Normal Elderly Population Research Articles

A - 12 Neuropsychological Test Best Fit for Identifying on-the-Road Driving Behaviors in Normal and Abnormal Aging Populations: a Systematic Review

Abstract Objective This systematic review’s purpose is to identify neuropsychological assessments that are accurate at predicting driving behaviors in geriatric populations. The population included normal aging, mild cognitive impairment (MCI), and dementia. Data Selection PubMed and APA PsycNet databases were searched using two separate keyword searches: cognitive evaluation and driving behaviors and aging; neuropsychological test and driving behaviors and aging. The databases were searched March 10, 2024, and again on April 26, 2024. This yielded 278 articles. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) method was used to identify articles. Articles were excluded if they did not have on-road driving behaviors or simulated driving behaviors, neuropsychological test, if the average participant age was not geriatric, or if it was a non-peer reviewed article. Data Synthesis After following PRISMA selections, eight articles were included, creating a combined sample size of 927 (Mean age = 74.16, SD = 2.38; mean years of education = 14.17, SD = 1.09; female percentage = 40.78). The test deemed most correlated were Neuropsychological Assessment Battery: Driving Scene Test, Clock Drawing, Useful Field of View, Trail making task, Mini-Mental State Exam, verbal and visual memory components from the Wechsler Memory Scale, Rey-Osterrieth Complex Figure, and Maze Navigation Task. Conclusion General cognitive screening tests as well as visuomotor, visual–spatial, visual attention and verbal and non-verbal memory tests highly correlate with real driving behaviors and accurately predict on-the-road driving behaviors. This indicates the cognitive and behavioral complexity of driving. Though these tests accurately predict driving behaviors, their abilities to do so may differ depending on cultural groups.

Definition and analysis of gray matter atrophy subtypes in mild cognitive impairment based on data-driven methods.

Mild cognitive impairment (MCI) is an important stage in Alzheimer's disease (AD) research, focusing on early pathogenic factors and mechanisms. Examining MCI patient subtypes and identifying their cognitive and neuropathological patterns as the disease progresses can enhance our understanding of the heterogeneous disease progression in the early stages of AD. However, few studies have thoroughly analyzed the subtypes of MCI, such as the cortical atrophy, and disease development characteristics of each subtype. In this study, 396 individuals with MCI, 228 cognitive normal (CN) participants, and 192 AD patients were selected from ADNI database, and a semi-supervised mixture expert algorithm (MOE) with multiple classification boundaries was constructed to define AD subtypes. Moreover, the subtypes of MCI were obtained by using the multivariate linear boundary mapping of support vector machine (SVM). Then, the gray matter atrophy regions and severity of each MCI subtype were analyzed and the features of each subtype in demography, pathology, cognition, and disease progression were explored combining the longitudinal data collected for 2 years and analyzed important factors that cause conversion of MCI were analyzed. Three MCI subtypes were defined by MOE algorithm, and the three subtypes exhibited their own features in cortical atrophy. Nearly one-third of patients diagnosed with MCI have almost no significant difference in cerebral cortex from the normal aging population, and their conversion rate to AD are the lowest. The subtype characterized by severe atrophy in temporal lobe and frontal lobe have a faster decline rate in many cognitive manifestations than the subtype featured with diffuse atrophy in the whole cortex. APOE ε4 is an important factor that cause the conversion of MCI to AD. It was proved through the data-driven method that MCI collected by ADNI baseline presented different subtype features. The characteristics and disease development trajectories among subtypes can help to improve the prediction of clinical progress in the future and also provide necessary clues to solve the classification accuracy of MCI.

Data-driven clustering approach to identify novel clusters of high cognitive impairment risk among Chinese community-dwelling elderly people with normal cognition: A national cohort study.

