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)

We report a case of high uptake of 11C-methionine (MET), 18F-FDG (FDG) and 201Tl-Cl (Tl) in brain radiation necrosis. Twenty-one years previously, the patient had undergone surgery and radiation therapy consisting of 60-Gy for ependymoma in the anterior horn of the right lateral ventricle. The clinical features consisting of frequent seizures of the left face and arm suddenly appeared 2 wk before admission. MRI depicted a Tl and T2-prolonged lesion in the right frontal lobe. Abnormally high uptake in this area demonstrated by MET-PET, FDG-PET, Tl-SPECT or HMPAO-SPECT suggested the presence of a recurrent tumor. A craniotomy was then performed and an intraoperative electrocorticogram showed continuous epileptic spikes in the lesion. The epileptic foci were resected and the histological features of the lesion were consistent with radiation necrosis. After surgery, the seizures disappeared and the postoperative examinations with MET-PET, FDG-PET, Tl-SPECT and HM-PAO-SPECT no longer showed abnormally high uptake. Hypermetabolism and hyperperfusion related to epileptic fits are therefore thought to result in high uptake of MET, FDG and Tl in radiation necrosis.
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PMID:Hyperperfusion and hypermetabolism in brain radiation necrosis with epileptic activity. 896 92

Proton magnetic resonance spectroscopy (MRS) has demonstrated reduction of N-acetylaspartate (NAA) in the epileptogenic temporal lobe. However, the correlation of NAA reduction with cerebral metabolic abnormalities is unknown in temporal lobe epilepsy (TLE). Proton MRS and 18F-fluorodeoxyglucose positron emission tomography (FDG/PET) were used to study 12 unilateral TLE patients with medically intractable seizures and 26 age-matched healthy volunteers. The epileptogenic temporal lobe of each patient was determined by both electroencephalography and FDG/PET. The NAA/choline-plus-creatine (NAA/(Cho+Cr)) ratio correlated significantly with the interictal glucose metabolism (r = 0.54, P < 0.01) in 12 TLE patients. The mean NAA/(Cho+Cr) ratio in the epileptogenic temporal lobe was significantly less than that in the contralateral side (P < 0.01), and less than that in normal control temporal lobes (P < 0.0001). These results suggest that quantitative MRS abnormalities reflect underlying metabolic pathology in TLE.
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PMID:Temporal lobe epilepsy: correlation of proton magnetic resonance spectroscopy and 18F-fluorodeoxyglucose positron emission tomography. 897 28

The involvement of opioid neurotransmitter systems in seizure mechanisms is well documented. In previous positron emission tomography (PET) studies in patients with unilateral temporal lobe epilepsy, we have found evidence for differential regulation of the opioid-receptor subtypes. The present study extends our previous observations to delta-opioid receptors by using the delta-receptor-selective antagonist [11C]methylnaltrindole ([11C]MeNTI). Paired measurements of delta- and mu-opioid receptor binding and metabolic activity were performed with PET using [11C]MeNTI and [11C]carfentanil ([11C]CFN) and [18F]fluorodeoxyglucose ([18F]FDG), respectively. Binding of [11C]MeNTI and [11C]CFN increased and [18F]FDG uptake decreased in the temporal cortex (TC) ipsilateral to the focus. Decreases in [18F]FDG uptake were more widespread regionally than were increases in opioid receptors. Increases in the delta- and mu-receptor binding showed different regional patterns. Increases in mu-receptor binding were confined to the middle aspect of the inferior TC, whereas binding of delta receptors increased in the mid-inferior TC and anterior aspect of the middle and superior TC. The increase in delta receptors suggests their anticonvulsant action, as previously shown for the delta-receptor subtype, whereas the different regional pattern of receptor alterations suggest the distinct roles of different opioid-receptor subtypes in seizure phenomena.
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PMID:Imaging of delta- and mu-opioid receptors in temporal lobe epilepsy by positron emission tomography. 906 57

