Application of a Standardized Treatment Paradigm as a Strategy to Achieve Optimal Onco-Functional Balance in Glioma Surgery.

BACKGROUND: Gliomas, characterized by their invasive persistence and tendency to affect critical brain regions, pose a challenge in surgical resection due to the risk of neurological deficits. This study focuses on a personalized approach to achieving an optimal onco-functional balance in glioma resections, emphasizing maximal tumor removal while preserving the quality of life. METHODS: A retrospective analysis of 57 awake surgical resections of gliomas at the National University Hospital, Singapore, was conducted. The inclusion criteria were based on diagnosis, functional boundaries determined by direct electrical stimulation, preoperative Karnofsky Performance Status score, and absence of multifocal disease on MRI. The treatment approach included comprehensive neuropsychological evaluation, determination of suitability for awake surgery, and standard asleep-awake-asleep anesthesia protocol. Tumor resection techniques and postoperative care were systematically followed. RESULTS: The study included 53 patients (55.5% male, average age 39 years), predominantly right-handed. Over half reported seizures as their chief complaint. Tumors were mostly low-grade gliomas. Positive mapping of the primary motor cortex was conducted in all cases, with awake surgery completed in 77.2% of cases. New neurological deficits were observed in 26.3% of patients at 1 month after operation; most showed significant improvement at 6 months. CONCLUSION: The standardized treatment paradigm effectively achieved an optimal onco-functional balance in glioma patients. While some patients experienced neurological deficits postoperatively, the majority recovered to their preoperative baseline within 3 months. The approach prioritizes patient empowerment and customized utilization of functional mapping techniques, considering the challenge of preserving diverse languages in a multilingual patient population.

Cognition, Emotional States and Health-Related Quality of Life in Awake Craniotomy for Glioma: A Case Series.

BACKGROUND: Awake craniotomy is an effective procedure for optimizing the onco-functional balance of resections in glioma. However, limited data exists on the cognition, emotional states, and health-related quality of life (HRQoL) of patients with glioma who undergo awake craniotomy. This study aims to describe 1) perioperative cognitive function and emotional states in a multilingual Asian population, 2) associations between perioperative cognitive function and follow-up HRQoL, and 3) associations between preoperative emotional states and follow-up HRQoL. METHODS: This is a case series of 14 adult glioma patients who underwent awake craniotomy in Singapore. Cognition was assessed with the Montreal Cognitive Assessment and the Repeatable Battery for the Assessment of Neuropsychological Status, emotional states with the Depression, Anxiety and Stress Scale-21 Items, and HRQoL using the EuroQol-5D-5L, the European Organisation for Research and Treatment of Cancer (EORTC) QLQ-C30, and the European Organisation for Research and Treatment of Cancer (EORTC) QLQ-BN20. RESULTS: Patients with better preoperative cognitive scores on all domains reported better HRQoL. Better postoperative immediate memory and language scores were associated with better HRQoL. Moderate preoperative depression scores and mild and moderate preoperative stress scores were associated with poorer HRQoL compared to scores within the normal range. Mild preoperative anxiety scores were associated with better HRQoL compared to scores within the normal range. CONCLUSION: This descriptive case series showed that patients with higher preoperative cognitive scores reported better follow-up HRQoL, while patients who reported more preoperative depressive and stress symptomatology reported worse follow-up HRQoL. Future analytical studies may help to draw conclusions about whether perioperative cognition and emotional states predict HRQoL on follow-up.

Awake craniotomy for brain tumor resection: Patient experience and acceptance in an Asian population.

