Follow-Up Care for Brain Tumors in Low- and Middle-Income Countries: A Systematic Review of Existing Challenges and Strategies for the Future.

BACKGROUND AND OBJECTIVES: Brain tumors have a poor prognosis and a high death rate. Sufficient aftercare is necessary to enhance patient results. But follow-up care provision is fraught with difficulties in low- and middle-income countries (LMICs), where a variety of variables can impede access to care. Therefore, our systematic review aimed to identify challenges to follow-up care for brain tumors and possible solutions in LMICs. METHODS: A thorough search of the literature was performed from the beginning until October 20, 2022, using Google Scholar, PubMed, Scopus, and CINAHL. Studies focusing on the aftercare of brain tumors in LMICs met the inclusion criteria. Two reviewers used the National Surgical, Obstetric, and Anesthesia Plan categories to identify themes, extract relevant data, and evaluate individual articles. After being discovered, these themes were arranged in Microsoft Excel to make reporting and comprehension simpler. RESULTS: A total of 27 studies were included in the review. Among the studies included, the most frequently cited barriers to follow-up care were financial constraints (54%), long-distance travel (42%), and a lack of awareness about the importance of follow-up care (25%). Other challenges included preference for traditional or alternative medications (4%) and high treatment costs (8%). Proposed strategies included implementing mobile clinics (20%), establishing a documentation system (13%), and educating patients about the importance of follow-up care (7%). CONCLUSION: In LMICs, several issues pertaining to personnel, infrastructure, service delivery, financing, information management, and governance impede the provision of follow-up treatment for patients with brain tumors. As established by the suggested techniques found in the literature, addressing these issues will necessitate concurrent action by stakeholders, legislators, health ministries, and government agencies.

Financing of Neurosurgical Care for Brain Tumors in LMICs: A Scoping Review of Barriers and Strategies.

BACKGROUND: Making neurosurgical care accessible to a larger portion of the population in low- and middle-income countries (LMICs) is integral due to the high mortality and morbidity associated with brain tumors. However, the high cost of care often makes it financially out of reach for many individuals. Therefore, this review aims to identify barriers to neurosurgical care of brain tumors in terms of financing in LMICs. METHODS: Without restriction to language, a search of the literature was undertaken in a number of databases, including PubMed, Scopus, Google Scholar, and CINAHL, in order to find the most pertinent research involving financing of brain tumors in LMICs. The last day of the search was October 20, 2022. Following screening and data extraction, significant themes were found and categorized using thematic analysis. RESULTS: A total of 28 studies were analyzed in this review. The review highlighted some of the barriers to providing surgical care of brain tumors in LMICs. In the cited studies, surgical expenses (41%), neuroimaging costs (30%), and care-related expenses (33%) were the primary concerns. Addressing these challenges involves cross-border collaboration (23%), transparent financing systems (46%), awake craniotomy (15%), cost-effective/reusable intra-operative supplies (8%), and optimizing resources in healthcare systems (8%). CONCLUSION: This study explored barriers and challenges to financing neurosurgical care of brain tumors in LMICs. Government support and transparency in healthcare financing should be prioritized to ensure that all individuals have access to surgical care of brain tumors.

Neurosurgical Care of Brain Tumors in Low- and Middle-Income Countries: A Scoping Review of the Workforce Challenges.

