Left or right? Lateralizing temporal lobe epilepsy by dynamic amygdala fMRI.

Area of Science:

• Neuroimaging
• Epilepsy Research
• Functional Magnetic Resonance Imaging (fMRI)

Background:

• Temporal lobe epilepsy (TLE) diagnosis and lateralization can be challenging.
• Functional MRI (fMRI) with specific paradigms may offer insights into brain activity in epilepsy.
• Previous studies suggest amygdala activation patterns differ between healthy individuals and TLE patients.

Purpose of the Study:

• To evaluate the utility of a dynamic fearful face fMRI paradigm for lateralizing TLE.
• To compare fMRI findings with electroencephalography (EEG) in TLE patients.
• To assess amygdala activation patterns in TLE and extra-temporal lobe epilepsy (ETLE).

Main Methods:

• A case series of 85 functional MRI studies using a dynamic fearful face paradigm.
• Participants included 60 TLE patients, 12 ETLE patients, and 13 healthy controls.
• Studies were conducted on a 1.5T scanner and results compared with EEG findings.

Main Results:

• Amygdala activations were lateralized concordant with EEG in 76% of unilateral TLE patients (77% left TLE, 74% right TLE).
• Significant differences in lateralized indices were observed between left TLE, right TLE, and control groups.
• Concordance with EEG was lower (31%) in ETLE patients, with most showing bilateral amygdala activation.

Conclusions:

• The dynamic fearful face fMRI paradigm is a valuable adjunctive tool for lateralizing TLE.
• The 1.5T fMRI approach demonstrates utility in clinical epilepsy assessment.
• Findings support the role of limbic system dysfunction in TLE lateralization.