Presurgical Identification of Patients With Glioblastoma at Risk for Cognitive Impairment at 3-Month Follow-up

Predicting Cognitive Functioning for Patients with a High-Grade Glioma: Evaluating Different Representations of Tumor Location in a Common Space

Cognitive functioning is increasingly considered when making treatment decisions for patients with a brain tumor in view of a personalized onco-functional balance. Ideally, one can predict cognitive functioning of individual patients to make treatment decisions considering this balance. To make accurate predictions, an informative representation of tumor location is pivotal, yet comparisons of representations are lacking. Therefore, this study compares brain atlases and principal component analysis (PCA) to represent voxel-wise tumor location. Pre-operative cognitive functioning was predicted for 246 patients with a high-grade glioma across eight cognitive tests while using different representations of voxel-wise tumor location as predictors. Voxel-wise tumor location was represented using 13 different frequently-used population average atlases, 13 randomly generated atlases, and 13 representations based on PCA. ElasticNet predictions were compared between representations and against a model solely using tumor volume. Preoperative cognitive functioning could only partly be predicted from tumor location. Performances of different representations were largely similar. Population average atlases did not result in better predictions compared to random atlases. PCA-based representation did not clearly outperform other representations, although summary metrics indicated that PCA-based representations performed somewhat better in our sample. Representations with more regions or components resulted in less accurate predictions. Population average atlases possibly cannot distinguish between functionally distinct areas when applied to patients with a glioma. This stresses the need to develop and validate methods for individual parcellations in the presence of lesions. Future studies may test if the observed small advantage of PCA-based representations generalizes to other data.

Cognitive functioning in untreated glioma patients: The limited predictive value of clinical variables

BACKGROUND

Previous research identified many clinical variables that are significantly related to cognitive functioning before surgery. It is not clear whether such variables enable accurate prediction for individual patients' cognitive functioning because statistical significance does not guarantee predictive value. Previous studies did not test how well cognitive functioning can be predicted for (yet) untested patients. Furthermore, previous research is limited in that only linear or rank-based methods with small numbers of variables were used.

METHODS

We used various machine learning models to predict preoperative cognitive functioning for 340 patients with glioma across 18 outcome measures. Predictions were made using a comprehensive set of clinical variables as identified from the literature. Model performances and optimized hyperparameters were interpreted. Moreover, Shapley additive explanations were calculated to determine variable importance and explore interaction effects.

RESULTS

Best-performing models generally demonstrated above-random performance. Performance, however, was unreliable for 14 out of 18 outcome measures with predictions worse than baseline models for a substantial number of train-test splits. Best-performing models were relatively simple and used most variables for prediction while not relying strongly on any variable.

CONCLUSIONS

Preoperative cognitive functioning could not be reliably predicted across cognitive tests using the comprehensive set of clinical variables included in the current study. Our results show that a holistic view of an individual patient likely is necessary to explain differences in cognitive functioning. Moreover, they emphasize the need to collect larger cross-center and multimodal data sets.

Baseline neurocognitive dysfunction is ubiquitous in intrinsic brain tumors- results from a large Indian cohort of patients and analysis of factors associated with domain-specific dysfunction

Background

Neurocognitive function (NCF) before surgery is an important marker of baseline performance in patients with brain tumors. Increasingly, neurocognitive deficits (NCD) have been demonstrated in a high proportion of patients. Selection bias (patient, tumor, and surgical procedure related) may influence the prevalence and type of domains involved in patients with gliomas.

Methods

We evaluated baseline NCF in a consecutive cohort of intra-axial tumors in Indian patients (n = 142). A comprehensive battery evaluating five domains - attention & executive function (EF), memory, language, visuospatial function and visuomotor abilities was used. Deficits were categorized as severe and mild-moderate. Factors associated with severe NCD were evaluated.

Results

Severe NCD was present in 90% of the patients, 70% of them having affection of at least 2 domains. Attention-EF, memory and visuomotor speed were most affected. 132 underwent surgery (69 awake, 63 under general anesthesia - GA). The awake cohort had younger patients with lower grade gliomas and more left sided tumors. Multi-domain dysfunction was seen almost equally in awake/GA groups as well as left/right sided tumors. On multivariate analysis, older age, lower educational status and larger tumor volume adversely affected NCF in many of the domains. Only language dysfunction was location specific (temporal lobe tumors) though not laterality (left/right) specific.

Conclusions

NCD were seen in a large majority of cases before surgery, including those undergoing awake surgery. Language may be affected even in tumors in the non-dominant hemisphere. Attention-EF and memory are most affected and need to be factored in while assessing patient performance intraoperatively during awake surgery as well as tailoring rehabilitative measures subsequently.

Foundations of Neuropsychology: Collaborative Care in Neurosurgery

The disciplines of neuropsychology and neurosurgery have a history of partnership that has improved prognoses for patients with neurologic diagnoses that once had poor outcomes. This article outlines the evolution of this relationship and describes the current role that clinical neuropsychology has within a department of neurological surgery across the preoperative, intraoperative, and postoperative stages of treatment. Understanding the foundations of collaboration between neuropsychology and neurosurgery contextualizes present challenges and future innovations for advancing excellence along the continuum of care for all neurosurgical patients.

