Induction of brain injury and depression in rats by chronic unpredictable stress associated with the augmentation of nitrosative stress and apoptosis / Inducción de lesión cerebral y depresión en ratas por estrés crónico impredecible asociado con el aumento del estrés nitrosativo y la apoptosis

SUMMARY: Repeated stress is a risk factor for memory impairment and neurological abnormalities in both humans and animals. We sought to investigate the extent of (i) brain tissue injury; (ii) nitrosative and oxidative stress in brain tissue homogenates; (iii) apoptotic and survival biomarkers in brain tissue homogenates; and (iv) immobility and climbing abilities, induced over a period of three weeks by chronic unpredictable stress (CUS). Wistar rats were either left untreated (Control group) or exposed to a variety of unpredictable stressors daily before being sacrificed after 3 weeks (model group). Assessment of depression-like behavior was performed and animals were then culled and harvested brain tissues were stained with basic histological staining and examined under light microscopy. In addition, brain tissue homogenates were prepared and assayed for these parameters; inducible nitric oxide synthase (iNOS), malondialdehyde (MDA), superoxide dismutase (SOD), caspase-3, and B-cell lymphoma 2 (Bcl-2). Histology images showed CUS induced profound damage to the cerebral cortex as demonstrated by severe neuronal damage with shrunken cells, disrupted atrophic nuclei, perineuronal vacuolation and swollen glial cells. CUS also significantly (p<0.05) induced iNOS, MDA, and caspase-3, whereas SOD and Bcl-2 brain tissue levels were inhibited by CUS. In addition, data from the depression-like behavior, forced swimming test showed significant (p<0.05) increase in animal immobility and decrease in climbing ability in the model group of rats. Thus, here we demonstrated a reliable rat model of chronic stress-induced brain injury, which can further be used to investigate beneficial drugs or agents used for a period of three weeks to protect against CUS-induced brain damage.

RESUMEN: El estrés crónico es un factor de riesgo para el deterioro de la memoria y las anomalías neurológicas tanto en humanos como en animales. Intentamos investigar el alcance de lesión del tejido cerebral; (ii) estrés nitrosativo y oxidativo en homogeneizados de tejido cerebral; (iii) biomarcadores apoptóticos y de supervivencia en homogeneizados de tejido cerebral; y (iv) inmovilidad y habilidades de escalada, inducidas durante un período de tres semanas por estrés crónico impredecible (ECI). Se dejaron sin tratamiento (grupo control) ratas Wistar, o se expusieron a una variedad de factores estresantes impredecibles diariamente antes de ser sacrificadas después de 3 semanas (grupo modelo). Se realizó una evaluación del comportamiento similar a la depresión y luego se sacrificaron los animales y se tiñeron los tejidos cerebrales con tinción histológica básica y se examinaron con microscopía óptica. Además, se prepararon homogeneizados de tejido cerebral y se analizaron los siguientes parámetros; óxido nítrico sintasa inducible (iNOS), malondialdehído (MDA), superóxido dismutasa (SOD), caspasa- 3 y linfoma de células B 2 (Bcl-2). Las imágenes histológicas mostraron que el CUS indujo un daño profundo en la corteza cerebral como lo demuestra el daño neuronal severo con células encogidas, núcleos atróficos alterados, vacuolación perineuronal y células gliales inflamadas. ECI también indujo significativamente (p <0,05) iNOS, MDA y caspase-3, mientras que los niveles de tejido cerebral SOD y Bcl-2 fueron inhibidos por ECI. Además, los datos del comportamiento similar a la de- presión, la prueba de natación forzada mostró un aumento significativo (p <0,05) en la inmovilidad animal y una disminución en la capacidad de escalada en el grupo modelo de ratas. Por lo tanto, aquí demostramos un modelo confiable de daño cerebral crónico en rata inducido por el estrés, que se puede utilizar para investigar medicamentos o agentes beneficiosos usados durante un período de tres semanas para proteger el daño cerebral inducido por ECI.

