Subjective, but not objective, language functions predict fatigue in patients with lower-grade gliomas during longitudinal follow-up

PURPOSE

To investigate the course of fatigue, subjective and objective language functions in patients with lower-grade gliomas during the first year of disease. Further, to examine if subjective and objective language variables predicted ratings of fatigue.

METHODS

Fatigue was assessed with the Fatigue Severity Scale, subjective language with self-reported word-finding, expression of thoughts, reading and writing from the Functional Assessment of Cancer Therapy - Brain, and objective language with standardized tests. Mixed models were used to investigate changes in variables over time and predictors of fatigue.

RESULTS

Twenty-three patients with gliomas (WHO 1-3) were included. Average ratings of fatigue did not change significantly, but altering patterns were observed. Subjective concerns about word-finding and expression of thoughts increased significantly during follow-up. The regression analyses showed that concerns about abilities to read and write significantly predicted fatigue. The results indicated that less concerns about reading and writing were associated with lower levels of fatigue.

CONCLUSIONS

Patients with lower-grade gliomas report fatigue and language concerns throughout the first year. Concerns about reading and writing call for careful consideration as they seem to provoke fatigue. The findings underline the importance of the patients' perspective in treatment and follow-up.

Self- and informant-reported cognitive concerns associated with primary brain tumour: systematic review

PURPOSE

People with primary brain tumour (PBT) experience objective cognitive impairment, but subjective cognitive concerns have received less attention. This review sought to determine the type of self- and informant-reported cognitive concerns following PBT and to ascertain if they vary according to patient, tumour and/or treatment characteristics. Further objectives were to determine whether subjective reports aligned with objective findings or informant reports.

METHODS

Literature searches were conducted using PsycINFO and Medline, limited to English-language and full-text format. Studies focusing on non-PBTs, objective cognition without subjective reports, or paediatric PBT were excluded.

RESULTS

Eleven studies were included, representing the cognitive concerns of 957 PBT participants, with varying tumour types/treatment, and ranging from pre-surgery to an average of 5 years post-diagnosis. Subjective concerns regarding global perceived cognitive impairment, language, memory, executive function, and attention were common, but change in processing speed, visual function, and reading/spelling were also reported. Few studies investigated factors impacting subjective cognition, but there was some suggestion that left-lateralised and larger tumours resulted in more subjective concerns. The alignment between objective and subjective cognition varied, ranging from strong to weak, whereas the overlap between patient and informant reports was robust.

CONCLUSIONS

Identifying the alignment between patient and informant reports is of significant benefit when considering treatment interventions and outcomes for people with PBT, particularly in instances where they may not be able to report their cognitive concerns. Overall, the importance of the patient perspective was highlighted, which can often be replaced by objective measures in clinical research.

Congress of Neurological Surgeons systematic review and evidence-based guidelines for the role of surgery in the management of patients with diffuse low grade glioma: update

Target populationAdults with imaging suggestive of a WHO grade II diffuse gliomas (oligodendrogliomas or astrocytomas)QuestionIn adults with imaging suggestive of a WHO grade II diffuse gliomas (oligodendrogliomas or astrocytomas), does surgical resection improve overall survival compared to observation or biopsy?Updated Recommendation from the Prior Version of These Guidelines:Level III: In adults with imaging suggestive of a WHO grade II diffuse gliomas (oligodendrogliomas or astrocytomas), surgical resection is suggested over observation or biopsy to improve overall survival.Question Q2In adults with imaging suggestive of a WHO grade II diffuse gliomas (oligodendrogliomas or astrocytomas), does maximal surgical resection improve progression free survival (PFS) and overall survival (OS) compared to subtotal resection/biopsy?Unchanged Recommendations from the Prior Version of These GuidelinesLevel II It is recommended that GTR or STR be accomplished instead of biopsy alone when safe and feasible so as to decrease the frequency of tumor progression recognizing that the rate of progression after GTR is fairly high.Level III Greater extent of resection can improve OS in WHO grade II diffuse gliomas patients. New RecommendationsLevel III: It is suggested that extent of resection be maximized as is safely possible for IDH mutant and IDHwt WHO grade II diffuse gliomas. to improve PFS and OS. Level III: There is insufficient evidence that greater extent of resection of 1p19q codeleted oligodendrogliomas (WHO grade II diffuse gliomas) improves OS Question Q3In adults with imaging suggestive of a WHO grade II diffuse gliomas (oligodendrogliomas or astrocytomas), does the addition of intraoperative MRI and/or intraoperative ultrasound during surgery improve extent of resection?Unchanged Recommendation from the Prior Version of These GuidelinesLevel III: The use of intraoperative MRI is suggested to increase the extent of resection for adults with WHO grade II diffuse glioma.New RecommendationLevel III: The use of intraoperative ultrasound is suggested to increase the extent of resection compared to conventional surgery for adults with WHO grade II diffuse glioma.Question 4In adults with imaging suggestive of a WHO grade II diffuse glioma (oligodendrogliomas or astrocytomas) with seizures, does maximal surgical resection improve seizure control compared to observation or subtotal resection/biopsy?Updated Recommendation from the Prior Version of These GuidelinesLevel III: In adults with imaging consistent with a WHO Grade II diffuse glioma who present with seizure activity, surgical resection of greater than 90% of the lesion, when it can be accomplished safely, is suggested over observation or lesser extent of resection/biopsy to improve seizure control.New Questions and RecommendationsQuestion 5In adults with imaging suggestive of a WHO grade II diffuse glioma (oligodendrogliomas or astrocytomas), does use of intraoperative fluorescent guided surgery improve extent of resection?RecommendationLevel III: Intraoperative fluorescent guided surgery with 5-ALA is not suggested to improve the extent of resection for WHO grade II gliomas.Question 6In adults with imaging suggestive of a WHO grade II diffuse glioma (oligodendrogliomas or astrocytomas) in eloquent brain cortex, does awake craniotomy or other methods of intraoperative mapping increase extent of resection compared to conventional surgery without these techniques?RecommendationLevel III: It is suggested that awake craniotomy and other methods of intraoperative mapping can be used to increase the extent of resection for adults with WHO grade II diffuse glioma.Question 7In adults with imaging suggestive of a WHO grade II diffuse glioma (oligodendrogliomas or astrocytomas) in eloquent brain cortex, does use of advanced preoperative imaging modalities in the form of fMRI and/or DTI decrease surgical morbidity?RecommendationLevel III: The use of functional MRI and DTI related modalities are suggested to decrease surgical morbidity in adults with WHO grade II diffuse glioma.

Disfluencies in spontaneous speech in persons with low-grade glioma before and after surgery

Impaired lexical retrieval is common in persons with low-grade glioma (LGG). Several studies have reported a discrepancy between subjective word-finding difficulties and results on formal tests. Analysis of spontaneous speech might be more sensitive to signs of word-finding difficulties, hence we aimed to explore disfluencies in a spontaneous-speech task performed by participants with presumed LGG before and after surgery. Further, we wanted to explore how the presence of disfluencies in spontaneous speech differed in the participants with and without objectively established lexical-retrieval impairment and with and without self-reported subjective experience of impaired language, speech and communication. Speech samples of 26 persons with presumed low-grade glioma were analysed with regard to disfluency features. The post-operative speech samples had a higher occurrence of fillers, implying more disfluent language production. The participants performed worse on two of the word fluency tests, and after surgery the number of participants who were assessed as having an impaired lexical retrieval had increased from 6 to 12. The number of participants who experienced a change in their language, speech or communication had increased from 9 to 12. Additional comparisons showed that those with impaired lexical retrieval had a higher proportion of false starts after surgery than those with normal lexical retrieval, and differences in articulation rate and speech rate, favouring those not having experienced any change in language, speech or communication. Taken together, the findings from this study strengthen the existing claim that temporal aspects of language and speech are important when assessing persons with gliomas.

Understanding language and cognition after brain surgery - Tumour grade, fine-grained assessment tools and, most of all, individualized approach

Cognitive performance influences the quality of life and survival of people with glioma. Thus, a detailed neuropsychological and language evaluation is essential. In this work, we tested if an analysis of errors in naming can indicate semantic and/or phonological impairments in 87 awake brain surgery patients. Secondly, we explored how language and cognition change after brain tumour resection. Finally, we checked if low-tumour grade had a protective effect on cognition. Our results indicated that naming errors can be useful to monitor semantic and phonological processing, as their number correlated with scores on tasks developed by our team for testing these domains. Secondly, we showed that - although an analysis at a whole group level indicates a decline in language functions - significantly more individual patients improve or remain stable when compared to the ones who declined. Finally, we observed that having LGG, when compared with HGG, favours patients' outcome after surgery, most probably due to brain plasticity mechanisms. We provide new evidence of the importance of applying a broader neuropsychological assessment and an analysis of naming errors in patients with glioma. Our approach may potentially ensure better detection of cognitive deficits and contribute to better postoperative outcomes. Our study also shows that an individualized approach in post-surgical follow-ups can reveal reassuring results showing that significantly more patients remain stable or improve and can be a promising avenue for similar reports. Finally, the study captures that plasticity mechanisms may act as protective in LGG versus HGG after surgery.

