Psychological capacity profiles of different age groups and gender in a national representative sample

Beyond the specific cognitive capacities like numerical or verbal intelligence and cognitive speed, the so-called soft skills, namely, psychological capacities, have become highly important in modern life. This is the first representative study on the distribution of work-relevant psychological capacities in the general population. We investigate capacities in different age groups, gender, and their relation with basic sociodemographics. A representative sample of 2531 people aged 14-95 years was investigated concerning work-relevant psychological capacities with the mini self-rating for psychological activities and participation (Mini-ICF-APP-S). The strongest capacities in young people were mobility, flexibility, proactivity, contact to thirds, and group interaction. Other capacities were stronger in midlife (30-59 years), such as adjustment to rules and routines, planning and structuring, decision making and judgement, application of competence and knowledge, assertiveness, dyadic relationships, endurance, and self-care. Women reported better dyadic relationship capacities, and men felt more assertive. The study provides, for the first time, representative data on a broad range of psychological capacities according to an internationally validated capacity concept. Good psychological capacities occur not primarily in youth, but especially in midlife and older age. Regarding demographic change, this implies older people are highly competent in the working world.

The Feasibility and Efficacy of a Virtual Reality Tandem Cycling Program for Persons with Parkinson's Disease and Their Care Partners

INTRODUCTION

Persons with Parkinson's disease (PwPD) suffer from motor and non-motor symptoms which significantly affect their quality of life (QoL), and the QoL of their care partners (CP). Tandem cycling reduces PwPD motor symptoms; however, no studies have examined other benefits or included PwPD CP. We conducted an 8-week community virtual reality (VR) tandem cycling intervention to assess the feasibility and efficacy for PwPD and their CP (i.e., PD dyads). We hypothesized that dyadic tandem cycling would improve (1) PwPD motor and non-motor symptoms and (2) dimensions of PD dyads' QoL and physiologic health.

METHODS

Ten PD dyads were recruited to complete 8 weeks of progressive intensity, bi-weekly tandem cycling. At pre- and post-testing, PwPD were assessed using the Movement Disorder Society-Unified Parkinson's Disease Rating Scale-III (MDS-UPDRS-III), functional gait assessment (FGA), and 10-m gait speed test. PD dyads also completed emotional and cognitive status questionnaires [e.g., Geriatric Depression Scale-Short Form (GDS-SF)], and wore BodyGuard 2 heart rate (HR) monitors for 48 h to assess surrogate measures of heart rate variability. Statistical analyses were conducted using Student's t tests with significance set at p ≤ 0.05.

RESULTS

Eight PD dyads and one PwPD completed the intervention. Retention of PwPD (90%) and CP (80%) was adequate, and PD dyad adherence ranged from 91.67 to 97.91%. PwPD demonstrated significant clinical improvements in MDS-UPDRS-III scores (- 7.38, p < 0.01), FGA scores (+ 3.50, p < 0.01), and 10-m gait speed times (+ 0.27 m/s, p < 0.01), in addition to significant self-reported improvements in mobility (- 13.61, p = 0.02), fatigue (- 5.99, p = 0.02), and social participation (+ 4.69, p < 0.01). CP depressive symptoms significantly decreased (- 0.88, p = 0.02), and PD dyads shared a significant increase in root mean square of the successive differences (RMSSD; p = 0.04).

CONCLUSION

Our pilot study demonstrated feasibility and multiple areas of efficacy supporting further investigation of community VR tandem cycling as a therapeutic intervention for PD dyads.

Unraveling the Epigenetic Landscape: Insights into Parkinson's Disease, Amyotrophic Lateral Sclerosis, and Multiple Sclerosis

Parkinson's disease (PD), multiple sclerosis (MS), and amyotrophic lateral sclerosis (ALS) are examples of neurodegenerative movement disorders (NMDs), which are defined by a gradual loss of motor function that is frequently accompanied by cognitive decline. Although genetic abnormalities have long been acknowledged as significant factors, new research indicates that epigenetic alterations are crucial for the initiation and development of disease. This review delves into the complex interactions that exist between the pathophysiology of NMDs and epigenetic mechanisms such DNA methylation, histone modifications, and non-coding RNAs. Here, we examine how these epigenetic changes could affect protein aggregation, neuroinflammation, and gene expression patterns, thereby influencing the viability and functionality of neurons. Through the clarification of the epigenetic terrain underpinning neurodegenerative movement disorders, this review seeks to enhance comprehension of the underlying mechanisms of the illness and augment the creation of innovative therapeutic strategies.

