[Functional neuroimaging in children]

In pharmacoresistant partial epilepsy (PRPE) in children, functional cerebral imaging helps localizing the epileptogenic zone using SPECT (Single Photon Emission Computed Tomography) and PET (Positron Emission Tomography) and the functional motor and language cortex using functional MRI. Regarding SPECT, only ictal SPECT exhibits an acceptable sensitivity (80 p. 100), together with interictal SPECT and subtraction image processing. Regarding PET, sensitivity has not been validated yet compared with intracranial EEG, neither using 18FDG, nor using more recent tracers such as 11C-flumazénil or 11C-alpha-méthyl-tryptophane. However, both techniques are useful to decide the placement of the intracranial electrodes, particularly in cryptogenic cases or when preoperative data are discordant. Functional MRI for language is going to be validated compared with WADA test and to provide a very useful and non invasive alternative method to lateralize the language networks in children able to cooperate. FMRI also provides a unique opportunity to follow the post-lesional or post-surgery plasticity of these networks using repeated examinations in a same patient. Functional imaging techniques therefore provide a useful additional contribution in the presurgery work-up of PRPE in children.