Neuroimaging adolescents with depression in a middle-income country: feasibility of an fMRI protocol and preliminary results

Objective: To test the feasibility and to present preliminary results of a neuroimaging protocol to evaluate adolescent depression in a middle-income setting. Methods: We assessed psychotropic medication-free adolescents (age range 14-16 years) with a diagnosis of major depressive disorder (MDD). Participants underwent a comprehensive clinical evaluation and both structural and functional magnetic resonance imaging (fMRI). In this pilot study, a preliminary single-group analysis of resting-state fMRI (rs-fMRI) data was performed, with a focus on the default mode network (DMN), cognitive control network (CCN), and salience network (SN). Results: The sample included 29 adolescents with MDD (mean age 16.01, SD 0.78) who completed the protocol. Only two participants were excluded due to MRI quality issues (head movement), and were not included in the analyses. The scans showed significant connectivity between the medial prefrontal cortex and posterior cingulate cortex (DMN), the ACC and anterior insula (SN), and the lateral prefrontal cortex and dorsal parietal cortex (CCN). Conclusion: We demonstrated the feasibility of implementing a complex neuroimaging protocol in a middle-income country. Further, our preliminary rs-fMRI data revealed patterns of resting-state connectivity consistent with prior research performed in adolescents from high-income countries.

Displasias corticales como causa de epilepsia y sus representaciones en las imágenes: [revisión] / Cortical dysplasia as a cause of epilepsy and its images respresentation: [review]

Epilepsy is a chronic neurological disorder characterized by spontaneous recurrent seizures, which are clinically classified as generalized or partial. Approximately, 30 percent of patients with partial epilepsy is refractory to medical treatment. Within the refractory group we must discard the presence of cortical dysplasia as an underlying cause of the crisis. Cortical dysplasias are a type of malformations of cortical development (MCD) that are increasingly recognized as a cause of refractory epilepsy. From the radiological point of view this kind of pathology is of particular interest since imaging manifestations can be subtle or may show completely normal examinations. The aim of this paper is to review the literature, describing the imaging appearance of the normal cortical development, the classifications of cortical malformations, mainly cortical dysplasias, by highlighting the most frequent radiological signs. We also examine the current role of positron emission tomography (PET) in epilepsy, which in conjunction with magnetic resonance imaging findings and electrophysiological studies are used to define a possible surgical treatment. Through this treatment we expect to be provided with details of histopathological alterations found in the surgical specimen to be compared to the radiographic changes revealed in the pre-surgical study.

La epilepsia es una alteración neurológica crónica caracterizada por crisis convulsivas recurrentes y espontáneas, que clínicamente se clasifican como generalizadas o parciales, dentro de las cuales aproximadamente el 30 por ciento de los pacientes con epilepsia parcial son refractarios al tratamiento médico. Dentro del grupo refractario debemos descartar la presencia de una displasia cortical como causa subyacente de las crisis. Las displasias corticales son un tipo de malformaciones del desarrollo cortical que en forma cada vez más frecuente se reconocen como causante de epilepsia refractaria. Desde el punto de vista radiológico, este tipo de patología tiene especial interés debido a que las manifestaciones imaginológicas pueden ser sutiles o presentar exámenes completamente normales. El objetivo de este artículo es realizar una revisión de la literatura, describiendo el desarrollo cortical normal con su aspecto en imágenes, las clasificaciones de las malformaciones corticales y en especial de las displasias corticales, destacando los signos radiológicos más frecuentes. Además revisaremos el rol en la actualidad de la Tomografía por Emisión de Positrones (PET) en epilepsia, que en conjunto con las imágenes por resonancia magnética y los estudios electrofisiológicos se utilizan para definir un eventual tratamiento quirúrgico, el que una vez realizado nos da detalles del análisis de las alteraciones histopatológicas en la pieza quirúrgica versus las alteraciones radiológicas visualizadas en el estudio pre-quirúrgico.

O envelhecimento cortical e a reorganização neural após o acidente vascular encefálico (AVE): implicações para a reabilitação / Cortical aging and neural reorganization following cerebral vascular accident (CVA): implications for rehabilitation

Este artigo apresenta uma síntese sobre o envelhecimento do córtex cerebral humano e uma revisão das abordagens para a reabilitação do controle motor após o acidente vascular encefálico (AVE). Na discussão sobre as implicações clínicas na compensação das perdas, é enfatizado que os profissionais de reabilitação devem incentivar os pacientes idosos a usarem os dois membros superiores para a realização das atividades da vida diária (AVDs) ao invés de reforçarem o uso do membro superior não afetado.

This article presents a synthesis on aging of the human cerebral cortex, and also a review of the approaches to motor control rehabilitation following a cerebral vascular accident (CVA). Throughout the discussion on the clinical implications, the author advises the rehabilitation professionals to encourage older patients perform their activities of daily living (ADL) using both upper extremities, rather than reinforcing the use of the unaffected upper extremity.