Facial emotion expressivity in patients with Parkinson's and Alzheimer's disease

Parkinson's disease (PD) and Alzheimer's disease (AD) are neurodegenerative disorders with some overlapping clinical features. Hypomimia (reduced facial expressivity) is a prominent sign of PD and it is also present in AD. However, no study has experimentally assessed hypomimia in AD and compared facial expressivity between PD and AD patients. We compared facial emotion expressivity in patients with PD, AD, and healthy controls (HCs). Twenty-four PD patients, 24 AD patients and 24 HCs were videotaped during neutral facial expressions and while posing six facial emotions (anger, surprise, disgust, fear, happiness, and sadness). Fifteen raters were asked to evaluate the videos using MDS-UPDRS-III (item 3.2) and to identify the corresponding emotion from a seven-forced-choice response format. We measured the percentage of accuracy, the reaction time (RT), and the confidence level (CL) in the perceived accuracy of the raters' responses. We found the highest MDS-UPDRS 3.2 scores in PD, and higher in AD than HCs. When evaluating the posed expression captures, raters identified a lower percentage of correct answers in the PD and AD groups than HCs. There was no difference in raters' response accuracy between the PD and AD. No difference was observed in RT and CL data between groups. Hypomimia in patients correlated positively with the global MDS-UPDRS-III and negatively with Mini Mental State Examination scores. PD and AD patients have a similar pattern of reduced facial emotion expressivity compared to controls. These findings hold potential pathophysiological and clinical implications.

The effects of exercise dose on patients with Parkinson's disease: a systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

The effects of different exercise doses on motor function, balance, mobility, and quality of life (QOL) in patients with Parkinson's disease (PD) were evaluated.

METHOD

The exercise intervention dose was evaluated based on the recommendations of the American College of Sports Medicine (ACSM) for developing and maintaining cardiorespiratory health, muscle strength, and physical function for PD patients and classified into high ACSM compliance and low or uncertain ACSM compliance. The impact of ACSM compliance on Unified Parkinson's Disease Rating Scale, Part III (UPDRS-III), Berg Balance Scale (BBS), Timed Up and Go (TUG), and 39-item Parkinson's Disease Questionnaire (PDQ-39) in patients with PD was compared using the standardized mean difference (SMD) along with the corresponding 95% confidence interval (95% CI).

RESULTS

A total of 26 articles were included, comprising 32 studies. Twenty-one studies were classified as high ACSM compliance, and 11 studies were classified as low or uncertain ACSM compliance. For the four outcome measures, the SMD ratio of exercise interventions with high ACSM compliance to those with low or uncertain ACSM compliance was as follows: UPDRS-III (- 0.74: - 0.17), TUG (- 0.62: - 0.17), PDQ-39 (- 0.58: - 0.31), and BBS (0.51: 0.52).

CONCLUSION

The results suggest that compared with exercise interventions with low or uncertain ACSM compliance, exercise interventions with high ACSM compliance had a more significant improvement effect on motor function, mobility, and QOL in PD patients. However, the effect on balance was not as pronounced, and further research is needed to validate these findings.

Association between regular physical activity and biomarker changes in early Parkinson's disease patients

INTRODUCTION

Physical activity benefits patients with Parkinson's disease (PD) and is assumed to possess disease-modifying potential. PD-related biomarkers, such as dopamine transporter (DAT) imaging and cerebrospinal fluid (CSF) α-synuclein (α-syn) and amyloid β (Aβ), correlate with disease severity and, to some extent, reflect disease progression and pathology. However, the association between regular physical activity and PD biomarker changes remains unknown. This study aimed to investigate the association between physical activity and longitudinal trajectories of PD biomarkers.

