[The neuropathology of temporal lobe epilepsy: primary and secondary changes in the cortical circuits and epileptogenicity].

نویسندگان

  • J DeFelipe Oroquieta
  • J I Arellano
  • L Alonso
  • A Muñoz
چکیده

INTRODUCTION Temporal lobe epilepsy is associated to many disorders localized to the neocortex, the hippocampal formation or both (dual pathology). The most common pathologies are mesial sclerosis, tumours, malformations and scars. However, these alterations are not intrinsically epileptogenic, as they are also seen in patients who do not develop epilepsy. Thus, the cortical tissue in the damaged brain undergoes changes that may become a primary epileptogenic region. This region, in turn, may induce the formation of secondary epileptogenic regions situated at some distance from the primary focus. DEVELOPMENT In this paper we consider the possibility that in both the primary and secondary epileptogenic regions there are similar changes in the neuronal circuits which induce epileptic activity. In the case of the primary epileptogenic regions, these changes occur non specifically following an initial lesion or precipitating factor (e.g. a tumour) which induces gliosis and neuronal loss around the lesion. These changes give rise to a perilesional synaptic reorganization (elimination of connections with or without the formation of new synapses) which causes the onset and continuation of epileptic activity. However, the changes in the circuits in the secondary epileptogenic regions are the result of epileptic activity originated in the primary epileptogenic region which is propagated by specific anatomical connections. This anomalous activity causes changes in the target region (gliosis and neuronal loss) which leads to epileptogenic synaptic reorganization similar to that occurring in the primary perilesional areas.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Ictal and Interictal Electroencephalography of Mesial and Lateral Temporal Lobe Epilepsy; A Comparative Study

Background: Epilepsy is considered as one of the most important disorders in neurology. Temporal lobe epilepsy is a form of epilepsy including two main types of mesial and lateral (neocortex). Objectives: Determination and comparison of electroencephalogram (EEG) pattern in the ictal and interictal phases of mesial and lateral temporal lobe epilepsy. Materials and Methods: This cross-sectiona...

متن کامل

The protective effect of carvacrol on kainic acid-induced model of temporal lobe epilepsy in male rat

Background and Objective: Temporal lobe epilepsy (TLE) is a chronic neurological disorder with spontaneous recurrent seizures and abnormal intracranial waves. Since the role of oxidative stress in the occurrence of epilepsy is inevitable, it seems that the use of antioxidants can prevent some of the complications resulting from this disease. This study was designed to assess the protective effe...

متن کامل

P119: Animal Models of Epilepsy: The Impact of some Chemoconvalsants on Animal Models

We summarize some of the most frequenthly used rodent animal models of temporal lobe epileps and the impact of chemoconvulsants on them. Temporal lobe epilepsy is the most common epilepsy in humans in which seizures spread to the neighboring cortiase and hippocampal neuron loss and other neuropathological take place. Temporal lobe epilepsy and the other form of epilepsy cannot acquired in chini...

متن کامل

The Effect of Withania somnifera Alcoholic Extract on Learning and Memory Disturbance in a Model of Temporal Lobe Epilepsy in the Rat

Background and Objective: Temporal lobe epilepsy (TLE) usually leads to memory deficit. In this study, we tried to assess the effect of Withania somnifera extract on the impaired learning and memory in the intrahippocampal kainate model of TLE in the rat. Materials & Methods: Male rats (n=32) were divided into sham, extract+sham, kainite, and kainite+extract. For induction of epilepsy, unilate...

متن کامل

The effect of silymarin on prevention of hippocampus neuronal damage in rats with temporal lob epilepsy

Background and Objective: Temporal lobe epilepsy is hallmarked with neuronal degeneration in some areas of hippocampus and mossy fiber sprouting in dentate area. Considering some evidences on neuroprotective and antioxidant activity of silymarin (SM), this study was undertaken to evaluate the preventive effect of this agent on structural changes in hippocampus of kainate-epileptic rats. Materia...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:
  • Revista de neurologia

دوره 34 5  شماره 

صفحات  -

تاریخ انتشار 2002