A Prospective Study of Longitudinal Risks of Cognitive Deficit for People Undergoing Glioblastoma Surgery Using a Tablet Computer Cognition Testing Battery: Towards Personalized Understanding of Risks to Cognitive Function

Glioblastoma and the surgery to remove it pose high risks to the cognitive function of patients. Little reliable data exist about these risks, especially postoperatively before radiotherapy. We hypothesized that cognitive deficit risks detected before surgery will be exacerbated by surgery in patients with glioblastoma undergoing maximal treatment regimens. We used longitudinal electronic cognitive testing perioperatively to perform a prospective, longitudinal, observational study of 49 participants with glioblastoma undergoing surgery. Before surgery (A1), the participant risk of deficit in 5/6 cognitive domains was increased compared to normative data. Of these, the risks to Attention (OR = 31.19), Memory (OR = 97.38), and Perception (OR = 213.75) were markedly increased. These risks significantly increased in the early period after surgery (A2) when patients were discharged home or seen in the clinic to discuss histology results. For participants tested at 4-6 weeks after surgery (A3) before starting radiotherapy, there was evidence of risk reduction towards A1. The observed risks of cognitive deficit were independent of patient-specific, tumour-specific, and surgery-specific co-variates. These results reveal a timeframe of natural recovery in the first 4-6 weeks after surgery based on personalized deficit profiles for each participant. Future research in this period could investigate personalized rehabilitation tools to aid the recovery process found.

T2 FLAIR Hyperintensity Volume Is Associated With Cognitive Function and Quality of Life in Clinically Stable Patients With Lower Grade Gliomas

Survival outcomes for patients with lower grade gliomas (LrGG) continue to improve. However, damage caused both by tumor growth and by the consequences of treatment often leads to significantly impaired cognitive function and quality of life (QoL). While neuropsychological testing is not routine, serial clinical MRIs are standard of care for patients with LrGG. Thus, having a greater understanding of MRI indicators of cognitive and QoL impairment risk could be beneficial to patients and clinicians. In this work we sought to test the hypothesis that in clinically stable LrGG patients, T2 FLAIR hyperintensity volumes at the time of cognitive assessment are associated with impairments of cognitive function and QoL and could be used to help identify patients for cognitive and QoL assessments and interventions. We performed anatomical MR imaging, cognitive testing and QoL assessments cross-sectionally in 30 clinically stable grade 2 and 3 glioma patients with subjective cognitive concerns who were 6 or more months post-treatment. Larger post-surgical T2 FLAIR volume at testing was significantly associated with lower cognitive performance, while pre-surgical tumor volume was not. Older patients had lower cognitive performance than younger patients, even after accounting for normal age-related declines in performance. Patients with Astrocytoma, IDH mutant LrGGs were more likely to show lower cognitive performance than patients with Oligodendroglioma, IDH mutant 1p19q co-deleted LrGGs. Previous treatment with combined radiation and chemotherapy was associated with poorer self-reported QoL, including self-reported cognitive function. This study demonstrates the importance of appreciating that LrGG patients may experience impairments in cognitive function and QoL over their disease course, including during periods of otherwise sustained clinical stability. Imaging factors can be helpful in identifying vulnerable patients who would benefit from cognitive assessment and rehabilitation.

The APOE ε4 allele in relation to pre- and postsurgical cognitive functioning of patients with primary brain tumors

BACKGROUND

Recent studies suggest a relationship between the APOE ε4 allele and cognitive outcome in patients treated for malignant brain tumors. Still, longitudinal investigations that include a pretreatment cognitive assessment are lacking and APOE's effects in patients with benign tumors are understudied. This study investigated presurgical cognitive performance and postsurgical change in ε4-carrying and non-carrying patients with glioma and meningioma.

METHODS

Neuropsychological test scores (CNS Vital Signs battery [seven measures], Digit Span Forward/Backward, Letter Fluency test) were obtained as part of a prospective study in which patients with meningioma and glioma underwent cognitive assessment 1 day before (T0, n = 505) and 3 (T3, n = 418) and 12 months after (T12, n = 167) surgery. APOE isoforms were identified retrospectively. ε4 carriers and non-carriers were compared with regard to pretreatment cognitive performance on the group and individual level. Changes in performances over time were compared with longitudinal mixed model analysis in the total sample and the subgroup receiving adjuvant treatment.

RESULTS

Carriers and non-carriers did not differ with regard to pretreatment performance. No significant main effect of ε4 carrier status or interaction between time (T0-T12) and carrier status was found on any of the tests in the whole sample nor in the sample receiving adjuvant treatment.

CONCLUSIONS

This study found no evidence of increased vulnerability for pretreatment cognitive dysfunction or cognitive decline within 1 year after surgery in APOE ε4-carrying meningioma and glioma patients. Investigations that include larger samples at longer-term follow-up are recommended to investigate potential late treatment effects.