[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.

Cuerpos amiláceos en la neocorteza de pacientes con epilepsia del lóbulo temporal y displasia cortical focal / Corpora amylacea in the neocortex in patients with temporal lobe epilepsy and focal cortical dysplasia

Introducción: Los cuerpos amiláceos (CoA) se presentan en aproximadamente el 60% de los hipocampos atróficos resecados de pacientes con epilepsia del lóbulo temporal farmacorresistente (ELTFR). Su presencia en la neocorteza temporal lateral ha sido observada con menor frecuencia. Objetivo: El objetivo es evaluar la presencia, la distribución y la densidad de CoA en el lóbulo temporal lateral de pacientes con ELTFR y displasia cortical focal (DCF) y la relación de su densidad con variables demográficas y clínicas. Métodos: Analizamos histológicamente el tejido resecado de 35 pacientes con ELTFR. La densidad de los CoA fue evaluada con una escala semicuantitativa según los criterios de Cherian et al. Resultados: La presencia de CoA en la neocorteza de 9 pacientes estuvo asociada a esclerosis hipocampal (DCF tipo IIIa, 7 casos), tumor neuroepitelial disembrioplásico (DCF tipo IIIb, un caso) y angioma cavernoso (DCF tipo IIIc, un caso). Todos los pacientes tuvieron afectación de la superficie meníngea (SM) y en 8 casos se localizaron en el parénquima cerebral (sustancia blanca) y alrededor de los vasos sanguíneos. La densidad de los CoA en SM tuvo una correlación negativa con la edad de inicio de las crisis (r = -0,828, p < 0,05) y positiva con la duración de la enfermedad (r = 0,678, p < 0,05) pero no con la evolución clínica postquirúrgica. Conclusiones: En pacientes con ELTFR con lesión principal (EH, tumor, malformación vascular) asociada a DCF ligeras se constata la acumulación de CoA en la neocorteza. No se encontró una asociación entre la presencia de CoA y la evolución clínica al año de la cirugía

Introduction: Corpora amylacea (CoA) are present in about 60% of atrophic hippocampi resected from patients with drug resistant temporal lobe epilepsy (DRTLE). They have also been described in the lateral temporal neocortex, although less frequently. Objective: The objective is to measure the presence, distribution and density of CoA in the lateral temporal lobes of patients with DRTLE and focal cortical dysplasia (FCD), also examining how CoA density may be linked to demographic and clinical traits. Methods: Resected tissue from 35 patients was analysed. CoA density was assessed with a semi-quantitative scale according to the criteria established by Cherian et al. Results: Presence of CoA in the neocortex of 9 patients was associated with hippocampal sclerosis (FCD type IIIa, 7 cases), disembryoplastic neuroepithelial tumour (FCD type IIIb, 1 case), and cavernous angioma (FCD type IIIc, 1 case). The meningeal surface (MS) was involved in all cases, and 8 cases displayed CoA in the cerebral parenchyma (white matter) and around blood vessels. CoA density on the MS showed a negative correlation with age at seizure onset (r = -0.828, P < .05) and a positive correlation with disease duration (r = 0.678, P < .05) but not with postoperative clinical outcome. Conclusions: Patients with DRTLE and a primary lesion (hippocampal sclerosis, tumour, vascular malformation) associated with mild FCD were shown to have CoA deposits in the neocortex. No association was found between presence of CoA and clinical outcome one year after surgery

Corpora amylacea in the neocortex in patients with temporal lobe epilepsy and focal cortical dysplasia.

INTRODUCTION: Corpora amylacea (CoA) are present in about 60% of atrophic hippocampi resected from patients with drug resistant temporal lobe epilepsy (DRTLE). They have also been described in the lateral temporal neocortex, although less frequently. OBJECTIVE: The objective is to measure the presence, distribution and density of CoA in the lateral temporal lobes of patients with DRTLE and focal cortical dysplasia (FCD), also examining how CoA density may be linked to demographic and clinical traits. METHODS: Resected tissue from 35 patients was analysed. CoA density was assessed with a semi-quantitative scale according to the criteria established by Cherian et al. RESULTS: Presence of CoA in the neocortex of 9 patients was associated with hippocampal sclerosis (FCD type iiia, 7 cases), disembryoplastic neuroepithelial tumour (FCD type iiib, 1 case), and cavernous angioma (FCD type iiic, 1 case). The meningeal surface (MS) was involved in all cases, and 8 cases displayed CoA in the cerebral parenchyma (white matter) and around blood vessels. CoA density on the MS showed a negative correlation with age at seizure onset (r = -0.828, P<.05) and a positive correlation with disease duration (r = 0.678, P<.05) but not with postoperative clinical outcome. CONCLUSIONS: Patients with DRTLE and a primary lesion (hippocampal sclerosis, tumour, vascular malformation) associated with mild FCD were shown to have CoA deposits in the neocortex. No association was found between presence of CoA and clinical outcome one year after surgery.

