Risk of epilepsy after electrographically proven neonatal seizures

ABSTRACT

Neonatal seizures often are manifestations of significant neurological disease and major predictors of adverse neurological outcome in the newborn. The present work aimed at estimation of outcomes of neonatal seizures especially the development of epilepsy. The present study was conducted on 30 patients [15 males and 15 females] with neonatal seizures, their ages ranged from one to 30 days. All patients were subjected to full history taking and through clinical examination. Laboratory investigations included complete blood picture, metabolic screening tests [blood glucose, serum Ca, Mg and Na, blood urea, serum creatinine, serum bilirubin and ferric chloride test], sepsis screen [blood, CSF and urine culture, and TORCH titers], brain C. T. scan and EEG [interictal and follow up]. The etiologic diagnosis of neonatal seizures was based on positive clinical data, laboratory data and/or imaging data. Follow up for at least 6 months was performed with serial neurological evaluation and EEG. From this study, it was found that the seizures etiologies were diverse, hypoxic ischemic encephalopathy [HIE] was the most common cause 46.7%, meningitis 16.7%, cerebral dysgenesis 10%. Metabolic causes 13.3% and intracranial hemorrhage 13.3%. Etiology of seizures was significantly correlated with total outcome, subsequent development of epilepsy and developmental delay. There was significant correlation between findings of neurological examination and total outcome, epilepsy and developmental delay. Neonates with mildly abnormal neurological findings had favorable outcome in 100% of cases. Patients with severely abnormal neurological findings were associated with unfavorable outcome [mortality, epilepsy or developmental delay] in 81.8% of cases. Type of seizures was significantly correlated with the total outcome and mortality. Generalized tonic seizures had the worst prognosis. There was significant correlation between brain CT findings and total outcome, subsequent development of epilepsy and developmental delay. EEG findings were significantly correlated with the outcomes findings of neurological examination and frequency of seizures but insignificantly correlated with type of seizures, onset of seizures and brain CT findings. The 3-months follow up EEG was significantly correlated with the development of epilepsy. Seizure etiology, neurological evaluation of the newborn at birth [mildly, moderately and severely abnormal], clinical characteristics of seizures [onset, frequency and types], brain CT. and EEG findings [interdicted EEG background activity], 3-months follow-up EEG and meticulous follow-up clinical examination were the most important determinants for prediction of the neurological outcome of neonatal seizures. Epilepsy and developmental delay after neonatal seizures were more frequent in presence of one or more of the following severely abnormal neurological examination at birth, cerebral dyesgenesis as an etiology of seizures, generalized tonic seizures, seizure frequency >/= 2 seizures/h, abnormal brain CT scan findings and abnormal inter-ictal EEG background. EEG is recommended to be performed for all cases with neonatal convulsions as a diagnostic and prognostic tool. Meticulous follow up [clinical examination, EEG] of cases with neonatal seizures is essential to predict the subsequent development of epilepsy and developmental delay