Assessment of EEG as a Diagnostic and Prognostic Indicator Tool in the Febrile Seizures.

ABSTRACT

Objective: To assess the sensitivity, specificity, and predictive value of EEG as a diagnostic and prognostic tool in the febrile seizures. Method: This study was conducted on 50 consecutive children with febrile seizures attending the pediatric OPD of a tertiary care hospital. The children were prospectively identified and EEG was carried out on two occasions. First EEG was done within one week of febrile seizure episode and second EEG was done after 03 months of first EEG. EEG records were obtained with the standard international protocols for duration of 35 minutes which included 25 minutes of sleep record in all the children. Photic stimulation, hyperventilation and sleep deprivation were used as activation procedures. Descriptive analysis of EEG tracings was done in terms of background activity and presence of abnormal waveforms. Result: Paroxysmal EEG abnormalities were present in 54% of children. Most common epileptiform discharges were of generalized epileptic discharge followed by focal polyspikes. Sleep deprivation was the most effective activation procedure in evaluating febrile seizure with abnormal epileptiform discharge patterns. Validity measures of EEG in febrile seizure were found to have 90% sensitivity, 70% specificity, 72% positive predictive value and 88% negative predictive value within 95% confidence interval. Conclusion: EEG is a sensitive method for identifying and quantifying electrical activity in febrile seizures. EEG is useful as a diagnostic and prognostic tool in febrile seizures and can provide information regarding presence of abnormalities, degree of encephalopathy and electrographic features but like all diagnostic tool it is not fully infallible and requires further alternative diagnostic and clinical support.