7 research outputs found
Consensus guidelines for the management of intracranial ependymoma for low- and middle-income countries
This paper presents comprehensive consensus guidelinesfor the management of intracranial ependymoma,neoplasms arising from ependymal cells in the centralnervous system's ventricular system, in low- and middleincomecountries (LMICs). Acknowledging the distinctepidemiological patterns of ependymomas, notably theirhigher incidence in paediatric patients, and variablesurvival rates, these guidelines emphasize tailoredmanagement approaches for different age groups. Anexpert panel, comprising specialists in neuro-oncology,convened to address gaps in diagnosis and managementwithin LMICs, considering the varying clinicalpresentation based on tumour size and location.Emphasizing surgical intervention as the cornerstone oftreatment, the guidelines also address challenges such asintraoperative bleeding and tumour location impactingcomplete resection. The role of molecular subgrouping instratifying treatment and predicting prognosis ishighlighted, alongside a careful consideration ofradiotherapy timing, dose, and volume based on riskfactors. Chemotherapy's role, especially in paediatriccases, is explored. The paper synthesizes current researchand expert opinions, including the need forstandardisation, genetic testing, and exploration of lessinvasive treatment modalities, to address the uniquehealthcare infrastructure challenges in LMICs. Theguidelines also emphasize multidisciplinary teams,aiming to bridge the care gap between high-incomecountries and LMICs, and improve survival rates andquality of life for patients with intracranial ependymoma.This article serves as a valuable resource for clinicians,researchers, and policymakers in Pakistan and beyond,facilitating the development of evidence-based strategiesin diverse healthcare settings.
Keywords: Nervous system, genetic, ependymoma,prognosis, ependymoma, surgery, radiotherapy
Default Mode Network and Neural Phase Synchronization in Healthy Aging: A Resting State EEG Study
The Effects of Aging and Time of Day on Inhibitory Control: An Event-Related Potential Study
Time of day (TOD) influences on executive functions have been widely reported, with greater efficiency demonstrated at optimal relative to non-optimal TOD according to one’s chronotype (i.e., synchrony effect). Older adults (OAs) show declines in inhibitory control and are more sensitive to the effects of circadian variation on executive functioning. To date, no studies have investigated the effects of TOD and aging on executive functioning using electrophysiological measures. The present study investigated the effects of aging and TOD on the neural correlates of inhibitory processing (N2 and P3) using event-related potentials (ERPs). Go-NoGo and Flanker tasks were administered to 52 OAs of morning chronotype and 51 younger adults (YAs) of afternoon-to-evening chronotype who were randomly assigned to morning or afternoon test sessions, with the optimal TOD for OAs in the morning and for YAs in the afternoon/evening. While behavioral results demonstrated no TOD effects, ERPs indicated synchrony effects. Both YAs and OAs showed greater modulation of Go-NoGo N2 and greater P3 amplitude during the non-optimal than optimal TOD, consistent with the synchrony effect. For the Flanker task, age differences in P3 amplitude were only apparent during the non-optimal TOD. These results suggest that processes associated with inhibitory control are differentially affected by TOD and aging, with age-related reductions in inhibitory efficiency during off-peak test times on measures of interference control. These findings highlight the sensitivity of ERPs to detect TOD effects in the absence of behavioral differences, confirm more pronounced TOD effects in OAs relative to YAs on ERP measures of interference control, and reinforce the need to assess and control for circadian typology in research studies.</jats:p
Reaction Time Intraindividual Variability Reveals Inhibitory Deficits in Single- and Multiple-Domain Amnestic Mild Cognitive Impairment
Abstract
Objectives
Amnestic mild cognitive impairment (aMCI), a prodromal stage of Alzheimer’s disease and other dementias, is characterized by episodic memory impairment. Recent evidence has shown inhibitory control deficits in aMCI, but the extent of these deficits across inhibitory domains (i.e., response inhibition and interference control) and aMCI subtypes (i.e., single vs multiple domain) remains unclear. Few studies have included reaction time intraindividual variability (RT IIV) in these efforts. The aim of this study was to compare response inhibition and interference control between aMCI subtypes using measures of accuracy, mean RT, and RT IIV.
Methods
We report data from 34 individuals with single-domain aMCI (sdaMCI, 66–86 years), 20 individuals with multiple-domain aMCI (mdaMCI, 68–88 years), and 52 healthy controls (HC, 64–88 years) who completed tasks of response inhibition (Go–NoGo) and interference control (Flanker). Group differences in accuracy, mean RT, and RT IIV were examined for both tasks.
Results
Individuals with mdaMCI had higher RT IIV than the other groups on both tasks. In RT IIV, we observed an interference control deficit in mdaMCI and sdaMCI relative to healthy controls, a finding not observed through accuracy or mean RT.
Discussion
RT IIV may detect subtle differences in inhibition deficits between aMCI subtypes that may not be evident with conventional behavioral measures. Findings support the supplementary use of RT IIV when assessing early executive function deficits.