Microscopic mild focal cortical dysplasia in temporal lobe dual pathology: an electrocorticography study.

BACKGROUND: Associations between electrophysiological and histological findings might provide an insight into the epileptogenicity of mild focal cortical dysplasia (FCD) in patients with temporal lobe epilepsy (TLE) and a dual pathology. SUBJECTS AND METHODS: A total of 22 patients with pharmacoresistant TLE were included in the study, 16 of them with histologically confirmed hippocampal sclerosis (HS) associated with neocortical temporal mild Palmini Type-I FCD subtypes and 6 with HS. Intraoperative electrocorticography (ECoG) recordings were analysed for epileptiform discharge frequency and morphology. Associations between histological, and electrocorticography pattern findings in these patients were analysed. Electroclinical outcomes in these patients were also evaluated. RESULTS: Neocortical areas with mild Palmini Type-I FCD showed a significantly higher spike frequency (SF) recorded in the inferior temporal gyrus than those neocortical areas in patients with HS. There was a tendency to higher spike frequency and lower amplitude in neocortical areas with histopathologic subtype IB FCD in relation with IA during intraoperative ECoG. Post-SF excision and amplitude were significantly lower during neocortical post-excision intraoperative ECoG than during neocortical pre-excision recording. There was no difference found in the clinical outcome between patients with and without FCD. CONCLUSIONS: Intraoperative electrocorticographic interictal spike frequency recorded in the neocortical inferior temporal gyrus may help to characterize the histopathologic subtypes of mild Palmini Type-I FCD in patients with temporal lobe epilepsy (TLE) and a dual pathology. Our data support the epileptogenicity of neocortical mild FCD in TLE and assessments of ECoG patterns are relevant to determine the extent of the resection in these patients which can influence the electroclinical outcome.

Brain magnetic resonance imaging findings in acute relapses of neuromyelitis optica spectrum disorders.

We studied cranial magnetic resonance imaging (MRI) lesions in three women with acute attacks of recurrent longitudinally extensive transverse myelitis (r-LETM), recurrent-optic neuritis (r-ON) and r-LETM-CNS. Neuromyelitis Optica -immunoglobulin (IgG) antibody was positive in all cases. Brain MRI (1.5 Tesla) was performed according to protocol from consortium MS centre. We described the cranial lesions in brain MRI of acute relapses. These lesions were different from MS, most had an asymptomatic course which disappeared with time, protocol from consortium of MS centre criteria for brain MRI and seropositivity of NMO-IgG are useful tools for differentiate acute lesions of NMO/MS.

[Effects of lobectomy on the auditory mid-latency response in temporal lobe epileptic patients]. / Efectos de la lobectomía sobre el potencial evocado auditivo de latencia media en pacientes con epilepsia del lóbulo temporal.

AIM: Auditory mid-latency response (MLR) has been studied in temporal lobe epileptic patients in order to evaluate the relationship between the different components of this evoked response and their probable generators in the most rostral part of auditory pathway. PATIENTS AND METHODS: MLR was studied in eight patients with temporal lobe epilepsy before lobectomy, and 1, 6 and 12 months after the surgical treatment, and eight healthy subjects matched for age and gender. Recording electrodes were placed in Cz, T3 and T4 according to the international 10-20 system. Comparisons were carried out in terms of peak to peak amplitude, latency and interpeak intervals of the main components (Mann-Whitney U test, Wilcoxon test). RESULTS: Epileptic patients showed statistically significant prolonged latency of all components, and increased Pa-Pb interpeak interval duration respect to control group. No significant variations were found in the amplitude of the studied components. There were no differences between left and right lobotomized patients. However, a marked tendency to the shortening of latency was observed in the left group after the surgical treatment. CONCLUSIONS: The differences between the pre-surgical records of patients and controls reflect an impaired activity in the generating areas for MLR components. There appears to be a trend to a different behaviour after right or left lobectomy, probably related to the extension of the removed tissue.