Cognitive impairment is a highly heterogeneous disorder that necessitates further investigation into the distinct characteristics of populations at varying risk levels of cognitive impairment. Using a large-scale registry cohort of elderly individuals, we applied a data-driven approach to identify novel clusters based on diverse sociodemographic features. A prospective cohort of 6398 elderly people from the Chinese Longitudinal Healthy Longevity Survey, followed between 2008-14, was used to develop and validate the model. Participants were aged ≥60 years, community-dwelling, and the Chinese version of the Mini-Mental State Examination (MMSE) score ≥18 were included. Sixty-nine sociodemographic features were included in the analysis. The total population was divided into two-thirds for the derivation cohort (n = 4265) and one-third for the validation cohort (n = 2133). In the derivation cohort, an unsupervised Gaussian mixture model was applied to categorise participants into distinct clusters. A classifier was developed based on the most important 10 factors and was applied to categorise participants into their corresponding clusters in a validation cohort. The difference in the three-year risk of cognitive impairment was compared across the clusters. We identified four clusters with distinct features in the derivation cohort. Cluster 1 was associated with the worst life independence, longest sleep duration, and the oldest age. Cluster 2 demonstrated the highest loneliness, characterised by non-marital status and living alone. Cluster 3 was characterised by the lowest sense of loneliness and the highest proportions in marital status and family co-residence. Cluster 4 demonstrated heightened engagement in exercise and leisure activity, along with independent decision-making, hygiene, and a diverse diet. In comparison to Cluster 4, Cluster 1 exhibited the highest three-year cognitive impairment risk (adjusted odds ratio (aOR) = 3.31; 95% confidence interval (CI) = 1.81-6.05), followed by Cluster 2 and Cluster 3 after adjustment for baseline MMSE, residence, sex, age, years of education, drinking, smoking, hypertension, diabetes, heart disease and stroke or cardiovascular diseases. A data-driven approach can be instrumental in identifying individuals at high risk of cognitive impairment among cognitively normal elderly populations. Based on various sociodemographic features, these clusters can suggest individualised intervention plans.

Natural History of Intradiscal Vacuum Phenomenon and its Role in Advanced Disc Degeneration.

Observational serial computed tomography (CT) analysis of the lumbar spine in a normal-aging population. To assess the natural history of the intradiscal vacuum phenomenon (IDVP) and its role in disc degeneration. The natural history of disc degeneration is well described but our understanding of the end stage of pathogenesis remains incomplete. Magnetic resonance imaging loses accuracy with advanced degeneration, becoming hyporesonant and indistinct. Cadaveric specimens display adaptive changes in the disc with loss of the hydrostatic capacity of the nucleus, increased intradiscal clefts, and endplate impermeability. IDVP is associated with advanced disc degeneration and CT is the optimal modality to visualize this, yet these insights remain unreported. Patients only included historic CT abdomen scans of those over 60 years of age without acute or relevant spinal pathology, with a diagnosis of at least one level with IDVP on the original CT scan, and all of whom had a similar scan >7 years later. A history of clinically significant back pain was also recorded. CT scans included 360 levels in 29 males and 31 females (mean: 68.9 y), displaying 82 levels of IDVP, with a second scan included after a mean of 10.3 years. Most levels displayed the same level of severity (persisted, 45) compared with where some progressed (26), regressed (8), and fused (3; P < 0.01). There was also an increased incidence, 37/60 (62%) of developing IDVP at another level. Disc heights were reduced with increased severity of IDVP. A record of back pain was evident in 31/60 patients, which was not significantly worse in those with worsening severity or additional level involvement over the study period. As disc degeneration advances, the associated IDVP persists in most cases, displaying a plateauing of severity over long periods, but rarely with progression to autofusion.

PREVALENCE AND SEVERITY OF INTRA-DISCAL VACUUM PHENOMENON IN A NORMAL AGEING POPULATION

Intra-Discal Vacuum Phenomenon (IDVP) represents an intradiscal nitrogen gas accumulation where a cavity opens in a supine position, lowering intra-discal pressure and generating a bubble. IDVP has been observed in up to 20% of elderly patients and reported in almost 50% of chronic LBP patients. With a highly accurate detection on CT, its significance lacks clarity and consideration within normative data. IDVP occurs with patterns of lumbar and/or lumbopelvic morphology and associated diagnoses. Over-60s population based sample of 2020 unrelated CT abdomen scans without acute spinal presentations, with sagittal reconstructions, inclusive of T12 to femoral heads, were analyzed for IDVP and pelvic incidence (PI). Subjects with diagnostic morphological associations of the lumbar spine, including previous fracture, autofusion, transitional vertebra and listhesis, were selected out and analyzed separately. Subjects were then equally grouped into low, medium and high PI. Prevalence of lumbar spine IDVP is 41.3%. 125 cases were excluded. 1603 subjects yielded 663 IDVP. This was increased in severity towards the lumbosacral junction (L1L2 9.4%, L2L3 10.9%, L3L4 13.7%, L4L5 19.9%, L5S1 28.5%) and those with low PI, while distribution was more even with high PI. 292 had positive diagnostic associations, which were more likely to occur at the level of isthmic spondylolisthesis, adjacent to a previous fracture or suprajacent to lumbosacral transitional vertebra (p&lt;0.05).This study has identified normative values for prevalence and severity of IDVP in a normal aging population. Morphological patterns that influence the pattern of IVDP such as pelvic incidence and diagnostic associations provide novel insights to the function of the aging spine.

