Language lateralization in temporal lobe epilepsy: A behavioral screening tool for surgical planning

Area of Science:

• Neuroscience
• Cognitive Psychology
• Epilepsy Research

Background:

• Temporal lobe epilepsy (TLE) frequently affects language processing due to the proximity of eloquent brain areas.
• Assessing language lateralization is crucial for surgical planning in drug-resistant TLE.
• Existing methods for language lateralization may have limitations.

Purpose of the Study:

• To evaluate the efficacy of a visually-mediated task in measuring language recognition lateralization in patients with drug-resistant TLE.
• To compare language lateralization patterns between patients with left TLE, right TLE, and healthy controls.

Main Methods:

• A translingual lexical decision task was administered to 26 patients with left TLE, 28 with right TLE, and 30 controls.
• Data were analyzed using repeated measures analyses of variance, considering visual half-field and group as factors.
• Performance was assessed based on accuracy and response time.

Main Results:

• A significant right visual field (left hemisphere) advantage for language recognition was observed in controls and patients with right TLE, but not in left TLE.
• Both TLE groups showed reduced accuracy compared to controls, with left TLE performing less accurately than right TLE.
• The interaction between group and visual half-field was significant for both accuracy and response time, indicating differential lateralization patterns.

Conclusions:

• The translingual lexical decision task effectively differentiates between left and right TLE based on language lateralization.
• Language lateralization is notably diminished in individuals with left TLE.
• This task shows promise as a noninvasive screening tool for presurgical language lateralization assessment.