Presurgical Executive Functioning in Low-Grade Glioma Patients Cannot Be Topographically Mapped

Area of Science:

• Neuroscience
• Oncology
• Cognitive Psychology

Background:

• Executive dysfunctions are prevalent in patients with low-grade gliomas, potentially due to structural brain disconnections.
• Limited research exists on preoperative executive function deficits in this patient population.
• The frontotemporoparietal network, supported by the superior longitudinal fasciculus, is crucial for executive functions.

Purpose of the Study:

• To investigate the relationship between structural predictors and executive functions in patients with IDH-mutated low-grade gliomas.
• To assess the impact of tumor proximity to the superior longitudinal fasciculus and network integrity on executive performance.

Main Methods:

• Analysis of 156 patients with IDH-mutated low-grade gliomas from two neurological centers.
• Preoperative predictors included tumor distance to the superior longitudinal fasciculus, its structural integrity, tumor-cortical network overlap, and white matter disconnection.
• Linear regression and random forest analyses were employed to evaluate these predictors.

Main Results:

• Patients exhibited significantly lower executive performance and a higher prevalence of impairments compared to normative data.
• Neither tumor structural proximity, white matter integrity, cortical network overlap, nor network disconnection significantly predicted executive performance.
• The study yielded null results, indicating no straightforward topographical explanation for executive deficits.

Conclusions:

• The findings suggest that executive deficits in low-grade glioma patients are not solely explained by simple topographical or structural disconnection models.
• Plasticity-induced network-level equipotentiality is discussed as a potential explanatory mechanism.
• There is a critical need for developing novel methodologies to elucidate the complex, interacting factors underlying executive dysfunction in these patients.