Unilateral intracarotid amobarbital procedure for language lateralization

Area of Science:

• Neurology
• Neurosurgery
• Neuroradiology

Background:

• Presurgical language dominance assessment in pharmacoresistant epilepsies has evolved with functional magnetic resonance imaging (fMRI).
• Despite fMRI advancements, limitations necessitate continued use of intracarotid amobarbital procedures (IAP) for reliable language lateralization.
• Investigating less invasive IAP methods is crucial for optimizing presurgical evaluation.

Purpose of the Study:

• To evaluate the adequacy and predictive value of unilateral IAP compared to bilateral IAP for language lateralization.
• To determine if unilateral IAP can accurately predict language dominance and identify atypical language representation.
• To assess the necessity of bilateral IAP in the context of modern presurgical workups.

Main Methods:

• Retrospective analysis of 75 patients undergoing unilateral IAP to predict bilateral IAP outcomes.
• Introduction and application of the Hemispheric Language Capacity (HLC) measure for unilateral IAP assessment.
• Validation using a separate cohort of 107 patients requiring presurgical language lateralization.

Main Results:

• Unilateral IAP effectively quantifies language capacity contralateral to the surgical site.
• The majority of patients with atypical language dominance (bilateral or right-hemisphere) were correctly identified.
• Bilateral IAPs were found to be redundant in over 80% of cases in a separate patient series.

Conclusions:

• Unilateral IAP is generally sufficient for language lateralization in presurgical epilepsy evaluations.
• Bilateral IAP is indicated only for specific situations, such as callosotomy planning.
• Unilateral IAP is recommended for verifying ambiguous fMRI findings in patients with pharmacoresistant epilepsy.