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2.
Spine Deform ; 11(6): 1539-1542, 2023 Nov.
Article in English | MEDLINE | ID: mdl-37306937

ABSTRACT

It is a historic and common practice while performing spine surgery on patients with a VNS has been to have the patient's neurologist turn off the VNS generator in the pre-operative anesthetic care unit and to use bipolar rather than monopolar electrocautery. Here we report a case of a 16-year-old male patient with cerebral palsy and refractory epilepsy managed with an implanted VNS who had scoliosis surgery (and subsequent hip surgery) conducted with the use of monopolar cautery. Although VNS manufacturer guidelines suggest that monopolar cautery should be avoided, perioperative care providers should consider its selective use in high-risk instances (with greater risks of morbidity and mortality due to blood loss which outweigh the risk of surgical re-insertion of a VNS) such as cardiac or major orthopedic surgery. Considering the number of patients with VNS devices presenting for major orthopedic surgery is increasing, it is important to have an approach and strategy for perioperative management of VNS devices.

3.
J Neurosurg Sci ; 59(2): 141-55, 2015 Jun.
Article in English | MEDLINE | ID: mdl-25649065

ABSTRACT

The general principle of epilepsy surgery is to achieve seizure freedom without causing any neurological deficit that would outweigh the clinical benefit. To achieve this, the epileptogenic zone, which is the part of the brain responsible for seizure generation, as well as the anatomic location of the eloquent cortex must be precisely identified in order to spare those functions during excision of the epileptogenic tissue. Major technical advances over the last decade have continuously contributed to increase our ability to map the brain and identify these critical areas. These technologies and innovations that can be routinely used today include non-invasive studies such as magnetoencephalography (MEG), functional MRI (fMRI), simultaneous EEG-fMRI, and nuclear medicine based methods like PET and SPECT as well as invasive studies through chronically implanted electrodes. Electrodes can be either placed subdurally via burr holes and craniotomies or within the brain parenchima via frame-based and frameless stereotactic methods. Apart from a continuous change in these insertion techniques, the most valuable advances here include recordings on high frequency bandwidth (100-600 Hz EEG) that are capable to delineate high-frequency oscillations (HFOs). These HFOs have been recognized as a biomarker for epileptogenic tissue. All of these technical advances have made epilepsy surgery a truly multidisciplinary field and surgeons have to be able to understand and interpret all of the gathered data. Moreover, this development has influenced surgical approaches and techniques and epilepsy surgery today includes a wide variety of procedures. These can be subdivided into resective, disconnective and neuromodulation procedures and vary from a small, targeted lesionectomy to disconnection/resection of one entire hemisphere. This review will give an overview of the available surgical techniques today and will focus on how the technical advances enable us to map the brain and delineate the critical areas.


Subject(s)
Brain Mapping/methods , Epilepsy/surgery , Neuroimaging/methods , Neurosurgical Procedures/methods , Brain Mapping/trends , Humans , Neuroimaging/trends , Neurosurgical Procedures/trends
4.
Oncogene ; 29(20): 3017-24, 2010 May 20.
Article in English | MEDLINE | ID: mdl-20208569

ABSTRACT

Medulloblastoma (MB) is the most common malignant pediatric brain tumor. Dysregulation of WNT signaling occurs in up to 20% of cases. Using a genome-wide approach, we identified the secreted frizzled-related protein 1, 2 and 3 (SFRP1, SFRP2 and SFRP3) family of WNT inhibitors as putative tumor suppressor genes silenced by promoter region methylation in MB. SFRP1, SFRP2 and SFRP3 expression increased after 5-aza-2'-deoxycytidine treatment. SFRP1, SFRP2 and SFRP3 methylation was identified in 23.5, 3.9 and 15.7% of primary MB specimens, respectively, by methylation-specific PCR. Stable SFRP1, SFRP2 and SFRP3 expression reduced phospho-DVL2 levels and hindered MB cell proliferation and colony formation in soft agar in vitro. In 60% of primary tumors, SFRP1 was expressed at levels twofold lower than that in normal cerebellum. SFRP1 expression impaired tumor formation in vivo in flank and orthotopic intracerebellar xenograft models and conferred a significant survival advantage (P<0.0001). We identify for the first time tumor suppressor gene function of SFRP genes in MB, and suggest that loss of WNT pathway inhibition due to SFRP gene silencing is an additional mechanism that may contribute to excessive WNT signaling in this disease.


