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Query: UMLS:C0014547 (focal epilepsy)
 1,627 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The contemporary neuroanatomist has a number of available methods to analyze epileptic brain tissue. Many studies have utilized Nissl- and Golgi-stained preparations to determine that gliosis and neuronal loss occur at epileptic foci as well as a decrease in the dendritic spine density. These structural changes did not reveal any specific basic mechanism that may cause epileptic activity. In contrast, the relatively newer techniques in neurocytology provide functional data that relate to the physiology and chemistry of the brain tissue. The use of immunocytochemical, histochemical, and receptor ligand-binding autoradiographic methods have aided in the understanding of cellular neurochemistry in both normal and epileptic tissue. In addition, the use of intracellular horseradish peroxidase and recording and quantitative morphological methods at both light- and electron-microscopic levels has helped gain insights into the functional state of synapses and neurons. Together, these methods have been utilized to help unravel the mystery of epilepsy. Our laboratory has utilized immunocytochemical and quantitative light- and electron-microscopic methods to analyze four models of epilepsy; two resemble posttraumatic focal epilepsy, and the other two are genetic models of epilepsy. Our data indicate that a preferential loss of cortical GABAergic, inhibitory terminals occurs at posttraumatic epileptic foci. In contrast, the genetic models of epilepsy did not display a loss of GABAergic terminals. Instead, specific brain regions of epileptic animals had an increased number of GABAergic neurons and terminals. These data indicate that two different neuronal circuits may provide the anatomical substrate for epileptic activity: loss of inhibition and disinhibition.
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PMID:Contemporary methods in neurocytology and their application to the study of epilepsy. 308 36

The lysosome-associated cathepsins B and D were localized by means of immunocytochemistry (peroxidase-antiperoxidase technique) in glial cells of rat brain. A specific reaction pattern of hippocampal neuroglia could be observed after intracerebroventricular application of the neurotoxin kainic acid. After the induction of a focal epilepsy in rats by the implantation of cobalt pellets there was a pronounced immunoreaction of glia near the primary focus as well as the mirror focus. It is concluded that both cathepsins are useful immunocytochemical markers to trace functionally activated glia.
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PMID:Cathepsins B and D in rat brain glia during experimentally induced neuropathological defects. An immunocytochemical approach. 310 45

Neurosurgical resection of an epileptic focus was performed in eleven patients suffering from drug resistant focal epilepsy. The clinical result was favourable in nine cases and corresponds to the earlier results. The routinely processed biopsy specimens obtained from the brain resections were stained with haematoxylin-eosin and with specific antisera to GFAP, S-100, NSE, laminin, and fibronectin using the peroxidase-antiperoxidase technique. The main pathological finding was gliosis in eight cases, neuronal degeneration in two cases, and a vascular malformation in one case. The anti-GFAP as a specific marker of astrocytes made the astroglial proliferation clearly visible, demonstrating an astroglial scar in four cases and a moderately to strongly increased amount of astroglial cells in another four cases. Anti-S-100 and anti-fibronectin are not as specific markers. They stained both neurones and glial cells with comparable results to that of anti-GFAP but with a lower specificity and sensitivity. Anti-NSE showed decreased amounts of neurones in most of the heavily gliotic lesions and also stained glial cells in some cases. Anti-laminin stained the pial and vascular basement membranes and revealed an increased vasculature in two cases. From these results, it appears that GFAP immunostaining is a highly demonstrative means for the visualization of astrogliosis in epileptic lesions and may be of help in identifying slight focal changes. An exact demonstration of neuronal loss or other neuronal changes still waits for a more specific marker than NSE. A favourable clinical outcome after neurosurgery seems to be associated with the patients showing a clearly gliotic brain lesion in one temporal lobe.
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PMID:Histopathological and immunohistochemical changes in neurosurgically resected epileptic foci. 343 49