Speech Acoustic Parameters for Predicting Presbyphagia: A Preliminary Study in the Elderly Shanghainese Population

PurposeAge is a high-risk factor for dysphagia. Speech and swallowing share the same anatomical and neurophysiological basis. Their functions are closely related; hence, speech assessment can predict the risk of dysphagia. This study aimed to investigate the factors influencing presbyphagia in a normal elderly Shanghainese population by analyzing speech acoustic parameters. MethodsRelevant speech acoustic parameters were compared between 15 people with dysphagia and 15 without dysphagia. After extracting sensitive speech acoustic parameters related to swallowing, changes in sensitive parameters were compared at different ages to analyze the relevant factors influencing presbyphagia in the normal elderly population. ResultsEight speech acoustic parameters related to swallowing, including maximum phonation time (MPT), max F0, /ʔʌ/Jitter, /ʔʌ/L-DDK, /hʌ/L-DDK, /pataka/DDK, F1/a/, and vowel space area, were extracted after comparing the relevant data between the two groups. Analyzing the changes in each of these parameters between different age groups (age 18–39, 40–64, and 65 and above), we discovered that three speech acoustic parameters, including MPT, /hʌ/L-DDK, and /pataka/DDK, had statistical differences, with a decreasing trend in their mean values with increasing age. ConclusionsThe elderly group had significantly lower MPT, /hʌ/L-DDK, and /pataka/DDK than the young and middle-aged groups. We hypothesized that reduced respiratory support and control, decreased range of mouth movements and coordination, closed control of the vocal cords, and inadequate airflow control in vocal cord abduction are risk factors for presbyphagia in the elderly Shanghainese population.

The relationship between hippocampal changes in healthy aging and Alzheimer's disease: a systematic literature review.

Neurobiological changes in the hippocampus are a common consequence of aging. However, there are differences in the rate of decline and overall volume loss in people with no cognitive impairment compared to those with mild cognitive impairment (MCI) and Alzheimer's disease (AD). This systematic literature review was conducted to determine the relationship between hippocampal atrophy and changes in hippocampal volume in the non-cognitively impaired brain and those with MCI or AD. This systematic review was guided by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) methodology. The PubMed database was searched up to September 15, 2022, for longitudinal magnetic resonance imaging studies reporting hippocampal atrophy or volume change in cognitively normal aging individuals and patients with MCI and/or AD. Study selection was divided into two steps: (1) identification and retrieval of relevant studies; (2) screening the studies by (a) title/abstract and (b) full text. Two teams, each consisting of two independent reviewers, determined whether the publications met the inclusion criteria for the systematic review. An evidence table was populated with data extracted from eligible publications and inclusion in the final systematic review was confirmed. The systematic search identified 357 publications that were initially screened by title/abstract, of which, 115 publications were retrieved and reviewed by full text for eligibility. Seventeen publications met the eligibility criteria; however, during data extraction, two studies were determined to not meet the inclusion criteria and were excluded. The remaining 15 studies were included in the systematic review. Overall, the results of these studies demonstrated that the hippocampus and hippocampal subfields change over time, with both decreased hippocampal volume and increased rate of hippocampal atrophy observed. Hippocampal changes in AD were observed to be greater than hippocampal changes in MCI, and changes in MCI were observed to be greater than those in normal aging populations. Published literature suggests that the rate of hippocampal decline and extent of loss is on a continuum that begins in people without cognitive impairment and continues to MCI and AD, and that differences between no cognitive impairment, MCI, and AD are quantitative rather than qualitative.

Determination of the Trans-Lamina Cribrosa Pressure Difference in a Community-Based Population and its Association with Open-Angle Glaucoma