Subject(s)
Gene Silencing , Genes, Tumor Suppressor/physiology , Glycoproteins/genetics , Intercellular Signaling Peptides and Proteins/genetics , Medulloblastoma/genetics , Membrane Proteins/genetics , Wnt Proteins/metabolism , Adaptor Proteins, Signal Transducing/antagonists & inhibitors , Adaptor Proteins, Signal Transducing/genetics , Adaptor Proteins, Signal Transducing/metabolism , Animals , Cell Line, Tumor , Cerebellum/metabolism , Cerebellum/pathology , DNA Methylation , Dishevelled Proteins , Gene Expression Regulation, Neoplastic , Glycoproteins/metabolism , Humans , Intercellular Signaling Peptides and Proteins/metabolism , Intracellular Signaling Peptides and Proteins , Medulloblastoma/metabolism , Medulloblastoma/pathology , Membrane Proteins/metabolism , Mice , Mice, Nude , Phosphoproteins/antagonists & inhibitors , Phosphoproteins/genetics , Phosphoproteins/metabolism , Phosphorylation , Promoter Regions, Genetic , Survival Rate , Xenograft Model Antitumor Assays
5.
Indian J Cancer ; 46(2): 120-6, 2009.
Article in English | MEDLINE | ID: mdl-19346645

ABSTRACT

The role of surgery in the management of human gliomas has been controversial. The results from numerous neurosurgical series are inconsistent. The current adjuvant therapies have facilitated treatment of patients, and have rendered neurosurgical removal without morbidity or mortality more commonplace than ever before. Here, we investigated the role of surgery in the management of adults with low- and high-grade gliomas. Even though there is substantial evidence which claims that surgery per se has a role to play in extending patient survival, there is a paucity of randomized clinical trials on this subject, and little in the way of Class II data to support these claims. However, this should not divert patients away from surgery, because there may be additional benefits from a concerted effort to remove a tumor completely. At the present time, it seems best that clinicians continue to individualize patient treatment based on a myriad of factors that relate to the patient, the patient's tumor, and the known biology of the disease.


Subject(s)
Brain Neoplasms/surgery , Glioma/surgery , Brain Neoplasms/mortality , Brain Neoplasms/pathology , Glioma/mortality , Glioma/pathology , Humans , Neurosurgical Procedures , Survival Rate
6.
Acta Neurol Scand Suppl ; 186: 29-36, 2007.
Article in English | MEDLINE | ID: mdl-17784535

ABSTRACT

Magnetoencephalography (MEG) provides accurate localizing information of the epileptogenic zones in localization-related epilepsies. Refractory status epilepticus (RSE) is a life-threatening emergency that often requires prolonged high-dose suppressive therapy (HDST) to stop frequent and prolonged seizures. Surgical treatments for patients with RSE secondary to pre-existing epilepsy were reported. This article addresses the role of MEG in localizing the epileptogenic zone for the surgical treatment of patients with RSE. Five pediatric patients with RSE underwent epilepsy surgery using MEG, scalp video EEG and magnetic resonance imaging (MRI). Ictal MEG spike sources (MEGSSs) were localized in the clustered interictal MEGSSs in right Rolandic region (patient 3) and right temporal region (patient 5). Interictal MEG revealed unilateral clustered MEGSSs in four patients (patients 1, 2, 4, and 5) and bilateral (patient 3). Ictal-onset EEG findings were localized to one region in three patients (patients 1, 3, and 5) and two regions in the other two patients (patients 2 and 4). In all five patients, interictal discharges were widespread involving over two lobes (patients 2 and 4) or three lobes (patients 1, 3, and 5). Suppression burst pattern was obtained by HDST (patient 5). MRI showed cortical dysplasia in three patients (patients 1, 3, and 4). Patient 2 had a normal MRI. Patient 5 had normal MRI at the onset. Repeat MRI 5 days later showed diffusion restriction in the right hippocampus associated with increased signal intensity on T2 and FLAIR sequences. We performed cortical excision in two patients (patients 1 and 4), hemispherectotomy one (patient 3) and anterior temporal lobectomy two patients (patients 2 and 5). Two patients (patients 1 and 3) became seizure free, the other three patients experienced residual seizures. MEG showed clustered MEGSSs during the RSE in the pre-existing epilepsy patients and at an early time window in the acute symptomatic RSE patients. The complete resection of clustered MEGSSs can control RSE and possibly lead to a seizure free outcome.


