Navegando por Palavras-chave "Seizure frequency"

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    Memory impairment is not necessarily related to seizure frequency in mesial temporal lobe epilepsy with hippocampal sclerosis
    (Wiley-Blackwell, 2014-08-01) Pacagnella, Denise; Lopes, Tatila M.; Morita, Marcia E.; Yasuda, Clarissa L.; Cappabianco, Fabio A. M. [UNIFESP]; Bergo, Felipe; Balthazar, Marcio L. F.; Coan, Ana C.; Cendes, Fernando; Universidade Estadual de Campinas (UNICAMP); Universidade Federal de São Paulo (UNIFESP)
    Objective: To investigate the effect of seizure frequency on memory, we performed a cross sectional study comparing mesial temporal lobe epilepsy (MTLE) patients with frequent and infrequent seizures.Methods: We performed magnetic resonance imaging (MRI) hippocampal volume (HV) measurements and neuropsychological assessment in 22 patients with frequent seizures (at least one dyscognitive seizure [DS] per month) that were refractory to antiepileptic drugs and 20 patients with infrequent seizures (three or less DS per year and no event evolving to a bilateral convulsive seizure), all with MRI signs of hippocampal sclerosis (HS) on visual analysis. We also included 29 controls for comparison of volumetric data.Results: There was no difference in memory performance between patients with frequent seizures and infrequent seizures. We observed a significant bilateral reduction of HV in patients with MTLE when compared to controls (p < 0.001). the degree of hippocampal atrophy (HA) between patients with frequent and infrequent seizures was not different. There was a negative correlation between seizure frequency and HV, with r = -0.3 for the HV ipsilateral to the HS and r = -0.55 for the contralateral side, thus, explaining only 9% and 30% of the HV loss. There was a positive correlation between age of onset and degree of HA (r = 0.37).Significance: Our data suggest that seizure frequency does not explain most of the HV loss or memory impairment in MTLE. Memory impairment appears to be more influenced by hippocampal damage than by seizure frequency. Further studies are necessary to identify the factors that influence memory decline in patients with MTLE.
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    Relationship between seizure frequency and number of neuronal and non-neuronal cells in the hippocampus throughout the life of rats with epilepsy
    (Elsevier Science Bv, 2016) Lopim, Glauber Menezes [UNIFESP]; Campos, Diego Vannucci [UNIFESP]; da Silva, Sergio Gomes; de Almeida, Alexandre Aparecido [UNIFESP]; Lent, Roberto; Cavalheiro, Esper Abrao [UNIFESP]; Arida, Ricardo Mario [UNIFESP]
    The relationship between seizure frequency and cell death has been a subject of controversy. To tackle this issue, we determined the frequency of seizures and the total number of hippocampal cells throughout the life of rats with epilepsy using the pilocarpine model. Seizure frequency varied in animals with epilepsy according to which period of life they were in, with a progressive increase in the number of seizures until 180 days (sixth months) of epileptic life followed by a decrease (330 days-eleventh month) and subsequently stabilization of seizures. Cell counts by means of isotropic fractionation showed a reduction in the number of hippocampal neuronal cells following 30, 90, 180 and 360 days of spontaneous recurrent seizures (SRS) in rats compared to their controls (about 25%-30% of neuronal cell reduction). In addition, animals with 360 days of SRS showed a reduction in the number of neuronal cells when compared with animals with 90 and 180 days of seizures. The total number of hippocampal non-neuronal cells was reduced in rats with epilepsy after 30 days of SRS, but no significant alteration was observed on the 90th, 180th and 360th days. The total number of neuronal cells was negatively correlated with seizure frequency, indicating an association between occurrence of epileptic seizures throughout life and neuronal loss. In sum, our results add novel data to the literature concerning the time-course of SRS and hippocampal cell number throughout epileptic life. (C) 2016 Elsevier B.V. All rights reserved.
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    Repeated amygdala-kindled seizures induce ictal rebound tachycardia in rats
    (Elsevier B.V., 2011-11-01) Pansani, Aline Priscila [UNIFESP]; Colugnati, Diego Basile [UNIFESP]; Schoorlemmer, Gerhardus Hermanus Maria [UNIFESP]; Sonoda, Eliza Yumi de Freitas [UNIFESP]; Cavalheiro, Esper Abrão [UNIFESP]; Arida, Ricardo Mario [UNIFESP]; Scorza, Fulvio Alexandre [UNIFESP]; Cravo, Sergio Luiz [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Universidade Federal de Goiás (UFG)
    It is thought that cardiovascular changes may contribute to sudden death in patients with epilepsy. To examine cardiovascular alterations that occur during epileptogenesis, we measured the heart rate of rats submitted to the electrical amygdala kindling model. Heart rate was recorded before, during, and after the induced seizures. Resting heart rate was increased in stages 1, 3, and 5 as compared with the unstimulated control condition. in the initial one third of the seizures, we observed bradycardia, which increased in intensity with increasing stage and was blocked by injecting methyl atropine. During stage 5 seizures, a rebound tachycardia was observed that also increased in intensity with increasing number of seizures. This study demonstrated the influence of seizure frequency on cardiac autonomic modulation, providing a basis for discussion of potential mechanisms that cause patients with epilepsy to die suddenly. (C) 2011 Elsevier Inc. All rights reserved.