Differential contribution of language and executive functioning to verbal fluency performance in glioma patients

Glioma patients often suffer from deficits in language and executive functioning. Performance in verbal fluency (generating words within one minute according to a semantic category-category fluency, or given letter-letter fluency) is typically impaired in this patient group. While both language and executive functioning play a role in verbal fluency, the relative contribution of both domains remains unclear. We aim to retrospectively investigate glioma patients' performance on verbal and nonverbal fluency and to explore the influence of language and executive functioning on verbal fluency. Sixty-nine adults with gliomas in eloquent areas underwent a neuropsychological test battery (verbal fluency, nonverbal fluency, language, and executive functioning tests) before surgery (T1) and a subgroup of 31 patients also at three (T2) and twelve months (T3) after surgery. Preoperatively, patients were impaired in all verbal fluency tasks and dissociations were found based on tumour location. In contrast, nonverbal fluency was intact. Different language and executive functioning tests predicted performance on category fluency animals and letter fluency, while no significant predictors for category fluency professions were found. The longitudinal results indicated that category fluency professions deteriorated after surgery (T1-T2, T1-T3) and that nonverbal fluency improved after surgery (T1-T3, T2-T3). Verbal fluency performance can provide information on different possible underlying deficits in language and executive functioning in glioma patients, depending on verbal fluency task selection. Efficient task (order) selection can be based on complexity. Category fluency professions can be selected to detect more permanent long-term deficits.

Neurorehabilitation for Adults with Brain and Spine Tumors

Central nervous system (CNS) malignancies (i.e. brain and spine tumors) and their treatments can result in a multitude of neurologic deficits. Patients with CNS malignancies experience physical, cognitive, and psychosocial sequelae that can impact their mobility and quality of life. Neurorehabilitation can play a critical role in maintaining independence, preventing disability, and optimizing safety with activities of daily living. This review provides an overview of the neurorehabilitation approaches for patients with CNS malignancies, neurologic impairments frequently treated, and rehabilitation interventions in various health care settings. In addition, we will highlight rehabilitative outcomes between patients with nononcologic neurologic conditions compared to brain and spine tumors. Finally, we address medical challenges that may impact rehabilitation care in these medically complex cancer patients.

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.

Magnetic Resonance Tractography and Intraoperative Direct Electrical Stimulation in Eloquent Area Glioma Surgery for 102 Cases: A Tertiary Care Center Experience From Northwest India

OBJECTIVE

Surgery of eloquent area gliomas is challenging and requires monitoring of the nearby white fiber tracts. In the present study, we analyzed 102 patients with eloquent region gliomas and discussed the concept of intraoperative dynamic white fiber tract navigation and monitoring.

METHODS

A total of 102 patients with an eloquent area glioma (52 insular, 29 motor area, 21 temporoparietal) were evaluated. The position of the white fiber tracts (corticospinal tract [or motor fiber; CST], inferior fronto-occipital fasciculus [ventral language fiber; IFOF], superior longitudinal fasciculus [SLF], and arcuate fasciculus [dorsal language fiber; AF) was recorded. Awake mapping of the cortical and subcortical eloquent structures was performed for all 102 patients. The suction stimulator was coregistered and used as a dynamic stimulator navigator.

RESULTS

Of the 102 patients, 60 were men and 42 were women, with an average age of 39.8 years. Most of the white fiber tracts were normal (CST, 31.3%; IFOF, 39.2%; SLF/AF, 40.19%) or displaced (CST, 59.8%; IFOF, 47.05%; AF/SLF, 44.11%). A few were disrupted (CST, 8.8%; IFOF, 13.7%; SLF/AF, 15.7%). The extent of tumor resection was 82.8%, 86.5%, and 94% for those with insular glioma, motor area glioma, and temporoparietal glioma, respectively. Of the 102 patients, 18 had developed transient speech and language disturbances with improvement, and 14 had developed motor deficits, of whom, all except for 2, had shown gradual improvement. When the dynamic suction stimulator navigator was used, the extent of resection was 96.5%, without any added deficits.

CONCLUSIONS

The use of intraoperative neuronavigation and neurophysiological assessment can help achieve maximal tumor resection of eloquent area gliomas. Use of the integrated suction stimulator navigator provided dynamic navigation and mapping of the peritumoral eloquent fibers.

Cognitive issues in patients with IDH mutant gliomas: from neuroscience to clinical neuropsychology

PURPOSE

The understanding of cognitive symptoms in patients with IDH-Mutant gliomas (IDH-Mut) is rapidly developing. In this article, we summarize the neuroscientific knowledge base regarding the influence of IDH-Mut tumors and their treatment on cognition and provide guidance regarding the management of these symptoms in patients.

METHODS

We performed a review of peer reviewed publications relevant to IDH-Mut glioma and cognitive outcomes and provide an overview of the literature as well as a case example to clarify management strategies.

RESULTS

At the time of presentation, patients with IDH-Mut gliomas have a favorable cognitive profile as compared with those with IDH-wild type (WT) tumors. The relatively low cognitive burden may reflect the slower growth rate of IDH-Mut tumors, which is less disruptive to both local and widespread neural networks. Human connectomic research using a variety of modalities has demonstrated relatively preserved network efficiency in patients with IDH-Mut gliomas as compared with IDH-WT tumors. Risk of cognitive decline from surgery can potentially be mitigated by careful integration of intra-operative mapping. Longer term cognitive risks of tumor treatment, including chemotherapy and radiation, are best managed by instituting neuropsychological assessment as part of the long-term care of patients with IDH-Mutant glioma. A specific timeline for such integrative care is provided.

CONCLUSIONS

Given the relative recency of the IDH-mutation based classification of gliomas, as well as the long time course of this disease, a thoughtful and comprehensive strategy to studying patient outcomes and devising methods of cognitive risk reduction is required.

The clinical and neurocognitive functional changes with awake brain mapping for gliomas invading eloquent areas: Institutional experience and the utility of The Montreal Cognitive Assessment

OBJECTIVE

Awake craniotomy with intraoperative brain functional mapping effectively reduces the potential risk of neurological deficits in patients with glioma invading the eloquent areas. However, glioma patients frequently present with impaired neurocognitive function. The present study aimed to investigate the neurocognitive and functional outcomes of glioma patients after awake brain mapping and assess the experience of a tertiary neurosurgical center in China over eight years.

METHODS

This retrospective study included 80 patients who underwent awake brain mapping for gliomas invading the eloquent cortex between January 2013 and December 2021. Clinical and surgical factors, such as the extent of resection (EOR), perioperative Karnofsky Performance Score (KPS), progression-free survival (PFS), and overall survival (OS), were evaluated. We also used the Montreal Cognitive Assessment (MoCA) to assess the neurocognitive status changes.

RESULTS

The most frequently observed location of glioma was the frontal lobe (33/80, 41.25%), whereas the tumor primarily invaded the language-related cortex (36/80, 45%). Most patients had supratotal resection (11/80, 13.75%) and total resection (45/80, 56.25%). The median PFS was 43.2 months, and the median OS was 48.9 months in our cohort. The transient (less than seven days) neurological deficit rate was 17.5%, whereas the rate of persistent deficit (lasting for three months) was 15%. At three months of follow-up, most patients (72/80, 90%) had KPS scores > 80. Meanwhile, compared to the preoperative baseline tests, the changes in MoCA scores presented significant improvements at discharge and three months follow-up tests.

CONCLUSION

Awake brain mapping is a feasible and safe method for treating glioma invading the eloquent cortex, with the benefit of minimizing neurological deficits, increasing EOR, and extending survival time. The results of MoCA test indicated that brain mapping plays a critical role in preserving neurocognitive function during tumor resection.

