Neuropathologic Studies of 'Epileptogenic' Tissue

Abstract

Suppl. 6 -S20The surgical treatment of intractable epilepsy is now a widely accepted therapeutic modality. The University of Western Ontario (UWO) Epilepsy Surgery Programme, whose success was celebrated at this symposium in London, Ontario, has contributed greatly to that acceptance, and deserves hearty congratulations for this effort, which continues today. Indeed, as presentations during the celebratory day proved, the innovative UWO Epilepsy Programme moves from strength to strength.One result of the growth of epilepsy surgery programs worldwide is that this innovative treatment provides a bounty of interesting lesions for Neuropathologists to examine and study. Unfortunately, since epilepsy surgery is most commonly carried out in medical centers with excellent neuroimaging and EEG facilities, together with expensive intraoperative support including anesthesia, this procedure is often not available to thousands of individuals who would benefit from it 1 . In the early days of therapeutic epilepsy surgery, Neuropathologists often struggled with the appropriate nomenclature for unique lesions that originated within epileptogenic brain-and to some extent this remains a problem to the present time. However, the meticulous approach to specimen analysis, exemplified by the early work of Gordon Mathieson at the Montreal Neurological ABSTRACT: This mini-review will summarize some of the major contributions of Neuropathology to understanding the structural basis of several forms of intractable epilepsy. Because of space limitations, only selected morphologically defined brain abnormalities will be considered and illustrated. By definition, the types of specimen encountered by Neuropathologists are those resected to treat intractable seizure disorders. One can therefore infer that the 'lesions' encountered in some way caused or at least contributed to the epilepsy, though the leap from observed neuropathologic abnormalities to 'seizuregenesis' is not always straightforward-indeed often is very tortuous and obscure. Nevertheless, a Neuropathologist working with a team of neurologists, neurosurgeons, electrophysiologists, neuropsychologists, and others, can contribute to a richer understanding of why seizures are triggered within human brain tissue, and therefore how they may be more effectively treated.RÉSUMÉ: Études neuropathologiques du tissu épileptogène. Cette mini-revue constitue un sommaire de certaines des contributions majeures de la neuropathologie à la compréhension des éléments structuraux de base de plusieurs types d'épilepsies pharmacorésistantes. Nous avons choisi de traiter et d'illustrer certaines anomalies cérébrales définies au point de vue morphologique, étant donné les contraintes d'espace. Par définition, les spécimens qu'examinent les neuropathologistes sont ceux qui ont été prélevés au cours du traitement chirurgical de l'épilepsie pharmacorésistante. On peut donc déduire que les « lésions » observées ont causé en quelque sorte ou ont pour le moins contribué à l'épilepsie, bien que le lien entre ...