Impaired creative cognition after surgery for an IDH-mutated glioma: A proof-of-concept study.

Assessment of high cognitive functions, such as creativity, is often overlooked in medical practice. However, it is crucial to understand the impact of brain tumors, specifically low-grade gliomas, on creative cognition, as these tumors predominantly affect brain regions associated with cognitive creativity. In this study, we investigated creative cognition using the Alternative Uses Task (AUT) and the Combination of Associates Task (CAT) in a cohort of 29 patients who underwent brain surgery for a low-grade glioma, along with 27 control participants. While the group of patients did not exhibit deficits in clinical neuropsychological assessments, our results revealed significant impairment in generating original and creative ideas compared to the control group. Furthermore, when analyzing the specific brain regions affected by the tumors, patients with lesions overlapping the left rostro-lateral prefrontal cortex, a critical region for creativity, displayed more pronounced impairments in the CAT compared to patients with lesions outside this region. These findings provide proof of concept that patients can experience impaired creative cognition following surgery for low-grade glioma, highlighting the importance of assessing higher-order cognitive functions, including creativity, in neurosurgical patients. Moreover, beyond its clinical relevance, our study contributes to advancing our understanding of the neuroscience of creativity.

Present bias in economic choice demonstrates increased cognitive fatigability of glioma patients.

Fatigue is a frequent symptom in many clinical conditions that is still poorly understood despite having a major impact on quality of life. Here, we propose a novel approach using model-based analysis of choice behaviour to extract fatigue markers. We applied this approach to the case of low-grade glioma, with the aim of testing the hypothesis that fatigability in this condition may manifest as limited control over choice impulsivity. Patients with intact or resected glioma (n = 29) and matched healthy controls (n = 27) performed a series of behavioural tasks included in a 4 h-long neuropsychological assessment. Intertemporal choices, opposing smaller-sooner to larger-later monetary rewards, were intermixed with tasks designed to test cognitive and motor performance and to assess perceived fatigue with subjective ratings. All dependent variables were analysed with generalised linear models testing the main effects of group and time-on-task, as well as their interaction. While absent in standard measures of fatigue (subjective rating and objective performance), a significant group-by-time interaction was observed in the rate of impulsive choices: contrary to controls, patients developed a preference for the smaller-sooner option in the course of neuropsychological assessment. This preference shift was captured by computational modelling as an increase in the present bias, a parameter that assigns an additive bonus to immediate rewards. Thus, choice impulsivity was the only reliable marker that reflected the enhanced fatigability of patients relative to controls. These results suggest that the impact of glioma (or its resection) on brain functioning limits the exertion of cognitive control during decision-making. More generally, they pave the way to using model-based analysis of choice behaviour for future investigations of the many clinical conditions plagued with cognitive fatigue.

Group-level stability but individual variability of neurocognitive status after awake resections of right frontal IDH-mutated glioma.

Awake surgery for low-grade gliomas is currently considered the best procedure to improve the extent of resection and guarantee a "worth living life" for patients, meaning avoiding not only motor but also cognitive deficits. However, tumors located in the right hemisphere, especially in the right frontal lobe, are still rarely operated on in awake condition; one of the reasons possibly being that there is little information in the literature describing the rates and nature of long-lasting neuropsychological deficits following resection of right frontal glioma. To investigate long-term cognitive deficits after awake surgery in right frontal IDH-mutated glioma. We retrospectively analyzed a consecutive series of awake surgical resections between 2012 and 2020 for right frontal IDH-mutated glioma. We studied the patients' subjective complaints and objective neuropsychological evaluations, both before and after surgery. Our results were then put in perspective with the literature. Twenty surgical cases (including 5 cases of redo surgery) in eighteen patients (medium age: 42.5 [range 26-58]) were included in the study. The median preoperative volume was 37 cc; WHO grading was II, III and IV in 70%, 20%, and 10% of cases, respectively. Preoperatively, few patients had related subjective cognitive or behavioral impairment, while evaluations revealed mild deficits in 45% of cases, most often concerning executive functions, attention, working memory and speed processing. Immediate postoperative evaluations showed severe deficits of executive functions in 75% of cases but also attentional deficits (65%), spatial neglect (60%) and behavioral disturbances (apathy, aprosodia/amimia, emotional sensitivity, anosognosia). Four months after surgery, although psychometric z-scores were unchanged at the group level, individual evaluations showed a slight decrease of performance in 9/20 cases for at least one of the following domains: executive functions, speed processing, attention, semantic cognition, social cognition. Our results are generally consistent with those of the literature, confirming that the right frontal lobe is a highly eloquent area and suggesting the importance of operating these patients in awake conditions.

Network-level causal analysis of set-shifting during trail making test part B: A multimodal analysis of a glioma surgery case.

The trail making test part B (TMT-B) is one of the most widely used task for the assessment of set-shifting ability in patients. However, the set of brain regions impacting TMT-B performance when lesioned is still poorly known. In this case report, we provide a multimodal analysis of a patient operated on while awake for a diffuse low-grade glioma located in the right supramarginal gyrus. TMT-B performance was probed intraoperatively. Direct electrical stimulation of the white matter in the depth of the resection generated shifting errors. Using the recent methodology of axono-cortical-evoked potentials (ACEP), we demonstrated that the eloquent fibers were connected to the posterior end of the middle temporal gyrus (MTG). This was further confirmed by a tractography analysis of the postoperative diffusion MRI. Finally, the functional connectivity maps of this MTG seed were assessed in both pre- and post-operative resting state MRI. These maps matched with the Control network B (13th) and Default B (17th) from the 17-networks parcellation of (Yeo et al., 2011). Last but not least, we showed that the dorsal attention B (6th), the control A & B networks (12th and 13th) and the default A (16th) have been preserved here but disconnected after a more extensive resection in a previous glioma case within the same area, and in whom TMT-B was definitively impaired. Taken together, these data support the need of a network-level approach to identify the neural basis of the TMT-B and point to the Control network B as playing an important role in set-shifting.