Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0036572 (seizures)
 80,221 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Elevated levels of extracellular glutamate ([Glu]o) cause uncontrolled Ca2+ increases in most neurons and are believed to mediate excitotoxic brain injury following stroke and other nervous system insults. In the normal brain, [Glu]o is tightly controlled by uptake into astrocytes. Because the vast majority of primary brain tumors (gliomas) are derived from astrocytes, we investigated glutamate uptake in glioma cells surgically isolated from glioma patients (glioblastoma multiforme) and in seven established human glioma cell lines, including STTG-1, D-54 MG, D-65 MG, U-373 MG, U-138 MG, U-251 MG, and CH-235 MG. All glioma cells studied showed impaired glutamate uptake, with a Vmax < 10% that of normal astrocytes. Moreover, rather than removing glutamate from the extracellular fluid, glioma cells release large amounts of glutamate, resulting in elevations of [Glu]o in excess of 100 microM within hours in a space that is 1000-fold larger than the cellular volume. Exposure of cultured hippocampal neurons to glioma-conditioned medium elicited sustained [Ca2+]i elevations that were followed by widespread neuronal death. Similarly, coculturing of hippocampal neurons and glioma cells, either with or without direct contact, resulted in neuronal death. Glioma-induced neuronal death could be completely prevented by treating neurons with the N-methyl-D-aspartate receptor antagonists MK-801/D(-)-2-amino-5-phosphonopentanoic acid or by depletion of glutamate from the medium. Interestingly, several phenylglycine derivatives including the metabotropic glutamate receptor agonist/antagonist (S)-4-carboxyphenylglycine (S-4CPG) potently and selectively inhibited glutamate release from glioma cells and prevented neurotoxicity. These data suggest that growing glioma tumors may actively kill surrounding neuronal cells through the release of glutamate. This glutamate release may also be responsible in part for tumor-associated seizures that occur frequently in conjunction with glioma. These data also suggest that neurotoxic release of glutamate by gliomas may be prevented by phenylglycine derivatives, which may thus be useful as an adjuvant treatment for brain tumors.
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PMID:Glioma cells release excitotoxic concentrations of glutamate. 1048 87

Between December 1996 and September 1998, 13 patients with advanced recurrent malignant brain tumors (9 with glioblastoma multiforme, 1 with gliosarcoma, and 3 with anaplastic astrocytoma) were treated with a single intratumoral injection of 2 x 10(9), 2 x 10(10), 2 x 10(11), or 2 x 10(12) vector particles (VP) of a replication-defective adenoviral vector bearing the herpes simplex virus thymidine kinase gene driven by the Rous sarcoma virus promoter (Adv.RSVtk), followed by ganciclovir (GCV) treatment. The VP to infectious unit ratio was 20:1. Our primary objective was to determine the safety of this treatment. Injection of Adv.RSVtk in doses <==2 x 10(11) VP, followed by GCV, was safely tolerated. Patients treated with the highest dose, 2 x 10(12) VP, exhibited central nervous system toxicity with confusion, hyponatremia, and seizures. One patient is living and stable 29.2 months after treatment. Two patients survived >25 months before succumbing to tumor progression. Ten patients died within 10 months of treatment, 9 from tumor progression and 1 with sepsis and endocarditis. Neuropathologic examination of postmortem tissue demonstrated cavitation at the injection site, intratumoral foci of coagulative necrosis, and variable infiltration of the residual tumor with macrophages and lymphocytes.
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PMID:Phase I study of adenoviral delivery of the HSV-tk gene and ganciclovir administration in patients with current malignant brain tumors. 1093 31

Glioblastoma multiforme (GBM) is the commonest primary malignant neoplasm of the CNS. Usually, patients present with seizures and headache but in the elderly, confusion and generalised cognitive decline are more frequently the initial features. Multiple cranial nerve lesions as a manifestation of leptomeningeal meningitis is a rare presentation of GBM. The diagnosis is not often suggestive on either brain computed tomography (CT) or magnetic resonance imaging (MRI) and is usually confirmed by cerebrospinal fluid (CSF) cytology or histology. We describe the case of an 80-year-old man, who presented with multiple cranial nerve palsies and confusion secondary to leptomeningeal gliomatosis, in whom GBM was detected along the intra-ventricular lining of the left lateral ventricle at ventriculoscopy, in the absence of a distinct parenchymal lesion.
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PMID:Leptomeningeal glioblastoma presenting with multiple cranial neuropathies and confusion. 1115 9