METHODS

This retrospective study included 444 patients with a median follow-up time of 5 years from the Parkinson's Progression Markers Initiative cohort. Data collection included physical activity as scaled by the Physical Activity Scale for the Elderly questionnaire, dopamine transporter imaging, CSF assessment, and serum biomarkers. We analyzed the data using a linear mixed regression model.

RESULTS

Regular physical activity was associated with a slower decline of DAT uptake in the caudate (β = 0.063, p = 0.011) and the putamen (β = 0.062, p = 0.023). No association was detected between regular physical activity and CSF, as well as serum biomarkers.

CONCLUSION

Regular physical activity is associated with favorable PD biomarker progression, indicating a potential disease-modifying effect.

Association between regular physical activity and biomarker changes in early Parkinson's disease patients

INTRODUCTION

Physical activity benefits patients with Parkinson's disease (PD) and is assumed to possess disease-modifying potential. PD-related biomarkers, such as dopamine transporter (DAT) imaging and cerebrospinal fluid (CSF) α-synuclein (α-syn) and amyloid β (Aβ), correlate with disease severity and, to some extent, reflect disease progression and pathology. However, the association between regular physical activity and PD biomarker changes remains unknown. This study aimed to investigate the association between physical activity and longitudinal trajectories of PD biomarkers.

METHODS

This retrospective study included 444 patients with a median follow-up time of 5 years from the Parkinson's Progression Markers Initiative cohort. Data collection included physical activity as scaled by the Physical Activity Scale for the Elderly questionnaire, dopamine transporter imaging, CSF assessment, and serum biomarkers. We analyzed the data using a linear mixed regression model.

RESULTS

Regular physical activity was associated with a slower decline of DAT uptake in the caudate (β = 0.063, p = 0.011) and the putamen (β = 0.062, p = 0.023). No association was detected between regular physical activity and CSF, as well as serum biomarkers.

CONCLUSION

Regular physical activity is associated with favorable PD biomarker progression, indicating a potential disease-modifying effect.

Alzheimer’s disease as a synaptopathy: Evidence for dysfunction of synapses during disease progression

The synapse has consistently been considered a vulnerable and critical target within Alzheimer’s disease, and synapse loss is, to date, one of the main biological correlates of cognitive decline within Alzheimer’s disease. This occurs prior to neuronal loss with ample evidence that synaptic dysfunction precedes this, in support of the idea that synaptic failure is a crucial stage within disease pathogenesis. The two main pathological hallmarks of Alzheimer’s disease, abnormal aggregates of amyloid or tau proteins, have had demonstrable effects on synaptic physiology in animal and cellular models of Alzheimer’s disease. There is also growing evidence that these two proteins may have a synergistic effect on neurophysiological dysfunction. Here, we review some of the main findings of synaptic alterations in Alzheimer’s disease, and what we know from Alzheimer’s disease animal and cellular models. First, we briefly summarize some of the human evidence to suggest that synapses are altered, including how this relates to network activity. Subsequently, animal and cellular models of Alzheimer’s disease are considered, highlighting mouse models of amyloid and tau pathology and the role these proteins may play in synaptic dysfunction, either in isolation or examining how the two pathologies may interact in dysfunction. This specifically focuses on neurophysiological function and dysfunction observed within these animal models, typically measured using electrophysiology or calcium imaging. Following synaptic dysfunction and loss, it would be impossible to imagine that this would not alter oscillatory activity within the brain. Therefore, this review also discusses how this may underpin some of the aberrant oscillatory patterns seen in animal models of Alzheimer’s disease and human patients. Finally, an overview of some key directions and considerations in the field of synaptic dysfunction in Alzheimer’s disease is covered. This includes current therapeutics that are targeted specifically at synaptic dysfunction, but also methods that modulate activity to rescue aberrant oscillatory patterns. Other important future avenues of note in this field include the role of non-neuronal cell types such as astrocytes and microglia, and mechanisms of dysfunction independent of amyloid and tau in Alzheimer’s disease. The synapse will certainly continue to be an important target within Alzheimer’s disease for the foreseeable future.

