Linking late cognitive outcome with glioma surgery location using resection cavity maps

Patients with a diffuse glioma may experience cognitive decline or improvement upon resective surgery. To examine the impact of glioma location, cognitive alteration after glioma surgery was quantified and related to voxel-based resection probability maps. A total of 59 consecutive patients (range 18-67 years of age) who had resective surgery between 2006 and 2011 for a supratentorial nonenhancing diffuse glioma (grade I-III, WHO 2007) were included in this observational cohort study. Standardized neuropsychological examination and MRI were obtained before and after surgery. Intraoperative stimulation mapping guided resections towards neurological functions (language, sensorimotor function, and visual fields). Maps of resected regions were constructed in standard space. These resection cavity maps were compared between patients with and without new cognitive deficits (z-score difference >1.5 SD between baseline and one year after resection), using a voxel-wise randomization test and calculation of false discovery rates. Brain regions significantly associated with cognitive decline were classified in standard cortical and subcortical anatomy. Cognitive improvement in any domain occurred in 10 (17%) patients, cognitive decline in any domain in 25 (42%), and decline in more than one domain in 10 (17%). The most frequently affected subdomains were attention in 10 (17%) patients and information processing speed in 9 (15%). Resection regions associated with decline in more than one domain were predominantly located in the right hemisphere. For attention decline, no specific region could be identified. For decline in information speed, several regions were found, including the frontal pole and the corpus callosum. Cognitive decline after resective surgery of diffuse glioma is prevalent, in particular, in patients with a tumor located in the right hemisphere without cognitive function mapping.

A review of cognitive screening tools in cancer

PURPOSE OF REVIEW

Cancer-related cognitive impairment (CRCI) is highly prevalent, and assessment of cognition is crucial in providing optimal cancer care. Neuropsychological assessment (NPA) can be lengthy and expensive. Cognitive screening tools are plenty but validity has not been thoroughly studied for use in cancer patients.

RECENT FINDINGS

Our search of the recent literature revealed that the Montreal Cognitive Assessment, Mini-Mental State Examination, and Clock Draw Test were the most frequently studied objective screening tools. The Functional Assessment of Cancer Therapy-Cognitive Function and the Cognitive Symptom Checklist-Work 21 were the most commonly studied subjective measures of perceived cognitive impairment. Evidence supports using the Montreal Cognitive Assessment or the Clock Draw Test over the Mini-Mental State Examination to screen for cognitive impairment within specific patient populations. In addition, adding a subjective measure of cognitive impairment (e.g., Functional Assessment of Cancer Therapy-Cognitive Function) may increase diagnostic sensitivity.

SUMMARY

These suggest that cognitive screening tools may have a role in screening for CRCI, particularly when full NPA is not feasible. Researchers must continue to conduct high-quality studies to build an evidence to guide best practices in screening for CRCI.

An attempt to conceptualize the individual onco-functional balance: Why a standardized treatment is an illusion for diffuse low-grade glioma patients

In the era of evidence-based medicine, clinicians aim to establish standards of care from randomized studies. Following, personalized medicine has emerged, as new individualized biomarkers could help to predict sensitivity to specific treatment. In this paper, we show that, for diffuse low-grade glioma, some specificities - dual goal of both survival and functional gain, long duration of the disease with multistep treatments, multiparametric evaluation of the onco-functional balance of each treatment modality - call for a change of paradigm. After summarizing how to weight the benefits and risks of surgery, chemotherapy and radiotherapy, we show that the overall efficacy of a treatment modality cannot be assessed per se, as it depends on its integration in the whole sequence. Then, we revisit the notion of personalized medicine: instead of decision-making based solely on molecular profile, we plead for a recursive algorithm, allowing a dynamic evaluation of the onco-functional balance, integrating many individual characteristics of the patient's tumor and brain function.

