Resumen Objetivo: Profundizar en las relaciones electro- clínica y el análisis de fuentes de las crisis de ausencia en la infancia. Métodos: Se estudiaron 33 sujestos con el diagnóstico clínico y electrofisiológico de crisis de ausencia sin medicación antiepiléptica, se realizó Video-EEG. Se recogieron los comportamientos clínicos y variables electrofisiológicas durante las crisis y se aplicó un Modelo General Lineal, con p < 0.05. El análisis de las fuentes se realizó con el método VARETA. Resultados: Se evaluaron 174 crisis El 75,75% mostró descargas epileptiformes interictales (DEI) y el 12,12% mostró actividad delta posterior. Existió un comportamiento desigual en relación con el total de crisis electroclínicas y la presencia o no de DEI (p = 0.02) y entre los sujetos sin DEI y DEI multifocales (p = 0.008). El número de crisis registradas durante la HPV tuvo un comportamiento diferente entre sujetos sin DEI y EEG con DEI multifocales (p = 0.03) y entre EEG focal y multifocal (p = 0.04). El análisis de las fuentes evidenció el inicio frontal de las crisis en el 57,47%, con la participación de las regiones mesial y dorsolateral en el 43% y 57% respectivamente. Conclusiones: Los datos sugieren que las crisis de ausencia no son ¨generalizadas¨ si se considera la activación cortical global, sino que involucran descargas localizadas en regiones corticales específicas, principalmente del lóbulo frontal.

Abstract Purpose: This study was to deepen into the electro-clinical relationship and source analysis of absence seizures in childhood. Methods: Thirty-three subjects were studied with clinical and electrophysiological diagnosis of absence seizures without antiepileptic medication, video-electroencephalogram was applied. We obtained clinical behavior and electrophysiological variables during seizures and General Linear Model was applied, with p < 0.05. Source analysis was carried out with VARETA method. Results: 174 seizures were evaluated. 75.75% showed interictal epileptiform discharges (IED) and 12.12% showed posterior delta activity. There was an unequal behavior in relation with total electro-clinical seizures and presence or no of IED (p = 0.02), namely between subjects without IED in EEG and multifocal EEG (p = 0.008). Quantity of seizures recorded during HPV had a different behavior between subjects without IED in EEG and multifocal EEG (p = 0.03) and between focal and multifocal EEG (p = 0.04). Source analysis (VARETA) evidence the onset frontal of seizures in 57.47%, mesial and dorsolateral regions in 43% and 57%, respectively. Conclusion: These data suggest that absence seizures are not “generalized” if we considered global cortical activation but rather involve localized discharges from specific cortical regions, mainly frontal lobe.

ABSTRACT Introduction: The objective was to present the results of the first comprehensive epilepsy surgery program in Cuba. Methods: Video-electroencephalogram (EEG) complemented with a methodology that combines non-invasive functional modalities electroencephalography (EEG) and the subtraction of ictal and interictal single photon emission computed tomography (SPECT) co-registered with magnetic resonance imaging (SISCOM) was used to estimate the location of the epileptogenic zone. In addition, estimation of ictal EEG source imaging methods was also developed. Results: All the proposed methodology allowed for a non-invasive identification of the EZ in patients with non-lesional pharmacoresistant epilepsy. During epilepsy surgery, the intraoperative electrocorticography (ECoG) spike frequency allows for the characterization of the histopathological subtypes of mild cortical focal dysplasia in patients with Temporal Lobe Epilepsy (ELT). Pharmacoresistant temporal and extratemporal epilepsy operated patients were submitted to EEG and clinical follow-up assessment. Engel scores follow-up was described as follows: at 12 months 70,0 % class I, at 24 months after surgery 55,2 % of the patients were class I, These Engel class I figures changed to 48,6 % five years following surgery, whereas 50 % maintained this condition in the last follow-up period (fourteen years). On the other hand, one year after extra temporal epilepsy surgery, 52,6 % of the patients were seizure free. Logit regression (p < 0,05) revealed that six months after surgery, quantitative EEG can be a tool to predict the outcome of epilepsy surgery. An adequate social functioning was also found. Conclusion: Results confirm the feasibility of conducting a successful epilepsy surgery program with favorable long-term electroclinical and psychosocial functioning outcomes in a developing country as well.

