Quantitative Analysis of 18/FDG-PET in the Presurgical Evaluation of Patients Suffering from Refractory Partial Epilepsy Comparison with CT, MRI, and Combined Subdural and Depth. EEG

Summary CT, MRI, l8/FDG-PET and Depth. EEG, performed with subdural and depth electrodes were part of the presurgical evaluation in 22 patients. Statistical analysis of 18/FDG-PET was performed to com­ pare cerebral utilization of glucose to that of normal age matched controls. The findings ofCT, MRI, and quantitative analysis of PET are compared with those of ictal Depth. EEG. A positive correlation between CT and Depth. EEG was obtained in 23% of the patients and between MRI and Depth. EEG. in 50%. For both imaging techniques a negative correlation was found in 5%. Regional abnormalities were found with quantified PET in 95% of the patients and were concordant with Depth. EEG. for side of onset in 77% of the patients and for lobe of onset in 59%. A possibly false localising PET result for lobe of onset was obtained in 8 patients (36%). Limitations of PET were most apparent in patients with regional mesiolimbic or bilateral seizure onset. A favourable outcome of surgery was associated usually with positive convergence of both methods. PET may be a valuable contribution to the research and man­ agement of partial complex epilepsy, but at present cannot be con­ sidered a reliable alternative to invasive EEG methods in patients without clear unilateral focus localization on surface EEG.