The Statistical Parametric Mapping Analysis between Pre- and Post-Operative FDG-PET Images in Patients with Mesial Temporal Lobe Epilepsy / 대한간질학회지

ABSTRACT

BACKGROUND: To investigate postoperative changes in the cerebral glucose metabolism of patients with mesial temporal lobe epilepsy (MTLE), statistical parametric mapping (SPM) analysis was performed on pre- and post-operative 18F-fluorodeoxy glucose positron emission tomographic (FDG-PET) images. METHODS: We included 28 patients with MTLE who had under-gone surgery and had been seizure free postoperatively (16 had left MTLE and 12 right MTLE). All patients showed hippocampal sclerosis by pathology or brain MRI. FDG-PET images of the 12 right TLE patients were reversed to lateralize the epileptogenic zone to the left side in all patients. RESULTS: Application of the paired t-test in SPM to pre- and postoperative FDG-PETs showed that the postoperative glucose metabolism decreased in the caudate nucleus, pulvinar of thalamus, fusiform gyrus, lingual gyrus, and in the posterior region of the insular cortex in the hemisphere ipsilateral to resection, whereas postoperative glucose metabolism increased in the anterior region of the insular cortex, temporal stem white matter, midbrain, inferior precentral gyrus, anterior cingulate gyrus, and supramarginal gyrus in the hemisphere ipsilateral to resection. No significant postsurgical changes of cerebral glucose metabolism occurred in the contralateral hemisphere. Subtraction between pre- and postoperative FDG-PET images in individual patients produced similar findings to the SPM results. CONCLUSION: This study suggests that brain regions showing a postoperative increase in glucose metabolism appear to represent the propagation pathways of ictal and interictal epileptic discharges in MTLE while a postoperative decrease in glucose metabolism may be related to a permanent loss of afferents from resected anterior-mesial temporal structures.