Speech and Language Errors during Awake Brain Surgery and Postoperative Language Outcome in Glioma Patients: A Systematic Review

Awake craniotomy with direct electrical stimulation (DES) is the standard treatment for patients with gliomas in eloquent areas. Even though language is monitored carefully during surgery, many patients suffer from postoperative aphasia, with negative effects on their quality of life. Some perioperative factors are reported to influence postoperative language outcome. However, the influence of different intraoperative speech and language errors on language outcome is not clear. Therefore, we investigate this relation. A systematic search was performed in which 81 studies were included, reporting speech and language errors during awake craniotomy with DES and postoperative language outcomes in adult glioma patients up until 6 July 2020. The frequencies of intraoperative errors and language status were calculated. Binary logistic regressions were performed. Preoperative language deficits were a significant predictor for postoperative acute (OR = 3.42, p < 0.001) and short-term (OR = 1.95, p = 0.007) language deficits. Intraoperative anomia (OR = 2.09, p = 0.015) and intraoperative production errors (e.g., dysarthria or stuttering; OR = 2.06, p = 0.016) were significant predictors for postoperative acute language deficits. Postoperatively, the language deficits that occurred most often were production deficits and spontaneous speech deficits. To conclude, during surgery, intraoperative anomia and production errors should carry particular weight during decision-making concerning the optimal onco-functional balance for a given patient, and spontaneous speech should be monitored. Further prognostic research could facilitate intraoperative decision-making, leading to fewer or less severe postoperative language deficits and improvement of quality of life.

The need to consider return to work as a main outcome in patients undergoing surgery for diffuse low-grade glioma: a systematic review

OBJECTIVE

For a long time, return to work (RTW) has been neglected in patients harboring a diffuse low-grade glioma (LGG). However, a majority of LGG patients worked at time of diagnosis. Moreover, these patients now live longer given current treatment paradigms, especially thanks to early maximal surgery.

METHODS

We systematically searched available medical databases for studies that reported data on RTW in patients who underwent resection for LGG.

RESULTS

A total of 30 studies were selected: 19 considered RTW (especially rate and timing) as an outcome and 11 used scales of health-related quality of life (HRQoL) which included work-related aspects. Series that considered RTW as a main endpoint were composed of 1014 patients, with postoperative RTW rates ranging from 31 to 97.1% (mean 73.1%). Timing to RTW ranged from 15 days to 22 months (mean 6.3 months). Factors related to an increased proportion of RTW were: younger age, better neurologic status, having a white-collar occupation, working pre-operatively, being the sole breadwinner, the use of awake surgery, and greater extent of resection. Female sex, older age, poor neurologic status, pre-operative history of work absences, slow lexical access speed, and postoperative seizures were negatively related to RTW. No studies that used HRQoL scales directly investigated RTW rate or timing.

CONCLUSIONS

RTW was scarcely analyzed in LGG patients who underwent resection. However, because they are usually young, with no or only mild functional deficits and have a longer life expectancy, postoperative RTW should be assessed more systematically and accurately as a main outcome. As majority (61.5-100%) of LGG patients were working at time of surgery, the responsibility of neurosurgeons is to bring these patients back to their previous activities according to his/her wishes. RTW might also be included as a critical endpoint for future prospective studies and randomized control trials on LGGs.

Influences on cognitive outcomes in adult patients with gliomas: A systematic review

People with brain tumors, including those previously treated, are commonly affected by a range of neurocognitive impairments involving executive function, memory, attention, and social/emotional functioning. Several factors are postulated to underlie this relationship, but evidence relating to many of these factors is conflicting and does not fully explain the variation in cognitive outcomes seen in the literature and in clinical practice. To address this, we performed a systematic literature review to identify and describe the range of factors that can influence cognitive outcomes in adult patients with gliomas. A literature search was performed of Ovid MEDLINE, PsychINFO, and PsycTESTS from commencement until September 2021. Of 9,998 articles identified through the search strategy, and an additional 39 articles identified through other sources, 142 were included in our review. The results confirmed that multiple factors influence cognitive outcomes in patients with gliomas. The effects of tumor characteristics (including location) and treatments administered are some of the most studied variables but the evidence for these is conflicting, which may be the result of methodological and study population differences. Tumor location and laterality overall appear to influence cognitive outcomes, and detection of such an effect is contingent upon administration of appropriate cognitive tests. Surgery appears to have an overall initial deleterious effect on cognition with a recovery in most cases over several months. A large body of evidence supports the adverse effects of radiotherapy on cognition, but the role of chemotherapy is less clear. To contrast, baseline cognitive status appears to be a consistent factor that influences cognitive outcomes, with worse baseline cognition at diagnosis/pre-treatment correlated with worse long-term outcomes. Similarly, much evidence indicates that anti-epileptic drugs have a negative effect on cognition and genetics also appear to have a role. Evidence regarding the effect of age on cognitive outcomes in glioma patients is conflicting, and there is insufficient evidence for gender and fatigue. Cognitive reserve, brain reserve, socioeconomic status, and several other variables discussed in this review, and their influence on cognition and recovery, have not been well-studied in the context of gliomas and are areas for focus in future research.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42017072976.

Presurgical cognitive status in patients with low-grade glioma and epilepsy: Testing the effects of seizures, antiseizure medications, and tumor localization

BACKGROUND

Low-grade gliomas (LGGs) are frequently associated with epilepsy. There are few studies addressing the impact of seizures, antiseizure medications (ASMs), and lesion localization on presurgery cognitive functioning.

METHODS

We tested the relation between the above-mentioned variables in a continuous series of 73 young patients (mean age 38.3 years ± 11.7) affected by LGGs and epilepsy. The anatomical areas, involved in this sample, were the left insula with surrounding cortical and subcortical areas, the right precentral gyrus/rolandic operculum, and the white matter and cortical regions beneath.

RESULTS

Patients' presurgery cognitive status was within the normal range, with borderline performance for some tasks. We tested whether lower scores were related with lesion or with epilepsy-related factors. Multiple regression identified variables that predict test scores. The Token test score was predicted by a model (p = .0078) containing the DT2T1 MRI, corrected for seizure features. Object naming performance was predicted by a model (p = .0113) containing the localization, the DT2T1 MRI, corrected for sex, EEG, and onset. Verbal fluency score was predicted by a model (p = .0056) containing the localization and the DT2T1 MRI, corrected for AEDs and EEG. Working memory score was predicted by a model (p = .0117) containing Engel class, the DT2T1 MRI, corrected for sex. Clock drawing score was predicted by a model (p < .0001) containing the Engel class, AEDs, and EEG. TMT A score was predicted by a model (p = .0022) containing localization, corrected for EEG. TMT B-A score was predicted by a model (p = .0373) containing localization. Voxel Lesion Symptom Mapping analyses carried out on patients' lesion volumes confirmed that patients' level of performance correlated with lesion-related variables.

CONCLUSION

This preliminary study indicates that the presurgical level of performance for language tasks and for cognitive flexibility and shifting is mainly predicted by lesion-related variables, working memory by both lesion and epilepsy-related variables. Epilepsy clinical and instrumental characteristics predicted performance for visuospatial planning.

Changes in Cognitive Functioning After Surgical Resection of Language-related, Eloquent-area, High-grade Gliomas Under Awake Craniotomy

BACKGROUND

Dominant-hemisphere tumors, especially gliomas, as infiltrative tumors, frequently affect cognitive functioning. Establishing a balance between extensive resection, which is proven to result in longer survival, and less extensive resection, in order to maintain more cognitive abilities, is challenging.

OBJECTIVE

To evaluate changes in cognitive functioning before and after surgical resection of language-related, eloquent-area, high-grade gliomas under awake craniotomy.

METHOD

We provided individuals with newly diagnosed high-grade gliomas of the language-related eloquent areas with the same standard of care, including surgical resection of the glioma using intraoperative sensory-motor and cognitive mapping under awake craniotomy, and the same protocol for chemoradiotherapy. Cognitive functioning was assessed using Addenbrooke's Cognitive Examination-Revised (ACE-R) at four time points (preoperatively, early after surgery, and 3 and 6 months postoperatively).

RESULTS

The preoperative evaluation revealed a range of cognitive impairments in 70.7% of the individuals, affecting all of the cognitive subdomains (mostly attention and visuospatial abilities). Overall cognitive functioning (ie, ACE-R score) dropped by 13.5% (P= 0.169) early postoperatively. At the 3-month evaluation, an average of 15.3% (P= 0.182) recovery in cognitive functioning was observed (mostly in verbal fluency: 39.1%). This recovery improved further, reaching 29% (P< 0.001) at the 6-month evaluation. The greatest improvement occurred in verbal fluency: 68.8%,P= 0.001.

CONCLUSION

Extensive resection of eloquent-area gliomas with the aid of modern neuroimaging and neuromonitoring techniques under awake craniotomy is possible without significant long-term cognitive sequela.

Intraoperative localization and preservation of reading in ventral occipitotemporal cortex

OBJECTIVE

Resective surgery in language-dominant ventral occipitotemporal cortex (vOTC) carries the risk of causing impairment to reading. Because it is not on the lateral surface, it is not easily accessible for intraoperative mapping, and extensive stimulation mapping can be time-consuming. Here the authors assess the feasibility of using task-based electrocorticography (ECoG) recordings intraoperatively to help guide stimulation mapping of reading in vOTC.

