ObjectivesAdvances in therapeutic schemes for High Grade Gliomas, such as the introduction of Stupp protocol, have raised interest in elucidating its effects on quality of life and cognitive function. This study aims to examine executive functions, memory and attention in patients with High Grade Gliomas, before initiation and after completion of Stupp protocol. Patients and methodsA before-after study was executed. Patients were selected from a consecutive sample of subjects with High Grade Gliomas who had not initiated Stupp protocol. Neuropsi - Attention and Memory test (Second edition) was employed to evaluate subjects. Inferential analysis was conducted with Bayesian Mixed Effects Model for repeated measures, using a contrast coding scheme for estimating the change between mean neurocognitive scores obtained before and after Stupp protocol. Model was fitted employing random-effect predictors accounting for concomitant administration of bevacizumab and anticonvulsants, and by-subject performance variability. As excluding patients who did not complete Stupp protocol might bias results, complementary analyses were conducted for determining if those were consistent in alternative scenarios. ResultsTwenty-nine patients were included; 17 (58.6%) completed Stupp protocol and both neuropsychological evaluations. Inside Fixed Effects Model, 95% credible intervals for all cognitive functions crossed the zero threshold (No change); however, in all Mixed Effects Models, credible intervals for memory and attention did not cross zero. ConclusionResults showed significant recovery in memory and attention functions after treatment and suggest a confounding role for co-administered treatments and other factors related to subject cognitive performance variability. Nevertheless, these findings need to be corroborated with additional studies including more representative samples.