To determine the trans-lamina cribrosa pressure difference (TLCPD) in a cohort of normal community-based patients and the relationship to primary open-angle glaucoma (POAG) and normal-tension glaucoma (NTG). Retrospective cohort study of the Mayo Clinic Study of Aging. The Mayo Clinic Study of Aging is a prospective study evaluating the normal aging population. Mayo Clinic Study of Aging patients who underwent routine lumbar puncture (LP) studies with eye examinations were reviewed. The trans-lamina cribrosa pressure difference was calculated in 2 contexts of intraocular pressure (IOP): (1) maximum IOP at eye visit closest in time to the LP (closest-in-time TLCPD); and (2) IOP before IOP-lowering treatment (pretreatment IOP and pretreatment TLCPD) in POAG and NTG patients. Glaucoma patients without POAG or NTG were excluded. Regression analyses were performed to determine the relationship with glaucoma. IOP, intracranial pressure, TLCPD, POAG, normal-tension glaucoma (NTG) diagnosis, glaucoma parameters. Five hundred forty-eight patients were analyzed. Of these, there were 38 treated glaucoma patients (14 POAG and 24 NTG) and 510 nonglaucomatous patients. Cerebral spinal fluid (CSF) opening pressure was 155.0 ± 42.2 mmH2O in nonglaucomatous patients, 144.0 ± 34.0 mmH2O in POAG (P= 0.15 vs. nonglaucomatous patients), and 136.6 ± 29.3 mmH2O in NTG (P= 0.017 vs. nonglaucomatous patients). Intraocular pressure was 15.47 ± 2.9 mmHg in nonglaucomatous patients, 26.6 ± 3.7 mmHg in POAG, and 17.4 ± 3.4 mmHg in NTG. The closest-in-time TLCPD in the nonglaucomatous cohort was 4.07 ± 4.22 mmHg, which was lower than both the POAG cohort (7.19 ± 3.6 mmHg) and the NTG cohort (5.79 ± 4.5 mmHg, P= 0.04). Pretreatment TLCPD for the overall glaucoma cohort was 10.57 ± 6.1 mmHg. The POAG cohort had a higher pretreatment TLCPD (16.05 ± 5.2 mmHg) than the NTG cohort (7.37 ± 4.1 mmHg; P < 0.0001). Closest-in-time TLCPD for the nonglaucoma cohort (4.07± 4.2 mmHg) was significantly lower than pretreatment TLCPDs for both POAG (16.05 ± 5.2 mmHg; P < 0.0001) and NTG (7.37 ± 4.1 mmHg; P < 0.0001) cohorts. This study establishes the baseline TLCPD in a large cohort of normal, community-based patients. The differences in regression analysis between TLCPD and IOP suggests NTG pathophysiology is partially driven by TLCPD, but is also likely multifactorial. Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Glymphatic function plays a protective role in ageing-related cognitive decline

Abstract Objective The glymphatic pathway, characterised as a cerebral drainage system, influences cognitive function in neurodegenerative diseases; however, evidence is limited in a normal ageing population. The aim of this study was to investigate the effect of glymphatic function on ageing-related cognitive decline. Methods We retrospectively reviewed the Cognitive Impairment, Retinopathy, and Cerebrovascular Lesions in the Elderly (CIRCLE) study, and participants with multi-model magnetic resonance imaging (MRI) scans and Mini-Mental State Examinations (MMSE) were enrolled. Glymphatic function was evaluated via the diffusion tensor imaging along the perivascular space (DTI-ALPS) index. Regression models were used to estimate the impact of the DTI-ALPS index on cognitive decline cross-sectionally and longitudinally. We further analysed the mediation effect of the DTI-ALPS on age and cognitive function. Results A total of 633 participants were included in this study (48.2% female; mean age, 62.8 ± 8.9 years). The DTI-ALPS index was positively associated with cognitive function cross-sectionally (β = 0.108, P = 0.003), and was an independent protective factor for cognitive decline longitudinally (odds ratio (OR) = 0.029, P = 0.007). The DTI-ALPS index declined progressively with ageing (r = −0.319, P &amp;lt;0.001), and the decrease was more pronounced after 65 years of age. Furthermore, the DTI-ALPS index mediated the relationship between age and MMSE score (β = −0.016, P &amp;lt;0.001). The mediation effect accounted for 21.3%, which was higher in subjects aged over 65 years (25.3%) compared with those aged under 65 years (5.3%). Conclusion Glymphatic function played a protective role in normal ageing-related cognitive decline, which may serve as a potential therapeutic target against cognitive decline in future.

Plasma biomarkers predict amyloid pathology in cognitively normal monozygotic twins after 10 years.

