Outpatient monitoring of the A/EEG in pre-operative assessment of partial epilepsy
Introduction. Electroencephalography, together with new neuroimaging techniques is still the main diagnostic tool for pre-operative assessment of epilepsy. The electrical episodes, both ictal and intercritical, are random paroxystic phenomena with regard to presentation, so the conventional EEG is sometimes of limited value. Therefore, in recent years, long duration EEG monitoring techniques have been favoured, with or without simultaneous recording of clinical behaviour, permitting recording for an indefinite period. Amongst these techniques, monitoring using cassette recording (A/EEG) if of specific interest since it permits the study of outpatients. Objetive. The main aim of surgical treatment of epilepsy is to abolish or reduce the number of crises. Therefore it is essential to localize the epileptogenic area as precisely as possible. The A/EEG has made a major contribution to the procedure of pre-operative assessment because of the considerable information it gives regarding the recording and character of the crises. Material and methods. During the past three years, preoperative assessment has been carried out in our hospital on 44 patients with drug-resistant partial epilepsy. A total of 103 long duration cassette recordings (A/EEG) were done. Of these, 58 were done with surface electrodes and individualized set-up depending on the EEG findings, 8 with semi-invasive (sphenoid) electrodes, and 37 recordings used implanted sub-dural electrode strips. Results. Combined study of the results obtained with these techniques permitted localization of the lesive-epileptogenic complex in 42 of these patients. We present the results obtained and conclude that A/EEG monitoring is useful in the pre-operative assessment of epilepsy
Objetivo El principal objetivo del tratamiento quirúrgico de la epilepsia es abolir o reducir el número de crisis, motivo por el cual es imprescindible una localización del área epileptógena lo más precisa posible. La A/EEG ha contribuido en gran medida a este proceso de evaluación prequirúrgica debido a su alto rendimiento en cuanto a registro y caracterización de las crisis. Material y métodos. Durante los tres últimos años se ha realizado en este hospital la evaluación prequirúrgica de 44 pacientes con epilepsia parcial farmacorresistente. Se han practicado un total de 103 registros de larga duración mediante casete (A/EEG), 58 de ellos con electrodos de superficie y montaje individualizado en función de los hallazgos del EEG, 8 con electrodos seminvasivos (esfenoidales) y 37 registros con implantación de tiras de electrodos subdurales.
Resultados El estudio combinado de estas técnicas permitió la localización del complejo lesivo-epileptógeno en 42 de estos pacientes. Presentamos los resultados obtenidos y se concluye la utilidad de la monitorización A/EEG en la evaluación prequirúrgica de la epilepsia