Pre-operative language ability in patients with presumed low-grade glioma

In patients with low-grade glioma (LGG), language deficits are usually only found and investigated after surgery. Deficits may be present before surgery but to date, studies have yielded varying results regarding the extent of this problem and in what language domains deficits may occur. This study therefore aims to explore the language ability of patients who have recently received a presumptive diagnosis of low-grade glioma, and also to see whether they reported any changes in their language ability before receiving treatment. Twenty-three patients were tested using a comprehensive test battery that consisted of standard aphasia tests and tests of lexical retrieval and high-level language functions. The patients were also asked whether they had noticed any change in their use of language or ability to communicate. The test scores were compared to a matched reference group and to clinical norms. The presumed LGG group performed significantly worse than the reference group on two tests of lexical retrieval. Since five patients after surgery were discovered to have a high-grade glioma, a separate analysis excluding them were performed. These analyses revealed comparable results; however one test of word fluency was no longer significant. Individually, the majority exhibited normal or nearly normal language ability and only a few reported subjective changes in language or ability to communicate. This study shows that patients who have been diagnosed with LGG generally show mild or no language deficits on either objective or subjective assessment.

Is non-awake surgery for supratentorial adult low-grade glioma treatment still feasible?

In this short review, the author performs a database search, summarizes, and discusses studies that provide information on the need to perform awake surgery to preserve quality of life/return to work of adult patients who undergo resection for a supratentorial low-grade glioma (LGG). Based upon the currently available data, the author concludes that in LGG, patients with no or only mild deficits at diagnosis, non-awake surgery can no longer be achieved. Indeed, awake craniotomy with intrasurgical electrical mapping has resulted in an increase of the extent of resection and overall survival in LGG. Furthermore, in order to resume a normal familial, social, and professional life, LGG patients with a prolonged survival expectancy have to benefit not only from language mapping when the tumor involves the left "dominant" hemisphere, but also from intraoperative mapping of sensorimotor, visuospatial, higher cognitive, and emotional functions under local anesthesia, even for gliomas situated within presumed "non-language" areas such as the right "non-dominant" hemisphere. In other words, the ultimate goal is to map the functional connectome for each patient in order to perform the resection up to the eloquent networks and then to optimize the onco-functional balance of LGG surgery. To this end, an objective neuropsychological assessment has to be achieved in a more systematic manner before and after resection. Early postoperative cognitive rehabilitation is also recommended, whenever needed.

Tumor-related neurocognitive dysfunction in patients with diffuse glioma: a systematic review of neurocognitive functioning prior to anti-tumor treatment

Deficits in neurocognitive functioning (NCF) frequently occur in glioma patients. Both treatment and the tumor itself contribute to these deficits. Data about the role of the tumor are scarce, because NCF has mostly been studied postoperatively. We aimed to summarize data on pre-treatment NCF in glioma patients and to determine the overall and domain-specific prevalence of neurocognitive dysfunction. We searched PubMed and Embase according to PRISMA-P protocol for studies that evaluated pre-treatment NCF in glioma patients (1995-November 2016) and extracted information about NCF. We performed analysis of data for two main outcome measures; mean cognitive functioning of the study sample (at group level) and the percentage of impaired patients (at individual level). We included 23 studies. Most studies were small observational prospective cohort studies. In 11 (47.5%) studies, patient selection was based on tumor location. NCF was analyzed at the group level in 14 studies, of which 13 (92.9%) found decreased NCF at group level, compared to normative data or matched controls. The proportion of individuals with decreased NCF was reported in 15 studies. NCF was impaired (in any domain) in 62.6% of the individuals (median; interquartile range 31.0–79.0). Cognitive impairments were more common in patients with high-grade glioma than with low-grade glioma (OR 2.50; 95% CI 1.71–3.66). Cognitive impairment occurs in the majority of treatment-naive glioma patients, suggesting that neurocognitive dysfunction is related to the tumor. However, the literature about pre-treatment NCF in glioma patients is characterized by small-scale studies and strong heterogeneity in patient selection, resulting in high risk of bias.

Optical Neuronavigation without Rigid Head Fixation During Awake Surgery

OBJECTIVE

Optical neuronavigation without rigid pin fixation of the head may lead to inaccurate results because of the patient's movements during awake surgery. In this study, we report our results using a skull-mounted reference array for optical tracking in patients undergoing awake craniotomy for eloquent gliomas.