Efectos de la lobectomía sobre el potencial evocado auditivo de latencia media en pacientes con epilepsia del lóbulo temporal / Effects of lobectomy on the auditory mid-latency response in temporal lobe epileptic patients

Objetivo. Se estudió el potencial evocado auditivo de latenciamedia (PEALM) en pacientes epilépticos con lobectomíatemporal para evaluar la relación existente entre los componentesde esta respuesta evocada y sus probables generadores en los segmentosmás rostrales de la vía auditiva. Pacientes y métodos. Seevaluaron ocho pacientes con epilepsia temporal antes de la operacióny 1, 6 y 12 meses posteriores a la lobectomía, y ocho sujetossanos pareados en sexo y edad. Los electrodos de registro se colocaronen las posiciones Cz, T3 y T4 del sistema internacional 10-20.Se compararon los valores de latencia, amplitud pico a pico y duracióndel intervalo interpicos de los principales componentes (test Ude Mann-Whitney, test de Wilcoxon). Resultados. Los pacientes mostrarondiferencias significativas respecto al grupo control para lalatencia de todos los componentes y la duración del intervalo Pa-Pb, pero no para la amplitud. No encontramos diferencias significativasentre los pacientes con lobectomía derecha e izquierda, aunquese aprecia una marcada tendencia al acortamiento de latenciasen el grupo con lobectomía izquierda. Conclusiones. Las diferenciasevidenciadas en la evaluación prequirúrgica reflejan un deteriorofuncional de las áreas generadoras de los componentes delPEALM. Parece existir un comportamiento diferencial después dela lobectomía izquierda o derecha, probablemente relacionado conla extensión del área extirpada

Aim. Auditory mid-latency response (MLR) has been studied in temporal lobe epileptic patients in order toevaluate the relationship between the different components of this evoked response and their probable generators in the mostrostral part of auditory pathway. Patients and methods. MLR was studied in eight patients with temporal lobe epilepsy beforelobectomy, and 1, 6 and 12 months after the surgical treatment, and eight healthy subjects matched for age and gender.Recording electrodes were placed in Cz, T3 and T4 according to the international 10-20 system. Comparisons were carriedout in terms of peak to peak amplitude, latency and interpeak intervals of the main components (Mann-Whitney U test,Wilcoxon test). Results. Epileptic patients showed statistically significant prolonged latency of all components, and increasedPa-Pb interpeak interval duration respect to control group. No significant variations were found in the amplitude of thestudied components. There were no differences between left and right lobotomised patients. However, a marked tendency tothe shortening of latency was observed in the left group after the surgical treatment. Conclusions. The differences between thepre-surgical records of patients and controls reflect an impaired activity in the generating areas for MLR components. Thereappears to be a trend to a different behaviour after right or left lobectomy, probably related to the extension of the removedtissue

Effects of lobectomy on the auditory mid-latency response in temporal lobe epileptic patients / s. t

Se estudió el potencial evocado auditivo de latencia media (PEALM) en pacientes epilépticos con lobectomía temporal para evaluar la relación existente entre los componentes de esta respuesta evocada y sus probables generadores en los segmentos más rostrales de la vía auditiva. Pacientes y métodos. Se evaluaron ocho pacientes con epilepsia temporal antes de la operación y 1, 6 y 12 meses posteriores a la lobectomía, y ocho sujetos sanos pareados en sexo y edad. Los electrodos de registro se colocaron en las posiciones Cz, T3 y T4 del sistema internacional 10-20. Se compararon los valores de latencia, amplitud pico a pico y duración del intervalo interpicos de los principales componentes (test U de Mann-Whitney, test de Wilcoxon). Resultados. Los pacientes mostraron diferencias significativas respecto al grupo control para la latencia de todos los componentes y la duración del intervalo Pa-Pb, pero no para la amplitud. No encontramos diferencias significativas entre los pacientes con lobectomía derecha e izquierda, aunque se aprecia una marcada tendencia al acortamiento de latencias en el grupo con lobectomía izquierda...(AU)

[Mid-latency auditory evoked potential]. / Potencial evocado auditivo de media latencia.

