Innovative evaluation of visual field defects in epileptic patients after standard anterior temporal lobectomy, using partial field visual evoked potentials.

The purpose of this paper is to obtain an electrophysiological evaluation of visual field defects consecutive to the direct lesion of optic radiations in drug-resistant epileptic patients after a standard electrocorticographically adjusted lobectomy, and to correlate it with conventional perimetric results, and with the volume of resected tissue during surgical treatment. Twenty-four patients with temporal lobe epilepsy defined through long term EEG-video, ictal and interictal SPECT, as well as Magnetic Resonance Imaging were studied. Visual evoked potentials (VEPs) with partial and total visual field stimulation were carried out before and after 6, 12 and 24 months surgical treatment. A control group was also studied. No differences between patients and control subjects were observed during the evaluation of the full-field VEPs. However, there were statistical differences between groups in the half-field VEP recordings and in the VEP recordings of contralateral to resected side superior quadrant (CSQ) before lobectomy and 6 months later (Mann-Whitney's U-test, p<0.05). Significant associations were found between VEP abnormalities and perimetric results in CSQ. A close relationship between perimetry, VEPs and volume of the resected tissue in hippocampus, parahippocampus, medial and lower temporal giri was also found. Visual field defects consecutive to standard temporal lobe resection in epileptic patients could be objectively evaluated by partial stimulation VEPs corresponding to the size of resected tissue.

Correlación entre la memoria subjetiva y objetiva episódica en pacientescon epilepsia del lóbulo temporal medial intratable / Correlation between subjective memory and episodic objective memory in patients with intractable medial temporal lobe epilepsy

Introducción. En la literatura científica revisada prevalece una discordancia en las investigaciones sobre la relación entre la memoria subjetiva y objetiva en pacientes con Epilepsia del Lóbulo Temporal medial intratable (ELTmi). Objetivo. Identificar la existencia o no de relación entre la memoria subjetiva y objetiva episódica en pacientes con ELTmi. Metodología. Se estudiaron 32 pacientes, con edades entre 15 y 60 años, empleándose el método clínico. Se aplicó una entrevista semiestructurada, el Cuestionario de Eficiencia de Memoria; el Test de aprendizaje verbal-auditivo de Rey y el Test de reproducción y copia de la figura compleja de Rey-Osterreith. Se realizó el procesamiento de los datos obtenidos. Resultados. Los pacientes reportaron quejas sobre su memoria. La modalidad viso-perceptual se mostró preservada, no así en la verbal-auditiva. No existieron diferencias en función de la lateralización de la zona de inicio ictal para ambas modalidades. Se evidenció una correlación negativa entre la memoria subjetiva y la estabilidad de la huella (modalidad verbal-auditiva). Los pacientes con lateralización izquierda mostraron correlación positiva entre la memoria subjetiva y el recuerdo demorado (modalidad viso-perceptual). Conclusiones. Los pacientes mostraron afectación de la memoria subjetiva, independientemente de la lateralización. También revelaron un perfil heterogéneo en la memoria objetiva episódica; así como la existencia de relación entre la memoria subjetiva y la objetiva episódica en la estabilidad de la huella (modalidad verbal-auditiva) y el recuerdo demorado (modalidad viso-perceptual) solo en los pacientes con lateralización izquierda.

Introduction. In the scientific literature there is not agreement about the existence of relationship between subjective memory and the episodic objective memory in untreatable medial temporal lobe epileptic patients (UMTLE). Objective. To identify the presence of relationship between subjective memory and the episodic objective memory in UMTLE patients. Methods. We studied 32 patients, aged 15-60; all of them were interviewed using a semiestructured interview model and a Questionnaire of Memory Efficiency; the Rey´s Auditory Verbal Learning Test and the Reproduction and copy of complex figure Rey-Osterreith. Test data were analyzed. Results. Patients complained about their memory, viso-perceptual modality was preserved but verbal-auditive modality did not. We didnot find any differences related to the lateralization of the ictal zone for both modalities. There was a negative correlation between the subjective memory and the verbal-auditive modality. Patients with left side lateralization showed a positive correlation between the subjective memory and the delayed viso-perceptual memory type. Conclusions. Patients had abnormalities in the subjective memory unrelated to the lateralization. They also had an heterogeneous profile in the episodic memory and the existence of relationship between subjective memory and the episodic objective memory (verbal-auditive), and a delayed visoperceptual memory type only in patients with left lateralization.