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 metabo lism in relation to the interval from the last seizure, focus laterali ty, seizure frequency, and seizure type. Design: Metabolic study with the use of positron emission tomography with fludeoxyglucose F 18. Bli nded scan evaluation with use of a standard template. Multivariate reg ression analysis of positron emission tomographic data. Setting: Natio nal Institutes of Health Clinical Center, Bethesda, Md. Patients: Thir ty-two adults with intractable partial epilepsy and lateralized seizur e onset documented by video-electroencephalographic monitoring. Main O utcome Measure: Normalized metabolic rate for glucose ipsilateral and contralateral to the epileptic focus. Results: The most dramatic chang es occurred in inferior temporal regions; the midtemporal region was a ffected as well. Effects lasting 48 hours were found after both simple and complex partial seizures. The time course was different for the t wo types of seizures. The inferior temporal metabolic rate ipsilateral to the focus increased compared with the interictal rate during the 2 4-hour period following simple partial seizures; a nadir occurred in t he second 24 hours. The rate then rose to an intermediate level after 48 hours. The relative regional increase in ipsilateral metabolism fol lowing complex partial seizures persisted for 48 hours before falling. Conclusion: The brain may take longer than 24 hours after a partial s eizure to return to its baseline state.