Blood-based biomarkers could prove useful to predict Alzheimer's disease core pathologies in advance of clinical symptoms. Implementation of such biomarkers requires a solid understanding of their long-term dynamics and the contribution of confounding to their association with Alzheimer's disease pathology. Here we assess the value of plasma amyloid-β1-42/1-40, phosphorylated-tau181 and glial fibrillary acidic protein to detect early Alzheimer's disease pathology, accounting for confounding by genetic and early environmental factors. Participants were 200 monozygotic twins, aged ≥60 years with normal cognition from the european medical information framework for Alzheimer's disease study. All twins had amyloid-β status and plasma samples available at study enrolment. For 80 twins, additional plasma samples were available that had been collected approximately 10 years prior to amyloid-β status assessment. Single-molecule array assays were applied to measure amyloid-β1-42/1-40, phosphorylated-tau181 and glial fibrillary acidic protein. Predictive value of and longitudinal change in these biomarkers were assessed using receiver operating characteristic curve analysis and linear mixed models. Amyloid pathology could be predicted using blood-based biomarkers obtained at the time of amyloid status assessment (amyloid-β1-42/1-40: area under the curve = 0.65, P = 0.01; phosphorylated-tau181: area under the curve = 0.84, P < 0.001; glial fibrillary acidic protein: area under the curve = 0.74, P < 0.001), as well as using those obtained 10 years prior to amyloid status assessment (amyloid-β1-42/1-40: area under the curve = 0.69, P = 0.03; phosphorylated-tau181: area under the curve = 0.92, P < 0.001; glial fibrillary acidic protein: area under the curve = 0.84, P < 0.001). Longitudinally, amyloid-β1-42/1-40 levels decreased [β (SE) = -0.12 (0.01), P < 0.001] and phosphorylated-tau181 levels increased [β (SE) = 0.02 (0.01), P = 0.004]. Amyloid-β-positive individuals showed a steeper increase in phosphorylated-tau181 compared with amyloid-β-negative individuals [β (SE) = 0.06 (0.02), P = 0.004]. Also amyloid-β-positive individuals tended to show a steeper increase in glial fibrillary acidic protein [β (SE) = 0.04 (0.02), P = 0.07]. Within monozygotic twin pairs, those with higher plasma phosphorylated-tau181 and lower amyloid-β1-42/1-40 levels were more likely to be amyloid-β positive [β (SE) = 0.95 (0.26), P < 0.001; β (SE) = -0.28 (0.14), P < 0.05] indicating minimal contribution of confounding by genetic and early environmental factors. Our data support the use of amyloid-β1-42/1-40, phosphorylated-tau181 and glial fibrillary acidic protein as screening tools for Alzheimer's disease pathology in the normal aging population, which is of importance for enrolment of high-risk subjects in secondary, or even primary, prevention trials. Furthermore, these markers show potential as low-invasive monitoring tool of disease progression and possibly treatment effects in clinical trials.

Value of plasma biomarkers to predict memory change in cognitively unimpaired individuals

AbstractBackgroundPlasma levels of amyloid‐β1‐42/1‐40, phosphorylated‐tau (P‐tau) and glial fibrillary acidic protein (GFAP) can be used to predict amyloid‐β pathology in elderly cognitively unimpaired individuals, but their prognostic value in early Alzheimer’s Disease (AD) stages in the normal aging population needs further study. We aimed to investigate the value of these plasma biomarkers for predicting memory change in cognitively unimpaired individuals in a population‐based cohort.MethodFrom the EMIF‐AD PreclinAD study we selected 188 individuals with normal cognition, who had plasma samples, amyloid‐β status and at least one cognitive follow‐up available (total follow‐up years (mean(SD) = 4.3(.42)) (Table 1). Amyloid‐β status was defined using visual read of dynamic [18F]flutemetamol‐PET images or CSF amyloid‐β1‐42/1‐40&lt;0.066 (Euroimmun). Simoa assays were used to measure plasma amyloid‐β1‐42/1‐40 (AMYBLOOD), P‐tau181 (Eli Lilly) and GFAP (Quanterix) levels. Linear mixed models, adjusted for age, sex and years of education, were applied to test associations of baseline plasma biomarker levels with subsequent change in memory (plasma*time), and its interaction with amyloid‐β status (plasma*time*amyloid‐β status).ResultFrom the total cohort tested, 31 subjects (16.5%) were amyloid‐positive. These individuals were older, showed worse baseline memory performance, lower plasma amyloid‐β1‐42/1‐40, and higher plasma P‐tau181 and GFAP levels compared to amyloid‐negative individuals (Table 1). Higher plasma GFAP levels at baseline were significantly associated with worse memory performance over time (GFAP*time: β=‐.03, p=.01). Interestingly, this relation was significantly stronger in amyloid‐positive compared to amyloid‐negative individuals (GFAP*time*amyloid‐β status: β=‐.07, p=.001) (Table 2, Figure 1). No significant associations were observed for baseline plasma amyloid‐β1‐42/1‐40 and P‐tau181 levels with change in memory over time (P‐tau181*time: β=‐.02, p=.07; amyloid‐β1‐42/1‐40 *time: β=.02, p=.12) (Table 2).ConclusionOur data suggest plasma GFAP can be used as a predictor of future memory decline in cognitively unimpaired, amyloid‐positive, individuals in the normal aging population. This supports the use of plasma GFAP as a prognostic marker for disease and treatment‐effect monitoring in the early stages of AD development.