METHODS

In 11 patients undergoing extraoperative, intracranial seizure mapping, the authors recorded induced broadband gamma activation (70-150 Hz) during a visual category localizer. In 2 additional patients, whose pathologies necessitated resections in language-dominant vOTC, task-based functional mapping was performed intraoperatively using subdural ECoG alongside direct cortical stimulation.

RESULTS

Word-responsive cortex localized using ECoG showed a high sensitivity (72%) to stimulation-induced reading deficits, and the confluence of ECoG and stimulation-positive sites appears to demarcate the visual word form area. Intraoperative task-based ECoG mapping was possible in < 3 minutes, providing a high signal quality, and initial intraoperative data analysis took < 3 minutes, allowing for rapid assessment of broad areas of cortex. Cortical areas critical for reading were mapped and successfully preserved, while also enabling pathological tissue to be completely removed.

CONCLUSIONS

Eloquent cortex in ventral visual cortex can be rapidly mapped intraoperatively using ECoG. This method acts to guide high-probability targets for stimulation with limited patient participation and can be used to avoid iatrogenic dyslexia following surgery.

A New Functional Magnetic Resonance Imaging Localizer for Preoperative Language Mapping Using a Sentence Completion Task: Validity, Choice of Baseline Condition, and Test–Retest Reliability

To avoid post-neurosurgical language deficits, intraoperative mapping of the language function in the brain can be complemented with preoperative mapping with functional magnetic resonance imaging (fMRI). The validity of an fMRI “language localizer” paradigm crucially depends on the choice of an optimal language task and baseline condition. This study presents a new fMRI “language localizer” in Russian using overt sentence completion, a task that comprehensively engages the language function by involving both production and comprehension at the word and sentence level. The paradigm was validated in 18 neurologically healthy volunteers who participated in two scanning sessions, for estimating test–retest reliability. For the first time, two baseline conditions for the sentence completion task were compared. At the group level, the paradigm significantly activated both anterior and posterior language-related regions. Individual-level analysis showed that activation was elicited most consistently in the inferior frontal regions, followed by posterior temporal regions and the angular gyrus. Test–retest reliability of activation location, as measured by Dice coefficients, was moderate and thus comparable to previous studies. Test–retest reliability was higher in the frontal than temporo-parietal region and with the most liberal statistical thresholding compared to two more conservative thresholding methods. Lateralization indices were expectedly left-hemispheric, with greater lateralization in the frontal than temporo-parietal region, and showed moderate test-retest reliability. Finally, the pseudoword baseline elicited more extensive and more reliable activation, although the syllable baseline appears more feasible for future clinical use. Overall, the study demonstrated the validity and reliability of the sentence completion task for mapping the language function in the brain. The paradigm needs further validation in a clinical sample of neurosurgical patients. Additionally, the study contributes to general evidence on test–retest reliability of fMRI.

Recurrent Low-Grade Gliomas: Does Reoperation Affect Neurocognitive Functioning?

BACKGROUND

Reoperations in patients with recurrent low-grade gliomas (RLGG) were proposed to control tumor residual and delay the risk of malignant transformation over time.

OBJECTIVE

To investigate neurocognitive outcomes in patients with RLGG who underwent a second surgery with awake monitoring.

METHODS

In this retrospective study, patients who underwent a second awake surgery for RLGG were included. Patients had presurgical and 3-mo postsurgical neuropsychological assessments. Data were converted into Z-scores and combined by the cognitive domain. Number of patients with cognitive deficits (Z-score <-1.65), variations of Z-scores, and extent of resection (EOR) were analyzed.

RESULTS

Sixty-two patients were included (mean age: 41.2 ± 10.0 yr). None had permanent neurological deficits postoperatively. Eight patients (12.9%) had a cognitive deficit preoperatively. Four additional patients (6.5%) had a cognitive deficit 3 mo after reoperation. Among other patients, 13 (21.0%) had a mild decline without cognitive deficits while 29 (46.8%) had no change of their performances and 8 (12.9%) improved. Overall, 94.2% of the patients returned to work. There were no correlations between EOR and Z-scores. Total/subtotal resections were achieved in 91.9% of the patients (mean residual: 3.1 cm3). Fifty-eight patients (93.5%) were still alive after an overall follow-up of 8.3 yr.

CONCLUSION

Reoperation with awake monitoring in patients with RLGG was compatible with an early recovery of neuropsychological abilities. Four patients (6.5%) presented a new cognitive deficit at 3 mo postoperatively. Total/subtotal resections were achieved in most patients. Based on these favorable outcomes, reoperation should be considered in a more systematic way.

Large tumour volume reduction of IDH-mutated anaplastic glioma involving the insular region following radiotherapy

Background

The impact of near-total resection of IDH-mutated anaplastic glioma (IDHmutAG) is well-established but there remains uncertainty of benefit in tumours of the insular cortex where the extent of safe resection may be limited. This study aimed to assess tumour volume reduction in patients following IMRT and impact of residual post-surgical volume.

Methods and materials

Patients with IDHmutAG involving insular cortex managed with IMRT from 2008 to 2019 had baseline patient, tumour and treatment factors recorded. Volumetric assessment of residual disease on MRI was performed at baseline, month+ 3 and month+ 12 post-IMRT. Potential prognostic factors were analysed for tumour reduction and relapse-free survival, and assessed by log-rank and Cox regression analyses.

Results

Thirty two patients with IDHmutAG of the insular cortex were managed with median follow-up post-IMRT of 67.2 months. Pathology was anaplastic astrocytoma (AAmut) in 20, and anaplastic oligodendroglioma (AOD) in 12 patients. Median pre-IMRT volume on T1 and T2Flair was 24.3cm³ and 52.2cm³. Twenty-seven patients were alive with 5-year relapse-free survival of 80%. There was a median 67 and 64% reduction from baseline occurring at 3 months post-IMRT for T1 and T2Flair respectively; and subsequent median 78 and 73% at 12 months. At 12 months AOD patients had median 83% T1 volume reduction compared to 63% in AAmut (p < 0.01). There was no difference on T2Flair volume (p = 0.64). No other pathological factors influenced volume reduction at 12 months. No factors were associated with relapse-free survival including baseline T1 (p = 0.52) and T2Flair (p = 0.93) volume.

Conclusion

IMRT provides large tumour volume reduction in IDHmutAG of the insular cortex. While maximal safe debulking remains standard of care when feasible, this patient cohort reported no significant negative impact of residual disease volume on relapse-free survival.

Postacute Cognitive Rehabilitation for Adult Brain Tumor Patients

Intrinsic brain tumors often occur within functional neural networks, leading to neurological impairment and disability of varying degrees. Advances in our understanding of tumor-network integration, human cognition and language processing, and multiparametric imaging, combined with refined intraoperative tumor resection techniques, have enhanced surgical management of intrinsic brain tumors within eloquent areas. However, cognitive symptoms impacting health-related quality of life, particularly processing speed, attention, concentration, working memory, and executive function, often persist after the postoperative recovery period and treatment. Multidisciplinary cognitive rehabilitation is the standard of care for addressing cognitive impairments in many neurological diseases. There is promising research to support the use of cognitive rehabilitation in adult brain tumor patients. In this review, we summarize the history and usefulness of postacute cognitive rehabilitation for adult brain tumor patients.

Neuropsychological assessments before and after awake surgery for incidental low-grade gliomas

OBJECTIVE

Early surgery in presumed asymptomatic patients with incidental low-grade glioma (ILGG) has been suggested to improve maximal resection rates and overall survival. However, no study has reported on the impact of such preventive treatment on cognitive functioning. The aim of this study was to investigate neuropsychological outcomes in patients with ILGG who underwent preventive surgery.

METHODS

This was a retrospective analysis of a consecutive series of patients with ILGG who underwent awake surgery and who had presurgical and 3-month postsurgical neuropsychological assessments. Data were normalized into z-scores and regrouped by cognitive domains. Clinicoradiological data, histomolecular profile, and differences in z-scores (Δz-scores) were analyzed.

RESULTS

Forty-seven patients were included (mean age 39.2 ± 11.3 years). Twenty-eight patients (59.6%) underwent supratotal or total resections. All patients were still alive after a mean follow-up of 33.0 ± 30.8 months. Forty-one patients (87.2%) had stable (n = 34, 72.3%) or improved (Δz-score > 1; n = 7, 14.9%) neurocognitive outcomes after surgery. Six patients (12.8%) presented a slight impairment (Δz-score < -1) in at least one cognitive domain. The mean presurgical and postsurgical z-scores were comparable except in the psychomotor speed and attention domain. A significant correlation between presurgical executive functioning and tumor volume was reported, whereas the extent of resection and histomolecular profile did not impact neuropsychological outcomes.