Proton magnetic resonance spectroscopy of the frontal, cingulate and perirolandic cortices and its relationship to skin conductance in patients with schizophrenia

The aim of the present study was to determine whether specific subgroups of schizophrenic patients, grouped according to electrodermal characteristics, show differences in the N-acetylaspartate/creatine plus choline (NAA / (Cr + Cho)) ratios in the frontal, cingulate and perirolandic cortices. Skin conductance levels (SCL) and skin conductance responses to auditory stimulation were measured in 38 patients with schizophrenia and in the same number of matched healthy volunteers (control). All subjects were submitted to multivoxel proton magnetic resonance spectroscopic imaging. When compared to the control group, patients presented significantly lower NAA / (Cr + Cho) ratios in the right dorsolateral prefrontal cortex (schizophrenia = 0.95 ± 0.03; control = 1.12 ± 0.04) and in the right (schizophrenia = 0.88 ± 0.02; control = 0.94 ± 0.03) and left (schizophrenia = 0.84 ± 0.03; control = 0.94 ± 0.03) cingulates. These ratios did not differ between electrodermally responsive and non-responsive patients. When patients were divided into two groups: lower SCL (less than the mean SCL of the control group minus two standard deviations) and normal SCL (similar to the control group), the subgroup with a lower level of SCL showed a lower NAA / (Cr + Cho) ratio in the left cingulate (0.78 ± 0.05) than the controls (0.95 ± 0.02, P < 0.05) and the subgroup with normal SCL (0.88 ± 0.03, P < 0.05). There was a negative correlation between the NAA / (Cr + Cho) ratio in the left cingulate of patients with schizophrenia and the duration of the disease and years under medication. These data suggest the existence of a schizophrenic subgroup characterized by low SCL that could be a consequence of the lower neuronal viability observed in the left cingulate of these patients.

Hyperthermia induced after recirculation triggers chronic neurodegeneration in the penumbra zone of focal ischemia in the rat brain

Chronic neurodegenerative processes have been identified in the rat forebrain after prolonged survival following hyperthermia (HT) initiated a few hours after transient global ischemia. Since transient global ischemia and ischemic penumbra share pathophysiological similarities, this study addressed the effects of HT induced after recirculation of focal brain ischemia on infarct size during long survival times. Adult male Wistar rats underwent intra-luminal occlusion of the left middle cerebral artery for 60 min followed by HT (39.0-39.5°C) or normothermia. Control procedures included none and sham surgery with and without HT, and middle cerebral artery occlusion alone. Part I: 6-h HT induced at recirculation. Part II: 2-h HT induced at 2-, 6-, or 24-h recirculation. Part III: 2-h HT initiated at recirculation or 6-h HT initiated at 2-, 6- or 24-h recirculation. Survival periods were 7 days, 2 or 6 months. The effects of post-ischemic HT on cortex and striatum were evaluated histopathologically by measuring the area of remaining tissue in the infarcted hemisphere at -0.30 mm from bregma. Six-hour HT initiated from 6-h recirculation caused a significant decrease in the remaining cortical tissue between 7-day (N = 8) and 2-month (N = 8) survivals (98.46 ± 1.14 to 73.62 ± 8.99 percent, respectively). When induced from 24-h recirculation, 6-h HT caused a significant reduction of the remaining cortical tissue between 2- (N = 8) and 6-month (N = 9) survivals (94.97 ± 5.02 vs 63.26 ± 11.97 percent, respectively). These data indicate that post-ischemic HT triggers chronic neurodegenerative processes in ischemic penumbra, suggesting that similar fever-triggered effects may annul the benefit of early recirculation in stroke patients over the long-term.

Changes in cortical relative power in patients submitted to a tendon transfer: a pre and post surgery study

The aim of this study is analyze possible modifications in the cerebral cortex, through quantitative electroencephalography (qEEG) in patients submitted to a tendon transfer procedure (posterior tibialis) by the Srinivasan's technique. Four subjects (2 men and 2 women), 49.25 age average (SD±21.4) were studied. All subjects have been through surgical procedure due to leprosy and had, at least, two years of drop foot condition. The qEEG measured the electrocortical activity (relative power) between 8 and 25 Hz frequencies pre and post surgery. A paired t test analyzed all data (p<0,05). The results show significant alterations in the alpha relative power, electrodes F7 (p=0.01) and F8 (p=0.021). Altogether, based on findings of the current literature, we can conclude that the tendon transfer procedure suggests electrocortical alterations sensitive to specific qEEG bands.