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Consensus guidelines for the management of intracranial ependymoma for low- and middle-income countries
This paper presents comprehensive consensus guidelines for the management of intracranial ependymoma, neoplasms arising from ependymal cells in the central nervous system\u27s ventricular system, in low- and middleincome countries (LMICs). Acknowledging the distinct epidemiological patterns of ependymomas, notably their higher incidence in paediatric patients, and variable survival rates, these guidelines emphasize tailored management approaches for different age groups. An expert panel, comprising specialists in neuro-oncology, convened to address gaps in diagnosis and management within LMICs, considering the varying clinical presentation based on tumour size and location. Emphasizing surgical intervention as the cornerstone of treatment, the guidelines also address challenges such as intraoperative bleeding and tumour location impacting complete resection. The role of molecular subgrouping in stratifying treatment and predicting prognosis is highlighted, alongside a careful consideration of radiotherapy timing, dose, and volume based on risk factors. Chemotherapy\u27s role, especially in paediatric cases, is explored. The paper synthesizes current research and expert opinions, including the need for standardisation, genetic testing, and exploration of less invasive treatment modalities, to address the unique healthcare infrastructure challenges in LMICs. The guidelines also emphasize multidisciplinary teams, aiming to bridge the care gap between high-income countries and LMICs, and improve survival rates and quality of life for patients with intracranial ependymoma. This article serves as a valuable resource for clinicians, researchers, and policymakers in Pakistan and beyond, facilitating the development of evidence-based strategies in diverse healthcare settings
Data_Sheet_1_The Effects of Aging and Time of Day on Inhibitory Control: An Event-Related Potential Study.pdf
Time of day (TOD) influences on executive functions have been widely reported, with greater efficiency demonstrated at optimal relative to non-optimal TOD according to one’s chronotype (i.e., synchrony effect). Older adults (OAs) show declines in inhibitory control and are more sensitive to the effects of circadian variation on executive functioning. To date, no studies have investigated the effects of TOD and aging on executive functioning using electrophysiological measures. The present study investigated the effects of aging and TOD on the neural correlates of inhibitory processing (N2 and P3) using event-related potentials (ERPs). Go-NoGo and Flanker tasks were administered to 52 OAs of morning chronotype and 51 younger adults (YAs) of afternoon-to-evening chronotype who were randomly assigned to morning or afternoon test sessions, with the optimal TOD for OAs in the morning and for YAs in the afternoon/evening. While behavioral results demonstrated no TOD effects, ERPs indicated synchrony effects. Both YAs and OAs showed greater modulation of Go-NoGo N2 and greater P3 amplitude during the non-optimal than optimal TOD, consistent with the synchrony effect. For the Flanker task, age differences in P3 amplitude were only apparent during the non-optimal TOD. These results suggest that processes associated with inhibitory control are differentially affected by TOD and aging, with age-related reductions in inhibitory efficiency during off-peak test times on measures of interference control. These findings highlight the sensitivity of ERPs to detect TOD effects in the absence of behavioral differences, confirm more pronounced TOD effects in OAs relative to YAs on ERP measures of interference control, and reinforce the need to assess and control for circadian typology in research studies.</p
Intraoperative mapping and preservation of executive functions in awake craniotomy: A systematic review
Awake craniotomy (AC) allows intraoperative brain mapping (ioBM) for maximum lesion resection while monitoring and preserving neurological function. Conventionally, language, visuospatial assessment, and motor functions are mapped, while the assessment of executive functions (EF) is uncommon. Impaired EF may lead to occupational, personal, and social limitations, thus, a compromised quality of life. A comprehensive literature search was conducted through Scopus, Medline, and Cochrane Library using a pre-defined search strategy. Articles were selected after duplicate removal, initial screening, and full-text assessment. The demographic details, ioBM techniques, intraoperative tasks, and their assessments, the extent of resection (EOR), post-op EF and neurocognitive status, and feasibility and potential adverse effects of the procedure were reviewed. The correlations of tumor locations with intraoperative EF deficits were also assessed. A total of 13 studies with intraoperative EF assessment of 351 patients were reviewed. Awake-asleep-awake protocol was most commonly used. Most studies performed ioBM using bipolar stimulation, with a frequency of 60 Hz, pulse durations ranging 1-2 ms, and intensity ranging 2-6 mA. Cognitive function was monitored with the Stroop task, spatial-2-back test, line-bisection test, trail-making-task, and digit-span tests. All studies reported similar or better EOR in patients with ioBM for EF. When comparing the neuropsychological outcomes of patients with ioBM of EF to those without it, all studies reported significantly better EF preservation in ioBM groups. Most authors reported EF mapping as a feasible tool to obtain satisfactory outcomes. Adverse effects included intraoperative seizures which were easily controlled. AC with ioBM of EF is a safe, effective, and feasible technique that allows satisfactory EOR and improved neurocognitive outcomes with minimal adverse effects