BACKGROUND: Brain tumors pose a significant threat to public health, with high rates of mortality and morbidity, affecting individuals of all ages and having a significant impact on healthcare systems. Limited neurosurgical workforces remain one of the critical problems experienced in low resource settings. OBJECTIVE: To explore and summarize the key challenges to neurosurgical care of brain tumors in terms of workforce in LMICs METHODS: A comprehensive literature search was conducted using Scopus, PubMed, CINAHL, and Google Scholar from inception to October 20, 2022. All extracted data was screened independently by two reviewers and thematically analyzed. RESULTS: We found and screened 3764 articles, of which 33 studies were included in our final analysis as per our inclusion criteria. Among the studies included, 33% highlighted the limited number of neurosurgeons, 39% emphasized the absence of specialized surgical teams, 7% pointed out a shortage of nursing staff, and 4% noted suboptimal anesthesia teams. The study uncovered the need for improved training programs in neuro-oncology (32%) and neuro-anesthesia (3%), as well as improved collaboration (32%) and multidisciplinary team structures (15%), are essential for tackling these workforce challenges and improving patient outcomes. CONCLUSION: It is crucial to implement targeted interventions and policy changes to address the barriers to the workforce in providing effective neurosurgical care to patients with brain tumors in developing countries. This might entail capacity building and training programs for healthcare professionals. Policymakers should consider allocating resources and funding for workforce development and making neurosurgical care a priority in healthcare plans.

A guide to interpreting systematic reviews and meta-analyses in neurosurgery and surgery.

INTRODUCTION: Systematic reviews (SRs) and meta-analyses (MAs) are methods of data analysis used to synthesize information presented in multiple publications on the same topic. A thorough understanding of the steps involved in conducting this type of research and approaches to data analysis is critical for appropriate understanding, interpretation, and application of the findings of these reviews. METHODS: We reviewed reference texts in clinical neuroepidemiology, neurostatistics and research methods and other previously related articles on meta-analyses (MAs) in surgery. Based on existing theories and models and our cumulative years of expertise in conducting MAs, we have synthesized and presented a detailed pragmatic approach to interpreting MAs in Neurosurgery. RESULTS: Herein we have briefly defined SRs sand MAs and related terminologies, succinctly outlined the essential steps to conduct and critically appraise SRs and MAs. A practical approach to interpreting MAs for neurosurgeons is described in details. Based on summary outcome measures, we have used hypothetical examples to illustrate the Interpretation of the three commonest types of MAs in neurosurgery: MAs of Binary Outcome Measures (Pairwise MAs), MAs of proportions and MAs of Continuous Variables. Furthermore, we have elucidated on the concepts of heterogeneity, modeling, certainty, and bias essential for the robust and transparent interpretation of MAs. The basics for the Interpretation of Forest plots, the preferred graphical display of data in MAs are summarized. Additionally, a condensation of the assessment of the overall quality of methodology and reporting of MA and the applicability of evidence to patient care is presented. CONCLUSION: There is a paucity of pragmatic guides to appraise MAs for surgeons who are non-statisticians. This article serves as a detailed guide for the interpretation of systematic reviews and meta-analyses with examples of applications for clinical neurosurgeons.

A Two-Year Observational Study to Evaluate Conversion Rates from High- and Low-Risk Patients with Amnestic Mild Cognitive Impairment to Probable Alzheimer's Disease in a Real-World Setting.

Background: Predicting conversion to probable Alzheimer&s disease (AD) from amnestic mild cognitive impairment (aMCI) is difficult but important. A nomogram was developed previously for determining the risk of 3-year probable AD conversion in aMCI. Objective: To compare the probable AD conversion rates with cognitive and neurodegenerative changes for 2 years from high- and low risk aMCI groups classified using the nomogram. Methods: This prospective, multicenter, observational study was conducted in Korea. A total of patients were classified as high- or low-risk aMCI according to the nomogram and followed-up for 2 years to compare the annual conversion rate to probable AD and brain structure changes between the two groups. Results: In total, 176 (high-risk, 85; low-risk, 91) and 160 (high-risk, 77; low-risk, 83) patients completed the 1-year and 2-year follow-up, respectively. The probable AD conversion rate was significantly higher in the high-risk (Year 1, 28.9%; Year 2, 46.1%) versus low-risk group (Year 1, 0.0%; Year 2, 4.9%, both p < 0.0001). Mean changes from baseline in Seoul Neuropsychological Screening Battery-Dementia Version, Clinical Dementia Rating-Sum of Box, and Korean version of the Instrumental Activities of Daily Living scores and cortical atrophy index at Years 1 and 2 were significantly greater in the high-risk group (p < 0.0001). Conclusions: The high-risk aMCI group, as determined by the nomogram, had a higher conversion rate to probable AD and faster cognitive decline and neurodegeneration change than the low-risk group. These real-world results have clinical implications that help clinicians in accurately predicting patient outcomes and facilitating early decision-making.Trial Registration: ClinicalTrials.gov (NCT03448445).

