PMC5303618_01
1A: 3T MRI showing possible subtle right frontal lobe cortical dysplasia.. 1B: Electroencephalogram obtained at the time of the patient's first (ictal) FDG-PET study, showing a typical right frontal electrographic seizure (onset marked by arrow.) These seizures recurred every 5-30 seconds throughout the one hour scanning session.
nihms846700f1.jpg
PMC5303618_01_nihms846700f1.jpg
F1
Brain MRI was initially considered normal, though subsequent high-resolution studies showed possible subtle dysplasia of the right frontal lobe (Figure 1A). After treatment and clinical recovery, frequent right frontal electrographic seizures persisted (Figure 1B). 18-FDG Positron Emission Tomography (FDG-PET) performed at this time, considered to be an ictal study, showed intense right frontal hypermetabolism (Figure 2A).
2A: Ictal FDG-PET showing right frontal hypermetabolism.. 2B: Interictal FDG-PET showing right frontal hypometabolism.. 2C: PK11195-PET overlaid on CT showing increased tracer uptake in right frontal lobe (as well as thalamus, a normal finding).
nihms846700f2.jpg
PMC5303618_01_nihms846700f2.jpg
F2
After treatment and clinical recovery, frequent right frontal electrographic seizures persisted (Figure 1B). 18-FDG Positron Emission Tomography (FDG-PET) performed at this time, considered to be an ictal study, showed intense right frontal hypermetabolism (Figure 2A). A subsequent FDG-PET performed during a seizure-free period after treatment with lorazepam showed right frontal hypometabolism (Figure 2B). Using a two-parameter linearized reference tissue model implemented in PMOD (PMOD Technologies, Zurich, Switzerland), images of tracer uptake (relative to cerebellum) were generated (Figure 2C).
3A: 100x magnification H&E stain of right frontal lobe tissue showing enlarged, bizarrely-shaped, dysplastic neurons consistent with focal cortical dysplasia.. 3B: 100x magnification CD68 (KP1) stain showing excess microglia with activated morphology.
nihms846700f3.jpg
PMC5303618_01_nihms846700f3.jpg
F3
Examination of resected tissue revealed focal cortical dysplasia (FCD) with prominent microglial activation (Figure 3).