Neonatal and fetal response decrement of evoked responses: A MEG study

Abstract: Objective: To investigate the response decrements of visual evoked responses (VER) in newborns and assess the applicability of this paradigm to fetuses in magnetoencephalographic (MEG) recordings. Methods: Twelve newborns with no known risks or complications participated at chronological ages between 6 and 22days. They constituted the follow-up group to a prenatal study conducted on a sample of 25 fetuses whose gestational age (GA) varied between 29 and 37weeks at the time of recording. Trains of four light flashes with an interstimulus interval of 2s followed by 10s without stimulation were delivered to record VER. Results: Nine of the 12 newborns responded to the stimulation and showed response decrements in amplitude from the first to the last light flash. Furthermore, the response latency increased significantly from the first to the last stimulus. The remaining three recordings were discontinued early. Even though the prenatal visual evoked response rate was only 29%, the fetuses exhibited a response decrement after the first stimulus. Conclusions: The amplitude of VERs can be used to elicit a response decrement in newborns and, with limitations, even in fetuses. This paradigm might be a useful tool for a direct non-invasive assessment of neonatal and prenatal brain development and CNS functioning. Significance: The proposed method might be a first step towards an early detection of developmental deficits in newborns and fetuses. [Copyright &y& Elsevier]