Short and long term prediction of seizure freedom in drug-resistant focal epilepsy surgery.

BACKGROUND: The selection of candidates for drug-resistant focal epilepsy surgery is essential to achieve the best post-surgical outcomes. OBJECTIVE: To develop two prediction models for seizure freedom in the short and long-term follow-up and from them to create a risk calculator in order to individualize the selection of candidates for surgery and future therapies in each patients. METHODS: A sample of 64 consecutive patients who underwent epilepsy surgery at two Cuban tertiary health institutions between 2012 and 2020 constituted the basis for the prediction models. Two models were obtained through the novel methodology, based on biomarker selection reached by resampling methods, cross-validation and high-accuracy index measured through the area under the receiving operating curve (ROC) procedure. RESULTS: The first, to pre-operative model included five predictors: epilepsy type, seizures per month, ictal pattern, interictal EEG topography and normal or abnormal magnetic resonance imaging,. it's precision was 0.77 at one year, and with four years and more 0.63. The second model including variables from the trans-surgical and post-surgical stages: the interictal discharges in the post-surgical EEG, incomplete or complete resection of the epileptogenic zone, the surgical techniques employed and disappearance of the discharge in post-resection electrocorticography; the precision of this model was 0.82 at one year, and with four years and more 0.97. CONCLUSIONS: The introduction of trans-surgical and post-surgical variables increase the prediction of the pre-surgical model. A risk calculator was developed using these prediction models, which could be useful as an accurate tool to improve the prediction in epilepsy surgery.

Epilepsia del lóbulo temporal farmacorresistente como resultado de un programa quirúrgico / Drug-resistant temporal lobe epilepsy as a result of a surgical program

Introducción: La epilepsia del lóbulo temporal es la forma más común de epilepsia focal en el adulto y la que mejor responde al tratamiento quirúrgico. Objetivo: Identificar la asociación entre variables prequirúrgicas, transquirúrgicas y posquirúrgicas y la evolución en pacientes con epilepsia temporal farmacorresistente sometidos a cirugía de epilepsia. Métodos: Se estudiaron para la cirugía 24 pacientes con epilepsia temporal farmacorresistente, en el Instituto de Neurología y Neurocirugía, entre el año 2012 y 2020. Se utilizó el test de Fisher para identificar la asociación entre variables. Se evaluó la escala de Engel al año de la cirugía y en el último seguimiento. Resultados: Se alcanzó libertad de crisis (Engel I) en el 66,7 por ciento de los casos, según último seguimiento, con un período ente 1 a 8 años. La resección completa de la zona epileptogénica y la ausencia de crisis en los primeros 6 meses de la cirugía estuvieron relacionadas con Engel I al año y al último seguimiento. De igual forma las estadísticas estuvieron relacionadas: la ausencia de crisis posoperatorias agudas con Engel I al año y menos de 10 crisis al mes previo a la cirugía, la desaparición luego de la resección, del patrón epileptiforme encontrado en la electrocorticografía preresección, con Engel I al último seguimiento. Conclusiones: La mayoría de los pacientes operados de epilepsia del lóbulo temporal farmacorresistente quedaron libres de crisis en el último seguimiento. La resección completa de la zona epileptogénica y la ausencia de crisis en los primeros 6 meses de la cirugía estuvo asociada a las estadísticas de los resultados posquirúrgicos(AU)

Introduction: Temporal lobe epilepsy is the most common form of focal epilepsy in adults and the one that best responds to surgical treatment. Objective: to identify the association between pre-surgical, intra-surgical and post-surgical variables and evolution in patients with drug-resistant temporal epilepsy undergoing epilepsy surgery. Methods: Twenty four (24) patients with drug-resistant temporal epilepsy were studied for surgery at the Institute of Neurology and Neurosurgery, from 2012 to 2020. Fisher's test was used to identify the association between variables. The Engel scale was evaluated one year after surgery and at the last follow-up. Results: Seizure freedom (Engel I) was achieved in 66.7 percent of the cases, according to the last follow-up, with a period between 1 and 8 years. The complete resection of the epileptogenic zone and the absence of seizures in the first 6 months after surgery were related to Engel I at one year and at the last follow-up. In the same way, the statistics were related the absence of acute postoperative crises with Engel I a year and less than 10 crises a month prior to surgery, the disappearance, after resection, of the epileptiform pattern found in the pre-resection electrocorticography, with Engel I at last follow-up. Conclusions: The majority of patients operated on for drug-resistant temporal lobe epilepsy were seizure-free at the last follow-up. The complete resection of the epileptogenic zone and the absence of crises in the first 6 months after surgery were associated with the statistics of the postoperative results(AU)

