Clinical neurophysiology in preterm infants: a window on early phases of brain development

The sensory evoked potentials in the visual auditory and somatosensory modality reflect the activity of the corresponding sensory pathways ascending to cerebral cortex and its' activation following sensory input. By contrast the event related potentials generated within specific neuropsychological paradigms reflect cognitive processing of the stimuli. It has been shown that during the first 20-45 weeks of gestation the development of the complex cortical and subcortical networks is modulated by sensory driven development of the talamo-cortical afferents and their connections with the developing cortical plate. The cortical responses recorded before the 36 gestational weeks are negative and in opposite polarity with respect to those elicited in infants born at term. It could be hypothesized that the above pattern of neurophysiological development could reflect the transient organization of immature cortex in the period of coexistence of subplate and cortical plate. Event related potentials evoked by auditory stimulation using the oddball paradigm in the newborn is known to elicit obligate responses to sensory inputs as well as endogenous components similar to that reported in older children and adults. These responses may serve as an early index of developmental problems in the auditory cortex, in infants born pre-term. The aim of this publication is to review the emerging evidence that evoked potential techniques may index the above maturation processes, thus providing a unique window on the brain at work during the early phases of development, in normal and pathological conditions. © 2012 by Nova Science Publishers, Inc. All rights reserved.