[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.

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.

[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.

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.

[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.

[Neuronal death in the neocortex of drug resistant temporal lobe epilepsy patients]. / Muerte neuronal en la neocorteza de pacientes con epilepsia del lóbulo temporal resistente a fármacos.

Introduction. Participation of apoptotic death mechanisms in drug resistant temporal lobe epilepsy (DRTLE) is currently under great debate. We have investigated if there is neuronal loss and the immunodetection to different markers in neocortical tissue death in eigth patients with DRTLE. The neocortexes of five patients deceased due to non-neurological causes, paired in age and gender were evaluated as control tissue. Methods. The evaluation of neuronal loss was made by means of a stereological study and with immunohistochemical techniques with the synaptophysin marker. Immunopositivity to different apoptotic markers (annexin V, caspase 3 and 8, bcl-2 and p53) and detection of deoxyribonucleic acid (DNA) fragmentation (TUNEL) were analyzed and double labeling with synaptophysin was performed in every case. The results were evaluated with confocal microscope and analyzed with the Zeiss LSM 5 Image Browser Program, 2.80.1113 (Germany). Results. A statistically significant decrease in the total number of cells (p < 0.05) and the synaptophysin cells+ (p<0.01) in the neocortex (layer IV) of the patients with DRTLE when compared with the control tissue was found. No significant differences were found in the apoptotic markers bcl-2, p53, caspase 3 and 8 for any of the neocortex layers while there was a statistically significant increase in the number of TUNEL cells+ (p<0.05) and annexin V+ (p<0.05) in the neocortical layer IV of the patients. Conclusions. This group of evidence speaks in favor of the existence of an effect on the neuronal number in the neocortex layer IV that may be associated with noncaspase dependent apoptotic death process, without being able to rule out death by necrosis. Key words: Drug resistant temporal lobe epilepsy. Apoptosis. Necrosis. Neuronal loss. Neurología 2008;23(9):555-565.

[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.

[Immunological disorders in epileptic patients are associated to the epileptogenic focus localization]. / Alteraciones inmunológicas en pacientes epilépticos asociadas a la localización del foco epileptogénico.

OBJECTIVE: Clinical and experimental data support the role of immune mechanisms in the pathogeny of epilepsy. The purpose of this work was to study the immunological aspects in 30 epileptic patients with complex partial crisis resistant to antiepileptic drugs. PATIENTS AND METHODS: The patients were evaluated by EEG-Video and they were grouped attending to epileptogenic focus localization in: temporals (n = 16), lateralized (n = 6) and extratemporals (n = 4). We also studied a group with psychogenic epilepsy (n = 4), this group was diagnosed after EEG-video evaluation. The following immunological evaluations has been carried out: levels of serum immunoglobulins (IgG, IgM e IgA) by radial immunodiffusion test and lymphocytic subpopulations using immunocytochemical methods. We measured the percent of T and B lymphocytes (CD3 and CD20), helper/inductor lymphocyte T (CD4), suppressor/cytotoxic (CD8), interleukine-2 receptor (CD25) and human leukocyte antigen (HLA-DR). RESULTS: The results show a significant increase of CD8+ lymphocytes (p < 0.05) and in the activation markers (CD25+ and HLA-DR+ cells). The evaluation of immunological parameters applied to different group of epileptogenic focus localization shown that the increase of CD8+ lymphocytes is limited to temporal and lateralized patients (p < 0.01). The patients with extratemporal localization of focus and the psychogenic cases shown normal values for the evaluated immunological lymphocyte markers. We did not find a deficit in the humoral immunological aspects. CONCLUSIONS: Taking into account that patients diagnosed as psychogenic received an antiepileptic drug treatment identical to that of the other group, the observed immunological changes might be related with the patogeny of certain epilepsy variants associated with the focus localization and not with the medication.

[Magnetic resonance spectroscopy and functional magnetic resonance images: non-invasive alternatives for identifying epileptogenic foci]. / Espectroscopía por resonancia magnética e imágenes de resonancia magnética functional: alternativas no invasivas para la identificación de la zona epileptogénica.