Subject(s)
Brain/pathology , Brain/surgery , Magnetoencephalography/methods , Preoperative Care/methods , Status Epilepticus/diagnosis , Status Epilepticus/surgery , Action Potentials , Adolescent , Brain/physiopathology , Brain Mapping/methods , Child , Child, Preschool , Electroencephalography , Female , Gadolinium , Humans , Magnetic Resonance Imaging , Male , Neurosurgical Procedures/methods , Predictive Value of Tests , Status Epilepticus/physiopathology , Temporal Lobe/pathology , Temporal Lobe/physiopathology , Temporal Lobe/surgery , Treatment Outcome
7.
Acta Neurol Scand ; 116(1): 59-64, 2007 Jul.
Article in English | MEDLINE | ID: mdl-17587257

ABSTRACT

AIM OF THE STUDY: To report benign epileptiform discharges (BEDs) in the Rolandic region, coexisting in a pediatric patient with intractable localization-related epilepsy, secondary to hippocampal sclerosis. METHODS: We describe the clinical features, MRI, scalp video EEG, magnetoencephalography (MEG) and intracranial video EEG findings, and surgical outcome in a 9-year-old boy with BEDs and intractable complex partial seizures. RESULTS: MRI showed left hippocampal sclerosis. Scalp video EEG interictally demonstrated left temporal spike and sharply contoured slow waves, and right fronto-centro-temporal spike and waves. Ictal scalp video EEG showed left temporal rhythmic sharp waves after the clinical onset of epigastric aura, followed by staring. MEG showed interictal dipoles in the bilateral Rolandic regions with a uniform orientation and right hemispheric predominance. Intracranial video EEG, with bilateral mesial temporal depth and fronto-temporo-parietal strip electrodes, interictally showed polyspikes and slow waves with superimposed low-amplitude fast waves in the left mesial and posterior lateral temporal regions, and spike and waves in the bilateral fronto-parietal regions. Ictal onset was marked by low-amplitude fast waves in the left mesial and posterior lateral temporal regions. He underwent left anterior temporal lobectomy with hippocampectomy. Pathology was hippocampal sclerosis. Predominant right fronto-centro-temporal spike and waves and MEG right Rolandic dipoles persisted after surgery. He was seizure-free 14 months after surgery. CONCLUSION: This is the first report on MEG and intracranial video EEG features of BEDs in the Rolandic region, coexisting with hippocampal sclerosis. Persistence of contralateral benign MEG Rolandic dipoles after surgery indicates that BEDs are coincidental in mesial temporal lobe epilepsy. MEG identified Rolandic dipoles, although was unable to localize the deep and focal epileptogenic dipoles from the hippocampal sclerosis.


Subject(s)
Epilepsy, Complex Partial/physiopathology , Motor Cortex/physiopathology , Child , Electroencephalography , Epilepsy, Complex Partial/etiology , Epilepsy, Complex Partial/pathology , Hippocampus/pathology , Humans , Magnetic Resonance Imaging , Magnetoencephalography , Male , Motor Cortex/pathology , Sclerosis/complications
8.
Acta Neurol Scand ; 115(4 Suppl): 29-36, 2007 Apr.
Article in English | MEDLINE | ID: mdl-17362274

ABSTRACT

Magnetoencephalography (MEG) provides accurate localizing information of the epileptogenic zones in localization-related epilepsies. Refractory status epilepticus (RSE) is a life-threatening emergency that often requires prolonged high-dose suppressive therapy (HDST) to stop frequent and prolonged seizures. Surgical treatments for patients with RSE secondary to pre-existing epilepsy were reported. This article addresses the role of MEG in localizing the epileptogenic zone for the surgical treatment of patients with RSE. Five pediatric patients with RSE underwent epilepsy surgery using MEG, scalp video EEG and magnetic resonance imaging (MRI). Ictal MEG spike sources (MEGSSs) were localized in the clustered interictal MEGSSs in right Rolandic region (patient 3) and right temporal region (patient 5). Interictal MEG revealed unilateral clustered MEGSSs in four patients (patients 1, 2, 4, and 5) and bilateral (patient 3). Ictal-onset EEG findings were localized to one region in three patients (patients 1, 3, and 5) and two regions in the other two patients (patients 2 and 4). In all five patients, interictal discharges were widespread involving over two lobes (patients 2 and 4) or three lobes (patients 1, 3, and 5). Suppression burst pattern was obtained by HDST (patient 5). MRI showed cortical dysplasia in three patients (patients 1, 3, and 4). Patient 2 had a normal MRI. Patient 5 had normal MRI at the onset. Repeat MRI 5 days later showed diffusion restriction in the right hippocampus associated with increased signal intensity on T2 and FLAIR sequences. We performed cortical excision in two patients (patients 1 and 4), hemispherectotomy one (patient 3) and anterior temporal lobectomy two patients (patients 2 and 5). Two patients (patients 1 and 3) became seizure free, the other three patients experienced residual seizures. MEG showed clustered MEGSSs during the RSE in the pre-existing epilepsy patients and at an early time window in the acute symptomatic RSE patients. The complete resection of clustered MEGSSs can control RSE and possibly lead to a seizure free outcome.