AIMS: Given the diversity of criteria regarding the use of the midlatency auditory evoked potential (MLAEP) for diagnostic purposes, we carry out a review of the subject and highlight areas such as the generators of fundamental components, the conditions in which responses are obtained, factors that can modify results and the clinical uses that have been reported. DEVELOPMENT: There seems to be a strong tendency towards considering areas of the primary and secondary auditory cortex as generators of the response, with the subcortical structures playing a moderating role. Factors such as age, the method of stimulation used and the monitoring conditions can all exert an influence on the characteristics of this evoked response and modify its capacity for detection and repetition. Clinical uses of this potential range from the detection of the hearing threshold, monitoring the depth of anaesthesia, the functional evaluation of cochlear implants, and the diagnosis of neurological disorders, among others. CONCLUSIONS: MLAEP is a technique that is widely used in the study of the most rostral segments of the auditory pathway and this information complements that provided by short latency responses and increases the diagnostic sensitivity of auditory evoked potentials.

¿Onda hipervoltada en el potencialevocado auditivo de tallo cerebral? / Can hypervoltage waves exist in brain stem auditory evoked potentials?

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Potenciales evocados gigantes / Giant evoked potentials

Introducción. Múltiples y diversas son las entidades gnosológicas que tienen como factor común la génesis de respuestas evocadas corticales de gran amplitud y que han sido comúnmente denominados como potenciales evocados gigantes. En la mayor parte de los casos se trata de afecciones que tienen como característica clínica común la presencia de mioclonías de origen cortical, tales como las epilepsias mioclónicas progresivas, epilepsias idiopáticas generalizadas, mioclonías de origen tóxico, infeccioso y postanóxico. En el estudio de lesiones hemisféricas focales también se han demostrado potenciales gigantes, lo mismo que en algunos casos de pacientes con degeneración corticobasal. Objetivo. Este trabajo pretende ejemplificar a través de la presentación de casos interesantes algunas de las entidades mencionadas, y revisar algunos conceptos acerca de los mecanismos que podrían estar involucrados en la génesis de estas respuestas electrofisiológicas particulares. Pacientes y métodos. Se estudiaron 6 pacientes entre 2 y 22 años de edad a los que se realizaron estudios de potenciales evocados multimodales, electroencefalograma y estudios imaginológicos. Resultados. Se constataron potenciales somatosensoriales gigantes en los pacientes con mioclonías evidentes, en tanto que los potenciales visuales de gran amplitud fueron comunes al resto de los casos presentados, en presencia o no de mioclonías. Conclusiones. Los potenciales evocados gigantes responden a un estado de hiperexcitabilidad cortical que puede tener orígenes diversos (AU)

[Giant evoked potentials]. / Potenciales evocados gigantes.

INTRODUCTION: There are many, diverse nosological entities with the common factor of the genesis of cortical evoked potentials of great amplitude, commonly known as giant evoked potentials. In most cases they are conditions with the common clinical condition of myoclonic of cortical origin, such as progressive myoclonic epilepsy, generalized idiopathic epilepsy, myoclonias of toxic, infectious or postanoxic origin. Giant potentials have been shown both in studies of focal hemisphere lesions and in some cases of patients with corticobasal degeneration. OBJECTIVE: The aim of this paper was to show, by presenting interesting cases, some of the conditions mentioned and to review some concepts concerning the mechanisms which may be involved in the production of these electrophysiological responses. PATIENTS AND METHODS: We studied 6 patients aged between 2 and 22 years, in whom multimodal evoked potentials, electroencephalograms and imaging studies had been done. RESULTS: Giant somatosensory potentials were shown in the patients with obvious myoclonia. Visual potentials of great amplitude were common to the other patients presented, with or without myoclonia. CONCLUSION: Giant evoked potentials respond to a state of cortical hyperexcitability which may have various causes.

[Actual status of multiple sclerosis in Cuba. National cooperative group for the clinical trial "Recombinant interferon alpha-2b in multiple sclerosis"]. / Estado actual de la esclerosis múltiple en Cuba. Grupo Cooperativo Nacional para el Ensayo Clínico 'Interferón alfa-2b recombinante en la esclerosis múltiple'.