Ependymomas account for 3 to 9% of all neuroepithelial tumors and, although occurring most often within the ventricular system, they may arise from the extraventricular parenchyma as well. Several histologic patterns of these neoplasm are well known, but little attention has been devoted to a variant composed of giant elements. We describe the case of a 13-year-old girl experiencing a 3-month history of partial seizures in whom cranial magnetic resonance imaging showed an extraventricular, right parietotemporal neoplasm, adherent to the overlying dura mater. Histologic, immunohistochemical and ultrastructural findings were consistent with those of a high-grade ependymoma. The tumor was characterized by the presence of a major component of pleomorphic giant cells, as also seen in pleomorphic xantoastrocytoma, subependymal giant cell astrocytoma and glioblastoma multiforme. Similar elements have been described in two filum terminale and one supratentorial, intraventricular ependymoma, respectively. Histologic and evolutional data of those and of our own case suggest that isolated giant cells are not necessarily linked to a bad prognosis in ependymomas.
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PMID:Supratentorial giant cell ependymoma. 1122 Jun 93

Two hundred patients with supratentorial glioma; astrocytoma (pilocytic, fibrillary, gemistocytic) 82, mixed glioma (oligoastrocytoma) 46, oligodendroglioma 8, malignant (anaplastic) astrocytoma 33 and glioblastoma multiforme 31, surgically treated for the tumours and followed up for one to sixteen years, were retrospectively analysed for the incidence of pre and postoperative epileptic seizures. 122 patients (61%) had seizures preoperatively. 62 (50.8%) of them had at least one or more seizures during follow up. Seizures were persistent in 22 patients. Doubtful, or one or two minor seizures occurred in 19 cases. Six patients in this group had seizure only at the time of CT confirmed recurrence, after a seizure free interval of one to nine years. Amongst 78 patients who did not have seizures preoperatively, 24 (30.6%) developed seizures during the postoperative follow up period. Recurrent attacks were reported only by 5 patients while 15 patients had seizure(s) only at the time of recurrence of tumour. Two patients had a few seizures in the early postoperative period and none thereafter, while doubtful seizures were reported by two patients.
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PMID:Epileptic seizures in supratentorial gliomas. 1130 43

Glioblastoma multiforme (GBM) has associated with it one of the poorest prognoses among brain tumors. Postoperative seizures and the side effects of anticonvulsants, routinely given for prophylactic purposes, add to patient morbidity. The primary goal of this study was to determine who, of those undergoing craniotomy for GBM resection, is at risk for epilepsy. We studied 72 consecutive patients who underwent craniotomy and palliative resection for GBM. Twenty-nine presented with seizures and 17 had postoperative seizures. All patients were treated with a postoperative anticonvulsant for at least six months; anticonvulsants were continued longer if there was a postoperative seizure. Patient factors examined for an association with risk for postoperative seizure included age, sex, tumor size, tumor location, adjuvant therapy, postoperative complications and history of preoperative seizures. The majority of patients with no prior seizure history and who seized postoperatively had their first seizure after withdrawal from their anticonvulsant medication. All, but one, of the patients with both pre- and postoperative seizures had their first postoperative seizure while still on anticonvulsants. Smaller tumor size and frontal resection were associated with an increased risk of postoperative seizures. Our data suggests that those who do not present with seizures and undergo GBM resection may still be prone to seize but more easily protected from postoperative seizures with anticonvulsant therapy than patients who present with seizures; resection of frontal tumors and smaller tumors seemed to indicate an increased risk for postoperative seizures.
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PMID:Postoperative epilepsy in patients undergoing craniotomy for glioblastoma multiforme. 1137 Aug 29

Sometimes, the clinical presentation of a brain tumour mimics that of stroke or vice versa, as exemplified in the following three patients. In a 73-year-old patient the initial clinical picture was compatible with a brachial plexus lesion, as the weakness in his right hand appeared to have a traumatic, and not a central nervous system related, cause. When he experienced a focal seizure, the CT scan of the brain revealed a lesion in the motor cortex. This was presumed to be an infarction due to the lack of mass effect and the absence of contrast enhancement. Shortly afterwards the patient deteriorated and a follow-up scan revealed a large contrast-enhancing lesion. During surgery this proved to be a glioblastoma multiforme. A 76-year-old man was suffering from a progressive neurological deficit. An MRI scan of the brain revealed a contrast-enhancing lesion and a chest X-ray revealed an asymptomatic lung tumour; the diagnosis 'brain metastasis' was made. The surgeon removed the lung tumour, which proved to be a carcinoma. Later, when the patient was referred to the neurosurgeon for extirpation of the presumed brain metastasis, the MRI scan revealed that the lesion had decreased in size and no longer exhibited contrast enhancement. The metastasis proved to be an infarction. A 53-year-old man presented with sudden loss of consciousness due to a haemorrhage in the occipital lobe. An angiogram did not reveal a vascular malformation and during surgery no abnormal tissue was seen. The patient almost made a complete recovery. However, several months later he developed an elevated intracranial pressure due to a large occipital high-grade glioma, which had caused the original haemorrhage.
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PMID:[Brain tumor or stroke?]. 1137 93

