Personality and behavioral changes after brain tumor resection: a lesion mapping study.

Background: Cognitive functioning is generally well preserved in patients with diffuse low-grade glioma (DLGG), even in the case of extended tumor and resection. To date, the question of personality changes in these patients has received little attention. Our aim was to investigate to what extent certain aspects of personality and behaviors could be affected by DLGG resection.

Methods: We used self-reported personality questionnaires (NOEPI-R and TCI-R) and hetero-evaluation of executive behavioral changes in a large sample of 98 patients operated on for DLGG. To compare the patients' scores from the personality questionnaires, we recruited 47 healthy controls participants. To identify the putative neural networks associated with behavioral changes, a combination of voxel-wise and tract-wise lesion-symptom mapping was performed.

Results: First, results revealed no difference between patients and controls for each subdimension of the NOEPI-R. Regarding the TCI-R, the character dimensions and three out of four temperament dimensions did not differ. Second, behavioral changes (Irritability, Hypoactivity, Anticipative disorders, and disinterest) were reported between 40 and 50% of cases. Third, some personality dimensions (as neuroticism) were strongly predictive of postoperative behavioral disorders (as hypoactivity). Lastly, specific behavioral changes were associated with selective damage to cortical (left inferior frontal gyrus, supplementary motor area, and right fusiform gyrus) and white matter (left inferior fronto-occipital and uncinate fasciculi, right cingulum) structures.

Conclusion: This study demonstrates that extensive lesions caused by DLGGs and their surgical resection have no or minor impact on patients' personality. However, specific personality dimensions are strongly predictive of behavioral disorders suggesting that the observed surgically related behavioral changes are modulated by the personality profile. Finally, the lesion mapping analyses indicate that damage to differential cortical or white matter structures leads to distinct patterns of behavioral abnormalities.