[Pathological neocortical findings in patients with medication-resistant medial temporal lobe epilepsy submitted to surgery]. / Hallazgos patológicos neocorticales en pacientes con epilepsia del lóbulo temporal medial farmacorresistente sometidos a cirugía.

INTRODUCTION: The dual pathology consisting of hippocampal sclerosis plus focal cortical dysplasia (FCD) is often reported in patients with medication-resistant medial temporal lobe epilepsy (MTLE). AIMS: To determine the histopathological changes that take place in the neocortex of patients with medication-resistant MTLE submitted to surgery and to evaluate the relation between the histopathological changes, pathological background and the clinical course of patients who had received surgical treatment. MATERIALS AND METHODS: Tissue obtained by en bloc resection from the neocortex of 18 patients with MTLE refractory to medical treatment was processed histologically and a tailored temporal lobectomy was performed with electrocorticography. RESULTS: Dual pathology was diagnosed in 13 patients (72.2%). Imaging studies confirmed the existence of mesial sclerosis of the temporal in 100% of cases and there was no evidence of neocortical lesions. Histologically, 46.15% and 38.46% of the patients were diagnosed as belonging to FCD type 1a and FCD type 1b, respectively. Only one patient presented FCD type 2a. A statistically significant relation was found between the presence of dual pathology and the existence of an early precipitating injury (p = 0.04). One year after surgery, 72.7% (8/11) patients with dual pathology were classified as belonging to Engel class I. CONCLUSIONS: In patients with MTLE there are microscopic FCD-type alterations in the neocortex. There is an association between these alterations and the existence of an initial precipitating injury. Complete resection of the epileptogenic area, which is guaranteed by the lobectomy tailored by electrocorticography, allows patients to enjoy a favourable post-surgical progression one year after surgery.

Hallazgos patológicos neocorticales en pacientes con epilepsia del lóbulo temporal medial farmacorresistente sometidos a cirugía / Pathological neocortical findings in patients with medication-resistant medial temporal lobe epilepsy submitted to surgery

Introducción. La patología dual compuesta por esclerosis hipocampal y displasia cortical focal (DCF) se describecon frecuencia en pacientes con epilepsia del lóbulo temporal medial (ELTM) farmacorresistente. Objetivos. Determinar los cambios histopatológicos en la neocorteza de pacientes con ELTM farmacorresistente sometidos a cirugía y evaluar la relación entre los cambios histopatológicos, los antecedentes patológicos y la evolución clínica en los pacientes operados. Materialesy métodos. Se procesó histológicamente el tejido resecado en bloque (neocorteza) de 18 pacientes con ELTM refractaria a tratamiento médico, y se les realizó lobectomía temporal ajustada por electrocorticografía. Resultados. Se diagnóstico patología dual en 13 pacientes (72,2por ciento). Los estudios imagenológicos confirmaron en el 100por ciento de los casos la esclerosis mesial del temporal y no existieron evidencias de lesión neocortical. Histológicamente, el 46,15 por ciento y el 38,46 por ciento de los pacientesfueron diagnosticados como DCF tipo 1a y DCF tipo 1b, respectivamente. Sólo un paciente presentó DCF tipo 2a. Se demostró una relación estadísticamente significativa entre la presencia de patología dual y la existencia de una daño precipitante inicial (p = 0,04). El 72,7por ciento (8/11) de los pacientes con patología dual un año después de la cirugía se clasificó en la clase Ide Engel. Conclusiones. En los pacientes con ELTM existen alteraciones microscópicas en la neocorteza del tipo DCF. Estas alteraciones se asocian a la existencia de un daño precipitante inicial. La resección completa de la zona epileptogénica, garantizada por la lobectomía ajustada por electrocorticografía, permite una buena evolución posquirúrgica un año después de la cirugía(AU)