INTRODUCTION: Awake craniotomy is well-established for resection of brain tumor in the eloquent areas. Previous studies from Western countries have reported good level of patient tolerance and acceptance. However, its acceptability in non-Western populations, with different ethnic, social, cultural, religious, and linguistic backgrounds, has not been studied systematically. This study aims to evaluate the experience of patients from an Asian population who underwent awake craniotomy for tumor resection. METHODS: Data on patient experience were collected by interviewing patients using a structured questionnaire at follow-up appointment. Data on patient demographics and diagnosis were collected from medical records. RESULTS: Eighteen patients (age 16-68 years) who underwent 20 awake craniotomies were recruited. Preoperatively, all (100%) patients understood the indication for awake craniotomy. Almost all felt fully counseled by the neurosurgeon (90%), anesthetist (100%), and neuropsychologist (95%). Ninety-five percent reported their family to be supportive of awake craniotomy. Seventy-five percent felt adequately prepared on operation day. Intraoperatively, most patients did not experience pain/discomfort (55%) or anxiety (65%). Nearly all found intraoperative motor and language testing to be easy (100% and 90%, respectively). Postoperatively, 100% were satisfied with their care. One hundred percent rated their overall experience as good or excellent. Eighty percent were willing to undergo awake craniotomy again if indicated. CONCLUSION: Awake craniotomy is well-accepted in an Asian population. All patients had good-to-excellent overall experience, with most willing to undergo awake craniotomy again. Our findings underscore the generalizability of awake craniotomy across different socio-cultural backgrounds and support its utilization in countries with a significant Asian population.

Performing Awake Surgeries in Times of COVID-19 - A Singapore Experience.

INTRODUCTION: It has been 17 years since the severe acute respiratory syndrome outbreak and Singapore is facing yet another daunting pandemic - the novel coronavirus (COVID-19). To date, there are 57,607 cases and 27 casualties. This deadly pandemic requires significant changes especially in the field of awake surgeries for intra-axial tumors that routinely involve long clinic consults, significant interactions between patient and multiple other team members pre, intra, and postoperatively. MATERIALS AND METHODS: A retrospective review of all awake cases done during the COVID-19 pandemic from February to June 2020 was done. In this article, we outline the rigorous measures adopted during the COVID-19 pandemic that has allowed us to proceed with awake surgeries and intraoperative mapping at our institution. RESULTS AND DISCUSSION: We have divided the protocol into various phases of care of patients planned for an awake craniotomy. Preoperatively, teleconsults have been used where possible thereby limiting multiple hospital visits and interaction. Intraoperatively, safety nets have been established during asleep-awake-asleep phases of awake craniotomy for all the team members. Postoperatively, early discharge and teleconsult are being employed for rehabilitation and follow-ups. CONCLUSIONS: Multiple studies have shown that with intraoperative mapping, we can improve neurological outcomes. As the future of the pandemic remains unknown, the authors believe that surgical treatment should not be delayed for intracranial tumors. Awake craniotomies and intraoperative mapping can be safely carried out by adopting the described protocols with combination of multiple checkpoints and usage of telecommunication.

Optimizing the onco-functional balance in supratentorial brain tumour surgery: A single institution's initial experience with intraoperative cortico-subcortical mapping and monitoring in Singapore.

Intraoperative cortical mapping provides functional information that permits the safe and maximal resection of supratentorial lesions infiltrating the so-called eloquent cortex or subcortical white matter tracts. Primary and secondary brain tumours located in eloquent cortex can render surgical treatment ineffective if it results in new or worsening neurology. A cohort of forty-six consecutive patients with supratentorial tumours of variable pathology involving eloquent cortical regions and aided with intraoperative neurophysiology were included for retrospective analysis at a single-centre tertiary institution. Intraoperative neurophysiological data has been related to immediate post-operative neurologic status as well as 3-month follow-up in patients that underwent awake or asleep surgical resection. Patients that experienced new or worsening neurologic symptoms post-operatively demonstrated a high incidence of recovery at 3-months. Those without new neurologic symptoms post-operatively demonstrated little to no worsening at 3-months. Our study explored the extent to which cortical mapping permitted safe surgical resection whilst preserving neurologic function. To the authors' knowledge this is the first documented case series in Singapore that has incorporated a systematic and individually tailored multimodal workflow to cortico-subcortical mapping and monitoring for the safe resection of infiltrative lesions of the supratentorial region.