Subject(s)
Magnetoencephalography , Neurosurgery/methods , Status Epilepticus/physiopathology , Status Epilepticus/surgery , Adolescent , Brain Mapping , Child , Child, Preschool , Electroencephalography/methods , Female , Humans , Magnetic Resonance Imaging , Male , Time Factors , Treatment Outcome
9.
Eye (Lond) ; 21(1): 5-10, 2007 Jan.
Article in English | MEDLINE | ID: mdl-16311527

ABSTRACT

AIMS: To review the ocular manifestations of crush head injuries in children. METHODS: Retrospective clinical and pathological reviews. Group 1: A total of 16 children admitted with crush head injuries from television tip over. Group 2: Nine autopsy findings in crush head injury. RESULTS: Group 1: A total of 11 children had fundus examination: three by neurosurgeons, eight by ophthalmologists. Scattered posterior pole preretinal and blot haemorrhages extending to mid equator region observed in one child. No evidence of traumatic retinoschisis or retinal folds in any patient. Group 2: All with multiple skull fractures and six with subdural haemorrhage. Posterior pole retinal haemorrhages in four children, extending to the ora serrata in one after motor vehicle accident. No child had retinal folds. Subinternal limiting membrane haemorrhages in three children. Optic nerve sheath haemorrhage in three children. CONCLUSIONS: Intraretinal and preretinal haemorrhages, predominantly in the posterior pole, can occur in crush injury to the paediatric head. Haemorrhage under the internal limiting membrane or extending to the ora serrata were only seen in situations where crush injury was part of a fatal trauma scenario related to motor vehicles. Retinal folds and the typical macular retinoschisis associated with abusive head injury were not observed.


Subject(s)
Brain Injuries/complications , Retina/injuries , Retinal Hemorrhage/etiology , Wounds, Nonpenetrating/etiology , Accidents, Home , Accidents, Traffic , Child , Child, Preschool , Female , Hematoma, Subdural/complications , Humans , Infant , Male , Optic Nerve Injuries/etiology , Prospective Studies , Retinoschisis/etiology , Retrospective Studies , Skull Fractures/complications
10.
J Neurol Neurosurg Psychiatry ; 77(11): 1256-61, 2006 Nov.
Article in English | MEDLINE | ID: mdl-16891385

ABSTRACT

OBJECTIVE: To characterise magnetoencephalographic spike sources in paediatric patients with auditory auras and recurrent localisation-related epilepsy. METHODS: Six patients (four boys and two girls (ages 7-14 years) were retrospectively studied. All patients had auditory auras as part of their initial seizure manifestation, including four patients who underwent previous brain surgery. Scalp video electroencephalography and magnetoencephalography (MEG) were carried out in six patients, intraoperative electrocorticography in three patients and extraoperative intracranial video electroencephalography in one patient. MEG auditory-evoked fields (AEFs) were studied in four patients. RESULTS: Three patients had elementary auditory auras, one had complex auditory aura and two had both complex and elementary auras. All six patients had clustered MEG spike sources with coexisting scattered spike sources. MEG clusters were localised in the superior temporal gyrus with surrounding scatters in four patients (two left and two right); two patients had scattered spikes in the superior temporal gyrus in addition to clustered MEG spike sources in the left inferior and middle frontal gyri or parieto-occipital region. AEFs were located within an MEG cluster in one patient and within 3 cm of a cluster in two patients. Surgical resection, including the regions of MEG clusters, was carried out in four patients. Three of four patients who had previous surgeries were seizure free at 2 years after excision of the MEG cluster region. CONCLUSIONS: MEG spike sources clustered in the superior temporal gyrus in six patients with auditory auras. These spike sources were in close proximity or seemed to engulf the magnetic AEF. Areas with MEG spike sources contained the residual or recurrent epileptogenic zone after incomplete cortical excision for lesional epilepsy.


