The most common cause of focal epilepsies is the morphological brain abnormality, the epileptogenic lesion. Nowadays, by using MRI, the epileptogenic lesion can be demonstrated in vivo in more and more cases. Our knowledge regarding the clinical and pathophysiological features of epilepsy should be reevaluated in the highlight of the epileptogenic lesions demonstrated by MRI. The presence and the type of the epileptogenic lesion are important prognostic factors in the pharmacological and surgical treatments of epilepsy. Because the localization of the lesion is usually identical with the site of the seizure onset, the MRI investigation play an important role not only in identifying the epilepsy etiology but also in the non-invasive localization of the epileptic focus. Tumors, malformations of the cortical development, the hippocampal sclerosis, perinatal lesions, posttraumatic scars and the vascular malformations are the most important morphological abnormalities associated with epilepsy. Low-grade astrocytoma, pilocytic astrocytoma, oligodendroglioma, ganglioglioma, and the dysembrioplastic neuroepithelial tumors are the most common neoplasms associated with chronic epilepsy. Low grade astrocytomas or vascular malformations generate seizures due to chemical or mechanical effects of the lesion, the pacemaker area occurs obviously outside the lesion, in the adjacent brain tissue. Conversely, malformations of cortical development have intrinsic epileptogenicity. In them, the seizure onset zone is localized intralesional: the lesion generates seizures itself.
|Translated title of the contribution||Role of epileptogenic lesions in the development of ictal and interictal epileptic disturbance|
|Number of pages||6|
|Publication status||Published - May 5 2002|
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