Abstracts

Rationale: Encephalomalacia is a condition characterized by localized softening of brain tissues due to inflammation or hemorrhage. There were few studies about encephalomalacia and its association with epilepsy. This study aimed to analyze the characteristics and risk factors of epilepsy in the patients with encephalomalacia. Methods: We reviewed 221 pediatric patients with encephalomalacia who visited Pusan National University Children’s Hospital from November 2008 to March 2018. Inclusion criterias were patients below 18 years old, with encephalomalacia proved by brain MRI, and minimum follow up period more than 1 year after acute brain insult. Exclusion criterias were patients with hypoxic ischemic encephalopathy, neurodegenerative disease, mitochondrial disease, inborn errors of metabolism, and lesions confined only to white matter. We compared clinical and laboratory variables between the patients with (group A) or without epilepsy (group B). Results: There were 140 patients (73 Males, 67 Females, ratio 1:0.9) who met the criteria described above. The etiology of encephalomalacia were cerebrovascular disease (n=50, 36%), CNS infectious/inflammatory disease (n=34, 24%), head trauma or neurosurgery (n=30, 21%), and unknown (n=26, 19%). There were 52 patients in group A (37%). The median age at acute insult was 0.11(IQR, 0-5.32) years and the median age at diagnosis was 2.35 (IQR, 0.38-9.4) years. The duration between acute insult and diagnosis of epilepsy was 1.67±2.96 years. When compared with group B, seizure during acute insult (p=0.017). CNS infection as etiology (p=0.017), comorbidity of intellectual disability after acute insult (P<0.001), and EEG abnormality with interictal epileptiform discharges and abnormal background activity (P<0.001) were significantly higher in group A. There were no differences in etiologies other than CNS infection, gestational age, birth weight, history of NICU hospitalization, comorbidity of cerebral palsy after acute insult, focal dysfunction on EEG finding and distribution and localization of  lesions of encephalomalacia.  Conclusions: Seizure during acute insult and complication of intellectual disability after acute insult were risk factors of epilepsy. Abnormal EEG findings, especially abnormal background activity and interictal epileptiform discharges at the diagnosis of encephalomalcia were closely correlated with epilepsy. Funding: There was no funding source or conflict of interest.