Bradykinesia in Neurodegenerative Disorders: A Blinded Video Analysis of Pathology-Proven Cases

BACKGROUND

Bradykinesia is a cardinal feature in parkinsonisms. No study has assessed the differential features of bradykinesia in patients with pathology-proven synucleinopathies and tauopathies.

OBJECTIVE

We examined whether bradykinesia features (speed, amplitude, rhythm, and sequence effect) may differ between pathology-proven synucleinopathies and tauopathies.

METHODS

Forty-two cases who underwent autopsy were included and divided into synucleinopathies (Parkinson's disease and dementia with Lewy bodies) and tauopathies (progressive supranuclear palsy). Two raters blinded to the diagnosis retrospectively scored the Movement Disorders Society-Unified Parkinson's Disease Rating Scale Part III and Modified Bradykinesia Rating Scale on standardized videotaped neurological examinations. Bradykinesia scores were compared using the Mann-Whitney test and logistic regression models to adjust for disease duration.

RESULTS

Demographic and clinical parameters were similar between synucleinopathies and tauopathies. There were no differences between speed, amplitude, rhythm, and sequence effect in synucleinopathies and tauopathies in unadjusted comparisons and adjusted models (all P > 0.05).

CONCLUSIONS

Clinical bradykinesia features do not distinguish the underlying neuropathology in neurodegenerative parkinsonisms. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

The Potential Role of miRNAs in Cognitive Frailty

Frailty is an aging related condition, which has been defined as a state of enhanced vulnerability to stressors, leading to a limited capacity to meet homeostatic demands. Cognitive impairment is also frequent in older people, often accompanying frailty. Age is the main independent risk factor for both frailty and cognitive impairment, and compelling evidence suggests that similar age-associated mechanisms could underlie both clinical conditions. Accordingly, it has been suggested that frailty and cognitive impairment share common pathways, and some authors proposed "cognitive frailty" as a single complex phenotype. Nevertheless, so far, no clear common underlying pathways have been discovered for both conditions. microRNAs (miRNAs) have emerged as key fine-tuning regulators in most physiological processes, as well as pathological conditions. Importantly, miRNAs have been proposed as both peripheral biomarkers and potential molecular factors involved in physiological and pathological aging. In this review, we discuss the evidence linking changes of selected miRNAs expression with frailty and cognitive impairment. Overall, miR-92a-5p and miR-532-5p, as well as other miRNAs implicated in pathological aging, should be investigated as potential biomarkers (and putative molecular effectors) of cognitive frailty.

Alpha-Synuclein and Cognitive Decline in Parkinson Disease

Parkinson disease (PD) is the second most common neurodegenerative disorder in elderly people. It is characterized by the aggregation of misfolded alpha-synuclein throughout the nervous system. Aside from cardinal motor symptoms, cognitive impairment is one of the most disabling non-motor symptoms that occurs during the progression of the disease. The accumulation and spreading of alpha-synuclein pathology from the brainstem to limbic and neocortical structures is correlated with emerging cognitive decline in PD. This review summarizes the genetic and pathophysiologic relationship between alpha-synuclein and cognitive impairment in PD, together with potential areas of biomarker advancement.

Walking While Talking and Prefrontal Oxygenation in Motoric Cognitive Risk Syndrome: Clinical and Pathophysiological Aspects

BACKGROUND

Motoric cognitive risk syndrome (MCR) combines slow gait and cognitive complaints and has been proposed as a predementia syndrome. The nature of dual-task performance in MCR has not been established.

OBJECTIVE

To assess differences in dual-task performance between participants with and without MCR and to study the prefrontal cortex (PFC)-based brain activity during dual-task using functional near-infrared spectroscopy.

METHODS

Cohort study of community-dwelling non-demented older adults included in the "Central Control of Mobility in Aging" study. Comprehensive assessment included global cognition and executive function tests along with clinical variables. Dual-task paradigm consisted in walking while reciting alternate letters of the alphabet (WWT) on an electronic walkway. We compared dual-task performance between MCR (n = 60) and No MCR (n = 478) participants and assessed the relationship of dual-task performance with cognitive function. In a subsample, we compared PFC oxygenation during WWT between MCR (n = 32) and No MCR (n = 293).

