, an actin-bundling protein, in astrocytomas of varying grades.

Abstract: Malignant astrocytomas are highly infiltrative neoplasms that invade readily into regions of normal brain. On a cellular basis, the motility and invasiveness of human cancers can be ascribed in part to complex rearrangements of the actin cytoskeleton that are governed by several actin-binding proteins. One such actin-binding protein that has been linked to the invasive behavior of carcinomas is fascin, which serves to aggregate F actin into bundles. In this study, we examined the expression of fascin in a series of human malignant astrocytomas (WHO grades I–IV). Five grade I, 5 grade II, 10 grade III, and 26 grade IV human astrocytomas were examined for fascin and glial fibrillary acidic protein (GFAP) expression by double immunofluorescence confocal microscopy. Expression of fascin and GFAP was also determined by Western blot analysis. Fascin expression increased with increasing WHO grade of astrocytoma. This is in marked contrast to GFAP expression, which decreased with increasing WHO grade. In grades I and II neoplasms, and within non-neoplastic brain, fascin and GFAP were expressed diffusely within regions examined. However, in the higher-grade astrocytomas (grades III and IV), fascin and GFAP were expressed regionally in distinctly separate tumor cell populations. This is the first study to demonstrate the expression of fascin in human astrocytic neoplasms. The role that fascin plays in contributing to the invasive phenotype of anaplastic astrocytomas awaits further study and investigation.

Malformations of cortical development with balloon cells: Clinical and radiologic correlates

Abstract: Background: Balloon cells are a key feature of tuberous sclerosis (TS) but are also seen in focal cortical dysplasia (FCD). The authors compare the clinical and MRI characteristics in children with medically refractory localization-related epilepsy who were found to have balloon cells on histology after cortical resections. Methods: A retrospective review of clinical and MRI data in cases ascertained from a search of pathology records from 1990 until 2000 for those with a diagnosis of FCD or TS. Seventeen patients were identified with malformations of cortical development with balloon cells on histology. Seven had clinical diagnosis of TS and the remaining 10, FCD with balloon cells (FCDBC). Results: Seventy percent of patients with FCDBC (mean follow-up 3.3 years) and 33% of patients with TS (mean follow-up 5.1 years) are seizure free after surgery. There was agreement between the diagnosis based on preoperative MR imaging and on histology in 60% of patients with FCDBC and 71% of patients with TS. Myelin depletion and calcification were noted more frequently in patients with TS. Conclusions: No significant differences were noted between patients with refractory epilepsy caused by TS or FCDBC. There was a trend toward better postoperative seizure control in the FCDBC group. These two conditions are difficult to distinguish on the basis of MR and histologic appearances. The authors conclude that FCDBC likely represents a phenotypic variation of TS, and as such, all patients with balloon cell dysplasias should be carefully screened for other features of TS to enable appropriate genetic counseling.

Proton magnetic resonance spectroscopic imaging can predict length of survival in patients with supratentorial gliomas.

Abstract: OBJECTIVE: We compared the ability of proton magnetic resonance spectroscopic imaging ( 1 H-MRSI) measures with that of standard clinicopathological measures to predict length of survival in patienis with supratentorial gliomas. METHODS: We developed two sets of leave-one-out logistic regression models based on either 1) intratumoral 1 H-MRSI features, including maximum values of a) choline and b) lactate-lipid, c) number of 1 H-MRSI voxels with low N-acetyl group values, and d) number of 1 H-MRSI voxels with high lactate-lipid values, all (a-d) of which were normalized to creatine in normal-appearing brain, or 2) standard clinicopathological features, including a) tumor histopathological grade, b) patient age, c) performance of surgical debulking, and d) tumor diagnosis (i.e., oligodendroglioma, astrocytoma). We assessed the accuracy of these two models in predicting patient survival for 6, 12, 24, and 48 months by performing receiver operating characteristic curve analysis. Cox proportional hazards analysis was performed to assess the extent to which patient survival could be explained by the above predictors. We then performed a series of leave-one-out linear multiple regression analyses to determine how well patient survival could be predicted in a continuous fashion. RESULTS: The results of using the models based on 1 H-MRSI and clinicopathological features were equally good, accounting for 81 and 64% of the variability (r 2 ) in patients' actual survival durations. All features except number of 1 H-MRSI voxels with lactate-lipid/ creatine values of at least 1 were significant predictors of survival in the 1 H-MRSI model. Two features (tumor grade and debulking) were found to be significant predictors in the clinicopathological model. Survival as a continuous variable was predicted accurately on the basis of the 1 H-MRSI data (r = 0.77, P < 0.001; median prediction error, 1.7 mo). CONCLUSION: Our results suggest that appropriate analysis of 1 H-MRSI data can predict survival in patients with supratentorial gliomas at least as accurately as data derived from more invasive clinicopathological features.