Subject(s)
Epilepsies, Partial/physiopathology , Temporal Lobe/physiopathology , Adolescent , Auditory Perception , Child , Female , Humans , Magnetoencephalography , Male , Retrospective Studies
12.
Neurology ; 62(12): 2270-6, 2004 Jun 22.
Article in English | MEDLINE | ID: mdl-15210893

ABSTRACT

BACKGROUND: Dysembryoplastic neuroepithelial tumors (DNTs) are associated with medically intractable epilepsy and a favorable prognosis after surgical resection. The authors describe the clinical, radiologic, and pathologic characteristics and outcomes in children after surgical resection of pathologically confirmed DNT to ascertain prognostic features for seizure recurrence following surgery. METHODS: Neurology, neurosurgery, and pathology databases from 1993 to 2002 at the Hospital for Sick Children were searched to retrospectively identify children with confirmed DNT and presentation with seizures. Risk factors for postoperative seizure recurrence were examined with respect to seizure outcome at 12 months and long-term follow-up. RESULTS: Of the 26 children identified (mean age at surgery 10.0 years) seizure outcome was good in 22 children (85%) at 12 months (Class 1). At longer follow-up (mean 4.3, range 1.0 to 11.0 years) only 16 (62%) remained seizure-free. Residual DNT was evident in 15 of the 24 children with available postoperative MRI. Three children demonstrated recurrence of tumor. At 12 months follow-up, older age (>10 years) and longer duration of epilepsy (>2 years) were associated with seizure recurrence. The presence of residual tumor was a risk factor for seizure recurrence at long-term follow-up (p = 0.02). CONCLUSIONS: Children with DNT and epilepsy may benefit from surgical management; however, seizure outcome is not always favorable. Although the majority of children remain seizure free after surgical excision of DNT, a considerable number have recurrent seizures. Short-term outcome is influenced by older age at surgery and longer duration of epilepsy. Residual tumor is a significant risk factor for poor seizure outcome. Recurrent tumor can occur.


Subject(s)
Brain Neoplasms/complications , Brain Neoplasms/surgery , Epilepsy/etiology , Epilepsy/surgery , Neoplasms, Neuroepithelial/complications , Neoplasms, Neuroepithelial/surgery , Adolescent , Brain Neoplasms/diagnosis , Child , Child, Preschool , Female , Humans , Male , Neoplasms, Neuroepithelial/diagnosis , Prognosis , Recurrence , Treatment Outcome
13.
Cancer Lett ; 198(1): 21-7, 2003 Jul 30.
Article in English | MEDLINE | ID: mdl-12893426

ABSTRACT

Malignant astrocytomas have been found to express P-glycoprotein (Pgp, mdr1 gene product). It was hypothesized that in addition to conferring multidrug resistance, Pgp is intimately associated with the development of astrocytomas. Accordingly, we studied the effect of PSC 833 (PSC, Novartis), a potent inhibitor of Pgp, on the growth of Pgp-expressing astrocytoma cells. The results showed that in all the cell lines tested, PSC (10-60 microM) inhibited the growth as well as induced cell death. Cells exposed to PSC exhibited DNA ladder characteristic of apoptosis. PSC-induced cell death could be reversed by Z-VAD-fmk, a general caspase inhibitor, indicating that PSC-induced cell death was characteristic of caspase-mediated apoptosis. These results suggest a novel therapeutic strategy in the treatment of malignant astrocytomas by inhibitors of Pgp.


Subject(s)
ATP Binding Cassette Transporter, Subfamily B, Member 1/physiology , Astrocytoma/metabolism , Brain Neoplasms/metabolism , Cyclosporins/pharmacology , ATP Binding Cassette Transporter, Subfamily B, Member 1/antagonists & inhibitors , Amino Acid Chloromethyl Ketones/pharmacology , Apoptosis/drug effects , Caspases/metabolism , Cysteine Proteinase Inhibitors/pharmacology , Humans , Tumor Cells, Cultured
14.
Pediatr Neurosurg ; 35(5): 235-8, 2001 Nov.
Article in English | MEDLINE | ID: mdl-11741116

ABSTRACT

Although medulloblastoma is usually sporadic, there are a number of uncommon predisposing germline mutation syndromes, including: Gorlin's Syndrome, Turcot's Syndrome and Li-Fraumeni Syndrome. Patients with Rubenstein-Taybi Syndrome secondary to mutation/deletion of the CBP gene on chromosome 16 are predisposed to a variety of developmental anomalies as well as cancer. We report a child with Rubenstein-Taybi syndrome who developed a cerebellar medulloblastoma and review the literature on Rubenstein-Taybi Syndrome and pediatric medulloblastoma. As the product of the CBP gene functions in a variety of signaling pathways, we discuss the molecular implications of findings a medulloblastoma in a child with Rubenstein-Taybi Syndrome.