Awake Craniotomy and Excision of a Diffuse Low-Grade Glioma in a Multilingual Patient: Neuropsychology and Language.

BACKGROUND: Diffuse low-grade gliomas are a group of brain tumors that require an individualized and targeted therapeutic approach, such as awake craniotomy for surgical resection and intraoperative monitoring of speech and language functions. CASE DESCRIPTION: This case report presents a young, right-handed, Tamil-English-Malay multilingual man who underwent awake brain surgery for the excision of a diffuse low-grade glioma in the left frontal pars triangularis and opercularis region (i.e., Broca's area). Preoperative and postoperative neuropsychological assessments were conducted. Intraoperative language mapping was performed with electrostimulation. CONCLUSION: Awake craniotomy with speech and language monitoring allows a customized approach to the treatment and management of diffuse low-grade gliomas. Neuropsychological assessment and intraoperative findings are discussed in the context of functional reorganization and cortical representations of language.

Language Mapping of Hindi and English in a Bilingual Patient During Resection of a Right Frontal Glioma.

BACKGROUND: Recent advancements in understanding the molecular basis of gliomas and new concepts of neuronal plasticity have shown the importance of maximal resection in gliomas to improve progression-free overall survival. Awake craniotomies with intraoperative cortical and subcortical mapping have helped to achieve this aim while allowing us to preserve executive function including language. Language mapping becomes a daunting task in individuals who are bilingual because of the complexity of varied cortical representation of different languages. CASE DESCRIPTION: We present a case of a bilingual patient who underwent re-resection of right frontal astrocytoma using principles of awake surgery and language mapping. Our patient was fluent in English and Hindi. She underwent a complete neurophysiologic cognitive assessment in both languages preoperatively. She was tested for speech arrest, nominal aphasia, and semantic paraphasia intraoperatively for both English and Hindi. She underwent a gross total resection with postoperative preservation of both English and Hindi. Intraoperative language mapping revealed that while certain cortical areas overlapped between 2 languages, other aspects were represented by distinct areas. Postoperative assessment at 2 months revealed most major aspects of language remained preserved or had improved relative to the preoperative baseline. CONCLUSIONS: Advancements in anesthesia and neuromonitoring have further allowed for long awake periods, permitting complex language tasks to be tested intraoperatively. The results obtained from this case study have allowed us to further plan for awake surgeries for patients with bilingualism. With understanding bilingual representation of languages, we hope to achieve maximal resection with minimal postoperative deficits.

Directional associations between memory impairment and depressive symptoms: data from a longitudinal sample and meta-analysis.

BACKGROUND: Previous cross-lagged studies on depression and memory impairment among the elderly have revealed conflicting findings relating to the direction of influence between depression and memory impairment. The current study aims to clarify this direction of influence by examining the cross-lagged relationships between memory impairment and depression in an Asian sample of elderly community dwellers, as well as synthesizing previous relevant cross-lagged findings via a meta-analysis. METHODS: A total of 160 participants (Mage = 68.14, s.d. = 5.34) were assessed across two time points (average of 1.9 years apart) on measures of memory and depressive symptoms. The data were then fitted to a structural equation model to examine two cross-lagged effects (i.e. depressive symptoms→memory; memory→depressive symptoms). A total of 14 effect-sizes for each of the two cross-lagged directions were extracted from six studies (including the present; total N = 8324). These effects were then meta-analyzed using a three-level mixed effects model. RESULTS: In the current sample, lower memory ability at baseline was associated with worse depressive symptoms levels at follow-up, after controlling for baseline depressive symptoms. However, the reverse effect was not significant; baseline depressive symptoms did not predict subsequent memory ability after controlling for baseline memory. The results of the meta-analysis revealed the same pattern of relationship between memory and depressive symptoms. CONCLUSIONS: These results provide robust evidence that the relationship between memory impairment and depressive symptoms is unidirectional; memory impairment predicts subsequent depressive symptoms but not vice-versa. The implications of these findings are discussed.