Evaluation of dietetic intervention in children with medulloblastoma or supratentorial primitive neuroectodermal tumors.

Abstract: Evaluation of dietetic intervention in children with medulloblastoma or supratentorial primitive neuroectodermal tumors. BACKGROUND. Malnutrition is a common complication of cancer treatment; it can affect energy levels and, as a consequence, quality of life. The goal of the current study was to evaluate the effect of dietetic intervention in a cohort of children treated for medulloblastoma and supratentorial primitive neuroectodermal tumors (PNET) over a 10-year period. METHODS. A retrospective chart review (1992-2002) of newly diagnosed cases of medulloblastoma/supratentorial PNET was performed. Hospital records were reviewed for data, including demographic characteristics, patient heights and weights, and information on treatment modalities and the use of dietetic intervention. Percent changes in body weight were calculated at time points associated with particular stages of treatment or dietetic intervention. RESULTS. One hundred three of 112 cases were evaluable. Treatment methods included surgery only (7.8%), surgery + radiotherapy (16.5%), surgery + chemotherapy (14.5%), and surgery + radiotherapy + chemotherapy (61.2%). There was no significant change in patient weight due to surgery (median change in body weight [MCBW], -0.35%) or radiotherapy (MCBW, - 0.78%). In contrast, children experienced significant weight loss (MCBW, -4.35%; P < 0.0001) 3 months after starting chemotherapy. A dietician saw 53 of the 103 children in the study cohort. There were 84 dietetic interventions (oral, 36%; parenteral, 27%; enteral, 37%) among these 53 patients. Oral diets did not result in weight gain. Parenteral nutrition was associated with significant weight gain at I month (MCBW, +2.7%; P = 0.03), but not at 3 months. The use of enteral feeds resulted in significant weight gain at I month (MCBW, +4.8%; P = 0.006) and at 3 months (MCBW, + 11.8%; P < 0.0001). CONCLUSIONS. Current multimodality treatment of intracranial PNET results in significant nutritional morbidity, primarily due to the use of intensive chemotherapy regimens. Dietetic input for pediatric patients with medulloblastoma/PNET is essential, and the implementation of enteral feeding in these children can help to reverse their nutritional morbidity. (C) 2003 American Cancer Society.

Pediatric supratentorial high-grade gliomas.

Abstract: The purpose of this review is to highlight some of the pertinent concepts and controversies surrounding the diagnosis and treatment of pediatric supratentorial high-grade gliomas. Unlike the adult counterparts, pediatric high-grade gliomas are likely derived from distinct cytogenetic and molecular alterations. Surgery has been shown to play a role in extending patient survival. Some success is associated with the provision of chemotherapy. Radiotherapy remains an important adjunct in children older than age 3 years. The challenges involved in improving the poor prognosis of children in whom these very aggressive tumors have been diagnosed will be discussed, as well as some of the novel approaches being investigated to improve patient survival and quality of life.

Transcriptional profiling of medulloblastoma in children.

Abstract: Object. Although medulloblastoma is the most common malignant brain tumor found in children, little is known about its molecular pathogenesis. The authors have attempted to compare patterns of gene expression in medulloblastoma samples with those in the healthy cerebellum. Methods. The authors used complementary (c)DNA microarray analysis to compare the expression of genes in samples of medulloblastoma and normal cerebellum. The expression levels of a subset of genes were then verified by immunohistochemical analysis. Six genes were identified that were expressed at a much higher level in at least five of six medulloblastomas: ezrin, cyclin D2, high mobility group protein 2, MAPRE1, histone deacetylase 2, and ornithine decarboxylase 1. A number of potentially important genes whose expression was much lower in medulloblastomas than in control cerebellum were also identified: tenascin R, TRK-B, FGF receptor, and death receptor 3. The expression levels of a subset of the identified genes were confirmed by im...

