P01.075 Understanding cognitive functioning in diffuse glioma patients: the relevance of IDH mutation status and functional connectivity. (19th September 2018)

• Record Type: Journal Article
• Authors: Derks, J; Kulik, S; Wesseling, P; Numan, T; Hillebrand, A; de Witt Hamer, P C; Reijneveld, J C; Stam, C J; Klein, M; Douw, L
• Is Part Of: Neuro-oncology. Volume 20(2018)Supplement 3
• Page Start: iii247
• Page End: iii247
• Publication Date: 2018-09-19
• Subjects: Brain Neoplasms -- Periodicals; Brain -- Tumors -- Periodicals; Brain -- Cancer -- Periodicals; Nervous system -- Cancer -- Periodicals; 616.99481
• DOI: 10.1093/neuonc/noy139.117
• Languages: English
• ISSNs: 1522-8517

Abstract

Abstract: Background: Isocitrate dehydrogenase (IDH) mutation (IDH-mut) is an important marker for survival in diffuse glioma patients. Patients with an IDH-mut glioma have a better prognosis but more often suffer from epilepsy. Patients with a wildtype glioma (IDH-wt) are generally older and more often have cognitive deficits. Regardless of IDH status, cognitive deficits in glioma patients are associated with altered functional connectivity throughout the brain as calculated through statistical correlations between regional neurophysiological activity patterns measured with magnetoencephalography (MEG). Cognitive variation in glioma patients is specifically related to altered theta (4–8 Hz) and alpha (8–13 Hz) band functional connectivity. We investigated whether global brain functional connectivity differs between patients with an IDH-mut and IDH-wt diffuse glioma, and whether this measure reflects variations in cognitive functioning in these subpopulations beyond the associated differences in age and epilepsy. Material and Methods: IDH mutation status was determined in 54 diffuse glioma patients via immunohistochemistry (31 IDH-mut, 23 IDH-wt). We recorded MEG and patients underwent cognitive testing. Global functional connectivity between 78 atlas regions spanning the entire cortex was calculated in the theta and alpha frequency bands. Group differences in cognition and global functional connectivity were tested. Next, the association between functional connectivity and cognitive performance was tested. Results: As expected, patients with IDH-mut glioma were younger (P = 0.001) and more often had epilepsy (P = 0.010). Patients with IDH-wt glioma showed poorer verbal memory (P = 0.027, corrected for age, education and presence of epilepsy). More importantly, patients with IDH-wt glioma had lower functional connectivity in the alpha band than patients with IDH-mut glioma (P = 0.015, corrected for age and presence of epilepsy). Alpha band functional connectivity was positively associated with executive functioning (P = 0.049) and information processing speed (P = 0.009), regardless of IDH status and corrected for age, education, and presence of epilepsy. Conclusion: These results suggest that global functional connectivity is lower in patients with IDH-wt diffuse glioma compared to patients with IDH-mut diffuse glioma. Moreover, functional connectivity relates to cognitive performance in both IDH-wt and IDH-mut diffuse glioma patients, regardless of age, education and presence of epilepsy. These findings contribute to our understanding of cognitive functioning in patients with diffuse glioma in general, and cognitive deficits in patients with IDH-wt glioma specifically.