Nuclear Medicine uses a small amount of radioactive, injectable material to demonstrate the function of the brain.  It can be used to localize where seizures start. A scan before the seizure for a baseline image and then again with the radioactive material given during the seizure to locate activity in the brain.  This is not often used with HH, because by the time the nuclear medicine contrast is given and reaches the brain, the seizure has already moved out of the HH into the rest of the brain, giving false-localization results.