[Functional connectivity derived from an electroencephalogram during non-REM sleep in autism spectrum disorders]. / Conectividad funcional derivada del electroencefalograma durante el sueño no REM en los trastornos del espectro autista.

AIM: To know the differences in the patterns of functional connectivity, the topological characteristics of the network and the relationship between these latter and the interictal epileptiform anomalies in children with primary and secondary autism spectrum disorder (ASD). PATIENTS AND METHODS: A retrospective study was conducted with 27 children aged between 3 and 13 years diagnosed with ASD. Subjects were submitted to an electroencephalogram in a functional state of spontaneous sleep. Functional connectivity and the properties of the network were analysed using data obtained from the electroencephalogram during the N2 stage of non-REM sleep. The frequency of discharge of the interictal epileptiform activity (FDIEA) was determined and was correlated with the topological properties of the network. RESULTS: Synchronisation was diminished in patients with secondary ASD for the alpha frequency and increased for the theta and delta frequency compared with patients with primary ASD. Local alpha efficiency was higher in patients who presented interictal epileptiform activity. Additionally, in patients with secondary ASD there was a statistically significant positive and negative correlation between FDIEA and the topological properties of the network. CONCLUSIONS: Patients with secondary ASD display patterns of functional connectivity that are weaker for the alpha frequency and stronger for theta and delta than patients with primary ASD. In patients with secondary ASD, the interictal epileptiform activity is related to local and global connectivity of the network for the alpha and beta bands during non-REM sleep.

TITLE: Conectividad funcional derivada del electroencefalograma durante el sueño no REM en los trastornos del espectro autista.Objetivo. Conocer las diferencias en los patrones de conectividad funcional, las caracteristicas topologicas de la red y la relacion de estas con las anomalias epileptiformes interictales en niños con trastorno del espectro autista (TEA) primario y secundario. Pacientes y metodos. Se realizo un estudio retrospectivo con 27 niños de 3-13 años diagnosticados con TEA, a los que se les realizo un electroencefalograma en estado funcional de sueño espontaneo. Se analizo la conectividad funcional y las propiedades de la red a partir de los datos obtenidos del electroencefalograma durante la etapa N2 del sueño no REM. Se determino la frecuencia de descarga de la actividad epileptiforme interictal (FDAEI) y se correlaciono con las propiedades topologicas de la red. Resultados. Los pacientes con TEA secundario tenian una disminucion de la sincronizacion para la frecuencia alfa y un incremento para la frecuencia theta y delta en comparacion con los pacientes con TEA primario. La eficiencia local alfa fue mayor en los pacientes que presentaban actividad epileptiforme interictal. Ademas, en los pacientes con TEA secundario, existia una correlacion positiva y negativa estadisticamente significativa entre la FDAEI y las propiedades topologicas de red. Conclusiones. Los pacientes con TEA secundario muestran patrones de conectividad funcional mas debiles para la frecuencia alfa y mas fuerte para la theta y delta que los pacientes con TEA primario. En pacientes con TEA secundario, la actividad epileptiforme interictal se relaciona con la conectividad local y global de la red para las bandas de frecuencia alfa y beta durante el sueño no REM.

[A prospective, open, controlled and randomised study of clobazam versus carbamazepine in patients with frequent episodes of Rolandic epilepsy]. / Estudio prospectivo, abierto, controlado y aleatorizado de clobazam frente a carbamacepina en pacientes con crisis frecuentes de epilepsia rolándica.

INTRODUCTION: To date no controlled, randomised studies with flexible dose regimens have been conducted in children with rolandic epilepsy, and therapy is therefore still empirical. AIM: To evaluate the effectiveness and safety of clobazam (CLB) compared with that of carbamazepine (CBZ) in rolandic epilepsy. PATIENTS AND METHODS: A prospective, open, controlled and randomised study was carried out to compare CBZ and CLB in children with rolandic epilepsy with a follow-up over a two-year period. A random sample of 45 patients was taken and 38 of them finished the study. A flexible dose regimen was indicated. Control of seizures, academic performance, behaviour, adherence to treatment, parents' degree of satisfaction and side effect profiles were all evaluated. RESULTS: Both drugs were equally effective at controlling seizures (94.1% of patients with CLB and 100% of those with CBZ were free of seizures on ending the study; p = 0.26). CLB controlled seizures earlier (33.3 +/- 45 days versus 48.2 +/- 72.3; p < 0.05) and had fewer side effects than CBZ (side effects appeared in three patients with CLB and in eight of those on CBZ; p = 0). In two of the patients taking CBZ, the seizures got worse and a series of cognitive-behavioural complications also appeared. CONCLUSIONS: CBZ is an effective drug in rolandic epilepsy, but it may be associated with exacerbation of seizures as well as with cognitive-behavioural impairment. CLB in monotherapy seems to be an effective and better tolerated drug in this kind of epilepsy.

[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.

[Volumetric measurement and digital electroencephalography in patients with medication-resistant medial temporal lobe epilepsy submitted to surgery]. / Volumetria y electroencefalografía digital en pacientes con epilepsia del lobulo temporal medial farmacorresistente sometidos a cirugía.