CONCLUSIONS

Early surgical treatment in presumed asymptomatic patients with ILGG was associated with stable or improved neuropsychological outcomes in 87.2% of patients at 3 months, with only mild cognitive decline observed in 6 patients. In return, supratotal or total resections were achieved in most patients, and all patients were still alive at the end of the follow-up.

Neurocognitive deficits in patients suffering from glioma in speech-relevant areas of the left hemisphere

OBJECTIVE

Patients with brain tumors frequently present neurocognitive deficits. Aiming at better understanding the impact of tumor localization on neurocognitive processes, we evaluated neurocognitive function prior to glioma surgery within one of four specific regions in the left speech-dominant hemisphere.

METHODS

Between 04/2011 and 12/2019, 43 patients undergoing neurocognitive evaluation prior to awake surgery for gliomas (WHO grade I: 2; II: 6; III: 23; IV: 11) in the inferior frontal gyrus (IFG; n = 20), the anterior temporal lobe (ATL; n = 6), the posterior superior temporal region/supramarginal gyrus (pST/SMG; n = 7) or the posterior middle temporal gyrus (pMTG; n = 10) of the language dominant left hemisphere were prospectively included in the study. Cognitive performances were analyzed regarding an influence of patient characteristics and tumor localization.

RESULTS

Severe impairment in at least one neurocognitive domain was found in 36 (83.7%) patients. Anxiety and depression were observed most frequently, followed by verbal memory impairments. Verbal memory was more strongly affected in patients with ATL or pST/SMG tumors compared to IFG tumors (p = 0.004 and p = 0.013, resp.). Overall, patients suffering from tumors in the ATL were most frequently and severely impaired.

CONCLUSION

Patients suffering from gliomas involving different regions within the language dominant hemisphere frequently present impairments in neurocognitive domains also other than language. Considering individual functions at risk may help in better advising patients prior to treatment and in tailoring the individual therapeutic strategy to preserve patients' quality of life.

Assessment and Management of Cognitive Symptoms in Patients With Brain Tumors

Cognitive symptoms occur in almost all patients with brain tumors at varying points in the disease course. Deficits in neurocognitive function may be caused by the tumor itself, treatment (surgery, radiation, or chemotherapy), or other complicating factors (e.g., seizures, fatigue, mood disturbance) and can have a profound effect on functional independence and quality of life. Assessment of neurocognitive function is an important part of comprehensive care of patients with brain tumors. In the neuro-oncology clinic, assessment may include cognitive screening tools and inquiry into subjective cognitive function. Neuropsychological assessment is an important adjunct to identify cognitive symptoms and can be used as an opportunity to intervene through transformative feedback and treatment planning. Preventative measures can be taken to reduce cognitive side effects of treatment, such as awake craniotomies with intraoperative mapping during neurosurgery or prophylactic measures during radiation therapy (e.g., hippocampal avoidance, neuroprotectant treatment with memantine). Rehabilitative therapies, including cognitive rehabilitation and computerized cognitive exercise, are options for managing cognitive problems in an individualized manner. Pharmacotherapy, including use of stimulant medications and acetylcholinesterase inhibitors, has shown benefits for patients with brain tumors when tailored to an individual's cognitive profile. Identification and management of co-occurring issues, such as sleep disturbance, fatigue, and depression, can also improve neurocognitive function. There are promising therapies under development that may provide new options for treatment in the future. Integrating careful assessment and treatment of cognition throughout the disease course for patients with brain tumors can improve functional outcomes and quality of life.

Cognitive impact of lower-grade gliomas and strategies for rehabilitation

Outcomes for patients with lower-grade gliomas (LrGGs) continue to improve with advances in molecular characterization and treatment. However, cognitive sequela from the tumor and its treatment leave a significant impact on health-related quality of life for these patients. Several factors affect each patient's cognition, such as tumor location, treatment, medication, and comorbidities. However, impairments of processing speed, attention, concentration, working memory, and executive function are common across LrGG patients. Cognitive rehabilitation strategies, well established in traumatic brain injury and stroke populations, are based on neural plasticity and functional reorganization. Adapting these strategies for implementation in patients with brain tumors is an active area of research. This article provides an overview of cognitive domains commonly impaired in LrGG patients and evidence for the use of cognitive rehabilitation strategies to address these impairments with the goal of improving health-related quality of life in this patient population.

Updated perspectives on awake neurosurgery with cognitive and emotional assessment for patients with low-grade gliomas

Introduction: Thanks to early extensive surgical resection combined with medical oncological therapies, life expectancy dramatically increased in low-grade glioma (LGG), with an overall survival currently over 15 years. Therefore, patients should be able to maintain valuable family and socio-professional activities.Areas covered: For many decades, cognitive and emotional aspects were neglected by surgical and medical neurooncologists. The goal of surgery was to avoid hemiplegia and/or aphasia, with no considerations regarding behavior. However, because LGG patients live longer, they must be cognitively and affectively able to make long-term projects. Preservation of higher-order functions should be considered systematically in LGG surgery by means of awake cognitive/emotional mapping and monitoring.Expert opinion: The aim is to incorporate recent advances in neurosciences, which proposed revisited models of cerebral processing relying on a meta-network perspective, into the pre-, intra- and postoperative procedure. In this connectomal approach, brain functions result from complex interactions within and between neural networks. This improved understanding of a constant instability of the neural system allows a better cognitive/emotional assessment before and after each treatment over years, in order to preserve personality and adaptive behavior for each LGG patient, based on his/her own definition of quality of life. It is time to create oncological neurosciences.

The impact of high functional connectivity network hub resection on language task performance in adult low- and high-grade glioma

OBJECTIVE

Gliomas are intrinsic brain tumors with the hallmark of diffuse white matter infiltration, resulting in short- and long-range network dysfunction. Preoperative magnetoencephalography (MEG) can assist in maximizing the extent of resection while minimizing morbidity. While MEG has been validated in motor mapping, its role in speech mapping remains less well studied. The authors assessed how the resection of intraoperative electrical stimulation (IES)-negative, high functional connectivity (HFC) network sites, as identified by MEG, impacts language performance.

METHODS

Resting-state, whole-brain MEG recordings were obtained from 26 patients who underwent perioperative language evaluation and glioma resection that was guided by awake language and IES mapping. The functional connectivity of an individual voxel was determined by the imaginary coherence between the index voxel and the rest of the brain, referenced to its contralesional pair. The percentage of resected HFC voxels was correlated with postoperative language outcomes in tasks of increasing complexity: text reading, 4-syllable repetition, picture naming, syntax (SYN), and auditory stimulus naming (AN).

RESULTS

Overall, 70% of patients (14/20) in whom any HFC tissue was resected developed an early postoperative language deficit (mean 2.3 days, range 1-8 days), compared to 33% of patients (2/6) in whom no HFC tissue was resected (p = 0.16). When bifurcated by the amount of HFC tissue that was resected, 100% of patients (3/3) with an HFC resection > 25% displayed deficits in AN, compared to 30% of patients (6/20) with an HFC resection < 25% (p = 0.04). Furthermore, there was a linear correlation between the severity of AN and SYN decline with percentage of HFC sites resected (p = 0.02 and p = 0.04, respectively). By 2.2 months postoperatively (range 1-6 months), the correlation between HFC resection and both AN and SYN decline had resolved (p = 0.94 and p = 1.00, respectively) in all patients (9/9) except two who experienced early postoperative tumor progression or stroke involving inferior frontooccipital fasciculus.

CONCLUSIONS

Imaginary coherence measures of functional connectivity using MEG are able to identify HFC network sites within and around low- and high-grade gliomas. Removal of IES-negative HFC sites results in early transient postoperative decline in AN and SYN, which resolved by 3 months in all patients without stroke or early tumor progression. Measures of functional connectivity may therefore be a useful means of counseling patients about postoperative risk and assist with preoperative surgical planning.

Return to Work Following Surgery for Incidental Diffuse Low-Grade Glioma: A Prospective Series With 74 Patients

BACKGROUND

Therapeutic strategy concerning incidental low-grade glioma (ILGG) is still debated. Early "prophylactic" surgery has been proposed in asymptomatic patients with favorable neurological and oncological outcomes.

OBJECTIVE

To assess postoperative ability to resume employment following awake surgery in asymptomatic ILGG patients. To assess extent of resection (EOR), timeline for adjuvant oncological treatment, and survival.

