Evidencias de compromiso cerebral en el estadio crónico de la enfermedad de Chagas obtenidas por medio del potencial P300 y de electroencefalografía cuantificada

Abstract

RESUMEN -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=1,62834E-5) 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 % en los EEGc y el 11,43 % 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. PALABRAS-CLAVE: enfermedad de Chagas, sistema nervioso central, potencial p300, electroencefalografía cuantificada (EEGc), mapeo cerebral. P300 event related potentials and qEEG evidenced a cerebral dysfunction in human chronic Chagas diseaseABSTRACT -It is already known the involvement of the peripheral nervous system in chronical stages of Chagas disease. Tomographic and neuropsychological evidence of brain compromise has been included recently. In order to evaluate the neurophysiological counterpart of cerebral involvement, we studied P300 evoked potential and quantified EEG (qEEG) of 35 patients (26-55 years), and compared to an equal number of control subjects (29-55 years). We have found increased P300 latency compared to the control group (331.24 ± 24.02 vs 318.86 ± 23.18) (p=0.01716). qEEG showed lower relative Beta 1 power in the patients group (p=1.6E-5), and the principal frequency 1 Hz slower in the same group (p=0.01077). Multivariate analysis showed three subpopulations: a normal one, pathological one with higher Alpha power and pathological with Alpha decrement and Delta-Theta increment. Pathological findings represented 20% for the qEEG and 11.43% for cognitive potentials. Cardiac and neurologic involvement were not correlated. We conclude that there is clear electrophysiological evidence of cerebral involvement in chronic Chagas disease, thus reinforcing findings obtained by other methods.KEY WORDS: Chagas disease, central nervous system, event related potential P 300, quantitative electroencephalography (qEEG), brain mapping.

A Population-Based Study of the Association between <i>Trypanosoma cruzi</i> Infection and Cognitive Impairment in Old Age (The Bambuí Study)

“…There is some electrophysiological evidence of cerebral involvement in chronic ChD, which is not correlated with chagasic cardiomyopathy [46] . Also, autoimmune mechanisms may interfere with cholinergic transmission; there is an association between circulating antipeptide autoantibodies (anti-M2) in chagasic patients and the presence of dysautonomia [12][13][14] .…”

Involvement of the central nervous system in the chronic form of Chagas' disease

“…Electroencephalographic (EEG) studies in patients with the chronic form of Chagas' disease [10,11] are scanty and the findings are unspecific. Recently, quantitative electroencephalogram (EEG) and event-related potentials have revealed alterations in all frequency bands -mainly the lower alpha and beta1 relative power, and higher theta and delta relative powerand have increased P300 latency, respectively [12]. A mild or asymptomatic somatic-sensitive peripheral neuropathy occurs in 8 to 11% of the patients [13][14][15][16][17][18][19].…”

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“…The influence of T. cruzi infection on behavioral alterations, particularly on memory loss, is questioned. Importantly, cognitive and memory impairments have been described in chronic CD patients, mainly detected as disturbs of comprehension and perception, orientation and attention loss, as well as impaired capacity to answer to visualpaired comparison tests [11][12][13][14][15]. However, it is a controversial matter as immediate and delayed memory impairment were not detected in patients with Chagas' heart disease, the main clinical form of CD [7].…”

“…patients [11][12][13][14][15]. This progressive decline of memory is a common feature of mnemonic deficits in aging and neurodegenerative disorders [20,33].…”

“…An association between T. cruzi infection and cognitive abnormalities has been detected using the mini-mental state examination score to test elderly CD patients, which were not mediated by CD-related electrocardiographic alterations or digoxin medication [10]. Furthermore, cognitive dysfunction in chronic CD patients has been supported by deficiency in orientation, attention, non-verbal reasoning, information processing and learning [11,12]. More import, memory loss has been described in chronic chagasic infection [13][14][15].…”