INTRODUCTION: The dual pathology consisting of hippocampal sclerosis plus focal cortical dysplasia (FCD) is often reported in patients with medication-resistant medial temporal lobe epilepsy (MTLE). AIMS: To determine the histopathological changes that take place in the neocortex of patients with medication-resistant MTLE submitted to surgery and to evaluate the relation between the histopathological changes, pathological background and the clinical course of patients who had received surgical treatment. MATERIALS AND METHODS: Tissue obtained by en bloc resection from the neocortex of 18 patients with MTLE refractory to medical treatment was processed histologically and a tailored temporal lobectomy was performed with electrocorticography. RESULTS: Dual pathology was diagnosed in 13 patients (72.2percent). Imaging studies confirmed the existence of mesial sclerosis of the temporal in 100 percent of cases and there was no evidence of neocortical lesions. Histologically, 46.15 percent and 38.46 percent of the patients were diagnosed as belonging to FCD type 1a and FCD type 1b, respectively. Only one patient presented FCD type 2a. A statistically significant relation was found between the presence of dual pathology and the existence of an early precipitating injury (p = 0.04). One year after surgery, 72.7percent (8/11) patients with dual pathology were classified as belonging to Engel class I. CONCLUSIONS: In patients with MTLE there are microscopic FCD-type alterations in the neocortex. There is an association between these alterations and the existence of an initial precipitating injury. Complete resection of the epileptogenic area, which is guaranteed by the lobectomy tailored by electrocorticography, allows patients to enjoy a favourable post-surgical progression one year after surgery(AU)

Hallazgos patológicos neocorticales en pacientes con epilepsia del lóbulo temporal medial farmacorresistente sometidos a cirugía / Pathological neocortical findings in patients with medication-resistant medial temporal lobe epilepsy submitted to surgery

La patología dual compuesta por esclerosis hipocampal y displasia cortical focal (DCF) se describecon frecuencia en pacientes con epilepsia del lóbulo temporal medial (ELTM) farmacorresistente. Objetivos. Determinar los cambios histopatológicos en la neocorteza de pacientes con ELTM farmacorresistente sometidos a cirugía y evaluar la relación entre los cambios histopatológicos, los antecedentes patológicos y la evolución clínica en los pacientes operados. Materialesy métodos. Se procesó histológicamente el tejido resecado en bloque (neocorteza) de 18 pacientes con ELTM refractaria a tratamiento médico, y se les realizó lobectomía temporal ajustada por electrocorticografía. Resultados. Se diagnóstico patología dual en 13 pacientes (72,2%). Los estudios imagenológicos confirmaron en el 100% de los casos la esclerosis mesialdel temporal y no existieron evidencias de lesión neocortical. Histológicamente, el 46,15% y el 38,46% de los pacientes fueron diagnosticados como DCF tipo 1a y DCF tipo 1b, respectivamente. Sólo un paciente presentó DCF tipo 2a. Se demostró una relación estadísticamente significativa entre la presencia de patología dual y la existencia de una daño precipitante inicial (p = 0,04). El 72,7% (8/11) de los pacientes con patología dual un año después de la cirugía se clasificó en la clase Ide Engel. Conclusiones. En los pacientes con ELTM existen alteraciones microscópicas en la neocorteza del tipo DCF. Estas alteraciones se asocian a la existencia de un daño precipitante inicial. La resección completa de la zona epileptogénica, garantizadapor la lobectomía ajustada por electrocorticografía, permite una buena evolución posquirúrgica un año después de la cirugía

The dual pathology consisting of hippocampal sclerosis plus focal cortical dysplasia (FCD) is oftenreported in patients with medication-resistant medial temporal lobe epilepsy (MTLE). Aims. To determine the histopathological changes that take place in the neocortex of patients with medication-resistant MTLE submitted to surgery and to evaluate the relation between the histopathological changes, pathological background and the clinical course of patients whohad received surgical treatment. Materials and methods. Tissue obtained by en bloc resection from the neocortex of 18 patients with MTLE refractory to medical treatment was processed histologically and a tailored temporal lobectomy was performed with electrocorticography. Results. Dual pathology was diagnosed in 13 patients (72.2%). Imaging studies confirmed the existenceof mesial sclerosis of the temporal in 100% of cases and there was no evidence of neocortical lesions. Histologically, 46.15% and 38.46% of the patients were diagnosed as belonging to FCD type 1a and FCD type 1b, respectively. Only one patient presented FCD type 2a. A statistically significant relation was found between the presence of dual pathology and the existenceof an early precipitating injury (p = 0.04). One year after surgery, 72.7% (8/11) patients with dual pathology were classified as belonging to Engel class I. Conclusions. In patients with MTLE there are microscopic FCD-type alterations in the neocortex.There is an association between these alterations and the existence of an initial precipitating injury. Complete resection of the epileptogenic area, which is guaranteed by the lobectomy tailored by electrocorticography, allows patients to enjoy a favourable post-surgical progression one year after surgery