Neurocognitive similarities between severe chronic schizophrenia and behavioural variant frontotemporal dementia.

This study focuses on a group of patients with chronic schizophrenia who have a more severe form of the disorder, as indicated by socio-functional decline, treatment resistance, and recurrent hospitalisation. Previous research has suggested that the pattern and severity of cognitive deficits in people with severe chronic schizophrenia is similar to that observed in behavioural variant frontotemporal dementia (bvFTD). In the current study, we compared neurocognitive performance in 16 cognitive domains in 7 inpatients with severe chronic schizophrenia, 13 community-dwelling outpatients with chronic schizophrenia, 12 patients with bvFTD, and 18 healthy controls. Our findings revealed more similar cognitive profiles between the schizophrenia inpatient and bvFTD groups compared to the schizophrenia outpatient group, who outperformed the former groups. The current results provide preliminary evidence for a distinct schizophrenia subgroup, distinguishable from other chronic schizophrenia patients by poorer clinical and functional status, who have levels of cognitive impairment comparable to those seen in bvFTD patients.

Comparing neurocognition in severe chronic schizophrenia and frontotemporal dementia.

OBJECTIVE: Previous research has suggested cognitive similarities between schizophrenia and frontotemporal dementia. In the current study, we compared neurocognition in a group of hospitalised patients with chronic schizophrenia, who may have a more severe form of schizophrenia resembling Emil Kraepelin's dementia praecox, with patients with frontotemporal dementia. We hypothesised minimal group differences in cognitive performance, and a large overlap in between-group score distributions in each cognitive domain. METHODS: Retrospective neuropsychological data for 26 patients with severe chronic schizophrenia and 34 patients with frontotemporal dementia (behavioural variant) was collated. Neuropsychological measures were categorised into 16 cognitive domains. Raw scores were converted into standardised z-scores for each measure, which were then averaged across measures within each domain. In addition to difference analysis, equivalence testing was utilised, whereby overlap percentages were computed to reflect the amount of score distribution overlap in each domain between groups. RESULTS: A statistically significant difference was observed only in the executive function sub-domain of Switching. Small-to-moderate and moderate effect sizes were noted in four other domains. Equivalence testing showed more than 85% of overlap in score distribution in most domains. CONCLUSIONS: Our findings suggest that some patients with severe chronic schizophrenia have cognitive deficits similar in degree and pattern to patients with frontotemporal dementia. The few differences observed between both groups of patients are important for differential diagnostic purposes. One limitation is the retrospective nature of the study. Suggestions for future research include longitudinal follow-up studies of these two patient populations and studies of aspects beyond neurocognition. An implication of our findings is that the 'dementia of schizophrenia' concept may be applicable to patients with severe chronic schizophrenia.

Simultaneous backward conditioned inhibition and mediated conditioning.

Demonstrations of retrospective revaluation suggest that remembered stimuli undergo a reduction in association with the unconditioned stimulus (US) present during learning. Conversely, demonstrations of mediated conditioning in flavor-conditioning experiments with rats suggest that remembered stimuli undergo an increase in association with the US present during learning. In a food allergy prediction task with 23 undergraduates, we demonstrated simultaneous backward conditioned inhibition and mediated conditioning effects. These results are compatible with the hypothesis that the direction of change (decrease or increase) in associative strength depends on whether the remembered stimulus was of a different category (conditioned stimulus/antecedent) or the same category (US/outcome) as the presented US.

Spatial learning and memory in the tortoise (Geochelone carbonaria).

A single tortoise (Geochelone carbonaria) was trained in an eight-arm radial maze, with the apparatus and general procedures modeled on those used to demonstrate spatial learning in rats. The tortoise learned to perform reliably above chance, preferentially choosing baited arms, rather than returning to arms previously visited on a trial. Test sessions that examined control by olfactory cues revealed that they did not affect performance. No systematic, stereotyped response patterns were evident. In spite of differences in brain structure, the tortoise showed spatial learning abilities comparable to those observed in mammals.