[Functional neuroimaging in adults].
A consensus has not been reached on the proper role of the different functional neuroimaging techniques available for the exploration of drug-resistant partial epilepsy, particularly in preparation for surgery. Several studies have suggested the potential contribution of positron emission tomography (PET) with [18F]-fluoro-deoxyglucose (FDG), [11C]-flumazenil (FMZ), or [11C]-alpha-methyl-tryptophane (AMT), single-photon emission computed tomography (SPECT) to measure ictal cerebral blood flow, magnetic resonance spectroscopy (MRS), and functional magnetic resonance imaging (fMRI) of language and memory functions, but to date there has been no impact study validating the clinical contribution of these different exploration techniques. The most robust data in the literature indicate that [18F]-FDG PET can help to predict surgical failures in patients with temporal lobe epilepsy. Studies with lesser power have suggested that SPECT measurement of ictal hyperperfusion blood flow, and [11C]-FMZ and [11C]-AMT PET can be useful in symptomatic neocortical epilepsy, particularly in patients with tuberous sclerosis explored with [11C]-AMT PET. Use of these different exploration techniques in epileptic patients with a normal MRI is warranted when complementary information could help in deciding on when and how to perform an invasive EEG, but there are significant risks of erroneous identification of the epileptogenic zone. Functional MRI assessment of language regions can be proposed as an alternative to the Wada test to determine hemispheric dominance in patients with temporal lobe epilepsy. Multicentric impact studies will be needed before evidence-based guidelines can be developed for the use of functional neuroimaging techniques in drug-resistant partial epilepsy.
Service de Neurologie Fonctionnelle et d'Epileptologie, Hôpital Neurologique, 59 boulevard Pinel, 69000 Lyon, France. ryvlin@cermep.fr
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D000328:Adult; D038481:Anterior Temporal Lobectomy; D000927:Anticonvulsants / Q000627:therapeutic use; D002250:Carbon Radioisotopes; D003131:Combined Modality Therapy; D004292:Dominance, Cerebral; D004351:Drug Resistance; D004828:Epilepsies, Partial / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000473:pathology / Q000601:surgery; D004833:Epilepsy, Temporal Lobe / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000473:pathology / Q000601:surgery; D005442:Flumazenil; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007807:Language Tests; D008279:Magnetic Resonance Imaging; D009682:Magnetic Resonance Spectroscopy; D008569:Memory Disorders / Q000517:prevention & control; D011300:Preoperative Care; D019275:Radiopharmaceuticals; D013702:Temporal Lobe / Q000000981:diagnostic imaging / Q000503:physiopathology; D014055:Tomography, Emission-Computed; D015899:Tomography, Emission-Computed, Single-Photon
D000927:Anticonvulsants; D002250:Carbon Radioisotopes; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D005442:Flumazenil