Surgical Outcome in Extratemporal Epilepsies Based on Multimodal Pre-Surgical Evaluation and Sequential Intraoperative Electrocorticography.

OBJECTIVE: to present the postsurgical outcome of extratemporal epilepsy (ExTLE) patients submitted to preoperative multimodal evaluation and intraoperative sequential electrocorticography (ECoG). SUBJECTS AND METHODS: thirty-four pharmaco-resistant patients with lesional and non-lesional ExTLE underwent comprehensive pre-surgical evaluation including multimodal neuroimaging such as ictal and interictal perfusion single photon emission computed tomography (SPECT) scans, subtraction of ictal and interictal SPECT co-registered with magnetic resonance imaging (SISCOM) and electroencephalography (EEG) source imaging (ESI) of ictal epileptic activity. Surgical procedures were tailored by sequential intraoperative ECoG, and absolute spike frequency (ASF) was calculated in the pre- and post-resection ECoG. Postoperative clinical outcome assessment for each patient was carried out one year after surgery using Engel scores. RESULTS: frontal and occipital resection were the most common surgical techniques applied. In addition, surgical resection encroaching upon eloquent cortex was accomplished in 41% of the ExTLE patients. Pre-surgical magnetic resonance imaging (MRI) did not indicate a distinct lesion in 47% of the cases. In the latter number of subjects, SISCOM and ESI of ictal epileptic activity made it possible to estimate the epileptogenic zone. After one- year follow up, 55.8% of the patients was categorized as Engel class I-II. In this study, there was no difference in the clinical outcome between lesional and non lesional ExTLE patients. About 43.7% of patients without lesion were also seizure- free, p = 0.15 (Fischer exact test). Patients with satisfactory seizure outcome showed lower absolute spike frequency in the pre-resection intraoperative ECoG than those with unsatisfactory seizure outcome, (Mann- Whitney U test, p = 0.005). CONCLUSIONS: this study has shown that multimodal pre-surgical evaluation based, particularly, on data from SISCOM and ESI alongside sequential intraoperative ECoG, allow seizure control to be achieved in patients with pharmacoresistant ExTLE epilepsy.

Cirugía de zona epileptogénica localizada en un área elocuente dellóbulo frontal en un adolescente con epilepsia / Epileptogenic zone surgery located in an eloquent area of the frontal lobe in an adolescent with epilepsy

Objetivo: Describir los resultados de la evaluación prequirúrgica, transquirúrgica y postquirúrgica, en un adolescente con epilepsia farmacorresistente con zona epileptogénica estimada en un área elocuente del lóbulo frontal izquierdo.Caso clínico: Paciente masculino, de 18 años, con epilepsia frontal izquierdafarmacorresistente desde los tres años, con una frecuencia de crisis de desconexión, atónicas y, en ocasiones, tónico clónico bilateral entre 30 y 40 diarias, previo a la cirugía. Laevaluación prequirúrgica identificó la zona de inicio ictal frontal izquierda, no lesional por imagen de resonancia magnética de 3 tesla. Se indicó tomografía computarizada por emisiónde fotón único interictal / ictal corregistrada con resonancia magnética, donde se identificó hiperperfusión frontal izquierda. Se realizó la cirugía con el uso de potenciales evocadossomatosensoriales para identificar el surco central, la estimulación cortical directa para mapear el área motora primaria, y la electrocorticografía transoperatoria para delimitar la zona de resección. Se empleó la técnica combinada desconectiva (callosotomía anterior) y resectiva del giro frontal superior y medio izquierdos, con modificación del patrón eléctrico en la electrocorticografía posterior a la cirugía. El resultado anatomopatológico fue displasia cortical focal tipo IA. En el seguimiento postquirúrgico, el paciente presenta solo entre 2-3 crisis semanales.Conclusiones: La cirugía de epilepsia extratemporal no lesional y con zona epileptogénica que incluye áreas elocuentes del lóbulo frontal es factible de realizar en nuestro país con mínima invasividad y buenos resultados(AU)