INTRODUCTION: Multiple sclerosis (MS) has been considered to be an uncommon disorder in Cuba. In recent years many Cuban investigators have worked hard studying MS in Cuba. DEVELOPMENT: We review the history, epidemiology, clinical characteristics, complementary investigations and clinical trials of recent studies published in national and international journals on the most important investigations done on MS in Cuba. There is an outstanding placebo-controlled, double blind, multicentric randomised clinical trial using recombinant alpha 2b-IFN in the relapsing-remitting clinical form in which the results obtained in the first 30 patients who completed 2 years treatment show a statistically significant reduction in the frequency of relapses and the number of patients free of relapses in patients who received alpha-IFN as compared with those given placebo treatment. CONCLUSIONS: There has been an increase in the number of studies made on MS in Cuba in the past two years. Numerous clinical, neuroepidemiological, neurophysiological, biochemical, immunological, imaging and neuropsychological investigations and clinical trials indicate a marked increase in understanding of MS. The results of all these studies indicated the need for the creation of a National Reference Centre for Patients with Multiple Sclerosis, due to the complexity of this type of patients and the need to offer improved medical attention from a specialist team and to integrate the investigations in Cuba and internationally so as to reach the level of more developed countries.

Estado actual de la esclerosis múltiple en Cuba / The current state of multiple sclerosis in Cuba

Introducción. La esclerosis múltiple (EM) se ha considerado una enfermedad poco frecuente en Cuba. En los últimos años, numerosos investigadores cubanos han trabajado intensamente en el conocimiento de esta enfermedad en nuestro país. Objetivo. Analizar y resumir las investigaciones sobre EM realizadas en Cuba. Desarrollo. Revisamos la historia, epidemiología, características clínicas, estudios complementarios y ensayos clínicos de los últimos trabajos publicados en revistas nacionales e internacionales sobre las investigaciones más prominentes sobre EM en Cuba. Es llamativo el ensayo clínico, aleatorizado, multicéntrico, a doble ciegas y controlado con placebo llevado a cabo con interferón-alfa 2b recombinante en la forma clínica exacerbación-remisión, cuyos resultados en los primeros 30 pacientes que concluyeron los dos años de tratamiento indican una reducción estadísticamente significativa de la frecuencia de las recaídas, así como del número de pacientes libres de brotes entre los enfermos que recibieron interferón-alfa al compararlos con los que recibieron placebo. Conclusiones. Los estudios sobre EM en Cuba se han incrementado en los dos últimos años; numerosas investigaciones clínicas, neuroepidemiológicas, neurofisiológicas, bioquímicas, inmunológicas, imaginológicas y neuropsicológicas, así como ensayos clínicos, indican un desarrollo notable en su conocimiento. Los resultados de todos estos estudios sugieren la necesidad de crear un Centro de Referencia Nacional para Pacientes con Esclerosis Múltiple, debido a la complejidad de este tipo de pacientes y a la necesidad de ofrecerles una mejor atención médica por parte de un equipo especializado y de integrar las investigaciones en el país y en el plano internacional para estar a la altura de los países más desarrollados (AU)

[Effects of monaural and binaural stimulation on middle latency auditory evoked responses]. / Efectos de la estimulación monoaural y binaural sobre la respuesta evocada auditiva de latencia media.

INTRODUCTION: Middle latency evoked potentials include a series of evoked responses which encompass/include myogenic potentials (which translate the existence of sonomotor reflexes), and others which are clearly of neurogenic origin. The latter are the most useful from the clinical point of view. OBJECTIVE: To evaluate the effects of monoaural (MA) and binaural (BA) stimulation on middle latency auditory evoked potentials. PATIENTS AND METHODS: We studied 15 healthy people, aged between 18 and 52 years, in whom Cz recording electrodes had been fitted to both short-circuited external ears with Fpz as earth. The stimuli used were alternate clicks of condensation and rarefication of 90 dBHL, first BA and them MA. The auditory evoked response from the brain stem was also recorded. RESULTS: We found more stability of most of the components evaluated during biauricular stimulation. All subjects had Pa waves and 93% had Pb waves. Statistically significant differences were only found for the amplitude of Po and Pa (BA against RE) (Wilcoxon test, p < 0.05). CONCLUSION: The use of BA stimulation to obtain middle latency evoked potentials is more useful for study of the more rostral parts of the auditory path, since its components are more stable.

