Importance of EEG, USG skull and CT/ MRI brain in neonatal seizures

Abstract

Aim and Objectives: The present study was undertaken to evaluate the importance of EEG, USG skull and CT/MRI brain in the diagnosis and management of neonatal seizures. Methods: Total 75 neonates with clinically identified seizure episodes were enrolled in the study.EEG was done for 73 neonates and USG skull was done for all, whereas CT/MRI brain study was undertaken only if indicated by history, examination or other basic investigations. The findings of these investigations were correlated with various demographic parameters like gestational age, gender and birth weight and clinical parameters like age of onset and type of seizure, etiology of seizure, presence of status epilepticus, need for anticonvulsants and mortality. Results: A greater percentage of neonates with 1 st seizure occurring before 72 hours of life were found to have an abnormal EEG (14.70%), USG (14.28%) and CT/MRI (50%) as compared to later age of onset (5.12% and 5.00% and 34.6% respectively). Multifocal clonic and multiple types of seizures have a greater association with EEG abnormalities as compared to other types. There was a statistically significant association between clonic neonatal seizures and USG as well as CT/ MRI abnormalities.EEG, USG and CT/MRI studies revealed a higher incidence of abnormalities in patients with status epilepticus and found a statistically significant correlation between presence of status epilepticus and CT/MRI abnormalities. Most cases of metabolic convulsions do not require anticonvulsants. Conclusion: Interictal EEG provides a useful non-invasive test to diagnose neonatal seizures due to diffuse brain lesions. USG is a rapid, inexpensive and sufficiently accurate modality in evaluation of neonatal brain pathology and in the diagnosis of various lesions that occur in the first weeks of life. CT/MRI further added to our knowledge in understanding the nature and extent of the underlying intracranial pathology by revealing findings which were not easily picked up on USG skull.