White-matter pathways and semantic processing: intrasurgical and lesion-symptom mapping evidence

Area of Science:

• Neuroscience
• Cognitive Science
• Neurosurgery

Background:

• Semantic processing relies on complex neural networks.
• The role of specific white matter tracts in semantic cognition remains an active area of research.
• Intraoperative mapping is essential for preserving function during brain surgery.

Purpose of the Study:

• To investigate the association between left ventral white matter pathways and semantic processing using intraoperative electrical stimulation.
• To identify brain regions critical for semantic tasks via lesion-symptom analyses.
• To enhance functional preservation during awake brain surgery.

Main Methods:

• Intraoperative electrical stimulation of white matter pathways in 62 awake surgery candidates.
• Novel language tasks assessing semantic processing.
• Voxel-based lesion-symptom mapping (VLSM) and track-wise lesion analysis.

Main Results:

• Electrical stimulation near the inferior longitudinal and inferior fronto-occipital fasciculi impaired semantic task performance.
• Track-wise analyses revealed significant associations between these tracts and semantic paraphasias.
• Boston Naming Test scores correlated with the integrity of the inferior fronto-occipital, inferior longitudinal, and uncinate fasciculi.

Conclusions:

• Left ventral white matter pathways are vital for semantic processing.
• Intraoperative assessment of semantic-conceptual functions is crucial for neurosurgery.
• Preserving these pathways minimizes post-surgical language deficits.