Hearing loss was associated with cognitive impairment evaluated by Bangla Adaptation of Mini‐mental State Examination in a rural Bangladeshi elderly population

AbstractBackgroundThe Mini Mental State Examination (MMSE) is the most commonly used, first line screening tool for dementia and cognitive decline in adults. The Bangla Adaptation of Mini‐mental State Examination (BAMSE) has been tested as a reliable instrument to assess cognitive function of the normal elderly Bangladeshi population with regards to the socio‐cultural context and low literacy rate of the country. However, there is lack of evidence regarding lifestyle and socioeconomic determinants of cognitive performance in Bangladeshi elderly population. The purpose of this study is to investigate the relationships between lifestyle and socioeconomic determinants and cognitive impairment by BAMSE among elderly Bangladeshi.MethodData was collected from an on‐going surveillance site at Tarail subdistrict in Kishorgonj district.Among the total of 410 study participants aged ≥65 years, after excluding history of stroke and Parkinson’s disease, finally 314 participants were included in this analysis. Trained interviewers assessed cognitive function using the BAMSE questionnaires and self‐reported lifestyle factors (smoking: never, past, current; hearing: normal, poor, smelling: normal, poor, lost), socioeconomic factors (marital status: married, widowed/divorced; working status: farmer, other workers, non‐workers), medication use (hypertension and diabetes) by a questionnaire, and physical measurements (weight, height and blood pressure). Hypertension was defined as either anti‐hypertensive medication use or systolic/diastolic blood pressure ≥140/90 mmHg. Literacy was defined as participants who had 1 year or more education. Cognitive impairment was defined by BAMSE score &lt; 21. A multivariable logistic regression analysis was performed to assess the independent relationships between lifestyle and socioeconomic factors and cognitive impairment. Sex, age, hypertension, diabetes, smoking, hearing, smelling, marital and working status, and literacy were used as explanatory variables.ResultMean age (standard deviation) was 72.5(years and literacy rate was 23.6% in men and 5.9% in women. People who have hearing loss was 1.94 higher odds ratio (95% confidence interval:1.08‐3.47) for cognitive impairment compared to normal hearing in the multivariable analysis. Each 5‐year age increments was also significantly associated with cognitive impairment in the same model.ConclusionHearing loss and older age were associated with cognitive impairment in elderly Bangladeshi in this study.

Cortical myelin profile variations in healthy aging brain: A T1w/T2w ratio study

Demyelination is observed in both healthy aging and age-related neurodegenerative disorders. While the significance of myelin within the cortex is well acknowledged, studies focused on intracortical demyelination and depth-specific structural alterations in normal aging are lacking. Using the recently available Human Connectome Project Aging dataset, we investigated intracortical myelin in a normal aging population using the T1w/T2w ratio. To capture the fine changes across cortical depths, we employed a surface-based approach by constructing cortical profiles traveling perpendicularly through the cortical ribbon and sampling T1w/T2w values. The curvatures of T1w/T2w cortical profiles may be influenced by differences in local myeloarchitecture and other tissue properties, which are known to vary across cortical regions. To quantify the shape of these profiles, we parametrized the level of curvature using a nonlinearity index (NLI) that measures the deviation of the profile from a straight line. We showed that NLI exhibited a steep decline in aging that was independent of local cortical thinning. Further examination of the profiles revealed that lower T1w/T2w near the gray-white matter boundary and superficial cortical depths were major contributors to the apparent NLI variations with age. These findings suggest that demyelination and changes in other T1w/T2w related tissue properties in normal aging may be depth-specific and highlight the potential of NLI as a unique marker of microstructural alterations within the cerebral cortex.

Effects of mind-body exercises on cognitive impairment in people with Parkinson's disease: A mini-review.

Parkinson's disease (PD) is an important health problem caused by the degeneration of brain neurons. Bradykinesia and lower balance ability seriously affect the quality of life of people with PD. Non-motor symptoms, such as cognitive impairment, accompany the course of the disease but still lack sufficient attention. In general, drugs combined with cognitive training are the most common ways to improve cognitive impairment in people with PD. However, long-term use of psychiatric drugs may lead to side effects such as brain death and movement disorders. Recently, mindfulness has been used by researchers in the treatment of cognitive impairment, because healthy older adults who engage in mind-body exercises for a long time have higher cognitive levels than normal aging populations. Mind-body exercise, as a therapy that combines concentration, breath control, and physical activity, is beneficial for improving practitioners' brain and mental health. Mind-body exercises such as Tai Chi, yoga, dance, and Pilates can improve cognitive performance in older adults with or without cognitive impairment. Therefore, mind-body exercise may be a feasible strategy for the treatment of cognitive impairment in people with PD. This study summarizes the latest evidence that mind-body exercises including Tai Chi, Qigong, yoga, and dance improve cognitive impairment associated with PD. We also explored the limitations of current mind-body exercise research, aiming to provide new ideas for improving mind-body exercise as a strategy to alleviate cognitive impairment in people with PD.

