The relationship between deviant brain activity and executive functioning in glioma patients

Background. Glioma patients frequently suffer from executive functioning (EF) deficits. The underlying neurophysiological mechanisms remain poorly understood. Studies have revealed bidirectional interactions between gliomas and their surroundings with neuronal activity promoting tumor growth and vice versa. Hyperactivity holds prognostic value for tumor progression, but how does pathological activity relate to neurocognitive deficits? We investigated the relationship between brain activity in the neurocognitively relevant frontoparietal network (FPN) and the peritumoral area and EF in glioma patients. Methods. We conducted neuropsychological assessments and measured resting-state brain activity using magnetoencephalography in 37 glioma patients (preoperatively and at 1-year follow-up) and 25 matched healthy controls (HCs). Broadband power and offset served as proxies for neuronal activity and were averaged separately for the peritumoral area and the FPN regions ipsilateral and contralateral to the tumor hemisphere. EF was operationalized with the concept-shifting and word-fluency tests. We used linear regression to relate activity and EF. Results. Brain activity became more deviant over time in the peritumoral area. While higher broadband power in the right FPN was associated with lower word fluency in HCs, there was no association between brain activity and EF in patients, neither at baseline nor longitudinally. Conclusions. These results indicate that resting-state activity might not hold clinical relevance for EF in glioma patients, while it does become more deviant over time. Patient-specific deviations in functional network properties, such as the integration of the network, may be more relevant for EF in this patient group, as a recent study in the same cohort has shown.