What method is used to localize the site of seizure onset by looking for hyperfusion?

The correct method to localize the site of seizure onset by observing hyperfusion is ICTAL SPECT. This imaging technique is particularly useful during or right after a seizure event. It involves the injection of a radioactive tracer that highlights regions of increased blood flow or metabolic activity in the brain, which is indicative of seizure activity.

When a seizure occurs, the affected area receives an increased blood supply, leading to hyperfusion, which is crucial for determining the localization of the seizure onset zone. The timing of the SPECT scan is critical, as it needs to be conducted during the ictal (seizure) phase to effectively capture this hyperfusion pattern.

The other methods listed are not primarily aimed at identifying hyperfusion during seizure activity. EEG monitoring focuses on electrical activity in the brain rather than blood flow, a CT scan provides structural images of the brain and does not capture real-time functional changes, and functional MRI measures brain activity by detecting changes associated with blood flow, but it does not directly address hyperfusion in the context of seizures. Thus, ICTAL SPECT stands out as the appropriate choice for this specific purpose.