Subject(s)
Abnormalities, Multiple/genetics , Cerebellar Neoplasms/genetics , Intellectual Disability/genetics , Medulloblastoma/genetics , Abnormalities, Multiple/pathology , Abnormalities, Multiple/surgery , Cell Division/physiology , Cerebellar Neoplasms/pathology , Cerebellar Neoplasms/surgery , Cerebellum/pathology , Cerebellum/surgery , Humans , Infant , Intellectual Disability/pathology , Intellectual Disability/surgery , Magnetic Resonance Imaging , Male , Medulloblastoma/pathology , Medulloblastoma/surgery , Syndrome , Tomography, X-Ray Computed
15.
Pediatr Neurol ; 25(4): 295-303, 2001 Oct.
Article in English | MEDLINE | ID: mdl-11704398

ABSTRACT

To describe the radiologic-pathologic correlation in children who underwent epilepsy surgery for medically intractable epilepsy with pathologically confirmed focal cortical dysplasia and hemimegalencephaly, we conducted a retrospective review on the magnetic resonance imaging and pathology of 18 children (10 boys and 8 girls). The preoperative MRIs were reviewed by one neuroradiologist who did not know the radiologic diagnosis and the pathology reports. MRI revealed focal cortical dysplasia (10), hemimegalencephaly (3), hamartomas (2), polymicrogyria (1), pial hemosiderosis (1), and no abnormality (1). Pathologic examination revealed focal cortical dysplasia (9), forme fruste of tuberous sclerosis (5), hemimegalencephaly (3), and focal cortical dysplasia with mesial temporal sclerosis (1). MRI was accurate in making the preoperative diagnosis in 16 out of 18 patients. On MRI, 12 patients had abnormal gyral formation and 12 had abnormal cortical thickness. Eleven patients manifested loss of gray-white differentiation, and 11 patients had abnormal signal on T(2)-weighted image. Pathologically, 15 patients had neuronal heterotopia, 12 had misalignment or disorientation of neurons, 11 had large neurons, and 10 had abnormal cortical lamination. The presence of ectopic and large neurons and abnormal cortical lamination may be responsible for the MRI characteristics.


Subject(s)
Brain Diseases/diagnostic imaging , Brain Diseases/pathology , Cerebral Cortex/abnormalities , Cerebral Cortex/diagnostic imaging , Cytomegalovirus/isolation & purification , Epilepsy/etiology , Magnetic Resonance Imaging , Neurons/pathology , Biopsy , Brain/abnormalities , Brain Diseases/complications , Cell Movement , Central Nervous System Viral Diseases/pathology , Central Nervous System Viral Diseases/virology , Child, Preschool , Cytomegalovirus Infections/pathology , Epilepsy/diagnostic imaging , Epilepsy/pathology , Female , Humans , Infant , Infant, Newborn , Male , Polymerase Chain Reaction , Radiography , Retrospective Studies
16.
J Neurooncol ; 53(2): 115-27, 2001 Jun.
Article in English | MEDLINE | ID: mdl-11716065

ABSTRACT

The extracellular matrix (ECM) of the central nervous system (CNS) is enriched in hyaluronate (HA). Ubiquitous receptors for HA are CD44 and the Receptor for HA-Mediated Motility known as RHAMM. In the present study, we have investigated the potential role of CD44 and RHAMM in the migration and proliferation of human astrocytoma cells. HA-receptor expression in brain tumor cell lines and surgical specimens was determined by immunocytochemistry and western blot analyses. The ability of RHAMM to bind ligand was determined through cetylpyridinium chloride (CPC) precipitations of brain tumor lysates in HA-binding assays. The effects of HA, CD44 blocking antibodies, and RHAMM soluble peptide on astrocytoma cell growth and migration was determined using MTT and migration assays. Our results show that the expression of the HA-receptors, CD44, and RHAMM, is virtually ubiquitous amongst glioma cell lines, and glioma tumor specimens. There was a gradient of expression amongst gliomas with high grade gliomas expressing more RHAMM and CD44 than did lower grade lesions or did normal human astrocytes or non-neoplastic specimens of human brain. Specific RHAMM variants of 85- and 58-kDa size were shown to bind avidly to HA following CPC precipitations. RHAMM soluble peptide inhibited glioma cell line proliferation in a dose-dependent fashion. Finally, while anti-CD44 antibodies did not inhibit the migration of human glioma cells, soluble peptides directed at the HA-binding domain of RHAMM inhibited glioma migration both on and off an HA-based ECM. These data support the notion that HA-receptors contribute to brain tumor adhesion, proliferation, and migration, biological features which must be better understood before more effective treatment strategies for these tumors can be found.