Primary central nervous system sarcomas in children: clinical, radiological, and pathological features

Abstract: The clinical, radiological, surgical, and pathological findings of 16 children with a primary central nervous system (CNS) sarcoma are reported. There were 8 (50%) girls and 8 (50%) boys ranging in age from 4 months to 14 years (mean age 4.8 years). Four patients (23%) were in their 1st year of life. Fourteen children (87%) had an intracranial sarcoma, and 2 (13%) had intraspinal tumors. Nine intracranial tumors (60%) were supratentorial. The parietal and temporal regions were the most frequently involved sites. Characteristic imaging findings included tumor cysts in 7 patients and marked tumoral enhancement in 9 (69%) with intratumoral calcification and hemorrhage. All patients underwent at least one operation to surgically remove the tumor with the aim of maximal resection and 3 patients underwent a second resection due to a recurrent tumor. Resection was total in 9 (53%) patients and subtotal in another 7 (41%). Dural attachment by tumor was confirmed in 7 (44%) patients and parenchymal invasion was present in 9 (56%). In one-third of the patients there was a well-defined plane of dissection around the tumor. Postoperative radiation was used in 10 patients. Postoperative chemotherapy was used in all but 2 patients. Immunohistochemical studies were available in 13 patients with the most consistent finding being strong vimentin positivity. Five out of the 6 patients in whom the proliferation markers were obtained demonstrated a high proliferation index (Ki-67 labeling index, 20–50%). The mean length of survival in the group was 4.6 years (range 1 month to 16 years). Children who presented in the 1st year of life had shorter survival than those who presented at an older age. Six patients (40%) had cerebrospinal fluid (CSF) dissemination of the tumor. CSF dissemination was associated with a shorter mean survival of 1.9 years. Our review of this series of patients indicates the requirement for adjuvant therapy and for continued efforts to classify tumor subtypes aimed at optimizing future treatments for patients with a primary CNS sarcoma.

The significance of ear plugging in localization-related epilepsy.

Abstract: Summary: Purpose: The localizing value of ear plugging in the treatment of auditory onset partial seizures, to our knowledge, has not been previously described. We propose that ear plugging is a clinical response to a sensory seizure manifested as an auditory hallucination and a tool for identifying the seizure focus in the auditory cortex on the superior temporal gyrus. Methods: We report on three children who had prior epilepsy surgery for recurrent symptomatic localization-related epilepsy and who, subsequent to their surgery, displayed stereotyped unilateral or bilateral ear plugging at the onset of partial seizures. We studied scalp video electroencephalography (VEEG), magnetoencephalography (MEG), and magnetic resonance imaging (MRI) in all three. Additionally, we used electrocorticography (ECoG) in two patients, intracranial VEEG monitoring in one patient, and functional MRI language mapping in two patients. Results: All three patients plugged their ears with their hands during auditory auras that localized to the superior temporal gyrus and were followed by partial seizures that spread to a wider field, as shown on scalp and intracranial VEEG. All three patients had MEG interictal discharges in the superior temporal gyrus. One patient who was nonverbal and unable to describe an auditory phenomenon plugged the ear contralateral to where temporal lobe‐onset seizures and MEG interictal discharges occurred. Conclusions: Ear-plugging seizures indicate an auditory aura and may also lateralize seizure onset to the contralateral temporal lobe auditory cortex. Stereotyped behaviors accompanied by epileptic seizures in children who have poor communication skills are important in the seizure semiology of localization-related epilepsy. Key Words: Ear plugging— Magnetoencephalography—Auditory hallucination—Temporal lobe epilepsy.

Imaging of murine brain tumors using a 1.5 Tesla clinical MRI system.

