Focal Interictal Positron Emission Tomography Hypermetabolism and Electrical Cortical Stimulation Accurately Localizes the Seizure Onset Zone: A Cohort Study

Li-Jia Song2#, Xiao-Peng Qu1#, Li Gao1#, Yu-Qian Li1#, Yue Zhang1, Chao Wang1, Chun-Hui Wang2, Yan Qu1* and Bei Li1*

1Department of Neurosurgery, Tangdu Hospital, Fourth Military Medical University, China
2Department of Pediatrics, Tangdu Hospital, Fourth Military Medical University, China
#These authors equally contributed to this work

^*Correspondance to: Bei Liu 

 PDF  Full Text DOI: 10.25107/2474-1647.3532

Abstract

Objective: To determine the value of interictal Positron Emission Tomography (PET) hypermetabolism and extraoperative electrical stimulation mapping in the location of the Epileptogenic Zone (EZ). Methods: A retrospective study was conducted on epileptic patients with interictal PET hypermetabolism from January 2007 to December 2017. Fifteen patients underwent cortical resection, and 11 of them underwent subdural electrode placement and extraoperative electrical stimulation mapping. Results: PET imaging of 15 patients showed that hypermetabolic regions were common in the frontal lobe, followed by the parietal lobe. Eight patients with abnormal brain lesions were found by Magnetic Resonance Imaging (MRI), and seven patients were negative. The EZ was determined by extraoperative electrical stimulation mapping in 11 patients. In nine patients, the hypermetabolic region of PET was identical with the EZ. In eight patients, the EZ was adjacent to the functional area. In the brain lobe with focal hypermetabolism, 182 electrode sites (22.2%) induced after discharges, and the sites that directly produced after Discharges (ADs) were often found in the center of the focal hypermetabolic area. Patients with high metabolic lesions near the functional area were more likely to induce AD than those with non-adjacent functional areas. Pathological results showed eight cases of cortical dysplasia, two cases of cortical malformation, four cases of gliosis, and one case of low-grade glioma. Engel scores in at least 3 years of follow-up were 60% (9) class I, 26.7% (4) class II, and 13.3% (2) class III. Conclusion: Interictal PET hypermetabolism can locate the epileptic focus. Combined with extraoperative electrical stimulation mapping, it was helpful in accurately locating the EZ to help surgeons make clinical decisions.

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Cite the article

Song L-J, Qu X-P, Gao L, Li Y-Q, Zhang Y, Wang C, et al. Focal Interictal Positron Emission Tomography Hypermetabolism and Electrical Cortical Stimulation Accurately Localizes the Seizure Onset Zone: A Cohort Study. Clin Surg. 2022; 7: 3532..