O objetivo deste estudo é analisar possíveis modificações no córtex cerebral, através da electrencefalografia quantitativa (EEGq), em pacientes submetidos a um procedimento de transferência de tendão (tibial posterior) pela técnica de Srinivasan. Quatro sujeitos (2 homens e 2 mulheres), com média de idade de 49,25 anos (±21,4 DP) foram estudados. Todos os sujeitos realizaram o procedimento cirúrgico devido a hanseníase e tinham, pelo menos, dois anos de pé caído. O EEGq mediu a atividade electrocortical (potencia relativa) entre freqüências de 8 e 25 Hz, no pré e pós-operatório. Um teste t pareado analisou todos os dados (p<0,05). Os resultados mostram alterações significativas na potência relativa em alfa, nos elétrodos F7 (p=0,01) e F8 (p=0,021). Baseados em recentes achados na literatura, podemos concluir que o procedimento de transferência de tendão sugere alterações eletrocorticais sensíveis às freqüên-cias específicas do EEGq.

Thinner abuse alters peak of frequency of EEG spectra analyses / El abuso de tíner altera el pico de frecuencia del análisis espectral del EEG

STUDY OBJECTIVE: The aim of the investigation was to use electroencephalography (EEG) to study whether long-term thinner abuse may result in the slowing, disorganization and asymmetry of the EEG cortical rhythms. METHOD: Twenty-two patients attending with antecedent of thinner abuse only, and twenty two controls without alcohol, smoking, and drug abuse in the same age range and gender were studied. EEG recording were compared by means of the analyses of peak of frequency (POF), frequency of disorganization, and asymmetry of the background activity in patients and controls at rest eyes-closed condition in electrodes P3, P4, O1, and O2. RESULTS: Significant differences in POF among groups was observed in P3 and P4 location showing lower values in thinner abusers, but not in O1 and O2 locations. Frequencies of disorganization and asymmetry showed significantly higher proportions in thinner abusers. Bivariate correlations among POF at the four electrode location and time of thinner abuse showed significant values. However after partial correlation calculation correcting for age, significant values disappeared. CONCLUSION: Thus thinner abuse relates with slowing of POF in the EEG of patients with thinner abuse associated with disorganization, and asymmetry depending on time of abuse.

OBJETIVO: Utilizar el electroencefalograma (EEG) para estudiar si el abuso o intoxicación crónica por tíner produce lentificación, desorganización y asimetría de la actividad eléctrica cortical. MÉTODO: Se estudiaron 22 pacientes con antecedentes de intoxicación crónica por tíner y 22 sujetos sin antecedentes de abuso de tíner, alcohol, cigarro o drogas en el mismo rango de edad y en igual número de acuerdo al género. Se registro el EEG cuantitativo y se compararon: el promedio del pico de frecuencia (PoF), la frecuencia de desorganización de la actividad de fondo y la presencia de asimetría inter-hemisférica en la condición de reposo físico y mental entre las regiones de los electrodos P3, P4, O1 y O2. RESULTADOS: Se encontraron diferencias significativas en el PoF entre los grupo estudiados en P3 y P4 observándose valores menores en el grupo con antecedente de intoxicación crónica con tíner, sin embargo estas diferencias no fueron observadas en O1 y O2. La frecuencia de desorganización y de asimetría fue mayor entre los pacientes con antecedente de intoxicación crónica con tíner. Las correlaciones bivariadas entre el PoF en las cuatro localizaciones y el tiempo de consumo de tíner mostraron valores significativos, sin embargo, cuando fueron corregidas por la edad desaparecieron. CONCLUSION: La intoxicación crónica por tíner se relaciona a una lentificación del PoF del EEG de estos pacientes asociada con desorganización y asimetría que dependen parcialmente del tiempo de consumo.

