Place de la TEP au FDG dans le bilan des épilepsies pharmacorésistantes

Abstract

The work-up of drug-resistant partial epilepsy is intended to localize epileptogenic foci in the purpose of a possible surgery. We aimed to assess the role of fluorodeoxyglucose Positron Emission Tomography (FDG PET) in this scope. This study involved 34 patients who underwent brain FDG PET, with a final diagnosis in 21. The value of FDG PET for lateralisation and localisation of the epileptogenic focus was evaluated by a blinded interpretation, and compared with the value of standard investigations. The impact of FDG PET was assessed by the means of a questionary intended for the neurologist in each case. All the epilepsy types together, FDG PET lateralised and localised the foci in 65 and 47% of the 34 subjects respectively. Among the 19 subjects with final diagnosis (patients with bilateral foci excluded), lateralisation was correct in 84% and localisation in 63% (and the values were greater for temporal epilepsy than for extratemporal foci). PET frequently provided additional information compared with MRI, but not with EEG. FDG PET was useful in 82.5% of cases (confirming management in 65% and changing it in 17.5% of the patients). Our experience corroborated the value of FDG PET for lateralisation and localisation of epileptogenic foci, and its role in case of normal MRI. However, FDG PET appears as a confirmation tool rather than an examination resulting in a change in management rate.