THE DYNAMICS OF METABOLIC CHANGE FOLLOWING SEIZURES AS MEASURED BY POSITRON EMISSION TOMOGRAPHY WITH FLUDEOXYGLUCOSE-F-18

Objective: To examine the time course of alterations in glucose metabolism in relation to the interval from the last seizure, focus laterality, seizure frequency, and seizure type. Design: Metabolic study with the use of positron emission tomography with fludeoxyglucose F 18. Blinded scan evaluation with use of a standard template. Multivariate regression analysis of positron emission tomographic data. Setting: National Institutes of Health Clinical Center, Bethesda, Md. Patients: Thirty-two adults with intractable partial epilepsy and lateralized seizure onset documented by video-electroencephalographic monitoring. Main Outcome Measure: Normalized metabolic rate for glucose ipsilateral and contralateral to the epileptic focus. Results: The most dramatic changes occurred in inferior temporal regions; the midtemporal region was affected as well. Effects lasting 48 hours were found after both simple and complex partial seizures. The time course was different for the two types of seizures. The inferior temporal metabolic rate ipsilateral to the focus increased compared with the interictal rate during the 24-hour period following simple partial seizures; a nadir occurred in the second 24 hours. The rate then rose to an intermediate level after 48 hours. The relative regional increase in ipsilateral metabolism following complex partial seizures persisted for 48 hours before falling. Conclusion: The brain may take longer than 24 hours after a partial seizure to return to its baseline state.