Real-time analysis and prediction method of ion concentration using the effect of O-H stretching bands in aqueous solutions based on ATR-FTIR spectroscopy.

Analyzing the concentration of ions in aqueous solutions in real-time plays an important role in the fields of chemistry and biology. Traditional methods for measuring ion concentrations, such as concentration analysis by measuring electrical conductivity, inductively coupled plasma mass spectrometry, and ion chromatography, have been used in many research fields. However, these methods are limited in determining ion concentrations instantaneously. Fourier-transform infrared-attenuated total reflectance (ATR-FTIR) spectroscopy provides a new approach for determining ion concentrations in aqueous solutions. This allows for fast analysis without pretreatment and is scalable for real-time measurements. In this study, we present a method for measuring ion concentrations by examining ion-water interactions in the O-H stretching band of aqueous solutions using ATR-FTIR spectroscopy. Five aqueous solutions, namely LiCl + HCl, LiOH + HCl, LiOH, Li3PO4, and NaCl were used in the experiments and prepared at concentrations between 0.5-2 M. The ion concentrations in the prepared aqueous solutions were measured using ATR-FTIR spectroscopy. We observed that the difference in absorbance increased and decreased linearly with changes in concentration. The concentration of ions in the aqueous solution could be measured by validating the designed linear regression analysis function model. In this study, we proposed five linear regression analysis function models, all of which showed high coefficients of determination above 0.9, with the highest coefficient of determination reaching 0.9969. These results show that ATR-FTIR spectroscopy has the potential to be applied as a rapid and simple concentration analysis system.

Temporal Delays in the Management of Traumatic Brain Injury: A Comparative Meta-Analysis of Global Literature.

OBJECTIVE: A meta-analysis was conducted to compare: 1) time from traumatic brain injury (TBI) to the hospital, and 2) time within the hospital to intervention or surgery, by country-level income, World Health Organization region, and healthcare payment system. METHODS: A comprehensive literature search was conducted and followed by a meta-analysis comparing duration of delays (prehospital and intrahospital) in TBI management. Means and standard deviations were pooled using a random effects model and subgroup analysis was performed using R software. RESULTS: Our analysis comprised 95,554 TBI patients from 45 countries. BY COUNTRY-LEVEL INCOME: From 23 low- and middle-income countries, a longer mean time from injury to surgery (862.53 minutes, confidence interval [CI]: 107.42-1617.63), prehospital (217.46 minutes, CI: -27.34-462.25), and intrahospital (166.36 minutes, 95% CI: 96.12-236.60) durations were found compared to 22 high-income countries. BY WHO REGION: African Region had the greatest total (1062.3 minutes, CI: -1072.23-3196.62), prehospital (256.57 minutes [CI: -202.36-715.51]), and intrahospital durations (593.22 minutes, CI: -3546.45-4732.89). BY HEALTHCARE PAYMENT SYSTEM: Multiple-Payer Health Systems had a greater prehospital duration (132.62 minutes, CI: 54.55-210.68) but greater intrahospital delays were found in Single-Payer Health Systems (309.37 minutes, CI: -21.95-640.69). CONCLUSION: Our study concludes that TBI patients in low- and middle-income countries within African Region countries face prolonged delays in both prehospital and intrahospital management compared to high-income countries. Additionally, patients within Single-Payer Health System experienced prolonged intrahospital delays. An urgent need to address global disparities in neurotrauma care has been highlighted.

