Sentence-level language processing speed in diffuse glioma: lesion location and contralesional structural...

Area of Science:

• Neuroscience
• Cognitive Psychology
• Neurology

Background:

• Diffuse gliomas often cause cognitive deficits, notably impacting language processing speed at both lexical and sentence levels.
• Sentence-level processing speed is critically affected, but the underlying neural mechanisms in glioma patients are poorly understood.

Purpose of the Study:

• To investigate the relationship between lesion location, brain structure differences, and sentence-level language processing speed in patients with diffuse glioma.
• To identify specific brain regions affected by glioma that correlate with slowed sentence processing.

Main Methods:

• Assessed sentence-level language processing speed in 28 patients with left hemispheric glioma and 20 healthy controls using a picture-sentence matching task.
• Employed region of interest-based lesion-symptom mapping to correlate lesion sites with processing speed deficits.
• Utilized surface-based morphometry to analyze cortical thickness and fractal dimension across the brain.

Main Results:

• Glioma involvement of the left superior temporal gyrus was significantly associated with slowed sentence-level processing speed.
• Increased cortical complexity in the right superior frontal gyrus correlated with faster sentence-level processing speed.
• Tumor volume in the left superior temporal gyrus and right superior frontal gyrus cortical complexity independently predicted processing speed.

Conclusions:

• Tumor-induced damage to the left superior temporal gyrus disrupts core language processing in diffuse glioma patients.
• Inter-individual differences in brain structure, specifically cortical complexity in the right superior frontal gyrus, contribute to language processing speed.
• Findings support a neural reserve framework, where structural brain differences modulate the impact of tumor-related damage on language function.