Coerência espectral do eletrencefalograma em pacientes submetidos a transposição tendinosa: estudo pré e pós-operatório / EEG spectral coherence at patients submitted to tendon transfer surgery: study pre and post surgery

A transferência tendinosa do músculo tibial posterior é intervenção cirúrgica bastante utilizada na ortopedia para correção do pé caído por seqüela de hanseníase. Poucos modelos propuseram investigações mais significativas sobre os fenômenos plásticos cerebrais nas transferências tendinosas. O presente estudo teve como objetivo analisar a coerência espectral (CE) na Eletroencefalografia (EEG) em pacientes submetidos a transferência do tendão do tibial posterior pela técnica de Srinivasan através da EEG quantitativa (EEGq). A amostra foi composta de quatro sujeitos com pé caído devido a seqüela de hanseníase. Os parâmetros de CE do EEG foram quantificados no momento pré e pós-operatório. Os resultados mostraram que houve efeito principal para o fator momento, significativo, no par de eletrodos C3-CZ, com aumento da coerência. Entretanto, os achados da ANOVA não revelaram interação significativa entre bandas versus momento. A recuperação funcional promovida por tal cirurgia parece gerar alterações corticais.

Radiocirurgia no tratamento das metástases cerebrais: resposta terapêutica e complicações baseadas na localização da lesão / Stereotactic radiosurgery in the treatment of brain metastases: efficacy and complications based on brain location

As metástases cerebrais são os tumores cerebrais mais frequentes do sistema nervoso central. Entre as modalidades terapêuticas, a radiocirurgia (SRS) vem ganhando destaque nas duas últimas décadas como forma efetiva de tratamento associada com baixa morbidade e mortalidade. Porém, mesmo após ampla revisão da literatura, várias perguntas permanecem sem resposta sobre a radiocirurgia no tratamento das metástases cerebrais, perguntas estas principalmente relacionadas sobre as complicações tardias, dependência ao corticóide e relação das complicações com áreas cerebrais funcionais eloquentes. O objetivo deste trabalho foi analisar a radiocirurgia como modalidade terapêutica das metástases cerebrais (MC) de uma grande série de casos, que estuda criteriosamente clínica e radiologicamente as lesões e identificando fatores preditivos para complicações, falha terapêutica e necrose pós-tratamento, a qual enfatiza principalmente localização da MC e suas relações com áreas eloquentes cerebrais. Foi realizado estudo retrospectivo em 213 pacientes com 261 metástases cerebrais tratadas com radiocirurgia. Várias características demográficas deste grupo de pacientes foram analisadas, onde destacamos a boa distribuição de lesões de várias histologias tratadas e na grande maioria de pacientes em bom estado geral. Além disso, dividimos estes tumores de acordo com uma classificação estabelecida para relação com áreas eloquentes em 3 grupos (graus I, II e III). No nosso estudo encontramos dependência ao corticóide em 24,3% dos casos, que se distribui em 15%, 25% e 29% nas lesões grau I, II e III respectivamente. O autor demonstra que o dobro das lesões localizadas nas áreas eloquentes apresenta dependência ao corticóide, comparando-se com tumores em áreas não eloquentes. Destacamos que a dependência ao esteróide ocorre em 54,5% dos tumores do tronco cerebral, 38,8% dos relacionados com centro motor/sensitivo, 35,5% daqueles relacionados com centros da fala e 20% dos casos...

Brain metastases are the most common Central Nervous System tumors. Among the therapy options stereotactic radiosurgery has became in the last two decades an usefulness treatment technique attending with lower complication and mortality rate. However, even an extended literature review, many questions remain unclear about this therapy modality, mainly related with long-term complications, steroids dependency, and relations with brain eloquent areas. The goal of this project is analyze stereotactic radiosurgery as treatment modality for brain metastases in a large series, considering clinics and radiologic lesions aspects and identifying predictors factors for complications, treatment failure and treatment necrosis regarding the relation with brain eloquent areas. We retrospectively review 213 patients with 261 brain metastases treated with stereotactic radiosurgery. Several demographics aspects were analysed. We noticed a good distribution of histological groups and the performing patient status. We also lump these lesions in groups based on their location in relation with eloquent brain areas (grade I, II and III). This study found a general steroids dependency rate of 24,3% for all cases, occurring in 15%, 25% and 29% in lesions grade I, II and III respectively. That's twice the frequency for lesions located in eloquent brain areas compared with non eloquent located lesions. Specifically, the steroids dependency occurred in 54,5% of brain stem tumors, 38,8% tumors related with motor/sensory centers, 35,5% speech center tumors related and 20% of cases related with visual areas. Even in these subgroups the dependency rate decreases with time. The long-term tumor local control was achieved in 184 treated lesion (70,5%). Complications were more often found in eloquent areas, specifically in 64,7%, 64,9% and 55,3% respectively for brain stem, speech centers and motor/sensory related lesions. Among all variables we found significant differences for...