Efectos de la estimulación monoaural y binaural sobre la respuesta evocada auditiva de latencia media / The effects of monoaural and binaural stimulation on middle latency auditory evoked responses

Introducción. Los potenciales evocados auditivos de latencia media engloban una serie de respuestas evocadas que abarcan potenciales miogénicos (que traducen la existencia de reflejos sonomotores), y otras que tienen un origen claramente neurogénico. Estas últimas resultan las de mayor utilidad desde el punto de vista clínico. Objetivo. Evaluar los efectos de la estimulación monoaural (MA) y binaural (BA) sobre el potencial evocado auditivo de latencia media. Pacientes y métodos. Estudiamos 15 sujetos sanos, con edades comprendidas entre 18 y 52 años, a los cuales se colocaron electrodos de registro en Cz, referidos a ambas orejas cortocircuitadas y Fpz como tierra. Los estímulos aplicados fueron clics alternos de condensación y rarefacción de 90 dBHL, primero BA y luego MA. Se registró además la respuesta evocada auditiva de tallo cerebral. Resultados. Constatamos una mejor estabilidad de la mayor parte de los componentes evaluados durante la estimulación biauricular. El 100 por ciento de los sujetos presentaron onda Pa y el 93 por ciento onda Pb, y detectamos diferencias estadísticamente significativas sólo para la amplitud de Po y Pa (BA frente a OD) (test de Wilcoxon, p< 0,05). Conclusión. El empleo de la estimulación BA para la obtención del potencial evocado auditivo de latencia media resultó de mayor utilidad para el estudio de las porciones más rostrales de la vía auditiva, dada la mayor estabilidad de sus componentes (AU)

[Follow-up study of the evolution of the quantitative EEG in intraventricular infusion of nerve growth factor in an aged baboon]. / Seguimiento evolutivo con EEG cuantitativo de la infusión intraventricular de factor de crecimiento nervioso en babuino envejecido.

The animal model of aged monkeys is a good homologue of Alzheimer's disease in humans, in which it has been shown that there is disproportionate slowing of the EEG when compared with healthy subjects paired for age. This is found both on the conventional EEG and quantitatively. In the latter, relative energy has been the measurement most commonly used for diagnosis and follow-up with various treatments. The follow-up parameters evaluated in this study were: absolute and relative energy of the quantitative EEG (EEGq) obtained in an aged (39 year old) baboon (Papio hamadryas) before and after infusion of intraventricular nerve growth factor (NGF). These findings were compared with those of a young animal (6 year old) of the same species, treated in the same way. Since the animals were first anaesthetized with ketamine and diacepam so as to be able to carry out the study, we used a cerebral function analyzer which allowed us to ascertain that the changes found on analysis of the EEGq were not due to the depth of anaesthesia. The analyzer evaluated the tendencies of amplitude and frequency of the EEG, which is a method widely used for the indirect evaluation of the level of anaesthesia.

Seguimiento evolutivo con EEG cuantitativo de la infusión intraventricular de factor de crecimiento nervioso en babuino envejecido / Evolutive follow up with quantitative EEG of the intraventricular of nerve growth factor in aged monkeys

El modelo animal de monos envejecidos constituye un buen homológo de la enfermedad de Alzheimer en humanos, en la cual se ha constatado un enlentecimiento desproporcional del EEG cuando se compara con sujetos sanos pareados en edad, hallazgo evidenciado tanto en el EEG convencional como en el cuantitativo; en este último la energía relativa ha sido la medida más comúnmente utilizada para el diagnóstico y seguimiento evolutivo con diversas terapéuticas. En el presente estudio se evalúan los parámetros: energía absoluta y relativa del EEG cuantitativo (EEGq) obtenido en un babuino (Papio hamadryas) envejecido (39 años) en los períodos pre y postinfusion intraventricular de factor de crecimiento de nervio (FCN) y se compara con un animal joven (6 años) de la misma especie sometido a idéntica terapia. Dado que para la realización de este estudio los animales fueron previamente anestesiados con ketamina y diacepam, empleamos un analizador de la función cerebral que nos permitió comprobar que los cambios reportados en el análisis del EEGq no respondían a la profundidad de la anestesia. Este analizador evalúa las tendencias de amplitud y frecuencia del EEG el cual ha sido un método frecuentemente utilizado en la evaluación indirecta del nivel de anestesia