Barriers to Neurosurgical Care of Brain Tumors in Low- and Middle-Income Countries: A Systematic Review of the Service Delivery Challenges.

INTRODUCTION: Brain tumors pose a major challenge in low- and middle-income countries (LMICs) due to limited resources and high costs, resulting in hampered service delivery of neurosurgical care and significant disparities in patient outcomes compared to high-income nations. Therefore, our systematic review aims to identify barriers to service delivery in providing adequate surgical care for the management of brain tumors in LMICs. METHODS: We searched Scopus, PubMed, Google Scholar, and CINAHL, from inception to October 20, 2022. The data from the eligible studies were extracted and analyzed qualitatively. RESULTS: The final analysis included 35 articles, which highlighted significant challenges in providing adequate surgical care for brain tumors in LMICs. Among the cited studies, 10% reported lack of multidisciplinary team structures, 61% noted delayed patient presentation, 16% highlighted delays in neuroimaging, 10% reported delays in scheduling surgery, lack of training for specialized surgery (3%), lack of intra-operative facilities (19%), power supply interruption (6%), and lack of advanced diagnostic and specialized surgery facilities (19%). Strategies for addressing these challenges include cross-border collaboration (7%), public education, and awareness (13%), establishing multidisciplinary teams (20%), utilizing alternative surgical techniques (13%), 7% intraoperative ultrasound, 13% intraoperative cytology smear), and establishing satellite hospitals for low-risk care (7%), standard operating procedure and infection control (13%). CONCLUSION: Targeted interventions considering economic constraints are essential to improve the availability, affordability, and quality of neuro-oncologic services in developing countries. International collaborations and building capacity are vital for improving patient outcomes and service delivery, as well as forming multidisciplinary teams and utilizing resource-saving, innovative methods.

Ecuador’s National Surgical Strengthening Plan: first in Latin America, provides hope for surgical care agenda

Since 2015, there has been a notable increase in global efforts by various stakeholders to promote and advance surgical care policies, as proposed by the Lancet Commission on Global Surgery (LCoGS) namely, the development of the National Surgical Obstetric Anesthesia Planning (NSOAP), a country- driven framework that offers a comprehensive approach to health ministries to enhance their surgical systems. Ecuador has affirmed its position as a leading advocate for surgical care in Latin America. Following a two-year process, Ecuador is the first country in the Region of the Americas to launch an NSSP as a key component of a robust health system, including improving emergency responsiveness and pre- paredness

Understanding pediatric surgical needs in North Korea: a modeling analysis.

Background: Sixty-five percent of children worldwide lack access to surgical care, the majority of whom live in low-income and middle-income countries (LMICs). Developing surgical infrastructure requires information on surgical need; however, this information is often limited in LMICs. North Korea (Democratic People's Republic of Korea, DPRK) has a low amount of publicly available data. Here, we analyzed available modeled data to understand the causes of pediatric deaths due to conditions treatable with surgery in DPRK. Methods: We used World Bank data and models from the Institute for Health Metrics and Evaluation to identify causes of pediatric deaths affecting pediatric patients (age <20 years). We compared mortality of disease between DPRK and countries with similar economic status. Results: Between 1990 and 2019, the number of overall pediatric deaths has decreased. In 2019, 32.2% of all pediatric deaths in DPRK were caused by surgical conditions. The leading categories of surgical conditions were injuries (53.9%), congenital conditions (34.2%), tumors (8.8%), and abdominal conditions (3.2%). DPRK has a lower relative rate of pediatric deaths compared with other LMICs with similar gross domestic product per capita. However, it has a higher relative rate of pediatric deaths due to conditions requiring treatment with surgery. Transport injuries contribute significantly to the high rate of pediatric deaths in DPRK. Conclusions: Although DPRK may be allocating overall resources toward pediatric healthcare more efficiently than economic peers, DPRK may benefit from improvement in pediatric surgical capacity. Improved availability of data and close international collaboration could be potential solutions to bridge this gap.