The purpose of this study was to compare 2-[18F]fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET), hippocampal volumetry (HV), T2 relaxometry, and proton magnetic resonance spectroscopic imaging (1H-MRSI) in the presurgical neuroimaging lateralization of patients with nonlesional, electroencephalogram (EEG)-defined unilateral temporal lobe epilepsy (TLE). Twenty-five patients were prospectively studied, along with age-matched controls. T2 relaxometry examinations were performed in 13 patients. Comparison of FDG-PET, HV, and 1H-MRSI was possible in 23 patients. FDG-PET lateralized 87% of patients, HV 65%, N-acetyl aspartate (NAA)/(choline [Cho] + creatine [Cr]) 61%, and [NAA] 57%. Combined HV and NAA/(Cho + Cr) results lateralized 83% of the patients, a value similar to PET. Of 10 patients with normal magnetic resonance imaging (MRI) scans, 2 were lateralized with HV, 6 with FDG-PET, 4 with NAA/(Cho + Cr), and 3 with [NAA]. T2 relaxometry lateralized no patients without hippocampal atrophy. Bilateral abnormality was present in 29 to 33% of patients with 1H-MRSI measures and 17% with HV. Only hippocampal atrophy correlated with postoperative seizure-free outcome. FDG-PET remains the most sensitive imaging method to correlate with EEG-lateralized TLE. Both FDG-PET and 1H-MRSI can lateralize patients with normal MRI, but only the presence of relative unilateral hippocampal atrophy is predictive of seizure-free outcome. Bilaterally abnormal MRI and 1H-MRSI measures do not preclude good surgical outcome.
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PMID:Presurgical multimodality neuroimaging in electroencephalographic lateralized temporal lobe epilepsy. 940 74

Depressions of regional cerebral metabolism beyond the epileptogenic zone have been demonstrated in patients with intractable temporal lobe epilepsy. However, their clinical relevance, and the causes of prefrontal metabolic asymmetries are less well understood. We investigated 96 temporal lobe epilepsy patients by FDG-PET and neuropsychological assessment who had a corresponding unilateral temporal hypometabolism, left hemisphere speech dominance, full scale IQ of > 70 and no extratemporal lesion in MRIs. The regional glucose metabolism was determined in each patient in homologous regions including prefrontal cortex, and normalized to whole brain metabolism. Regional differences of > 10% were regarded as asymmetrical. Prefrontal metabolic asymmetries were more frequent in patients with left temporal lobe epilepsy (21 left, six right) and a history of secondarily generalized seizures. A multivariate analysis of variance revealed a main effect for prefrontal metabolic asymmetry on neuropsychological 'frontal lobe measures', including verbal and performance intelligence measures. Prefrontal metabolic asymmetry was not related to 'measures of episodic memory', presence of psychiatric symptoms or frontal interictal epileptiform discharges. We conclude that prefrontal metabolic asymmetry is associated with cognitive impairment. Patients with temporal lobe epilepsy of the left speech dominant hemisphere and a history of secondarily generalized seizures are at considerable risk of developing prefrontal metabolic asymmetry.
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PMID:Prefrontal asymmetric interictal glucose hypometabolism and cognitive impairment in patients with temporal lobe epilepsy. 944 82

To analyse the presurgical evaluation process of mediotemporal lobe epilepsy (MTLE) in relation to electroclinical characteristics of the patients, we reviewed the presurgical data (clinical, EEG, neuropsychological, MRI, FDG-PET and sometimes intracranial EEG) and the post-operative results of 53 consecutive cases treated by antero-medial temporal resection for MTLE (without lesion other than mediotemporal sclerosis). Forty one patients (77 p. 100) had a typical and well-lateralised presentation and were operated without invasive procedure. Twelve patients (23 p. 100) presented less pure data: unusual or absent auras, divergent scalp EEG features (bitemporal, widespread or extratemporal) or absence of MRI-based hippocampal sclerosis or FDG-PET hypometabolism. They were explored by invasive monitoring which confirmed the medial temporal origin of seizures. Outcome (follow-up: 30 months) was excellent in 88 p. 100 of the pure cases (Engel's class I) and less favorable in the more difficult ones (50 p. 100 of class I). In conclusion, the diagnosis and surgical treatment of MTLE can be performed without invasive investigations in the majority of cases owing to the strong contribution of brain imaging and video EEG monitoring. Some patients however present a less pure presentation suggesting more complex epileptogenic networks and associated to relatively less favorable postsurgical results.
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PMID:[Strategy of evaluation and surgical results in medial temporal lobe epilepsy]. 968 51

