Ictal SPECT with intravenous injection in a cubital vein of a perfusion tracer is an
established technique to localize the ictal onset zone during presurgical evaluation of
refractory focal epilepsy. When seizures last less than 10 seconds, localizing information is
often not obtained. Since it takes around 30 seconds before the tracer reaches the brain
after intravenous injection, ictal hyperperfusion most likely has already switched to
postictal hypoperfusion. In this study, we plan to inject the perfusion tracer in the aorta
proximal to the cerebral arteries, which will allow a true ictal injection in patients with
seizures of short duration.