Mismatch response in preterm and asphyxic neonates: a functional electrophysiological investigation of attention and habituation

BACKGROUND AND AIM There is a lack of diagnostic tools for early risk stratification of cognitive outcome in infants born preterm and infants with asphyxia. Using auditory event-related potentials and mismatch response, we aimed to assess possible differences in early attention and learning, as a marker for brain maturation to subsequently improve the allocation of early neurodevelopmental support. STUDY DESIGN AND METHODS This cross-sectional study included 22 very preterm infants (gestational age (GA) < 32 weeks), eight term infants with asphyxia and 35 healthy term infants. An auditory oddball-paradigm with three consecutive stimulation blocks, separated by a two-minute break, was used as a cognitive discrimination task to assess attention and habituation. RESULTS The peak-to-peak analysis in the group comparisons showed no significant differences for the first stimulation block. In term healthy infants and term infants after asphyxia, no significant differences were found in amplitudes between block one and three. Preterm infants showed significantly (p = .007) lower amplitudes in the third block for F7 congruent to a positive habituation. The amplitude of the grouped electrodes correlated positively with GA for frontal (R = .271, p= .029) and parietal electrodes (R =.275, p = .027). CONCLUSION We found no differences in the auditory attention paradigm between preterm or term asphyxic and control infants when they were evaluated at term corrected age. Most infants did not show any electrophysiologically measurable learning effect indicating habituation or dishabituation. The small sample size of this study is a clear limitation. Therefore, the results must be evaluated with caution, especially regarding their potential predictive value for future cognitive development of infants with a developmental risk. However, our study underlines the possibility of an electrophysiological evaluation as a feasible tool to assess very early cognition in infants.