[Neuroimaging in epilepsy. Advances in SPECT and PET in epilepsy]

Area of Science:

• Neuroimaging
• Epileptology
• Nuclear Medicine

Background:

• Neuroimaging techniques have significantly reduced the need for intracranial electrodes in localizing epileptogenic foci.
• Magnetic resonance imaging (MR) may not reveal anomalies in all epilepsy cases.

Purpose of the Study:

• To evaluate the utility of Single-Photon Emission Computed Tomography (SPECT) and Positron Emission Tomography (PET) in epilepsy diagnosis and management.
• To explore the role of neuroreceptor imaging in understanding epilepsy etiopathogenesis.

Main Methods:

• Cerebral SPECT using perfused tracers (e.g., 99mTc-HMPAO, 123I-MP, 99mTc-ECD) for interictal and ictal phase studies.
• FDG-PET for interictal metabolic studies, comparing results with video-electroencephalography (EEG).
• SPECT and PET imaging of neuroreceptors using specific radiotracers.

Main Results:

• SPECT can detect increased cerebral blood flow in the epileptogenic focus during ictal phases in 90% of patients.
• FDG-PET shows reduced metabolism in epileptogenic regions, with high sensitivity and specificity in temporal lobe epilepsy compared to video-EEG.
• These techniques show utility in extratemporal and multifocal epilepsies, outperforming other diagnostic methods.

Conclusions:

• Neuroreceptor imaging with SPECT and PET offers potential for investigating epilepsy's underlying causes.
• Understanding neuroreceptor distribution (e.g., benzodiazepine, opiate) can improve epilepsy's clinical and therapeutic management.
• SPECT and PET are valuable tools for localizing epileptogenic foci and guiding post-surgical recovery prognosis.