General Discussion: RADIOPHARMACEUTICAL: 8.6 mCi F-18 Fluorodeoxyglucose i.v.
For the purpose of epileptic localization, PET imaging is usually done as an interictal evaluation. PET imaging for ictal evaluation are not performed because of the underlying technical challenges. Positive findings for interictal exams are generally hypometabolic, typically related to mesial temporal sclerosis. In this patient, who has a recent MRI that was unremarkable for any CNS malignancy, the unexpected findings of two hypermetabolic foci may reflect an ictal phase imaging rather than interictal. The patient was heavily sedated and medicated during the exam, which would explain the lack of any physical manifestation of her ongoing seizures during the uptake phase of the study.
Therefore, in combination with the subtle MRI finding and concordance of the video EEG, this is likely to represent focal cortical dysplasia and the patient's seizure focus.
The patient underwent surgical resection for these abnormal foci, which was revealed to be focal cortical dyplasia on pathology. Subsequently, she was seizure free.