[Peri-ictal SPECT in temporal lobe epilepsy: post-surgical evaluation]

Area of Science:

• Neurology
• Medical Imaging
• Epilepsy Surgery

Background:

• Medically refractory complex partial seizures (CPS) often necessitate surgical intervention.
• Temporal lobectomy is a common surgical treatment for drug-resistant epilepsy.
• Accurate localization of the epileptogenic region (ER) is crucial for successful surgical outcomes.

Purpose of the Study:

• To evaluate the utility of peri-ictal single-photon emission computed tomography (SPECT) in identifying the ER.
• To compare peri-ictal SPECT with MRI and video-electroencephalography (video-EEG) for ER localization.
• To determine the positive predictive value (PPV) of peri-ictal SPECT in patients with good surgical outcomes.

Main Methods:

• Retrospective analysis of 37 patients with temporal lobe epilepsy undergoing surgery.
• Pre-surgical evaluation included video-EEG, MRI, interictal SPECT, and peri-ictal SPECT (ictal or postictal).
• Comparison of imaging and EEG findings with the surgically confirmed ER and post-surgical seizure control (minimum 3-year follow-up).

Main Results:

• Peri-ictal SPECT showed 86% concordance with the ER, comparable to video-EEG (86%) and superior to interictal SPECT (54%).
• MRI demonstrated 84% concordance with the ER.
• In patients with good surgical outcomes (n=29), peri-ictal SPECT had a PPV of 90%, similar to MRI (90%) and video-EEG (95%).

Conclusions:

• Peri-ictal SPECT is a valuable tool for localizing the ER in temporal lobe epilepsy.
• Its diagnostic performance is comparable to video-EEG and MRI.
• Peri-ictal SPECT is particularly recommended when MRI and EEG findings are discordant, aiding pre-surgical planning.