RESUMEN Introducción: El objetivo fue presentar los resultados del programa integral para la evaluación, y tratamiento quirúrgico de las epilepsias farmacorresistentes (EFR) en Cuba. Métodos: Se introduce una estrategia de evaluación prequirúrgica multimodal contemplando técnicas de videoelectroencefalograma (EEG) complementada con análisis espectral en el dominio del tiempo, la tomografía por emisión de fotón único SPECT realizado en estado interictal e ictal (bajo monitoreo de EEG) corregistrado con imágenes de resonancia magnética (SISCOM), así como métodos de localización de fuentes electromagnéticas, utilizando varios modelos estadísticos. Resultados: La estrategia desarrollada devenida en programa nacional, permitió identificar de forma no invasiva la zona epileptogénica (ZE) en pacientes con EFR no lesionales. La asimilación de las diferentes técnicas quirúrgicas utilizadas en el tratamiento de las EFR, guiadas por monitoreo secuencial con electrocorticografía intraoperatoria (ECoG), demostraron la asociación entre los patrones ECoG y las displasias corticales focales ligeras en pacientes con epilepsia del lóbulo temporal (ELT), no visualidades en las imágenes de resonancia magnética. En las ELT y extra temporales se logra 70,0 % y 52,6 % de libertad de crisis un año después de la cirugía respectivamente. Precisamos estabilidad evolutiva en el comportamiento de las crisis a partir del segundo año y hasta los catorce después de la cirugía en pacientes con ELT, asociado a disminución de la frecuencia de descarga absoluta de actividad epileptiforme en el EEG y a modificaciones en la composición de frecuencias del EEG. Conclusiones: Se confirma la factibilidad del programa de cirugía de epilepsia, avalándolo como opción terapéutica eficaz y segura en las epilepsias farmacorresistentes.

ABSTRACT INTRODUCTION Alzheimer disease is the main cause of dementia associated with aging in Cuba and the world. Development of methods for early diagnosis is vital to increasing intervention effectiveness and improving patient quality of life. Recent studies have shown associations between alterations in serum levels of antineuronal antibodies and Alzheimer disease pathology. However, the specific relationship between such antineuronal antibodies and Alzheimer pathogenesis remains unclear because of the great variety of antibodies identified and their heterogeneity among patients and nondemented controls. OBJECTIVE Assess the association between serum levels of antibodies against neuronal antigens (total brain protein, aldolase and amyloid beta protein) and cognitive performance in older Cuban adults. METHODS A cross-sectional pilot study was conducted of adults aged ≥65 years living in Havana’s Playa Municipality and Artemisa Province (southwest of Havana). A sociodemographic and risk factor questionnaire was administered, neuropsychological assessment conducted, and physical and neurological examinations performed. A relative or caregiver was also interviewed. Laboratory tests included: complete blood count, glycemia, lipid panel, and apolipoprotein E genotype. Of 143 individuals studied, 33 were cognitively normal, 52 had mild cognitive impairment, and 58, probable Alzheimer disease. Serum antibody levels were determined by ELISA and compared using covariance analysis with a significance level of 0.05. ELISA specificity, sensitivity and predictive value were assessed by analyzing their respective diagnostic performance curves. RESULTS Patients with probable Alzheimer disease performed least well on the mini mental state examination (cognitively normal 28.8, SD 1.2; mild cognitive impairment 27.4, SD 2.2; probable Alzheimer disease 12.9, SD 6.5; ANOVA p <0.001). The percentage of Apo E4 carriers was seven times greater in the group with probable Alzheimer disease than in the cognitively normal group. Among the antibodies studied, only those against amyloid beta peptide had levels significantly higher in the Alzheimer disease group than in the cognitively normal group (p = 0.007) and the group with mild cognitive impairment (p = 0.002). CONCLUSIONS Results support the presence of an autoimmune component in Alzheimer disease and suggest that serum anti–amyloid-beta could be used for its diagnosis.

