,  Forouzan  Ahmadi , Khatamol Anbia hospital, Shafa Neurology building

Ictal SPECT is a safe and non-invasive procedure in determination of seizure focus and for evaluation of seizure focus extension in good selected patient. This method is usually done in pharmaco resistant patients before they become candidate for epilepsy surgery. This method is based on the phenomenon that blood perfusion to the seizure focus is rising during a seizure attack as double. Expert nurses inject Technetium 99 with proper dose through IV less than 30 seconds after starting Ictal EEG onset in selected patient during monitoring in LTM ward. Afterward, 10cc of Normal saline injects due to washing the vessel.

After this step, related physician should be informed for starting over of anticonvulsant drugs. The surface electrodes must be removed and the patient conduct to Gamma Scan ward for doing SPECT at the end of Ictal injection.

The second step of this procedure is Interictal SPECT. As its name shows, it will be done 24 hours after Ictal SPECT if no seizure occurred.

Although ictal SPECT shows hyper perfusion of seizure focus, Interictal SPECT shows hypo perfusion of this zone.

SPECT is a good radiologic method for cases that ictal onset zone of EEG is not completely clear or brain MRI with epilepsy protocol shows more than one lesion as epileptogenic zone.