Value of PET in patients with epilepsy
Most patients with epilepsy who are evaluated with PET scans are studied during the interictal period, when an area of hypometabolism may be seen in the region of seizure onset.
This reflects a decrease in glucose uptake by the involved abnormal brain. PET scanning can help to localize seizure onset in patients with intractable, complex partial seizures who are being evaluated for surgical therapy.
Between 60% and 90% of patients with temporal lobe epilepsy, and 67% with extratemporal lobe epilepsy, show hypometabolism in PET imaging, while about 44% of “nonlesional” epilepsy may show hypometabolism in PET.
When performed during or shortly following an epileptic seizure, PET imaging often reveals complex patterns of both hypometabolism and hypermetabolism.
A common tracer used in PET to evaluate epilepsy patients is [18F] fluoro-2-deoxy-glucose.
