Electrical Activity of the Brain in Children with Developmental Delay: A Preliminary Study

Abstract

Background and Aim: Developmental disorders are often irreversible and debilitating for a child. Hypoxic ischemic insult during perinatal period is an important cause of global/ focal developmental delay in children and may trigger epileptogenesis. Thus, it is crucial to explore electrical activity of the brain in patients with developmental delay and identify early electrophysiological correlates that could be used as potential signatures for its diagnosis/ prognosis. The objectives of this study were to explore electrical activity of the brain in children with developmental delay, to assess occurrence of seizures in these children and to find predominant type of seizure pattern. Methods: In this study, 70 referred cases from the Pediatrics Department of AIIMS, Rishikesh with a history of global/specific developmental delay underwent video-EEG (Nicolet) for 30-45 min to assess electrical activity of the brain and presence of any abnormal discharge. Along with EEG, a brief clinical history including symptomatology was also obtained. Results: 69 out of 70 referred cases showed EEG changes. 16 had focal seizures (1 focal, 15 focal with secondary generalization), 40 generalized presentations (none had absence seizures), 3 abnormal patterns, 10 had hysparrhythmia and only 1 had a normal pattern on EEG. Attenuation of waves/ background suppression was also observed in 12 out of 70 (17.14%) patients. This pattern was found predominantly in peripheral electrodes such as parietal and temporal. Conclusion: EEG could be a useful electrophysiological tool to evaluate cases of developmental delay. Not only can it diagnose subclinical inter-ictal seizures in such cases, EEG signatures such as suppression pattern may be useful biomarkers to assess severity or for prognostic purposes. It would be worthwhile to understand the mechanisms why certain areas of the brain could be more sensitive to developmental defects due hypoxia or other etiologies. The functional deficits corresponding to these areas could be further explored.