Clinical utility of flumazenil-PET versus [18F]fluorodeoxyglucose-PET and MRI in refractory partial epilepsy. A prospective study in 100 patients.
We assessed the clinical utility of [11C]flumazenil-PET (FMZ-PET) prospectively in 100 epileptic patients undergoing a pre-surgical evaluation, and defined the specific contribution of this neuro-imaging technique with respect to those of MRI and [18F]fluorodeoxyglucose-PET (FDG-PET). All patients benefited from a long term video-EEG monitoring, whereas an intracranial EEG investigation was performed in 40 cases. Most of our patients (73%) demonstrated a FMZ-PET abnormality; this hit rate was significantly higher in temporal lobe epilepsy (94%) than in other types of epilepsy (50%) (P < 0.001). Most FMZ-PET findings coexisted with a MRI abnormality (81%), including hippocampal atrophy (35%) and focal hypometabolism on FDG-PET (89%). The area of decreased FMZ binding was often smaller than that of glucose hypometabolism (48%) or larger than that of the MRI abnormality (28%). FMZ-PET did not prove superior to FDG-PET in assessing the extent of the ictal onset zone, as defined by intracranial EEG recordings. However, it provided useful data which were complementary to those of MRI and FDG-PET in three situations: (i) in temporal lobe epilepsy associated with MRI signs of hippocampal sclerosis, FMZ-PET abnormalities delineated the site of seizure onset precisely, whenever they were coextensive with FDG-PET abnormalities; (ii) in bi-temporal epilepsy, FMZ-PET helped to confirm the bilateral origin of seizures by showing a specific pattern of decreased FMZ binding in both temporal lobes in 33% of cases; (iii) in patients with a unilateral cryptogenic frontal lobe epilepsy, FMZ-PET provided further evidence of the side and site of seizure onset in 55% of cases. Thus, FMZ-PET deserves to be included in the pre-surgical evaluation of these specific categories of epileptic patients, representing approximately half of the population considered for epilepsy surgery.
Ryvlin
P
P
Epilepsy Surgery Unit, and CERMEP, Neurological Hospital, Lyon, France. ryvlin@cermep.fr
Bouvard
S
S
Le Bars
D
D
De Lamérie
G
G
Grégoire
M C
MC
Kahane
P
P
Froment
J C
JC
Mauguière
F
F
D001921:Brain / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology*; D004569:Electroencephalography; D004828:Epilepsies, Partial / Q000175:diagnosis* / Q000503:physiopathology / Q000601:surgery; D017034:Epilepsy, Frontal Lobe / Q000175:diagnosis; D004833:Epilepsy, Temporal Lobe / Q000175:diagnosis; D005442:Flumazenil / Q000493:pharmacokinetics; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics; D007839:Functional Laterality; D018757:GABA Modulators / Q000493:pharmacokinetics; D006801:Humans; D008279:Magnetic Resonance Imaging; D011446:Prospective Studies; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D014055:Tomography, Emission-Computed; D014741:Video Recording
D018757:GABA Modulators; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D005442:Flumazenil