Hipersinais subcorticais no exame de ressonância magnética: comparaçäo entre idosos deprimidos e idosos normais / Subcortical hyperintensities on magnetic resonance imaging: a comparison of normal and depressed elderly subjects

É relatado em alguns estudos que idosos deprimidos apresentam maior frequência de hipersinais ao exame de ressonância magnética do que controles normais. No entanto os indivíduos estudados tinham fatores de risco para doenças cerebrovasculares. Este estudo analisou pacientes com história de depressäo maior e indivíduos controles compatíveis, excluindo-se fatores de risco cerebrovasculares, com o objetivo de determinar se indivíduos deprimidos apresentam maior frequência de hipersinais em substância branca e outras lesöes. Avaliamos a prevalência e a severidade dos hipersinais à ressonância magnética de encéfalo em 30 pacientes idosos deprimidos e 20 controles pareados para a idade. Hipersinais de substância branca profunda, hipersinais periventriculares e hipersinais em substância cinzenta subcortical foram classificados em escala padräo 0-3, por dois radiologistas que desconheciam o diagnóstico clínico. Näo foram encontradas diferenças significativas entre os grupos para hipersinais subcorticais. Estes achados sugerem que os fatores de risco cerebrovasculares provavelmente medeiam a relaçäo entre depressäo e hipersinais, encontrada em estudos anteriores

Effect of acute and repeated restraint stress on glucose oxidation to CO2 in hippocampal and cerebral cortex slices

It has been suggested that glucocorticoids released during stress might impair neuronal function by decreasing glucose uptake by hippocampal neurons. Previous work has demonstrated that glucose uptake is reduced in hippocampal and cerebral cortex slices 24 h after exposure to acute stress, while no effect was observed after repeated stress. Here, we report the effect of acute and repeated restraint stress on glucose oxidation to CO2 in hippocampal and cerebral cortex slices and on plasma glucose and corticosterone levels. Male adult Wistar rats were exposed to restraint 1 h/day for 50 days in the chronic model. In the acute model there was a single exposure. Immediately or 24 h after stress, the animals were sacrificed and the hippocampus and cerebral cortex were dissected, sliced, and incubated with Krebs buffer, pH 7.4, containing 5 mM glucose and 0.2 æCi D-[U-14C] glucose. CO2 production from glucose was estimated. Trunk blood was also collected, and both corticosterone and glucose were measured. The results showed that corticosterone levels after exposure to acute restraint were increased, but the increase was smaller when the animals were submitted to repeated stress. Blood glucose levels increased after both acute and repeated stress. However, glucose utilization, measured as CO2 production in hippocampal and cerebral cortex slices, was the same in stressed and control groups under conditions of both acute and chronic stress. We conclude that, although stress may induce a decrease in glucose uptake, this effect is not sufficient to affect the energy metabolism of these cells

Evidencias de compromiso cerebral en el estadio crónico de la enfermedad de Chagas obtenidas por medio del potencial P300 y de electroencefalografía cuantificada / P300 event related potentials and qEEG evidenced a cerebral dysfunction in human chronic Chagas disease

Es reconocido el compromiso del sistema nervioso periférico en la etapa crónica de la enfermedad de Chagas, incorporándose últimamente evidencias tomográficas y neuropsicológicas de compromiso cerebral. Con el objetivo de evaluar dicho compromiso por medio del potencial P 300 y la electroencefalografía cuantificada (EEGc) se estudiaron 35 pacientes (26 a 55 años), comparados con un grupo control de similar número y edad (29 a 55 años). Se observó: latencia de la onda P 3 mayor en el grupo en estudio (331,24 +/- 24,02 contra 318,86 +/- 23,18) (p=0,01716). El EEGc mostró diferencias en la potencia relativa de la banda Beta 1, menor en los pacientes (p=1,62834E5) y en la frecuencia dominante, 1 Hz menor en los chagasicos (p=0,01077). El análisis multivariado discrimina tres subpoblaciones: una normal, una de enfermos con incremento alfa y otra de enfermos con decremento alfa e incremento delta y theta (p=0,00004). La proporción de resultados patológicos fue del 20 por ciento en los EEGc y el 11,43 por ciento en los potenciales cognitivos. No se correlacionó el compromiso neurológico y el cardíaco. Se concluye que existen francos indicadores electrofisiológicos de compromiso cerebral en el estadio crónico de la enfermedad de Chagas, hallazgo que refuerza a los obtenidos por otros métodos.