METHODS

A total of 74 patients with ILGG who underwent awake surgery with intraoperative mapping were prospectively included, with a minimum follow-up of 12 mo. All clinicoradiological data were collected, and statistical correlations with return to work (RTW) were performed.

RESULTS

A total of 66 patients (97.1%) among 68 patients with preoperative professional activities resumed their employment including 62 (91.2%) within 12 mo. Mean time before RTW was 6.8 mo (median: 6 mo, range: 1-36). Two patients experienced seizure-related legal issues impacting their RTW. Clinicoradiological features did not correlate with RTW apart from postoperative seizures (P = .02). Mean EOR was 95.7%. A total of 43 patients (58.1%) underwent supratotal/total resections. All patients recovered from transient deficits at 3 mo. No patients received consecutive adjuvant treatment. A total of 24 patients (32.4%) were reoperated, 24 patients received chemotherapy, and 7 patients (9.5%) received radiotherapy, on average 73.1 mo after surgery. Mean follow-up was 67 mo (range 12-240). Four patients (5.4%) died during the follow-up.

CONCLUSION

We observed a high rate of RTW (97.1%, including 91.2% within 12 mo) after awake surgery in ILGG patients. Delayed resumption of work was due to employer not clearing them for RTW, personal choice, and, in rare occasions, related to seizures.

A Neurosurgeon's Guide to Cognitive Dysfunction in Adult Glioma

Cognitive decline is common among patients with low- and high-grade glioma and can significantly impact quality of life. Although cognitive outcomes have been studied after therapeutic interventions such as surgery and radiation, it is important to understand the impact of the disease process itself prior to any interventions. Neurocognitive domains of interest in this disease context include intellectual function and premorbid ability, executive function, learning and memory, attention, language function, processing speed, visuospatial function, motor function, and emotional function. Here, we review oncologic factors associated with more neurocognitive impairment, key neurocognitive tasks relevant to glioma patient assessment, as well as the relevance of the human neural connectome in understanding cognitive dysfunction in glioma patients. A contextual understanding of glioma-functional network disruption and its impact on cognition is critical in the surgical management of eloquent area tumors.

Cognitive functioning in patients with low-grade glioma: effects of hemispheric tumor location and surgical procedure

OBJECTIVE

The authors evaluated the cognitive performance of patients with low-grade glioma (LGG) before and after surgery, and specifically investigated 1) the effects of hemispheric tumor location and 2) the type of surgery (either with or without intraoperative stimulation mapping [ISM]).

METHODS

Patients underwent neuropsychological assessment 1 day before (T0) and 3 months after (T3) surgery. ISM targeted motor and/or language functions, but no other cognitive functions. Using 2-way mixed ANOVAs, differences between groups (i.e., for patients with right- vs left-sided lesions and normative controls [NCs], and also for patients operated on with vs without ISM and NCs), effects over time (T0-T3), and interaction effects in cognitive functioning were explored. Individual changes over time were assessed with reliable change indices for each neuropsychological test.

RESULTS

In total, 77 patients with LGG were included (38 and 39 patients with right- and left-sided lesions, respectively; and 42 patients with and 35 patients without ISM). The majority of patients who were operated on with ISM had left-sided lesions. Patients with right- and left-sided lesions scored significantly lower on 6 and 3 out of 8 tests, respectively, compared to NCs. No significant differences between hemispheric groups were found at T0 or at T3. Patients with left-sided lesions showed significant deterioration of performance on verbal memory and sustained attention over time. Patients who underwent operation with versus without ISM scored significantly lower on 6 and 3 out of 8 tests, respectively, compared to NCs. Patients in the ISM group scored significantly lower on the Stroop test, shifting attention test, and verbal fluency test than patients without ISM. Also, the ISM group showed a significant decline in mean cognitive flexibility and sustained attention performance over time.

CONCLUSIONS

Cognitive impairments were found in patients irrespective of hemispheric tumor location, whereby patients who were operated on with ISM performed slightly worse after surgery than patients without ISM. The authors conclude that there is room for improvement of cognitive functioning in surgically treated patients with LGG. The use of specific tests for higher cognitive functions during surgery may potentially improve functional outcome, but that is to be determined in future studies and balanced against oncological outcome. Implementation of neuropsychological assessments into the clinical management of patients with LGG should be encouraged, to inform and alert patients and clinicians on the status of cognitive functioning.

Awake surgery for right frontal lobe glioma can preserve visuospatial cognition and spatial working memory

PURPOSE

Awake surgery is the standard treatment to preserve motor and language functions. This longitudinal study aimed to evaluate the resection rate and preservation of neurocognitive functions in patients with right frontal lobe glioma who underwent awake surgery.

METHODS

Thirty-three patients (mean age, 48.0 years) with right frontal lobe glioma who underwent awake surgery at our hospital between 2013 and 2019 were included. Fourteen, thirteen, and six cases had WHO classification grades of II, III, and IV, respectively. We evaluated visuospatial cognition (VSC) and spatial working memory (SWM) before and three months after surgery. Relevant brain areas for VSC and SWM were intraoperatively mapped, whenever the task was successfully accomplished. Therefore, patients were divided into an intraoperative evaluation group and a non-evaluation group for each function, and the resection rate and functional outcomes were compared.

RESULTS

The removal rate in the evaluation group for VSC and SWM were similar to that in the non-evaluation group. Chronic impairment rate of VSC was significantly lower in the evaluation than in the non-evaluation group (5.6% vs. 33.3%, p = 0.034). No patient showed postoperative SWM impairment in the evaluation group as opposed to the non-evaluation group (16.7%, p = 0.049). The probability of resection of the deeper posterior part of the middle frontal gyrus, the relevant area of VSC, was higher in the non-evaluation group than in the evaluation group.

CONCLUSIONS

We statistically verified that awake surgery for right frontal lobe glioma results in successful preservation of VSC and SWM with satisfying resection rates.

Neurocognitive and functional outcomes in patients with diffuse frontal lower-grade gliomas undergoing intraoperative awake brain mapping

OBJECTIVE

Lower-grade gliomas (LGGs) are often observed within eloquent regions, which indicates that tumor resection in these areas carries a potential risk for neurological disturbances, such as motor deficit, language disorder, and/or neurocognitive impairments. Some patients with frontal tumors exhibit severe impairments of neurocognitive function, including working memory and spatial awareness, after tumor removal. The aim of this study was to investigate neurocognitive and functional outcomes of frontal LGGs in both the dominant and nondominant hemispheres after awake brain mapping.

METHODS

Data from 50 consecutive patients with diffuse frontal LGGs in the dominant and nondominant hemispheres who underwent awake brain surgery between December 2012 and September 2018 were retrospectively analyzed. The goal was to map neurocognitive functions such as working memory by using working memory tasks, including digit span testing and N-back tasks.

RESULTS

Due to awake language mapping, the frontal aslant tract was frequently identified as a functional boundary in patients with left superior frontal gyrus tumors (76.5%). Furthermore, functional boundaries were identified while evaluating verbal and spatial working memory function by stimulating the dorsolateral prefrontal cortex using the digit span and visual N-back tasks in patients with right superior frontal gyrus tumors (7.1%). Comparing the preoperative and postoperative neuropsychological assessments from the Wechsler Adult Intelligence Scale-Third Edition (WAIS-III) and Wechsler Memory Scale-Revised (WMS-R), significant improvement following awake surgery was observed in mean Perceptual Organization (Z = -2.09, p = 0.04) in WAIS-III scores. Postoperative mean WMS-R scores for Visual Memory (Z = -2.12, p = 0.03) and Delayed Recall (Z = -1.98, p = 0.04) were significantly improved compared with preoperative values for every test after awake surgery. No significant deterioration was noted with regard to neurocognitive functions in a comprehensive neuropsychological test battery. In the postoperative course, early transient speech and motor disturbances were observed in 30.0% and 28.0% of patients, respectively. In contrast, late permanent speech and motor disturbances were observed in 0% and 4.0%, respectively.

CONCLUSIONS

It is noteworthy that no significant postoperative deterioration was identified compared with preoperative status in a comprehensive neuropsychological assessment. The results demonstrated that awake functional mapping enabled favorable neurocognitive and functional outcomes after surgery in patients with diffuse frontal LGGs.

Neuropsychological management of the awake patient surgery: A protocol based on 3-year experience with glial tumors

INTRODUCTION

Glial brain tumours usually require neurosurgical treatment and they are associated with cognitive, emotional and behavioural impairments. Awake intraoperative brain mapping is the gold standard technique used to optimize the onco-functional balance. Neuropsychological assessment and intervention have relevance in this type of procedures. Currently, there is a lack of protocolled structure for the neuropsychological intervention being able to satisfy patient needs.

