The diagnostic value of first EEG in children suspected with epilepsy

Epilepsy is one of the most common neurological illness in childhood.The Electroencehalogram (EEG) is the most important tool to support diagnosis and classification of epilepsy.In India, studies looking into the utility of EEG for diagnosis and prognostication of pediatric epilepsy are sparse and the results inconsistent.Aims and objectives: 1. to identify the diagnostic value of first EEG in children having clinically probable epilepsy, in order to support a correct diagnosis and early treatment.2. to analyze the necessity and yield of sleep EEG, activation procedures like hyperventilation and intermittent photic stimulation, the feasibility of classification into a specific electro-clinical syndrome, the need of neuroimaging in identifying etiology and prognostication.Methods: study conducted in the Pediatric Epilepsy Clinic, in a tertiary care medical college in kerala, India.Children aged between 1 month -15 years, with history of clinically probable epilepsy with strict inclusion and exclusion criteria.Detailed history, examination, EEG using standard protocol, careful interpretation and analysis of data were done.Results and Conclusions: The diagnostic yield of first EEG was 57%.As number of seizures increased, yield increased to two times.The difference in EEG yield between children in epilepsy group and first seizure group was significant (p< 0.00001).The yield of combined awake and sleep EEG was 62%, only awake 17%, only sleep 21%, Hyperventilation 13%, and intermittent photic stimulation 4%.Focal epileptiform discharges were the most common EEG abnormality 70.5%.Significant associations were found between symptomatic etiology and epilepsy (p<0.001) and abnormal EEG findings (p < 0.00003), and also between abnormal neuro-imaging findings and epilepsy (p < 0.007).Cerebral Palsy was the most common cause of symptomatic epilepsy ie 43%, and 20% of them had West Syndrome.Hence we conclude that a well taken first EEG in children suspected with epilepsy will help in early treatment thereby reducing the burden of neuro morbidity in a resource poor country like India.