Quantitative electroencephalographic measures during postmalarial epileptogenesis

OBJECTIVE: Severe malaria with neurologic involvement contributes significantly to the global burden of acquired pediatric epilepsy. We studied quantitative electroencephalographic (EEG) measures in postmalarial epileptogenesis. METHODS: A total of 186 patients, aged 6 months to 11 years, with confirmed central nervous system malaria were enrolled in a prospective observational study conducted in Chipata, Zambia. EEG data were collected during acute illness for 179 patients. Patients were followed for 12 months postdischarge with EEG and clinical reviews to assess postmalarial epilepsy (PME) outcomes. A total of 155 patients were seen for 1-month, 144 for 6-month, and 142 for 12-month follow-up. Twenty-six patients were diagnosed with PME. We examined EEG measures (relative power, magnitude-squared coherence [MSC], and approximate entropy [ApEn]) to identify differences between patients who developed PME and those who did not. RESULTS: Relative gamma power at admission was significantly greater in the PME group, whereas at 1-month and 6-month follow-up it was greater in the nonepilepsy group. Alpha and beta power increased in both groups over time, suggesting a prolonged process of neurologic recovery, with greater power in both bands observed in the nonepilepsy group at 12-month follow-up. ApEn was greater in the nonepilepsy group at admission and 1-month and 6-month follow-up. At admission and 1-month follow-up, we observed a significant decrease in beta and gamma MSC in the epilepsy group as compared to the nonepilepsy group. These differences were absent at 6-month follow-up but became more prominent again at 12-month follow-up. SIGNIFICANCE: These and related EEG measures may provide value for risk stratification of patients with severe malaria.