Glioblastoma multiforme (GBM) makes up as many as 30% of all primary brain tumors. Despite the employment of multimodal antitumor treatment, the overall survival is less than one year. Between 06/01/1998 and 06/01/2000 17 patients (Group A) with GBM (11 males, 6 females; median age 54.3 years) were administered local chemotherapy with cisplatin incorporated into biodegradable 6-carboxylcellulose polymer (cisplatin-depot (CDDP-D)). After the subtotal removal of GBM, twenty 1.5 x 1.5 cm polymer plates with a total area of 45 cm2 (the density of cisplatin immobilization on 6-carboxylcellulose being 1 mg/cm2, a total cisplatin dose of 45 mg) were implanted into the tumor bed. Group B (21 patients with GBM; 11 males, 10 females; median age 53.2 years) was control: the subtotal tumor ablation without CDDP-D implantation. Two to three weeks after the surgery all the patients of Groups A and B started a course of radiation therapy. A total dose of cranial irradiation was 20 Gy (1 fraction/day, 5 days/week; a daily dose of 2 Gy) followed by a boost tumor bed irradiation (1 fraction/day, 5 days/week; a daily dose of 2 Gy) up to the conventional dose of 60 Gy. Survival data for the patients were processed using the Kaplan-Meier method and analyzed by logrank test. All the patients of Group A tolerated surgical ablation of the brain tumor without side effects (brain edema, seizures, etc.). No patient of Group A had a reduction in blood cell counts during six weeks that would indicate systemic exposure to cisplatin. Blood chemistry and urinalysis did not show evidence of renal injury. No side effects of radiotherapy were registered in Group B either, regarding both the psychoneurological status of the patients and the basic values of homeostasis. Karnofsky performance scale (KPS) score of Group A and Group B patients demonstrated no significant differences before and after the surgery. The median overall survivals for patients of Group A and Group B were 427.5 and 211.0 days respectively (p = 0.00001; overall logrank test). Conclusion. Local chemotherapy of GBM with CDDP-D followed by irradiation is well tolerated and effective.
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PMID:Local chemotherapy with cisplatin-depot for glioblastoma multiforme. 1241 46

The mechanisms that regulate mammalian cell size during development and homeostatic maintenance are poorly understood. The tumor suppressor Pten is required for correct maintenance of mammalian neuronal soma size. Selective inactivation of Pten in postnatal granule neurons of the cerebellum and dentate gyrus in mouse causes cell-autonomous hypertrophy as well as more complex phenotypes, including progressive macrocephaly, seizures, and premature death. To determine the contribution of mTor signaling to Pten-mediated growth regulation in the mammalian nervous system, we treated Pten conditional knockout mice with CCI-779, a specific mTor inhibitor. mTor inhibition decreased the seizure frequency and death rate in Pten mutant mice, prevented the increase in Pten-deficient neuronal soma size in young mice, and reversed neuronal soma enlargement in adult mice. mTor inhibition did not decrease the size of wild-type adult neurons. Thus, mTor is required for neuronal hypertrophy downstream of Pten deficiency, but is not required for maintenance of normal neuronal soma size. mTOR inhibitors may be useful therapeutic agents for diseases in brain resulting from PTEN deficiency such as Lhermitte-Duclos disease or glioblastoma multiforme.
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PMID:mTor is required for hypertrophy of Pten-deficient neuronal soma in vivo. 1453 28

A 58-year-old woman presents with headache, mental status changes, and new-onset generalized seizures. MRI of the brain reveals a frontoparietal enhancing mass lesion suggestive of glioblastoma multiforme. Craniotomy for diagnosis, debulking, and likely placement of chemotherapy-impregnated wafers is planned. Venous thromboprophylaxis is prescribed.
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PMID:Patients undergoing surgical resection of primary brain tumors should receive pharmacologic venous thromboprophylaxis. 1468 Feb 99


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