Categorical Perception of Lexical Tones in Mandarin-Speaking Seniors.

This study aims to investigate the different degeneration processes of categorical perception (CP) of Mandarin lexical tones in the normal aging population and the pathological aging population with mild cognitive impairment (MCI). In Experiment I, we compared the identification and discrimination of Tone 1 and Tone 2 across young adults, seniors aged 60-65 years, and older seniors aged 75-80 years with normal cognitive abilities. In Experiment II, we compared lexical tone identification and discrimination across young adults, healthy seniors, and age-matched seniors with MCI. In Experiment I, tone perception was intact in seniors aged below 65 years. Those aged above 75 years could also maintain normal tone identification, whereas they showed poorer tone discrimination correlated with age-related poorer hearing level. In Experiment II, healthy seniors showed normal CP of Mandarin tones. Tone identification was also normal in those with MCI, whereas their tone discrimination had significantly degenerated. In the normal aging population, age-related hearing loss decreased signal audibility, accounting for poorer discrimination of Mandarin lexical tones in seniors above 75 years. In the pathological aging population with MCI, the poorer discrimination of lexical tones may be attributed to the additive effect of age, hearing loss, and cognitive impairment (e.g., impaired working memory and long-term phonological memory). This study uncovered the roles of low-level sensory processing and high-level cognitive processing in lexical tone perception in the Chinese aging population.

Free water diffusion MRI and executive function with a speed component in healthy aging

Extracellular free water (FW) increases are suggested to better provide pathophysiological information in brain aging than conventional biomarkers such as fractional anisotropy. The aim of the present study was to determine the relationship between conventional biomarkers, FW in white matter hyperintensities (WMH), FW in normal appearing white matter (NAWM) and in white matter tracts and executive functions (EF) with a speed component in elderly persons.We examined 226 healthy elderly participants (median age 69.83 years, IQR: 56.99–74.42) who underwent brain MRI and neuropsychological examination. FW in WMH and in NAWM as well as FW corrected diffusion metrics and measures derived from conventional MRI (white matter hyperintensities, brain volume, lacunes) were used in partial correlation (adjusted for age) to assess their correlation with EF with a speed component. Random forest analysis was used to assess the relative importance of these variables as determinants. Lastly, linear regression analyses of FW in white matter tracts corrected for risk factors of cognitive and white matter deterioration, were used to examine the role of specific tracts on EF with a speed component, which were then ranked with random forest regression.Partial correlation analyses revealed that almost all imaging metrics showed a significant association with EF with a speed component (r = -0.213 – 0.266). Random forest regression highlighted FW in WMH and in NAWM as most important among all diffusion and structural MRI metrics. The fornix (R2=0.421, p = 0.018) and the corpus callosum (genu (R2 = 0.418, p = 0.021), prefrontal (R2 = 0.416, p = 0.026), premotor (R2 = 0.418, p = 0.021)) were associated with EF with a speed component in tract based regression analyses and had highest variables importance.In a normal aging population FW in WMH and NAWM is more closely related to EF with a speed component than standard DTI and brain structural measures. Higher amounts of FW in the fornix and the frontal part of the corpus callosum leads to deteriorating EF with a speed component.

Joint independent component analysis for hypothesizing spatiotemporal relationships between longitudinal gray and white matter changes in preclinical Alzheimer's disease.