We assessed the clinical utility of [11C]flumazenil-PET (FMZ-PET) prospectively in 100 epileptic patients undergoing a pre-surgical evaluation, and defined the specific contribution of this neuro-imaging technique with respect to those of MRI and [18F]fluorodeoxyglucose-PET (FDG-PET). All patients benefited from a long term video-EEG monitoring, whereas an intracranial EEG investigation was performed in 40 cases. Most of our patients (73%) demonstrated a FMZ-PET abnormality; this hit rate was significantly higher in temporal lobe epilepsy (94%) than in other types of epilepsy (50%) (P < 0.001). Most FMZ-PET findings coexisted with a MRI abnormality (81%), including hippocampal atrophy (35%) and focal hypometabolism on FDG-PET (89%). The area of decreased FMZ binding was often smaller than that of glucose hypometabolism (48%) or larger than that of the MRI abnormality (28%). FMZ-PET did not prove superior to FDG-PET in assessing the extent of the ictal onset zone, as defined by intracranial EEG recordings. However, it provided useful data which were complementary to those of MRI and FDG-PET in three situations: (i) in temporal lobe epilepsy associated with MRI signs of hippocampal sclerosis, FMZ-PET abnormalities delineated the site of seizure onset precisely, whenever they were coextensive with FDG-PET abnormalities; (ii) in bi-temporal epilepsy, FMZ-PET helped to confirm the bilateral origin of seizures by showing a specific pattern of decreased FMZ binding in both temporal lobes in 33% of cases; (iii) in patients with a unilateral cryptogenic frontal lobe epilepsy, FMZ-PET provided further evidence of the side and site of seizure onset in 55% of cases. Thus, FMZ-PET deserves to be included in the pre-surgical evaluation of these specific categories of epileptic patients, representing approximately half of the population considered for epilepsy surgery.
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PMID:Clinical utility of flumazenil-PET versus [18F]fluorodeoxyglucose-PET and MRI in refractory partial epilepsy. A prospective study in 100 patients. 982 67

We report a patient with medically refractory mesial temporal lobe epilepsy treated by gamma knife radiosurgery. In lieu of a microsurgical procedure, an entorhinoamygdalohippocampectomy was performed with a gamma knife and low marginal doses (25 Gy). The clinical and imaging studies, including CT, MR imaging, 18F-fluorodeoxyglucose positron emission tomography (FDG-PET), and long-term follow-up MR examinations, are reported. The patient has been seizure-free since the day of treatment, with no clinical complications. MR studies accurately depicted the effect on the target structures and the transient secondary changes around them. FDG-PET scans showed decreased metabolism after gamma knife surgery throughout the anteromesial part of the epileptogenic temporal lobe. This metabolic decrease was reversible in the lateral temporal cortex. Our case suggests that gamma knife surgery is a promising tool for use as a minimally invasive approach to the treatment of epilepsy.
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PMID:Early and delayed MR and PET changes after selective temporomesial radiosurgery in mesial temporal lobe epilepsy. 1009 32

Abnormalities in plasma amino acid levels have been noted in patients with various epilepsies, and sometimes also in their first degree relatives. We sought to study plasma amino acid levels in children with epileptic encephalopathies and their parents, relating findings to the pattern of cortical glucose metabolism as determined by 18fluorodeoxyglucose (FDG) positron emission tomography (PET). Twenty-eight children with cryptogenic epileptic encephalopathies were studied prospectively. Cortical glucose metabolism was evaluated by FDG PET with combined visual and semiquantitative analysis used to detect focal cortical defects. The plasma concentration of 21 amino acids in the children and their parents was measured by ion exchange chromatography and compared with control values using non-parametric statistical methods. Multivariate analysis was used to assess antiepileptic drug effects. Children were classified as: Lennox-Gastaut syndrome following infantile spasms (six patients); de-novo Lennox-Gastaut syndrome (eight); severe myoclonic epilepsy in infancy (eight) and myoclonic-astatic epilepsy (two). Four patients remained unclassified. Fourteen patients had focal/multifocal abnormalities on PET scans. The plasma level of aspartate was significantly lower in both the children with epileptic encephalopathies and in their parents (P < 0.005). The lowered aspartate levels could not be accounted for by the antiepileptic drug medication taken by the children. Further analysis showed the lowered aspartate levels to be confined to children and their parents who lacked focal PET abnormalities. These findings suggest a possible genetic abnormality in the aspartate neurotransmitter systems in the pathogenesis of seizures in the childhood epileptic encephalopathies.
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PMID:Plasma amino acids in childhood epileptic encephalopathies. 1021 37

For successful surgical treatment of intractable epilepsy, identification of the epileptogenic area and functional cortex, by using the intracranial electrodes such as subdural and depth electrodes, is important. Since 1994, via chronic subdural electrodes recording, we performed anterior temporal lobectomy with hippocampectomy for 18 patients with temporal lobe epilepsy. For 10 patients with extratemporal lobe epilepsy, cortical resection of the epileptogenic cortex was performed. For the epileptogenic cortex overlapping with functional area, we added the multiple subpial transection. Favorable postoperative seizure outcome was obtained in most of the patients. Although non-invasive presurgical evaluation modalities such as MRI, video-EEG monitoring, MEG, and FDG-PET are useful in the diagnosis of epilepsy, it is impossible to localize precisely the exact epileptogenic zone and functional cortex.
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PMID:[Surgical treatment for intractable epilepsy: update and future]. 1037 10


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