The Usefulness of 18F-FDG PET to Differentiate Subtypes of Dementia: The Systematic Review and Meta-Analysis.

Background and Purpose: Dementia subtypes, including Alzheimer's dementia (AD), dementia with Lewy bodies (DLB), and frontotemporal dementia (FTD), pose diagnostic challenges. This review examines the effectiveness of 18F-Fluorodeoxyglucose Positron Emission Tomography (18F-FDG PET) in differentiating these subtypes for precise treatment and management. Methods: A systematic review following Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines was conducted using databases like PubMed and Embase to identify studies on the diagnostic utility of 18F-FDG PET in dementia. The search included studies up to November 16, 2022, focusing on peer-reviewed journals and applying the gold-standard clinical diagnosis for dementia subtypes. Results: From 12,815 articles, 14 were selected for final analysis. For AD versus FTD, the sensitivity was 0.96 (95% confidence interval [CI], 0.88-0.98) and specificity was 0.84 (95% CI, 0.70-0.92). In the case of AD versus DLB, 18F-FDG PET showed a sensitivity of 0.93 (95% CI 0.88-0.98) and specificity of 0.92 (95% CI, 0.70-0.92). Lastly, when differentiating AD from non-AD dementias, the sensitivity was 0.86 (95% CI, 0.80-0.91) and the specificity was 0.88 (95% CI, 0.80-0.91). The studies mostly used case-control designs with visual and quantitative assessments. Conclusions: 18F-FDG PET exhibits high sensitivity and specificity in differentiating dementia subtypes, particularly AD, FTD, and DLB. This method, while not a standalone diagnostic tool, significantly enhances diagnostic accuracy in uncertain cases, complementing clinical assessments and structural imaging.

Relationship Between Amyloid Positivity and Sleep Characteristics in the Elderly With Subjective Cognitive Decline.

Background and Purpose: Alzheimer's disease (AD) is a neurodegenerative disease characterized by a progressive decline in cognition and performance of daily activities. Recent studies have attempted to establish the relationship between AD and sleep. It is believed that patients with AD pathology show altered sleep characteristics years before clinical symptoms appear. This study evaluated the differences in sleep characteristics between cognitively asymptomatic patients with and without some amyloid burden. Methods: Sleep characteristics of 76 subjects aged 60 years or older who were diagnosed with subjective cognitive decline (SCD) but not mild cognitive impairment (MCI) or AD were measured using Fitbit® Alta HR, a wristwatch-shaped wearable device. Amyloid deposition was evaluated using brain amyloid plaque load (BAPL) and global standardized uptake value ratio (SUVR) from fluorine-18 florbetaben positron emission tomography. Each component of measured sleep characteristics was analyzed for statistically significant differences between the amyloid-positive group and the amyloid-negative group. Results: Of the 76 subjects included in this study, 49 (64.5%) were female. The average age of the subjects was 70.72±6.09 years when the study started. 15 subjects were classified as amyloid-positive based on BAPL. The average global SUVR was 1.598±0.263 in the amyloid-positive group and 1.187±0.100 in the amyloid-negative group. Time spent in slow-wave sleep (SWS) was significantly lower in the amyloid-positive group (39.4±13.1 minutes) than in the amyloid-negative group (49.5±13.1 minutes) (p=0.009). Conclusions: This study showed that SWS is different between the elderly SCD population with and without amyloid positivity. How SWS affects AD pathology requires further research.

Profile change of the volatile and non-volatile compounds in dried or baked laver by photooxidation.