METHOD

A retrospective descriptive study of 52 patients was performed, all of them with a diagnosis of glial tumour. The structure of the protocol developed in our centre is reported, also data of neuropsychological evaluation, comparing baseline performance with both immediate posterior performance, and long term performance.

RESULTS

We describe our experience in each step of the intervention, highlighting the development of eight neurocognitive protocols for intraoperative brain mapping. The results of the neuropsychological examination objectify deficits in the immediate after surgery assessment which are reduced in the long-term assessment.

CONCLUSIONS

We emphasize the need of providing and structuring the cognitive and emotional aspects of patients suffering from any pathology that entails acquired brain damage in hospital environment. This type of approach is aimed at increasing the quality of life of cancer patients by structuring and optimizing tasks during their surgical intervention and attending to the neuropsychological difficulties they suffer.

Primary Cognitive Factors Impaired after Glioma Surgery and Associated Brain Regions

Previous studies have shown that cognitive impairments in patients with brain tumors are not severe. However, to preserve the postsurgical QOL of patients with brain tumors, it is important to identify “primary” cognitive functions and associated brain regions that are more vulnerable to cognitive impairments following surgery. The objective of this study was to investigate primary cognitive factors affecting not only simple cognitive tasks but also several other cognitive tasks and associated brain regions. Patients with glioma in the left (n = 33) and the right (n = 21) hemisphere participated in the study. Seven neuropsychological tasks from five cognitive domains were conducted pre- and 6 months postoperation. Factor analyses were conducted to identify “primary” common cognitive functions affecting the task performance in left and right glioma groups. Next, lesion analyses were performed using voxel-based lesion-symptom mapping (VLSM) to identify critical brain regions related to impairments of the primary cognitive functions. Factor analysis revealed two primary cognitive components in each glioma group. The first cognitive component in the left glioma group affected the digit span forward and backward tasks and concept shifting and the letter-digit substitution tasks. VLSM analysis revealed significant regions from the posterior middle temporal gyri to the supramarginal gyrus. The second cognitive component affected verbal memory, and verbal fluency tasks and VLSM analysis indicated two different significant regions, the medial temporal regions and the middle temporal gyrus to the posterior parietal lobes. The first cognitive component in the right glioma group affected positive and negative factor loadings on the task, such that the positive cognitive component affected only the Stroop color-word task. VLSM related to deficits of the Stroop task revealed significant regions in the anterior medial frontal cortex. On the other hand, the negative component affected concept shifting, word fluency, and digit span forward tasks, and VLSM revealed significant regions in the right inferior frontal cortex. It is suggested that primary cognitive functions related to specific brain regions were possibly affected by glioma resection.

Intraoperative Identification and Preservation of Verbal Memory in Diffuse Gliomas: A Matched-Pair Cohort Study

BACKGROUND

Recent glioma surgery series with intraoperative electrical stimulation (IES) language mapping have demonstrated high rates of postoperative memory impairment, raising a question regarding the efficacy of this approach to preserve memory.

OBJECTIVE

To evaluate if intraoperative identification and preservation of verbal memory sites with IES mapping in diffuse gliomas in eloquent areas consistently protect patients from long-term postoperative decline in short-term memory.

METHODS

A cohort of 16 subjects with diffuse low-grade or anaplastic gliomas that were operated with IES and intraoperative evaluation of language and verbal memory (cohort A) was matched by tumor side, pathology, and radiotherapy with a cohort of 16 subjects that were operated with IES and evaluation of language (cohort B). Detailed neuropsychological assessment was performed before and 6 mo after surgery.

RESULTS

Intraoperative memory mapping was a strong predictor of verbal memory prognosis. In cohort A, 4 patients (26.7%) had a decline of at least one of the 4 short-term memory tests evaluated. In cohort B, 11 patients (73.3%) had a decline of at least one of the 4 tests. This difference was statistically significant in multivariate analysis (P = .022; odds ratio = 9.88; 95% confidence interval = 1.39-70.42).

CONCLUSION

Verbal memory areas identified intraoperatively with the current paradigm are critically involved in verbal memory, as memory impairment can be significantly reduced by adapting the resection to avoid those memory areas. Incorporation of verbal memory evaluation in stimulation mapping protocols might assist in reducing postoperative sequelae and preserving the patient's quality of life.

Monitoring of Neurocognitive Function in the Care of Patients with Brain Tumors

PURPOSE OF REVIEW

A detailed characterization of the nature of neurocognitive impairment in patients with brain tumors is provided, as well as considerations for clinical practice regarding neuropsychological assessment throughout the disease course.

RECENT FINDINGS

Neurocognitive impairment is common in patients with brain tumors and may result from the tumor itself, as a consequence of treatment, including surgery, chemotherapy, and radiation, or in association with supportive care medications (e.g., anticonvulsant and pain medications). Serial surveillance of neurocognitive functioning in this population can facilitate medical decision-making and inform recommendations to improve patient daily functioning and quality of life. Neuropsychological assessment is increasingly recognized as a critical component of the multidisciplinary care of patients with brain tumors and has already had practice-changing effects. Further understanding of genetic risk factors for neurocognitive decline along with the development of novel assessment and intervention strategies may further enhance functioning and general well-being in this patient population.

Functional characterization of tumor antigen-specific T-cells isolated from the tumor microenvironment of sleeping beauty induced murine glioma models

Diffuse Gliomas represent 80% of brain tumors with an average survival of the most aggressive form glioblastoma (GBM) 15-22 months from the time of diagnosis. The current standard of care includes tumor resection, chemotherapy and radiation, nevertheless, the incidence of recurrence remains high and there is a critical need for developing new therapeutic strategies. T-cell mediated immunotherapy that triggers an anti-tumor T cell-mediated memory response is a promising approach since it will not only attack the primary tumor but also prevent recurrence. Multiple immunotherapeutic strategies against glioma are currently being tested in clinical trials. We have developed an immune-mediated gene therapy (Thymidine kinase plus Fms-like tyrosine kinase 3 ligand: TK/Flt3L) which induces a robust anti-tumor T cell response leading to tumor regression, long-term survival and immunological memory in GBM models. Efficacy of the anti-glioma T cell therapy is determined by anti-tumor specific effector T cells. Therefore, assessing effector T cell activation status and function are critical readouts for determining the effectiveness of the therapy. Here, we detail methodologies to evaluate tumor specific T-cell responses using a genetically engineered Sleeping Beauty transposase-mediated glioma model. We first describe the glioma model and the generation of neurospheres (NS) that express the surrogate antigen cOVA. Then, we describe functional assays to determine anti-tumor T-cell response.

Management for Different Glioma Subtypes: Are All Low-Grade Gliomas Created Equal?

Following the identification of key molecular alterations that provided superior prognostication and led to the updated 2016 World Health Organization (WHO) Central Nervous System (CNS) Tumor Classification, the understanding of glioma behavior has rapidly evolved. Mutations in isocitrate dehydrogenase (IDH) 1 and 2 are present in the majority of adult grade 2 and 3 gliomas, and when used in conjunction with 1p/19q codeletion for classification, the prognostic distinction between grade 2 versus grade 3 is diminished. As such, the previously often used term of "low-grade glioma," which referred to grade 2 gliomas, has now been replaced by the phrase "lower-grade glioma" to encompass both grade 2 and 3 tumors. Additional molecular characterization is ongoing to even further classify this heterogeneous group of tumors. With such a colossal shift in the understanding of lower-grade gliomas, management of disease is being redefined in the setting of emerging molecular-genetic biomarkers. In this article, we review recent progress and future directions regarding the surgical, radiotherapeutic, chemotherapeutic, and long-term management of adult lower-grade gliomas.

Improvement in cognitive function after surgery for low-grade glioma

OBJECTIVE

Cognition is a key component in health-related quality of life (HRQoL) and is currently incorporated as a major parameter of outcome assessment in patients treated for brain tumors. The effect of surgery on cognition and HRQoL remains debatable. The authors investigated the impact of resection of low-grade gliomas (LGGs) on cognition and the correlation with various histopathological markers.

METHODS

A retrospective analysis of patients with LGG who underwent craniotomy for tumor resection at a single institution between 2010 and 2014 was conducted. Of 192 who underwent resective surgery for LGG during this period, 49 had complete pre- and postoperative neurocognitive evaluations and were included in the analysis. These patients completed a full battery of neurocognitive tests (memory, language, attention and working memory, visuomotor organization, and executive functions) pre- and postoperatively. Tumor and surgical characteristics were analyzed, including volumetric measurements and histopathological markers (IDH, p53, GFAP).