Characterizing relationships between gray matter (GM) and white matter (WM) in early Alzheimer's disease (AD) would improve understanding of how and when AD impacts the brain. However, modeling these relationships across brain regions and longitudinally remains a challenge. Thus, we propose extending joint independent component analysis (jICA) into spatiotemporal modeling of regional cortical thickness and WM bundle volumes leveraging multimodal MRI. We jointly characterize these GM and WM features in a normal aging (n=316) and an age- and sex-matched preclinical AD cohort (n=81) at each of two imaging sessions spaced three years apart, training on the normal aging population in cross-validation and interrogating the preclinical AD cohort. We find this joint model identifies reproducible, longitudinal changes in GM and WM between the two imaging sessions and that these changes are associated with preclinical AD and are plausible considering the literature. We compare this joint model to two focused models: (1) GM features at the first session and WM at the second and (2) vice versa. The joint model identifies components that correlate poorly with those from the focused models, suggesting the different models resolve different patterns. We find the strength of association with preclinical AD is improved in the GM to WM model, which supports the hypothesis that medial temporal and frontal thinning precedes volume loss in the uncinate fasciculus and inferior anterior-posterior association fibers. These results suggest that jICA effectively generates spatiotemporal hypotheses about GM and WM in preclinical AD, especially when specific intermodality relationships are considered a priori.

The Effect of α and SMR Enhancing Neurofeedback Training on Cognitive Function and Emotion in a Normal Elderly Population

본 연구는 α파 및 SMR파 강화 뉴로피드백 훈련이 65세 이상 정상노인의 작업기억, 억제기능, 불안 및 우울에 미치는 영향을 확인하기 위한 목적으로 수행된 실험연구이다. 건강하고 인지기능이정상인 노인을 선별하여 세 개의 집단(α파, SMR파, 가성 뉴로피드백 훈련)에 무선배정한 후 훈련전후 작업기억(단어기억력 검사, 숫자 외우기 검사), 억제기능(스트룹 검사), 불안(K-GAI) 및 우울(S-GDS) 수준을 측정하여 비교하였다. 뉴로피드백 훈련은 주 1회, 총 8번 실시되었으며, 총 37명의데이터를 반복측정분산분석으로 분석하였다. 연구결과 α파 및 SMR파 강화 훈련집단에서 작업기억력의향상, 억제기능 증진, 불안 수준의 완화가 관찰되었다. 이러한 결과를 바탕으로 정상노인의 인지기능과 정서 유지를 위한 뉴로피드백 훈련의 활용과 후속 연구를 위한 시사점들을 기술하였다.

Presbycusis and the Aging of Eye Movement: Common Attention Mechanisms.

Presbycusis, physiological age-related hearing loss, is a major health problem because it is the most common cause of hearing impairment, and its impact will grow in the coming years with the aging population. Besides auditory consequences, the literature recently found an association between hearing loss and cognitive decline over the last two decades, emphasizing the importance of the early detection of presbycusis. However, the current hearing tests are not sufficient to detect presbycusis in some cases. Furthermore, the underlying mechanisms of this association are still under discussion, calling for a new field of research on that topic. In that context, this study investigates for the first time the interaction between presbycusis, eye movement latency and Stroop scores for a normal aging population. Hearing abilities, eye movement latency and the Stroop Victoria test were measured for 69 elderly (mean 66.7 ± 8.4) and 30 young (mean 25.3 ± 2.7) participants. The results indicated a significant relationship between saccade latency and speech audiometry in the silence score, independently from age. These promising results suggest common attentional mechanisms between speech processing and saccade latency. The results are discussed regarding the relationship between hearing and cognition, and regarding the perspective of expanding new tools for presbycusis diagnosis.

Neurofilament light chain concentration in an aging population

BackgroundNeurofilament light chain (NF-L) concentration is recognized to be modified in neurological diseases and traumatic brain injuries, but studies in the normal aging population are lacking. It is, therefore, urgent to identify influencing factors of NF-L concentration in the aging population.MethodWe assessed NF-L concentration in sera of a large cohort of 409 community-dwelling adults aged over 65 years. We studied the association between NF-L and various physiological factors but also with self-reported comorbidities or life-style habits.ResultsWe showed that NF-L concentration in serum was tightly associated with cystatin C concentration (r = 0.501, p < 0.0001) and consequently, to the estimated glomerular filtration rate (eGFR) (r = − 0.492; p < 0.0001). Additionally, NF-L concentration was dependent on age and body mass index (BMI) but not sex. Among the self-reported comorbidities, subjects who reported neurological disorders, cardiovascular diseases or history of fracture had higher NF-L concentration in univariate analysis, whereas it was only the case for subjects who reported neurological disorders in the multivariate analysis. NF-L concentration was also increased when Mini-Mental State Examination (MMSE) was decreased (≤ 25 points) but not when geriatric depression score (GDS) was increased (> 5 points) in both univariate and multivariate analysis. Finally, we are providing reference ranges by age categories for subjects with or without altered renal function.ConclusionNF-L concentration in the aging population is not driven by the increasing number of comorbidities or depression. Yet, NF-L blood concentration is dependent on kidney function and NF-L interpretation in patients suffering from renal failure should be taken with caution.