Effects of light or dark storage condition on the profile changes of volatile and non-volatile compounds were evaluated in dried and baked laver for 60 days. Volatile and non-volatile compounds were analyzed using gas chromatography-mass selective detection and high-performance liquid chromatography-quadrupole-time of flight-mass spectrometry, respectively. Baked laver stored in light conditions for 60 days produced the most volatile compounds, whereas dried laver stored in the dark produced the least volatile compounds. Total 11 classes of volatile compounds were detected, including alkanes, alkenes, and ketones, with aldehydes being most abundant in dried laver stored under light. Metabolite analysis of non-volatile compounds led to the selection of 12 compounds with a higher variable importance projection (VIP) value of >1.0: 6 fatty acids (VIP 1.2-2.0), 2 flavanols (VIP 1.3-1.8), hydroxybenzoic acid (VIP 1.5), hydroxycinnamic acid (VIP 2.3), a phenolic acid ester (VIP 1.9), and phloroglucinol (VIP 1.2). Generally, levels of these compounds decreased more following storage in the light than under dark, irrespective of laver preparation. The content of linolenic acid was particularly affected by storage conditions, with light conditions causing a fourfold reduction in linolenic acid level compared with dark conditions, which could result in an increased formation of aldehydes. Gallic acid and sinapinic acid were detected in dried but not baked laver, as they are destroyed by heat treatment. Therefore, laver should be baked and stored in dark conditions to prevent the development of rancidity. PRACTICAL APPLICATION: Laver is one of the representative seaweeds, and the popularity among consumers increases. Although commercially available laver is prepared in dried or baked condition, scientific studies on the changes of metabolites, including volatile and non-volatile compounds during storage, are scarce. The results of this study can be applied to improve proper storage methods to maintain the quality of laver, which can be beneficial for consumers and food industry.

Neurosurgery and the World Health Organization Intersectoral Global Action Plan for Epilepsy and Other Neurological Disorders 2022-2031.

The World Health Organization's Intersectoral Global Action Plan (IGAP) on Epilepsy and Other Neurological Diseases 2022-2031 is a holistic, interdisciplinary, and intersectoral plan with a strong focus on equity and human rights. The IGAP was unanimously approved by all World Health Organization Member States at the 75th World Health Assembly in May 2022 and provides a framework for researchers and clinicians to study and address national and global inadequacies in the evaluation and management of people suffering from neurological disorders and their prevention. While IGAP has applied epilepsy as an entry point for other neurological disorders, advocacy by neurologists and neurosurgeons has broadened it to include diseases with a large and growing global health footprint such as stroke, hydrocephalus, traumatic brain injury, and brain and spine cancers. The IGAP is important to neurosurgeons globally because it provides the first ever roadmap for comprehensively addressing unmet neurological and neurosurgical care in low- and middle-income countries. Furthermore, it creates an opportunity for neurologists and neurosurgeons to scale up services for neurological diseases in tandem. As such, it provides a structure for the neurosurgery community to become involved in global health initiatives at all levels.

Global Neurosurgery at the 76th World Health Assembly (2023): First Neurosurgery-Driven Resolution Calls for Micronutrient Fortification to Prevent Spina Bifida.

Since 2018, a neurosurgery delegation has been actively engaged and consistently present at the World Health Assembly. Recognizing the growing impact of neurosurgical diseases, the neurosurgery delegation participated in the 76th World Health Assembly in May 2023, advocating for timely, safe, and affordable global neurosurgical care. The delegation focused on forging new collaborations, strengthening the World Health Organization-World Federation of Neurosurgical Societies official relations, and actively supporting resolutions that impact the neurosurgical patients. However, there is a long advocacy journey ahead to address unmet neurosurgical needs. Patient-centered advocacy is an inherent task of our profession and the essence of the Global Neurosurgery Bogota Declaration of 2016. The highlight of the 76th World Health Assembly was the adoption of the first neurosurgery-driven resolution calling for micronutrient fortification to prevent spina bifida and other micronutrient deficiencies. For the last 4 years, the Global Alliance for Prevention of Spina Bifida, a group spearheaded by neurosurgeons, advocated for spina bifida prevention. This Alliance collaborated with many stakeholders, notably, the Colombian government to promote the resolution: "Accelerating efforts for preventing micronutrient deficiencies and their consequences, including spina bifida and other neural tube defects, through safe and effective food fortification." This is a proud milestone for the neurosurgical profession. There are many strategies available for neurosurgeons, when working together with elected leaders, other stakeholders, and allied professionals, to implement initiatives that can prevent future cases of spina bifida and other neurological disorders and reduce the burden of neurosurgical disease.

