2011 Articles

Imaging Inflammation in a Patient with Epilepsy Due to Focal Cortical Dysplasia

Butler, Tracy; Ichise, Masanori; Teich, Andrew Franklin; Gerard, Elizabeth; Osborne, Joseph; French, Jacqueline; Devinsky, Orrin; Kuzniecky, Ruben; Gilliam, Frank; Pervez, Fahad; Provenzano, Frank; Goldsmith, Stanley; Vallabhajosula, Shankar; Stern, Emily; Silbersweig, David

BACKGROUND AND PURPOSE Evidence from animal models and examination of human epilepsy surgery specimens indicates that inflammation plays an important role in epilepsy. Positron emission tomography (PET) using [C11]PK11195, a marker of activated microglia, provides a means to visualize neuroinflammation in vivo in humans. We hypothesize that in patients with active epilepsy, [C11]PK11195 PET (PK-PET) may be able to identify areas of focally increased inflammation corresponding to the seizure onset zone. METHODS A young woman with intractable epilepsy underwent PK-PET as part of an approved research study. PK-PET results were compared with results from other clinical studies. RESULTS PK-PET revealed an area of focally increased radiotracer uptake in the right frontal lobe corresponding to this patient’s seizure focus as identified by ictal and interictal 18Ffluorodeoxyglucose (FDG)-PET and EEG. Routine brain magnetic resonance imaging (MRI) was initially considered normal, though high-resolution studies showed possible subtle dysplasia of the right frontal lobe. The patient underwent a right frontal lobe resection, and pathological evaluation showed focal cortical dysplasia with activated microglia. CONCLUSIONS PK-PET can identify neuroinflammation associated with subtle focal cortical dysplasia, and may therefore have a clinical role in guiding epilepsy surgery for patients with difficult-to-localize seizure foci.