Objective: To describe the results of pre-surgical, trans-surgical and post-surgical assessment of an adolescent with drug-resistant epilepsy and an estimated epileptogenic zone in an eloquent area of the left frontal lobe.Clinical case: Male patient, 18 years old, who had drug-resistant left frontal epilepsy since the age of three. Before surgery, the patient suffered 30 and 40 daily disconnection episodes, atonic and, occasionally, daily bilateral clonic tonic. The pre-surgical evaluation identifiedthe left frontal, non-lesional ictal onset zone using 3-tesla magnetic resonance imaging. An interictal / ictal single photon emission computed tomography corrected with magnetic resonance imaging was indicated, which identified left frontal hyperperfusion. Surgery wasperformed using somatosensory-evoked potentials to identify the central sulcus, direct cortical stimulation to map the primary motor area, and intraoperative electrocorticography to delimit the resection area. Combined disconnective technique (anterior callosotomy) andresective technique of the left superior and middle left gyrus was used, modifying the electrical pattern in the electrocorticography after surgery. The pathological result was type IA focal cortical dysplasia. In the post-surgical follow-up, the patient only has 2-3 weekly crises.Conclusions: Surgery is feasible in a non-lesional extra-temporal epilepsy with an epileptogenic zone that includes eloquent frontal lobe areas in our country with minimal invasiveness and good results(AU)

Actualización sobre la etiología de la epilepsia / Update on the etiology of epilepsy

Objetivo: Describir las causas de la epilepsia, a partir de los nuevos conceptos que se exponen en laclasificación de la Liga Internacional de Lucha contra la Epilepsia (2017).Adquisición de la evidencia: Se realizó una búsqueda bibliográfica en las bases de datos PubMed/Medline. Se utilizaron los siguientes criterios de búsqueda: artículos en idioma inglés y español, publicados en los últimos 10 años, sobre epilepsia y sus causas. Se incluyeron artículos de consenso, revisión y publicaciones oficiales de las comisiones para la clasificación de la epilepsia de laLiga Internacional de Lucha contra la Epilepsia. De un total de 2140 artículos, se revisaron 158.Resultados: Las causas genéticas están estrechamente relacionadas con la epilepsia. Las causas estructurales congénitas o adquiridas producen síndromes epilépticos focales o hemisféricos, muchos de los cuales conllevan a una epilepsia farmacorresistente, factibles de tratar con cirugía. Existen otras causas, como las metabólicas, autoinmunes e infecciosas, que también están relacionadas con esta enfermedad.Conclusiones: Las causas de epilepsia son varias, entre ellas, las genéticas, las estructurales, las mediadas por mecanismos inmunes, las metabólicas y errores congénitos de metabolismo, ylas infecciosas. Con el conocimiento de las mismas, podemos atender más eficazmente a los pacientes;identificar, de ser posible, la causa que produce su enfermedad; reconocer aquellas que son potencialmente curables; individualizar la terapéutica, y seleccionar precozmente los candidatos a la cirugía de epilepsia(AU)

