Repeated ictal SPECT in partial epilepsy patients: SISCOM analysis

Area of Science:

• Neurology
• Radiology
• Epilepsy Research

Background:

• Ictal single-photon emission computerized tomography (SPECT) often yields nonlocalized results in partial epilepsy.
• Accurate localization of the epileptic focus is crucial for effective surgical planning and treatment.

Purpose of the Study:

• To evaluate the efficacy of repeated ictal SPECT with subtraction ictal SPECT coregistered to MRI (SISCOM) in patients with nonlocalized initial SPECTs.
• To identify factors influencing the localizability of ictal SPECT in partial epilepsy.

Main Methods:

• 69 patients with partial epilepsy underwent repeated ictal SPECT.
• Subtraction ictal SPECT coregistered to MRI (SISCOM) was performed and analyzed.
• SISCOM results were compared with the established epileptic focus location.

Main Results:

• Second ictal SPECT with SISCOM localized the epileptic focus in 62.3% of patients.
• Shorter radiotracer injection times and localized ictal EEG patterns were significantly associated with successful localization.
• Early injection time in the second SPECT was significantly shorter in the localized group compared to the nonlocalized group.

Conclusions:

• Repeated ictal SPECT utilizing SISCOM analysis is a valuable tool for localizing epileptic foci in patients with initially nonlocalized SPECTs.
• Optimizing radiotracer injection timing and identifying localized ictal EEG patterns are critical for enhancing the diagnostic yield of ictal SPECT.