Abstract: xenotransplantees. Introduction: Nous avons evalue la possibilite d'utiliser un systeme d'imagerie par resonance magnetique (IRM) 1.5 Tesla (T) utilise en clinique pour l'etude in vivo de trois modeles differents au point de vue histopathologique de tumeurs cerebrales chez la souris. Methodes: Nous avons choisi des modeles presentant une tumeur dans differents compartiments intracrâniens: des souris knock-out heterozygotes Patched+/- pour les tumeurs du cervelet (n = 5); des cellules d'astrocytome humain U87 MG xenotransplantees dans le lobe frontal de souris athymiques (n = 15); et des cellules de meningiome malin humain F5 (n = 15) ou IOMM Lee (n = 15) xenotransplantees a la base du crâne ou a la convexite de souris athymiques. Une petite sonde de surface et un systeme IRM 1.5 T utilise en clinique ont ete utilises et on a obtenu des sequences ponderees T1 et echo de spin T2 chez tous les animaux. Du gadolinium a ete injecte par la veine de la queue pour mieux faire ressortir les tumeurs intracrâniennes. Vingt souris ont ete suivies par IRM serie pour suivre la croissance tumorale. Chez ces souris, les images ont ete obtenues apres l'implantation de la tumeur et aux deux semaines par la suite. Les souris ont ete sacrifiees apres la derniere seance d'imagerie et les tumeurs ont ete examinees en histopathologie. Les preparations histopathologiques ont ensuite ete comparees aux dernieres images obtenues par RM pour etablir des correlations entre l'imagerie et la pathologie. Resultats: L'IRM a mis en evidence les tumeurs dans le cervelet, les lobes frontaux et a la base du crâne chez tous les modeles de souris. La detection des tumeurs intracrâniennes etait rehaussee par l'administration prealable de gadolinium et la limite de resolution des tumeurs cerebrales chez les souris etait de 1-2 mm 3 . Des images sequentielles obtenues a differents intervalles ont montre une croissance progressive de la tumeur chez tous les animaux. Les images de la taille et de la localisation de la tumeur obtenues par RM correspondaient exactement aux resultats de l'analyse histopathologique. Conclusion: Il est possible d'utiliser un systeme de RM 1.5 T utilise en clinique et une sonde specialement concue pour l'IRM de tumeurs cerebrales dans differents compartiments intracrâniens chez la souris. Avec une bonne resolution, on peut detecter des tumeurs de 1 ou 2 mm3. On peut suivre des souris porteuses de tumeurs cerehrales naissantes par l'IRM en serie. Cette methode permet de suivre la croissance tumorale de facon non effractive et de tester de nouveaux traitements sans devoir sacrifier les souris.

Characteristics of dipoles in clustered individual spikes and averaged spikes

Abstract: The aim of this study is to analyze the characteristics of dipoles in clustered individual spikes and averaged spikes, we compared electroencephalography (EEG) dipole localizations from patients with intractable extratemporal lobe epilepsy (IETLE) and from patients with benign epilepsy with centrotemporal spikes (BECTS). We studied 10 patients; five with IETLE who underwent epilepsy surgery after subdural EEG and five with BECTS. We recorded 19-channel digital scalp EEGs and used clustering analysis for individual spikes to characterize interictal spikes. We selected and averaged one representative spike group at the maximum negative peak electrode. We used a single dipole method with three-shell spherical head model. We compared dipole localizations of both averaged and individual spikes.IETLE data had more identifiable spike clusters and fewer spikes in each cluster than BECTS (P or=95% in averaged spikes were less frequent in IETLE than in BECTS (P<0.05). For IETLE, averaged spikes showed no dipoles (two patients), while individual spikes gave dipole sources reliably in the epileptic region. For BECTS, individual and averaged spike sources were clustered. More than 80% of dipoles in averaged spikes were stable, in close proximity, for prolonged periods in BECTS. More spike groups after clustering and fewer acceptable dipoles from averaged spikes in IETLE reflect variable spike activity over extensive epileptic regions. Fewer spike groups producing more acceptable dipoles in BECTS correlate with stable spike sources within the isolated epileptic central region. Characteristics of clustered interictal spikes need careful examination before the use of dipole analysis of averaged spikes for epilepsy evaluation.

Nonmalignant pediatric brain tumors.