Subject(s)
Brain Neoplasms/metabolism , Extracellular Matrix Proteins/physiology , Glioma/metabolism , Hyaluronan Receptors/physiology , Hyaluronic Acid/metabolism , Neoplasm Invasiveness/physiopathology , Neoplasm Proteins/physiology , Antibodies, Monoclonal/pharmacology , Astrocytoma/metabolism , Astrocytoma/pathology , Blotting, Western , Brain Neoplasms/pathology , Cell Division , Cell Movement , Extracellular Matrix/metabolism , Extracellular Matrix Proteins/immunology , Ganglioglioma/metabolism , Ganglioglioma/pathology , Glioblastoma/metabolism , Glioblastoma/pathology , Glioma/pathology , Hyaluronan Receptors/immunology , Medulloblastoma/metabolism , Medulloblastoma/pathology , Microscopy, Fluorescence , Molecular Weight , Neoplasm Proteins/immunology , Tumor Cells, Cultured
17.
J Child Neurol ; 16(9): 661-7, 2001 Sep.
Article in English | MEDLINE | ID: mdl-11575607

ABSTRACT

We retrospectively compared electroencephalographic (EEG) dipoles of interictal spikes from prolonged video-EEG monitoring with magnetoencephalographic dipoles from short-term recording in four children with extratemporal lobe epilepsy. We analyzed both sets of dipoles using individual interictal spikes and single moving dipole modeling and evaluated the profiles of spike appearance, dipole position, and orientation in EEG and magnetoencephalography. We obtained more than 100 magnetoencephalographic spikes in two patients who manifested frequent interictal EEG spikes throughout both day and night but fewer than 40 magnetoencephalographic spikes in two patients who had interictal EEG spikes mainly during sleep. The dipole positions of EEG and magnetoencephalography were in close proximity and included in the surgical resection area. Most of the dipoles between EEG and magnetoencephalography were oriented perpendicularly. A combination of EEG dipole analysis from prolonged video-EEG monitoring and magnetoencephalographic dipole analysis provides complementary information for presurgical evaluation in children with intractable extratemporal lobe epilepsy.


Subject(s)
Electroencephalography , Epilepsies, Partial/diagnosis , Epilepsy, Frontal Lobe/diagnosis , Epilepsy, Temporal Lobe/diagnosis , Magnetoencephalography , Parietal Lobe , Video Recording , Adolescent , Brain Mapping , Child , Diagnosis, Differential , Epilepsies, Partial/physiopathology , Epilepsies, Partial/surgery , Epilepsy, Frontal Lobe/physiopathology , Epilepsy, Frontal Lobe/surgery , Epilepsy, Temporal Lobe/physiopathology , Epilepsy, Temporal Lobe/surgery , Evoked Potentials/physiology , Female , Humans , Length of Stay , Male , Monitoring, Physiologic , Parietal Lobe/physiopathology , Parietal Lobe/surgery , Predictive Value of Tests , Retrospective Studies , Signal Processing, Computer-Assisted
18.
J Neurosurg ; 95(3): 420-4, 2001 Sep.
Article in English | MEDLINE | ID: mdl-11565862

ABSTRACT

OBJECT: Two major criteria are necessary to diagnose cerebral salt wasting (CSW): a cerebral lesion and a large urinary excretion of Na+ and Cl- at a time when the extracellular fluid (ECF) volume is contracted. Nevertheless, it is difficult for the physician to confirm from bedside observation that a patient has a contracted ECF volume. Hyponatremia, although frequently present, should not be a criterion for a diagnosis of salt wasting. A contracted ECF volume is unlikely if there are positive balances of Na+ and Cl-. The goal of this study was to assess the accuracy of calculating balances for Na+ plus K+ and of Cl- over 1 to 10 days in an intensive care unit (ICU) setting. METHODS: A prospective comparison of measured and estimated quantities of Na+ plus K+ and of Cl- excreted over 1 to 10 days in 10 children and 12 adults who had recently received a traumatic brain injury or undergone recent neurosurgery. Plasma concentrations of electrolytes were recorded at the beginning and end of the study period. The total volumes infused and excreted and the concentrations of Na+, K+, and Cl- in the infusate were obtained from each patient's ICU chart. The electrolytes in the patients' urine were measured and calculated. Correlations between measured and calculated values for excretions of Cl- and of Na+ plus K+ were excellent. CONCLUSIONS: Mass balances for Na+ plus K+ and for Cl- can be accurately estimated. These data provide information to support or refute a clinical diagnosis of CSW. The danger of relying on balances for these electrolytes measured within a single day to diagnose CSW is illustrated.