Objective: Describe the causes of epilepsy, based on the new concepts of the International LeagueAgainst Epilepsy classification (2017).Acquisition of evidence: A bibliographic search was performed in PubMed/Medline databases. Thesearch criteria used were articles on epilepsy and its causes in English and Spanish, published in the last 10 years. Articles of consensus, review and official publications of the commissions for epilepsy classification of the International League against Epilepsy were included. We reviewed 158 articles out of 2140 in total.Results: Genetic causes are closely related to epilepsy. Congenital or acquired structural causes produce focal or hemispheric epileptic syndromes, many of which lead to drug-resistant epilepsy, feasible to treat with surgery. Metabolic, autoimmune and infectious causes also contribute to this disease.Conclusions: There are several causes of epilepsy, including genetic, structural, mediated by immune mechanisms, metabolic and congenital metabolism errors, and infectious. Knowing the causes of epilepsy would allow us to assist patients more effectively by identifying, if possible, the causes; byrecognizing those that are potentially curable; individualizing therapy, and early selecting candidates for epilepsy surgery(AU)

Mortality in patients with refractory temporal lobe epilepsy at a tertiary center in Cuba.

OBJECTIVES: We aimed to investigate the prevalence and risk of mortality in patients with refractory temporal lobe epilepsy. METHODS: Eligible patients included all adults referred to the National Institute of Neurology (NIN) in Havana, Cuba. All patients were followed up for 9 years. All analyses were made with the data available at the last follow-up. The frequency of death related to refractory TLE was analyzed taking into account the total number of patients included in the study. We analyzed the causes of death for each case. Multivariate analysis was made to determine the specific variables related to the death. All values were statistically significant if p<0.05. RESULTS: Six out of 117 patients died during follow-up. Fifty percent of patients died because of suicide. Only the presence of aura, specifically experiential psychic auras, and prodromal depressive disorders were associated significantly with the deaths (p<0.05). Patients who died had a higher concern about their seizures than patients who were still alive at last follow-up (p<0.01); they also had a poor perception of the overall QOL (p<0.01); and they were more concerned about the possible medication side effects than patients who did not die (p<0.05). Logistic regression provided only one variable related to the deaths in our cohort in multivariate analysis: presence of prodromal depressive disorder. CONCLUSION: The causes of death in patients with refractory temporal lobe epilepsy were similar to those documented in the general population of patients with epilepsy.

Suicidal risk, affective dysphoric disorders, and quality-of-life perception in patients with focal refractory epilepsy.

OBJECTIVES: We aim to study the frequency of (suicidal ideation) in patients with focal refractory epilepsy and its possible association with factors such as perceived QOL (quality of life) and ASDD (affective somatoform dysphoric disorder) using the 2007 ILAE proposal to classify affective disorders of epilepsy. METHODS: A total sample of 82 patients was divided into two groups depending on the presence of suicidal risk: (A) study group - with suicidal risk and (B) control group - without suicidal risk. Questionnaires, scales, interviews, and clinical charts were evaluated by professionals with expertise in neurology and epileptology (RAM and AGA), psychiatry (AGE), and neuropsychology (FGR). Suicidal risk was evaluated with the M.I.N.I. (Mini-International Neuropsychiatric Interview) suicidal module that specifies the current suicidal risk based on scores. Quality of life was evaluated with the Quality of Life in Epilepsy Inventory - 31 (QOLIE-31) survey. Logistic regression was conducted to ascertain if ASDD and QOL significantly predicted suicidal risk. The results were considered statistically significant when the p-value was <0.05. RESULTS: Suicidal risk was present in 33 (40.3%) patients. It was classified as severe in 31.7% of the patients, and it was only present in cases with temporal lobe epilepsy (p=0.002). More than half (52%) of patients with ASDD had risk of suicide (p=0.006). The presence of ASDD was found to be a risk factor for suicidal risk (OR=3.86; IC=1.3-12.2). Patients with suicidal risk had a lower QOL score compared with patients without suicidal risk (57.8±16.9 vs. 46.0±18.2; p<0.05), and an affected QOL significantly increased suicidal risk (OR=2.9; CI=1.3-7.8). Multivariate analysis demonstrated that an impaired QOL (OR=2.2) and the presence of ASDD (OR=4.1) significantly increased the probability of having suicidal risk (x(2)=13.6; OR=5.2; p=0.009). SIGNIFICANCE: Affective somatoform dysphoric disorder and low QOL perception increase, independently, the risk of suicide.