Multimodal Analysis of "Temporal Lobe Epilepsy": Correlation Between Functional Imaging (SISCOM,FDG-PET) and Electroclinical Evaluation.
Abstract number :
1.202
Submission category :
Year :
2000
Submission ID :
2607
Source :
www.aesnet.org
Presentation date :
12/2/2000 12:00:00 AM
Published date :
Dec 1, 2000, 06:00 AM
Authors :
Viviane Bouilleret, Maria Paola Valenti, Izzie J Namer, Franck Semah, Christian Marescaux, Pierre Kehrli, Edouard Hirsch, shfj, DRM, CEA, Orsay, France; Service de Neurologie, Strasbourg, France; Inst de Biophysique, Strasbourg, France; Service de Neuroch
RATIONALE:_Substraction of interictal from ictal SPECT images coregistered to 3D MRI (SISCOM) and fluorodeoxyglucose positron emission tomography (FDG-PET) participate to the definition of the epileptogenic zone in refractory partial temporal lobe epilepsy. The aim of the present study is i) to compare by visual analysis the localization of the metabolic and perfusion abnormalities ii) to correlate the results of the functional neuroimaging technics with the symptomatogenic zone. METHODS:_Symptomatogenic zone was determined in all patients using EEG-video monitoring. Interictal FDG-PET was performed in 12 patients with intractable "temporal lobe" epilepsy (6 women, 6 men, mean age: 25.1). We studied 9 hippocampal sclerosis or dysplasia (HS)(7 uni, 2 bilateral), 2 cavernomas (1 associated with HS), 1 arachnoidal cyst. Ten of these patients had a SISCOM (mean time of injection for ictal SPECT: 17.3s). FDG-PET were individually analyzed using Statistical Parametric Mapping software (SPM96, Wellcome Department of cognitive Neurology, London, UK; p<0.05) and SISCOM with a semi-quantitative method (software MEDIMAX developed at the Institute of Biophysic of Strasbourg). RESULTS:_Perfusion and metabolic patterns spread outside the temporal lobe in 10/12 patients. Abnormalities were concordant in 8/10 patients. For the 2 others, (1) ictal SPECT performed during the post-ictal phase induced a widespread hyperperfusion, (2) FDG-PET pattern was restricted to the lesion (right temporobasal cavernoma) associated with a limited zone in the homolateral inferior frontal gyrus. Conversely, bilateral hyperperfusion in the temporal lobe, the insula and the basal ganglia was found.In those cases of nonconcordance, SISCOM was correlated to the symptomatogenic zone only if early radiotracer injection is performed, while FDG-PET pattern is restricted to the lesional region CONCLUSIONS:_These data demonstrate that both interictal FDG-PET and SISCOM are topographically concordant and are highly correlated to the symptomatogenic zone which frequently spread outside the temporal lobe.