Magnetic resonance spectroscopy and functional magnetic resonance images are new non-invasive techniques which have the potential for localization of the epileptogenic focus in patients with refractory focal epilepsy, who are candidates for surgery. Determination of patterns of asymmetry of the N-acetyl-aspartic acid (NAA) between homologous regions of the temporal lobes, using magnetic resonance spectroscopy contributes to preoperative lateralization in patients with temporal lobe epilepsy. This technique may become a method for localization if its usefulness in the differentiation of mesial temporal lobe epilepsy from neocortical epilepsy is validated. Functional magnetic resonance images triggered by epileptiform discharges on the EEG, when combined with methods for localizing the source, permit the site of the epileptogenic focus to be found. This would particularly benefit patients with non-lesional extra-temporal epilepsy who are potential candidates for invasive recordings. The use of magnetic resonance spectroscopy and functional magnetic resonance images in the preoperative evaluation of patients with refractory focal epilepsy, especially if it is used together with the relevant clinical data and that from other structural and functional imaging techniques, will reduce invasive monitoring and increase the accessibility to surgical treatment for this condition.

[The use of zygomatic electrodes in the assessment of epileptic patients. Presentation of methodology for recording and assessing a digital EEG]. / Utilización de electrodos cigomáticos en la evaluación de pacientes epilépticos. Presentación de una metodología para el registro y evaluación del EEG digital.

INTRODUCTION AND OBJECTIVES: Electrographic anomalies of the temporal lobe may be seen in 70% of epileptic patients. Focalization if inter-ictal epileptiform discharges makes a major contribution to clinical diagnosis. Also, it is accepted that the detection and interpretation of such anomalies is influenced by the method of recording. Thus the use of additional extracranial electrodes has been shown to significantly increase the sensitivity of inter-ictal or ictal electroencephalograms (EEG) PATIENTS AND METHODS: We present the results of two years work in the Electroencephalogram Laboratory of the International Centre for Neurological Recovery, La Habana, Cuba (CIREN), using zygomatic electrodes for the standard assessment of epileptic patients. Recordings were made using the FCz position as reference electrode instead of the reference electrode (short-circuited ears) used as pre-programmed in the recording module of the software Track Walker 2 for Medicid 3E (used in the Clinical Neurophysiology Laboratories of the National Network). Epileptiform activity was seen on 196 recordings; in 100 (51%) of these, this activity involved the temporal lobe, with strictly temporal localization shown in 25 patients (25%) and in 7 (28%) we recorded focalization on the medial aspect. We present segments of EEGs with epileptiform discharges focalized in the temporal lobe (medial and lateral aspects) in bipolar systems (zygotemporal-parasagittal) and in reference electrodes. CONCLUSIONS: Our results support the usefulness of this methodology for the detection and localization of epileptiform activity in the temporal lobe and suggest an alternative which would increase the diagnostic sensitivity of EEG in epilepsies.

[Typical absence epilepsy in a patient with serious cranio-encephalic trauma]. / Ausencias típicas en un paciente con trauma craneoencefálico grave.

INTRODUCTION: Head injury is the commonest cause of symptomatic or secondary epilepsy and one of its most serious sequelas. Typical absence seizures are well defined clinically and electroencephalographically and are seen in age-related idiopathic epilepsies. There are very few descriptions of seizures of typical absences that were symptomatic of tumors or other structural lesions. CLINICAL CASE: We describe the case of a nine year old boy who had had a severe head injury at the age of four years. When he was seven years old he started to have seizures with all the clinical and electroencephalographic features of typical absences. CONCLUSIONS: In this case, taking the age of the patient into account, the APF, APP, electroclinical characteristics of the seizures, neurological and clinical condition, the problem was to decide whether the seizures were idiopathic or symptomatic of a cerebral lesion. This was important for treatment and prognosis. The answer could only be obtained by follow-up and assessment of the response to specific treatment for petit mal.

[Electroencephalogram findings in lesionectomies: preliminary results]. / Hallazgos del electrocorticograma en lesionectomías: resultados preliminares.

INTRODUCTION: Use of the electrocorticogram (EcoG) in planning lesionectomies is a controversial subject at present. MATERIAL AND METHODS: We describe a series of 5 patients with epileptic crises, 3 with arteriovenous malformations in whom the lesion was completely resected, followed by postoperative angiography, and two with gliomas with low grade malignancy in whom iridium 192 was implanted. RESULTS: 1. The most frequent reason for consultation was convulsions. 2. In our series of patients the commonest site was the frontal zone of the right hemisphere. 3. Potentials with epileptiform characteristics were registered at the edges of the lesions and occasionally over the lesion itself. In two cases electro-clinical crises were seen. 4. The lesions were resected from normal tissue independently of the EcoG results. CONCLUSION: Although they are preliminary findings, the results of the study support the usefulness of this technique to guide the surgical procedures used for the treatment of intractable epilepsy.

[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.

[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