SPECT in the localisation of extratemporal and temporal seizure foci

Area of Science:

• Neurology
• Nuclear Medicine
• Epileptology

Background:

• Accurate seizure focus localization is crucial for epilepsy surgery.
• Single-photon emission computed tomography (SPECT) is a neuroimaging technique used in epilepsy evaluation.
• Comparing different SPECT timing (ictal, postictal, interictal) is essential for optimizing diagnostic yield.

Purpose of the Study:

• To compare the diagnostic yield of ictal, postictal, and interictal SPECT for seizure focus localization.
• To evaluate the efficacy of ictal SPECT in both temporal lobe epilepsy and extratemporal epilepsies.

Main Methods:

• Retrospective analysis of 177 patients with partial epilepsy undergoing ictal, postictal, and interictal SPECT.
• Comparison of localization accuracy rates for each SPECT timing in unilateral temporal lobe epilepsy and extratemporal epilepsy cases.

Main Results:

• Ictal SPECT showed superior localization accuracy (97%) in temporal lobe epilepsy compared to postictal (71%) and interictal (48%) SPECT.
• Ictal SPECT also demonstrated a high diagnostic yield (92%) in extratemporal epilepsies.
• Postictal SPECT had lower accuracy (46%), with only early scans being diagnostic; interictal SPECT was of little value.

Conclusions:

• Ictal SPECT is the most accurate method for localizing seizure foci in temporal lobe epilepsy.
• Ictal SPECT is highly valuable for localizing extratemporal seizure foci, justifying specialized efforts for its acquisition.
• Interictal SPECT provides limited diagnostic value for seizure focus localization in partial epilepsy.