Consensus-Based Development of a Global Registry for Traumatic Brain Injury: Establishment, Protocol, and Implementation.

BACKGROUND AND OBJECTIVES: Global disparity exists in the demographics, pathology, management, and outcomes of surgically treated traumatic brain injury (TBI). However, the factors underlying these differences, including intervention effectiveness, remain unclear. Establishing a more accurate global picture of the burden of TBI represents a challenging task requiring systematic and ongoing data collection of patients with TBI across all management modalities. The objective of this study was to establish a global registry that would enable local service benchmarking against a global standard, identification of unmet need in TBI management, and its evidence-based prioritization in policymaking. METHODS: The registry was developed in an iterative consensus-based manner by a panel of neurotrauma professionals. Proposed registry objectives, structure, and data points were established in 2 international multidisciplinary neurotrauma meetings, after which a survey consisting of the same data points was circulated within the global neurotrauma community. The survey results were disseminated in a final meeting to reach a consensus on the most pertinent registry variables. RESULTS: A total of 156 professionals from 53 countries, including both high-income countries and low- and middle-income countries, responded to the survey. The final consensus-based registry includes patients with TBI who required neurosurgical admission, a neurosurgical procedure, or a critical care admission. The data set comprised clinically pertinent information on demographics, injury characteristics, imaging, treatments, and short-term outcomes. Based on the consensus, the Global Epidemiology and Outcomes following Traumatic Brain Injury (GEO-TBI) registry was established. CONCLUSION: The GEO-TBI registry will enable high-quality data collection, clinical auditing, and research activity, and it is supported by the World Federation of Neurosurgical Societies and the National Institute of Health Research Global Health Program. The GEO-TBI registry ( https://geotbi.org ) is now open for participant site recruitment. Any center involved in TBI management is welcome to join the collaboration to access the registry.

A Longitudinal Study on Memory Enhancement in Subjective Cognitive Decline Patients: Clinical and Neuroimaging Perspectives.

BACKGROUND: Subjective cognitive decline (SCD) refers to the self-reported persistent cognitive decline despite normal objective testing, increasing the risk of dementia compared to cognitively normal individuals. OBJECTIVE: This study aims to investigate the attributes of SCD patients who demonstrated memory function improvement. METHODS: In this prospective study of SCD, a total of 120 subjects were enrolled as part of a multicenter cohort study aimed at identifying predictors for the clinical progression to mild cognitive impairment or dementia (CoSCo study). All subjects underwent 18F-florbetaben PET and brain MRI scans at baseline and annual neuropsychological tests. At the 24-month follow-up, we classified SCD patients based on changes in memory function, the z-score of the Seoul verbal learning test delayed recall. RESULTS: Of the 120 enrolled patients, 107 successfully completed the 24-month follow-up assessment. Among these, 80 patients (74.8%) with SCD exhibited memory function improvements. SCD patients with improved memory function had a lower prevalence of coronary artery disease at baseline and performed better in the trail-making test part B compared to those without improvement. Anatomical and biomarker analysis showed a lower frequency of amyloid PET positivity and larger volumes in the left and right superior parietal lobes in subjects with improved memory function. CONCLUSIONS: Our prospective study indicates that SCD patients experiencing memory improvement over a 24-month period had a lower amyloid burden, fewer cardiovascular risk factors, and superior executive cognitive function. Identifying these key factors associated with cognitive improvement may assist clinicians in predicting future memory function improvements in SCD patients.