Background: Glioma patients may experience behavioral and personality changes (BPC), negatively impacting their lives and that of their relatives. However, there is no clear definition of BPC for... Show moreBackground: Glioma patients may experience behavioral and personality changes (BPC), negatively impacting their lives and that of their relatives. However, there is no clear definition of BPC for adult glioma patients, and here we aimed to determine which characteristics of BPC are relevant to include in this definition.Methods: Possible characteristics of BPC were identified in the literature and presented to patients and (former) caregivers in an online survey launched via the International Brain Tumour Alliance. Participants had to rate the relevance of each presented characteristic of BPC, the three characteristics with the most impact on their lives, and possible missing characteristics. A cluster analysis and discussions with experts provided input to categorize characteristics and propose a definition for BPC.Results: Completed surveys were obtained from 140 respondents; 35% patients, 50% caregivers, and 15% unknown. Of 49 proposed characteristics, 35 were reported as relevant by at least 25% (range: 7%-44%) of respondents. Patients and caregivers rated different characteristics as most important. Common characteristics included in the top 10 of both patients and caregivers were lack of motivation, change in being socially active, not able to finish things, and change in the level of irritation. No characteristics were reported missing by >= 5 respondents. Three categories of BPC were identified: (1) emotions, needs, and impulses (2) personality traits, and (3) poor judgement abilities.Conclusion: The work resulted in a proposed definition for BPC in glioma patients, for which endorsement from the neuro-oncological community will be sought. A next step is to identify or develop an instrument to evaluate BPC in glioma patients. Show less