Abstract
BACKGROUND: Management of isocitrate dehydrogenase (IDH) mutated gliomas is multidisciplinary and current guidelines support early multimodal treatment. The effects of this treatment approach on cognition are less studied. We aimed to study changes in cognitive functioning the first year following treatment in these patients and explore predictors of cognitive deterioration. METHODS: Patients with a first-time diagnosis of IDH mutated glioma were neuropsychologically assessed before and one year after surgery. Results were compared to published norms, and impairment defined as z <-1.645. Matched controls were assessed at corresponding times, and reliable change indices (RCIs) were calculated to account for practice effects. Logistic regression models investigated predictors for cognitive declines. Tumor locations for declined versus non-declined patients were visualized using heatmaps. RESULTS: Of the 127 included patients, 104 underwent multi-modal treatment. Pre-operative impairments ranged from 3% to 24%, depending on the specific test. Cognitive declines according to RCI domains were largest in tests of executive functioning (24%), learning/memory (23%), and language (21%). Tests of inhibition/flexibility (32%), naming speed (29%), verbal memory (28%), object naming (28%), and verbal fluency (22%) showed the largest proportions of declines. Regression models revealed that older age and chemoradiotherapy predicted declines in specific domains as well as in individual tests (P < 0.05). CONCLUSIONS: Significant changes occurred in several cognitive domains after guideline-based treatment. Older age and chemoradiotherapy increased the risk of cognitive declines one year after surgery, but to which extent the deficits are persistent or progressing remains unknown.