RESULTS

Postoperatively, significant improvement was found in memory and executive functions. A subgroup analysis of patients with dominant-side tumors, most of whom underwent intraoperative awake mapping, revealed significant improvement in the same domains. Patients whose tumors were on the nondominant side displayed significant improvement only in memory functions. Positive staining for p53 testing was associated with improved language function and greater extent of resection in dominant-side tumors. GFAP positivity was associated with improved memory in patients whose tumors were on the nondominant side. No correlation was found between cognitive outcome and preoperative tumor volume, residual volume, extent of resection, or IDH1 status.

CONCLUSIONS

Resection of LGG significantly improves memory and executive function and thus is likely to improve functional outcome in addition to providing oncological benefit. GFAP and pP53 positivity could possibly be associated with improved cognitive outcome. These data support early, aggressive, surgical treatment of LGG.

Mapping in Low-Grade Glioma Surgery: Low- and High-Frequency Stimulation

Surgery for lower grade glioma requires the use of brain mapping techniques to identify functional boundaries, which represent the limit of the resection. Two stimulation paradigms are currently available and their use should be tailored to the clinical context to extend tumor removal and decrease the odds of postoperative permanent deficits.

Tumour volume reduction following PET guided intensity modulated radiation therapy and temozolomide in IDH mutated anaplastic glioma

The role of maximal surgical debulking in isocitrate dehydrogenase (IDH) mutated anaplastic glioma prior to adjuvant radiation therapy remains uncertain. This study assessed the reduction in tumour volume following intensity modulated radiation therapy (IMRT) and temozolomide in this favourable and more responsive tumour pathology. 56 patients were managed from 2011 to 2014 and 53 had residual disease. To assess radiological response, tumour volumes were created on representative T1/T2Flair MRI sequences using identical slice-levels in three planes for pre-IMRT, month + 3 and month + 12 post-IMRT scans. Change in volumes was assessed between time periods. Progression-free survival (PFS) was calculated from start of radiotherapy. Median follow-up for survivors is 48.2 months. Pathology was anaplastic oligodendroglioma (AOD) and anaplastic astrocytoma IDH-mutated (AAmut) in 32 and 21 patients respectively. 93% received sequential chemotherapy. The median residual disease on T1 and T2Flair imaging was 9.7 cm³ and 20.6 cm³. 17 patients relapsed for projected 5 year PFS of 74.9%; with 8 isolated relapses within initial surgical site. On MRI at month + 3, the median volume for T1 and T2Flair reduced by 69.4% and 67.3% respectively; which further decreased to 82.4% and 81.3% at month + 12. By month + 12, 69.2% and 62.2% of patients had >75% volume reduction. Patients with AOD had superior reduction at month + 3 compared with AAmut (p = 0.02); but equivalent reduction at month + 12 (p = 0.14). Thus, in patients with anaplastic glioma harbouring an IDH mutation, where an attempt at near-total resection may be associated with unacceptable morbidity, this data suggests that the radiation therapy may provide effective cytoreduction of residual disease.

Evidence for Improving Outcome Through Extent of Resection

Surgical resection plays a central role in the management of gliomas however many tumors are within areas resulting in sensorimotor and cognitive consequences. This article reviews the evidence in support of extent of resection to improve survival, symptom management, and time to malignant transformation in low-grade gliomas. The authors summarize the evolving literature regarding the role of maximal safe resection in light of WHO subclassification of low-grade gliomas. Long lasting neurological deficits following glioma resection may hinder both survival and quality of life. New insights into glioma related central nervous system plasticity impact both surgical planning and timing of interventions.

Post-surgical effects on language in patients with presumed low-grade glioma

OBJECTIVES

Low-grade glioma (LGG) is a slow-growing brain tumour often situated in or near areas involved in language and/or cognitive functions. Thus, language impairments due to tumour growth or surgical resection are obvious risks. We aimed to investigate language outcome following surgery in patients with presumed LGG, using a comprehensive and sensitive language assessment.

MATERIALS AND METHODS

Thirty-two consecutive patients with presumed LGG were assessed preoperative, early post-operative, and 3 months post-operative using sensitive tests including lexical retrieval, language comprehension and high-level language. The patients' preoperative language ability was compared with a reference group, but also with performance at post-operative controls. Further, the association between tumour location and language performance pre- and post-operatively was explored.

RESULTS

Before surgery, the patients with presumed LGG performed worse on tests of lexical retrieval when compared to a reference group (BNT: LGG-group median 52, Reference-group median 54, P = .002; Animals: LGG-group mean 21.0, Reference-group mean 25, P = 001; Verbs: LGG-group mean 17.3, Reference-group mean 21.4, P = .001). At early post-operative assessment, we observed a decline in all language tests, whereas at 3 months there was only a decline on a single test of lexical retrieval (Animals: preoperative. median 20, post-op median 14, P = .001). The highest proportion of language impairment was found in the group with a tumour in language-eloquent areas at all time-points.

CONCLUSIONS

Although many patients with a tumour in the left hemisphere deteriorated in their language function directly after surgery, their prognosis for recovery was good.

Glioma surgery with intraoperative mapping-balancing the onco-functional choice

BACKGROUND

Balancing survival versus risk of inducing functional deficits is a challenge when resecting gliomas in or near eloquent areas. Our objectives were to assess deficits prior to and at 6 and 12 months after awake craniotomies with cortical and subcortical mapping in patients with suspected grade 2 gliomas in eloquent areas. We analyzed whether pre- and intraoperative factors were linked to an increased risk of postoperative deficits.

METHOD

Retrospective study of 92 consecutive patients operated between January 2010 and June 2014. All deficits reported by any healthcare professional and KPS-score preoperatively, immediately postoperatively (day 1-10), at 6 months and 12 months, were analyzed.

RESULTS

A decrease in neurological and or cognitive function was common in the first days after surgery, with a significant improvement at 6 months after surgery and further improvement at 12 months. Immediately after surgery, 33% of the patients had severe deficits compared to 2% prior to surgery; this improved to 9% at 6 months and 3% at 12 months. However, at 12 months, 18% of the patients had new or worsened minor or moderate deficits and only 10% had no deficits compared to 39% prior to surgery. There were only minor changes in KPS. None of the recorded pre/intraoperative factors were found significantly to influence the risk of moderate/severe late postoperative deficits.

CONCLUSION

A significant amount of the patients in this study experienced new or worsened neurological and or cognitive deficits during follow-up. We found a higher frequency of deficits than normally reported. This is due to the inclusion of mild deficits, the use of patient-reported data, and our focus on cognitive deficits. Our study indicates that the impact of awake craniotomy with mapping on patient outcome is larger than expected. This in no way negates the use of the technique.

Surgical Management of Incidental Gliomas

Detailed brain imaging studies discover gliomas incidentally before clinical symptoms or signs show. These tumors represent an early stage in the natural history of gliomas. Left untreated, they are likely to progress to a symptomatic stage and transform to malignant gliomas. A greater extent of resection delays the onset of malignant transformation and prolongs patient survival. Because incidental gliomas are typically smaller and less likely to be in eloquent brain locations, there is a strong case for early surgical intervention to maximize resection and improve outcomes. This article discusses developments in the surgical management of low-grade gliomas.

Navigated 3D-ultrasound versus conventional neuronavigation during awake resections of eloquent low-grade gliomas: a comparative study at a single institution

BACKGROUND

The data showing usefulness of navigated 3D-ultrasound (3DUS) during awake resections of eloquent gliomas are sparse. Results of surgeries performed using 3DUS were never compared to procedures guided by standard neuronavigation. The aim of this work is to assess the effectiveness of 3DUS during awake resections of eloquent low-grade gliomas (LGGs) by comparing surgical results of two series of patients operated on using conventional neuronavigation and using 3DUS. To our knowledge, a similar study is lacking in the literature.

METHODS

During a 4-year period (September 2006 to August 2010) 21 awake resections of LGGs guided by neuronavigation (series 1, S1) were consecutively performed in Department of Neurosurgery in Bratislava. During another 4-year period (August 2010 to July 2014) 28 awake resections of LGGs guided by 3DUS (series 2, S2) were consecutively conducted. In both patients series, the eloquent cortical and subcortical structures were intraoperatively detected by direct electrical stimulation. Extent of tumor resection (EOR) and functional outcome in both series were compared.

RESULTS

EOR was significantly greater (p = 0.022) in S2 (median = 93.25%; mean = 86.79%), as compared to S1 (median 87.1%; mean = 75.85%). One permanent minor deficit in S1 and 2 minor deficits in S2 occurred, the difference was not significant (p = 0.999).

CONCLUSIONS

Our work represents the first study comparing results of surgeries guided by 3DUS versus conventional navigation. The extent of awake resections of eloquent LGG guided by 3DUS was greater comparing to awake resections guided by standard neuronavigation; use of 3DUS had no impact on the number of new permanent deficits.