Abstract: Brain tumors are the most common solid neoplasms in the pediatric population. Each year in the United States, approximately 1500 to 2000 children are affected by one of these tumors. About 50% of pediatric brain tumors are malignant. Nonmalignant pediatric brain tumors comprise an eclectic group of pathologic entities that have fascinating clinical features. Many of these tumors demonstrate a favorable prognosis. In this report, we review the epidemiology, histopathology, genetics, clinical presentation, neuroimaging, and treatment of the common nonmalignant pediatric brain tumors, including low grade astrocytomas (such as cerebellar astrocytoma and optic pathway glioma), subependymal giant cell astrocytomas, central neurocytomas, dysembryoplastic neuroepithelial tumor, choroid plexus papilloma, and craniopharyngioma. Advances in the therapeutic management of patients with these tumors have considerably improved their prognosis.

Characteristics of prolonged afterdischarges in children with malformations of cortical development.

Abstract: We investigated aberrant cortical excitability in malformations of cortical development. From subdural electrodes, we recorded afterdischarges lasting ≥ 6 seconds in 12 of 13 patients with malforma...

Clival osteoblastoma in a child. Case illustration.

Abstract: clival lesion that was resected via a transoral approach. The patient presented with a 6-month history of retropharyngeal and upper-neck pain. On examination, there was no neurological deficit. A computerized tomography (CT) scan of the skull base and upper cervical spine revealed an expansive, sclerotic lesion located at the tip of the clivus (Fig. 1 left and center). A methylene diphosphonate (MDP) bone scan revealed intense tracer activity in the clivus with evidence of hyperemia (Fig. 1 right). The intense metabolic activity and hyperemia was suggestive of an osteoblastoma. The patient began a regimen of nonsteroidal antiinflammatory medication, which led to some improvement in his pain. The patient underwent transoral curettage of the lesion with the aid of image guidance (ISG Viewing Wand; Surgical Navigation Network, Mississauga, ON, Canada). Pathological examination of the resected lesion confirmed the diagnosis of osteoblastoma (Fig. 2). Postoperatively, the patient was free from pain and a follow-up CT scan obtained 1 year postoperatively revealed that the bulk of the lesion had been removed (Fig. 3). Osteoblastomas are common primary bone tumors within the bony spine. The present case represents the fourth case of clival osteoblastoma described in the literature.1–3 The diagnosis is highly suggested by findings on CT scans in conjunction with those on MDP bone scans. The treatment of choice is curettage.

Bioinformatics in neurosurgery.

Abstract: WITH THE COMPLETION of the Human Genome Project, the amount of molecular biological sequence data available in public databases has reached staggering proportions. Data continue to accumulate at an exponential rate in the postgenomic era. Compilation, storage, searching, sharing, studying, and transmitting of all these data present formidable challenges. To keep pace with this extant database, the science of bioinformatics (sometimes called computational biology) has evolved. Bioinformatics is the combination of biology and computers and usually involves the storage or analysis of molecular biological sequence data at either the deoxyribonucleic acid, ribonucleic acid, or protein (amino acid) level. Most bioinformatics tools are freely available on the Internet for use by investigators around the globe. The collective wisdom from bioinformatics databases worldwide will continue to spawn advances in the neurological sciences for generations to come. Neurosurgeons must be aware of the power and potential applications of bioinformatics for the analysis of neurosurgical diseases.

Effects of moderate hyperthermia on the rabbit sarcoma model. Commentary

Abstract: A method of induction of moderate hyperthermia with a plate heater and a direct current energy source was investigated in the VX-2 rabbit sarcoma model. The theoretical distribution of temperature in the rabbit brain was calculated under various heating conditions. The calculated temperatures coincided well with the temperatures of moderate hyperthermia measured by a thermocouple to a depth of 7 mm under the heater. Moderate hyperthermia was induced in the VX-2 sarcoma. Hyperthermia at 40°C for 20 minutes caused no changes in the lesion. Hyperthermia at 45°C for 20 minutes destroyed the lesion partially to a maximum depth of 3 mm. Hyperthermia at 50°C for 20 minutes caused greater destruction, but also caused edema in the lesion and the surrounding normal brain. Hyperthermia at 55°C for 20 minutes caused severe damage in both the lesion and the surrounding normal brain. Comparison of the actual destruction by hyperthermia and the theoretical temperature distribution indicated that hyperthermia at 43°C for 20 minutes was effective against brain tumor, and destruction reached at least 3 mm from the heater.