Potenciais relacionados a eventos em pesquisa clínica: diretrizes para eliciar, gravar, e quantificar o MMN, P300 e N400

Abstract

Event-related potentials in clinical research: guidelines for eliciting, recording, and quantifying Mismatch Negativity, P300, and N400Potenciais relacionados a eventos em pesquisa clínica: diretrizes para eliciar, gravar, e quantificar o MMN, P300 e N400 Event-Related Potentials (ERP) refer to electrical responses generated by the thalamus, auditory cortex and cortical association areas and involve discrimination, integration and attention tasks. Furthermore, they consist of a series of positive and negative peaks which take place from 50 ms after the stimulus onset and can be useful in investigating neural mechanisms related to auditory perception (1,2)

Mismatch Negativity in Children: Reference Values

“…Mismatch negativity is elicited by the presentation of low probability (rare) auditory stimuli that constitute a physical change from repetitive standard stimulation (frequent stimuli). This is generated automatically, regardless of the attention of the subject, 3 6 7 8 9 10 11 whenever an afferent stimulus does not coincide with the sensorial representation of the repetitive stimulation presented. 3 12 The MMN reflects the ability of the brain to discriminate sounds, 13 auditory memory and involuntary attention.…”

“…Nevertheless, despite the possibility of clinical application in the children population, it is still necessary to standardize the values of latencies and amplitudes of the MMN due to the variability in its measurements and the protocols used. 10…”

Aplicabilidade do Mismatch Negativity na população infantil: revisão sistemática de literatura

“…This potential has as main generator the auditory cortex and receives contributions from the frontal cortex, thalamus and hippocampus (8) . It is a cerebral automatic response, promoted by any discriminable change in some repetitive aspect of auditory stimulation (6,9,10,11) , indicating a mismatch between the new sensory input, in relation to a stored standard stimulus In the short-term auditory sensorial memory (1,6,12) . MMN is obtained by subtracting the response evoked by the rare stimulus in relation to the standard stimulus presented (4,9,10) , and the result appears as a wave with negativity (6,9) .…”

“…When latencies increase or decrease in amplitudes, clinical and subclinical changes are objectively evidenced (2) . Latency informs the course time of processing activity, while wave amplitude demonstrates the extent of neural allocation involved in the cognitive processes of potentials (10) . MMN is a procedure that has a good correlation with the results found in subjective evaluations that, similarly, analyzed the ability of auditory discrimination (6,13) .…”

“…MMN is a procedure that has a good correlation with the results found in subjective evaluations that, similarly, analyzed the ability of auditory discrimination (6,13) . Its main advantage, compared to other exams, is that the wave appears independently of the attention of the individual to the presented sound stimuli (1,4,6,7,10,14) , that is, it can be registered without the influence of the attention of the subject and without requiring tasks, making it particularly suitable for clinical studies in evaluating the child population (4,11) . Studies have shown that MMN can be a very useful evaluative means for recognizing changes in language (4,9) in children due to the possibility of assessing auditory processing deficit at an early age (9,13,15) Capable of analyzing neurophysiological plasticity (13) .…”