Subject(s)
Brain Injuries/complications , Brain Neoplasms/surgery , Electrolytes/urine , Inappropriate ADH Syndrome/diagnosis , Postoperative Complications/diagnosis , Subarachnoid Hemorrhage/complications , Adolescent , Adult , Aged , Brain Injuries/urine , Brain Neoplasms/urine , Child , Child, Preschool , Critical Care , Female , Humans , Inappropriate ADH Syndrome/urine , Male , Middle Aged , Postoperative Complications/urine , Prospective Studies , Risk Factors , Subarachnoid Hemorrhage/urine , Water-Electrolyte Balance/physiology
19.
Pediatr Neurol ; 24(5): 344-50, 2001 May.
Article in English | MEDLINE | ID: mdl-11516607

ABSTRACT

The purpose of the study was to investigate factors altering the amperage threshold needed to provoke functional responses in children with epilepsy. Twenty patients (4-18 years of age) who underwent epilepsy surgery at our institution from 1996-2000 after insertion of subdural grid electrodes were reviewed retrospectively. Extraoperative electrical cortical stimulation was performed with 50-Hz biphasic pulses of 0.2 ms in duration using a "distance reference" technique. Amperage thresholds of primary motor responses and afterdischarges were evaluated. The patients were grouped according to underlying pathology: eight with neuronal migration disorders (group A) and 12 with other disorders (group B). The motor cortex was defined successfully in all children because the afterdischarges threshold was higher than the motor cortical threshold. Amperage thresholds ranged from 2-20 mA (mean = 7.7) for primary motor function. An inverse relationship was found between amperage threshold and age: the younger the patient, the higher the threshold (P = 0.0005). Patients in group A required a higher amperage (2-20 mA, mean = 8.6) for motor cortical mapping than those in group B (2-14 mA, mean = 6.4). Younger children with neuronal migration disorders require a higher amperage threshold to achieve adequate motor functional mapping with careful observation of afterdischarges.


Subject(s)
Brain Mapping , Cerebral Cortex/physiopathology , Electroencephalography , Motor Cortex/physiopathology , Adolescent , Brain Damage, Chronic/physiopathology , Brain Damage, Chronic/surgery , Cerebral Cortex/surgery , Child , Child, Preschool , Electric Stimulation , Female , Follow-Up Studies , Humans , Male , Motor Activity/physiology , Motor Cortex/surgery , Psychosurgery , Sensory Thresholds/physiology , Signal Processing, Computer-Assisted , Video Recording
20.
Neurology ; 57(4): 590-6, 2001 Aug 28.
Article in English | MEDLINE | ID: mdl-11524465

ABSTRACT

OBJECTIVE: To describe the diagnosis, treatment, and outcomes in children with malignant rolandic-sylvian epilepsy (MRSE), defined as a form of epilepsy characterized by sensorimotor seizures, medical refractoriness, normal MRI, frontocentrotemporal EEG spikes, rolandic-sylvian spike sources on magnetoencephalography (MEG), and cognitive problems. METHODS: A retrospective chart analysis of seven patients who had shown these characteristics and undergone extensive diagnostic testing, including MEG and intracranial video-EEG was performed. RESULTS: Interictal scalp EEG spikes were seen over the frontocentrotemporal regions bilaterally (6) and unilaterally (1). MEG showed spike sources in the perisylvian region in two patients (both bilateral) and in the perirolandic fissure in five (two bilateral). Three patients required bilateral subdural strips to lateralize seizures before electrocorticography. Final electrocorticograms showed an ictal onset zone around the rolandic (four cases) and rolandic-sylvian regions (three cases). Six patients showed neuropsychological deficits. After cortical excision and multiple subpial transection, three were seizure free and four had seizures rarely (30 months' mean follow-up). No child had a permanent deficit in sensorimotor or cognitive functions, although two showed exacerbation of preexisting attentional deficits. Tissue analysis showed definite evidence of neuronal migration disorders (3) and gliosis (2). CONCLUSIONS: MEG was helpful for localizing both malignant rolandic-sylvian neuronal activities and functional cortex. Successive neuropsychological assessments are necessary to detect cognitive deterioration and indicate remedial programming. If, after careful observation over at least 5 years, surgery is considered to control refractory seizures, intracranial video-EEG is needed to localize the epileptogenic zone.


Subject(s)
Electroencephalography , Epilepsy, Rolandic/diagnosis , Magnetoencephalography , Adolescent , Child , Electroencephalography/methods , Epilepsy, Rolandic/psychology , Epilepsy, Rolandic/surgery , Evoked Potentials, Somatosensory/physiology , Female , Humans , Magnetoencephalography/methods , Male , Neuropsychological Tests , Retrospective Studies , Telemetry/methods , Video Recording/methods
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