AIM: To assess the value of volumetric measurement by means of magnetic resonance imaging (MRI) and interictal electroencephalogram (EEG) in pre- and post-operative assessment of patients with medication-resistant medial temporal lobe epilepsy (MTLE) who were submitted to surgery. PATIENTS AND METHODS: We evaluated 12 volumetric studies carried out using MRI and 24 digital EEG records for six patients suffering from complex partial seizures that were resistant to medical treatment and had their origin in the temporal lobe. A volumetric analysis was performed using MRI to study the epileptogenic region and the frequencies at which interictal epileptiform discharges (IED/minute) appeared before, at six months and at one year after surgery were calculated; a correlation was observed between the volumetric analysis and the irritative and epileptogenic region. RESULTS: The volumes of both the ipso and contralateral hippocampuses were smaller in comparison to the increased frequency of the IED in the mesial regions. The inferior temporal lobes and the parahippocampal cortex have reduced volumes ipsolateral to the epileptogenic region. At six months after performing the temporal lobectomy, the IED frequency decreased with respect to the pre-operative IED. A negative correlation was found between the resected volume of the parahippocampal cortex and the inferior temporal lobe, and the post-operative IED frequency at one year. CONCLUSIONS: In patients with medication resistant MTLE the volumes of other structures in the medial temporal lobe are diminished, in addition to the hippocampus, and they are seen to have a smaller volume on the side that is ipsolateral to the epileptogenic region. There is a relation between the volume of the resected hippocampus and the post-operative IED frequency in patients with MTLE who successfully underwent a temporal lobectomy. Volumetric analysis of the epileptogenic lesion using MRI provides localising information that is valuable in the pre-operative assessment of patients with medication resistant MTLE who are submitted to surgery.

[Video-EEG evaluation complemented by spectral and EEG source analysis in patients with medication-resistant medial temporal lobe epilepsy]. / Evaluación videoelectroencefalográfica complementada con análisis espectral y de las fuentes generadoras del electroencefalograma en pacientes con epilepsia del lóbulo temporal medial resistente a los fármacos.

AIM: To evaluate the value of prolonged video-electroencephalographic (video-EEG) monitoring complemented with spectral and EEG source analysis in identifying the epileptogenic area in patients with medial temporal lobe epilepsy who are candidates for non-lesional resective surgery. PATIENTS AND METHODS: The electrographic patterns during the onset of seizures were evaluated in over 667 seizures from 41 patients with a clinical diagnosis of medication-resistant partial epilepsy. Analyses were performed using Harmonie software and variable resolution electrical tomography (VARETA). RESULTS: Video-EEG was used to determine that 53.6% of the patients evaluated suffered complex partial seizures of a temporal origin; these were characterised by having an average frequency of 5.56 +/- 1.56 Hz, while the non-temporal seizures displayed a frequency within the range 9.17 +/- 3.32 Hz. The topographic location of the dominant ictal frequency during the period of maximum spectral energy in patients with temporal lobe epilepsy enabled us to draw a distinction between a group of patients with mesial seizures and those with non-mesial seizures that exceeded the number that was determined by visual inspection of the EEG, that is, 78.9 versus 47.3%, respectively. There was a 100% coincidence between the area where the seizures began as defined by surface EEG complemented with spectral analysis, the generator of this activity as defined by VARETA and the epileptogenic region. CONCLUSIONS: The localising information provided by video-EEG complemented with spectral and EEG source analysis allows for non-invasive location of the epileptogenic region in patients with medial temporal lobe epilepsy even when structural imaging studies show an absence or bilaterality of abnormalities.

[Contribution of thalamic somatosensory evoked potentials to stereotaxic thalamometry]. / Contribución de los potenciales somatosensoriales talámicos a la talamotomía estereotáxica.

INTRODUCTION: In order to use short latency somatosensory thalamic evoked potentials (PES) to locate therapeutic targets in functional surgery, thalamic PES were recorded during stereotactic thalamotomy in 25 patients with Parkinson's disease, using a concentric bipolar semi-micro-electrode, 4 mm in diameter. In the 72 trajectories planned. 628 registers were made, obtaining 314 PES in 55 trajectories. These recordings were divided into 5 groups, according to the electrical variables evaluated in each case (absolute latency, inter-peak latency, absolute amplitude and number of phases). MATERIAL AND METHODS: The electrophysiological characteristics of the PES groups obtained, and the spatial representation of these in a tridimensional system of coordinates, is shown. We analyze the sequence of the groups of potentials in each of the trajectories followed. CONCLUSIONS: We consider that the limit between adjacent nuclear edges, ventral intermediate (Vim)-ventro-caudal (Vc), may be represented by the transition of potentials in group 1 to potentials in group 4 and/or potentials of group 3 to those of group 2. This study shows that thalamic PES are useful for locating targets during stereotactic thalamotomy.

Contribución de los potenciales somatosensoriales talámicos a la talamotomía estereotáxica / Contribution of the thalamic somatosensory evoked potentials to stereotactic thalamotomy

Introducción. En un esfuerzo por utilizar los potenciales evocados somatosensoriales (PES) talámicos de corta latencia, como localizadores de blancos terapéuticos en la cirugía funcional, se registraron PES talámicos durante la talamotomía estereotáxica de 25 pacientes parkinsonianos, utilizando un semimicroelectrodo bipolar concéntrico de 0,4 mm de diámetro. A lo largo de las 72 trayectorias planificadas, se realizaron 628 registros obteniéndose 314 PES en 55 trayectorias. Estos registros se dividieron en cinco grupos, atendiendo a las variables eléctricas evaluadas para cada uno de ellos (latencia absoluta, latencia interpico, amplitud absoluta y número de fases). Material y métodos. Se muestra la caracterización electrofisiológica de los grupos de PES obtenidos, y la representación espacial de los mismos en un sistema de coordenadas tridimensional. Analizamos la secuencia de los grupos de potenciales en cada una de las trayectorias realizadas. Conclusiones. Planteamos que el límite entre bordes nucleares adyacentes ventral intermedio (Vim)-ventrocaudal (Vc) puede estar representado por la transición de potenciales del grupo 1 a potenciales del grupo 4 y/o de potenciales del grupo 3 a los del grupo 2. Con este estudio se demuestra la utilidad de los PES talámicos en la localización de los blancos durante la talamotomía estereotáxica