METHODS

Between March 2013 and December 2014, 18 consecutive patients (10 men, 8 women) with frontotemporal (n = 16) or frontoparietal (perirolandic; n = 2) lesions underwent awake craniotomy without rigid pin fixation. All patients had a skull-mounted reference array for optical tracking placed on the forehead. Accuracy of navigation was determined with pointer tip deviation measurements on superficial and bony anatomic structures. Good accuracy was defined as a tip deviation <2 mm.

RESULTS

Gross total resection (>98%) was achieved in 7 patients (38%); >90% of tumor was resected in 8 patients (44%). In 3 patients, only subtotal resection or biopsy was performed secondary to stimulation results. In all patients, good accuracy of the optical neuronavigation system could be demonstrated without intraoperative peculiarities or complications. The reference array had to be repositioned because of loosening in 1 patient. Neuronavigation could be reliably applied to support stimulation-based resection.

CONCLUSIONS

A skull-mounted reference array is a simple and safe method for optical neuronavigation tracking without rigid pin fixation of the patient's head.

The Use of the Target Cancellation Task to Identify Eloquent Visuospatial Regions in Awake Craniotomies: Technical Note

The success of awake craniotomies relies on the patient's performance of function-specific tasks that are simple, quick, and reproducible. Intraoperative identification of visuospatial function through cortical and subcortical mapping has utilized a variety of intraoperative tests, each with its own benefits and drawbacks. In light of this, we developed a simple software program that aids in preventing neglect by simulating a target-cancellation task on a portable electronic device. In this report, we describe the interactive target cancellation task and have reviewed seven consecutive patients who underwent awake craniotomy for parietal and/or posterior temporal infiltrating brain tumors of the non-dominant hemisphere. Each of these patients performed target cancellation and line bisection tasks intraoperatively. The outcomes of each patient and testing scenario are described. Positive intraoperative cortical and subcortical sites involved with visuospatial processing were identified in three of the seven patients using the target cancellation and confirmed utilizing the line-bisection task. No identification of visuospatial function was accomplished utilizing the line-bisection task alone. Complete visuospatial function mapping was completed in less than 10 minutes in all patients. No patients had preoperative or postoperative hemineglect. Our findings highlight the feasibility of the target cancellation technique for use during awake craniotomy to aid in avoiding postoperative hemineglect. Target cancellation may offer an alternative method of cortical and subcortical visuospatial mapping in patients unable to perform other commonly used modalities.

Neurocognitive Deficits and Neurocognitive Rehabilitation in Adult Brain Tumors

OPINION STATEMENT

Neurocognitive deficits are common with brain tumors. If assessed at presentation using detailed neurocognitive tests, problems are detected in 80 % of cases. Neurocognition may be affected by the tumor, its treatment, associated medication, mood, fatigue, and insomnia. Interpretation of neurocognitive problems should be considered in the context of these factors. Early post-operative neurocognitive rehabilitation for brain tumor patients will produce rehabilitation outcomes (e.g., quality of life, improved physical function, subjective neurocognition) equivalent to stroke, multiple sclerosis, and head injury, but the effect size and duration of benefit needs further research. In stable patients treated with radiotherapy +/- chemotherapy, the most frequent causes of distress include neurocognitive problems, psychological factors of anxiety, depression, fatigue, and sleep. Exercise, neurocognitive training, neurocognitive behavioral therapy, and medications to treat fatigue, behavior, memory, mood, and removal of drugs that may be associated with neurocognitive side effects (e.g., anti-epileptic drugs) all show promise in helping patients to manage the effects of their neurocognitive impairments better. As these are complex symptoms, multidisciplinary expertise is necessary to evaluate the influence of each variable to plan appropriate support and intervention. Neurocognitive rehabilitation should therefore occur in parallel with disease-centered, medical management from the outset. It should not occur in series, as a restricted phase in a patient's pathway. It should be considered in the pre- and post-operative period where there are good prospects of recovery, as one would for any brain-injured patient, so that the person may reach their optimal physical, sensory, intellectual, psychological, and social functional level. Yet the identification and selection of patients for early neurological rehabilitation and routine evaluation of cognition is uncommon in neurosurgical wards.