Objectives: Identify the relationship between electroencephalographic alterations and initial cerebrovascular lesions among neurologically asymptomatic hypertensive patients using the GTE scale. Methods: Magnetic resonance (0.35 Tesla, T1, T2, FLAIR) and 19-channel electroencephalogram images were obtained from 49 asymptomatic hypertensives, who were divided into three groups: A, without cerebrovascular lesion; B, with non-classical cerebrovascular lesion; and C, with classical ischemic cerebrovascular lesion. Results: Group C showed higher mean values on the GTE scale (4.42) than Groups B (3.36) and A (2.63), with a significant difference in the median for each group (p=0.03). Conclusion: The electroencephalographic alterations found in the patients studied are associated with cerebrovascular changes induced by arterial hypertension. The GTE scale is a simple method which could be used for the screening of subclinical cerebrovascular lesions among hypertensive patients.

Objetivos: en este trabajo nos propusimos identificar la relación entre las alteraciones electroencefalográficas y las lesiones vasculares cerebrales iniciales en pacientes hipertensos neurológicamente asintomáticos, con el uso de la escala GTE. Métodos: se obtuvieron imágenes de resonancia magnética (0.35 Tesla, T1,T2, FLAIR) y electroencefalograma de 19 canales en 49 hipertensos asintomáticos, los cuales fueron divididos en 3 grupos: A, sin lesiones cerebrovasculares; B, con lesión vascular cerebral no clásica y C, con lesión cerebrovascular isquémica clásica. Resultados: el grupo C mostró valores promedios superiores de la escala GTE (4,42) que el grupo B (3,36) y A (2,63) con una diferencia significativa de la mediana alcanzada por cada grupo (p=0,03). Conclusión: las alteraciones electroencefalográficas en los pacientes de nuestro estudio están asociadas con los cambios cerebrovasculares inducidos por la hipertensión arterial. La escala GTE es un método simple que podría ser empleado en el pesquisaje de lesión cerebrovascular subclínica en pacientes hipertensos.

The involved neural bases were studied in the generation of the auditory steady state response, obtained by stimulation with 40 hertz multiple frequency amplitude modulate tones, for which a high space resolution registration protocol was designed, the Bayes`method was applied to estimate their neurogenerators and restrictions were previously defined to focus the initial calculation from the primary activation areas to the auditory system. The results are able to detect generating sources at the level of the upper temporal lobe of both hemispheres; but the cortical activation is not symmetrical and an interhemispheric lateralization effect is registered, with activation of the contralateral upper temporal lobe to the stimulated ear as a response to tones of 500 hertz, while for the tones of 4 000 hertz, the cortical activation level is higher at the level of the ipsilateral upper temporal lobe to the stimulated ear. The present results obtain a new methodology for the evaluation of the auditory system that can be applied in the characterization of the cortical reorganization and neuroplasticity in severe neurosensory hearing loss and other sensory deprivations.

Se estudiaron las bases neurales involucradas en la generación de los potenciales evocados auditivos de estado estable, obtenidos por estimulación con tonos modulados en amplitud a 40 hertzios de múltiples frecuencias, para lo cual se diseñó un protocolo de registro de alta resolución espacial, se aplicó el método bayesiano para estimar sus neurogeneradores y se definieron restricciones a priori para focalizar el cálculo inicial de las áreas de activación primaria al sistema auditivo. Los resultados logran activar fuentes generadoras a nivel del lóbulo temporal superior de ambos hemisferios; pero la activación cortical no es simétrica y se registra un efecto de lateralización interhemisférica, con activación del lóbulo temporal superior contralateral al oído estimulado en respuesta a tonos de 500 hertzios, mientras que para los tonos de 4 000 hertzios, el nivel de activación cortical es máximo a nivel del lóbulo temporal superior ipsilateral al oído estimulado. Los presentes resultados obtienen una nueva metodología para la evaluación del sistema auditivo, que puede ser aplicada en la caracterización de la reorganización cortical y neuroplasticidad en hipoacusias neurosensoriales severas y otras deprivaciones sensoriales.