Koushik Ghosh1, Anand Acharya2, Anshuman Paria3, Ardhendu Mazumdar4, Debalina Das5, Sabyasachi Mandal6
INTRODUCTION
Evoked potentials are small magnitude electrical potentials that originate within neural tissues in response to a variety of stimuli which are depicted as a wave or a series of waves. Changes in the wave latencies and amplitudes have been shown to reflect disturbances in neuronal growth rates & myelination of the developing nervous system. Among the different evoked potentials, the Visual Evoked Potentials (VEP), have been shown to be a significantly accurate tool for assessing the degree of neurological handicap among survivors of perinatal asphyxia, especially in the full-term neonates. Thus, the development of a normative database of VEP parameters like wave latencies and amplitudes for term, appropriate-for-gestational age neonates in an Indian NICU set-up was the primary objective of our study as such data can be of great use for future clinical use. The study was a prospective observational study carried out jointly by the Departments of Neonatology and Physiology, of IPGME & R and SSKM Hospital, Kolkata from June’ 2012 to September’ 2013. Normative statistics like ‘mean±2SD’ values for N1, P1 & N2 wave latencies of both right & left eyes & also for inter-peak amplitudes (i.e. N1-P1 & P1-N2) of both the eyes was obtained by studying 40 healthy, term newborns. It was also observed that the ‘latencies’ of VEP waves do not vary significantly between normal male & female newborn babies and the latencies of both the eyes are comparable. The ‘inter-peak amplitudes’ on the other hand showed much more variability. Hence establishing a normative database of VEP parameters can be of much use and further studies with much larger sample size is highly recommended.