RESULTS

In our sample of 538 high-functioning older adults (76.6±6.5 years), with 11.2% prevalence of MCR, dual-task cost was not significantly different, compared to No MCR participants. Among MCR participants, no significant relationship was found between WWT velocity and cognitive function, whereas No MCR participants with better cognitive function showed faster WWT velocities. PFC oxygenation during WWT was higher in MCR compared to No MCR (1.02±1.25 versus 0.66±0.83, p = 0.03).

CONCLUSION

MCR participants showed no significant differences in the dual-task cost while exhibiting higher PFC oxygenation during dual-task walking. The dual-task performance (WWT velocity) in MCR participants was not related to cognition.

Early recognition and diagnosis of multiple system atrophy: best practice and emerging concepts

Introduction: Multiple system atrophy (MSA) is a progressive degenerative disorder of the central and autonomic nervous systems characterized by parkinsonism, cerebellar ataxia, dysautonomia, and pyramidal signs. The confirmatory diagnosis is pathological, but clinical-diagnostic criteria have been developed to help clinicians. To date, the early diagnosis of MSA is challenging due to the lack of reliable diagnostic biomarkers.Areas covered: The authors reappraised the main clinical, neurophysiological, imaging, genetic, and laboratory evidence to help in the early diagnosis of MSA in the clinical and in the research settings. They also addressed the practical clinical issues in the differential diagnosis between MSA and other parkinsonian and cerebellar syndromes. Finally, the authors summarized the unmet needs in the early diagnosis of MSA and proposed the next steps for future research efforts in this field.Expert opinion: In the last decade, many advances have been achieved to help the correct MSA diagnosis since early stages. In the next future, the early diagnosis and correct classification of MSA, together with a better knowledge of the causative mechanisms of the disease, will hopefully allow the identification of suitable candidates to enroll in clinical trials and select the most appropriate disease-modifying strategies to slow down disease progression.

Neurodegenerative movement disorders: An epigenetics perspective and promise for the future

Neurodegenerative movement disorders (NMDs) are age‐dependent disorders that are characterised by the degeneration and loss of neurons, typically accompanied by pathological accumulation of different protein aggregates in the brain, which lead to motor symptoms. NMDs include Parkinson's disease, multiple system atrophy, progressive supranuclear palsy, and Huntington's disease, among others. Epigenetic modifications are responsible for functional gene regulation during development, adult life and ageing and have progressively been implicated in complex diseases such as cancer and more recently in neurodegenerative diseases, such as NMDs. DNA methylation is by far the most widely studied epigenetic modification and consists of the reversible addition of a methyl group to the DNA without changing the DNA sequence. Although this research field is still in its infancy in relation to NMDs, an increasing number of studies point towards a role for DNA methylation in disease processes. This review addresses recent advances in epigenetic and epigenomic research in NMDs, with a focus on human brain DNA methylation studies. We discuss the current understanding of the DNA methylation changes underlying these disorders, the potential for use of these DNA modifications in peripheral tissues as biomarkers in early disease detection, classification and progression as well as a promising role in future disease management and therapy.

Effects of head trauma and sport participation in young-onset Parkinson's disease

Head trauma (HT) is emerging as an event anticipating onset of neurodegenerative disorders. However, the potential contribution of HT in young-onset cases (YOPD, age at onset < 50) of Parkinson’s disease (PD) has not been examined yet. Here, we systematically assessed HT history in PD patients to estimate the risk associated, especially in terms of age of onset, and define the correlations with the clinical-biochemical profile. The Brain Injury Screening Questionnaire (BISQ) was administered to 94 PD patients (31 with YOPD, known monogenic forms excluded) and 70 controls. HT history was correlated with motor and non-motor scores in all patients, and to CSF biomarkers of neurodegeneration (α-synuclein, amyloid-β42, total and phosporiled-181 tau, lactate, CSF/serum albumin) into a subgroup. HT increased the risk for both PD and YOPD. In PD patients, but not in those with YOPD, the number of HTs directly correlated with CSF total-tau levels. No other correlations resulted between HT and clinical parameters. Sport-related HT was a specific risk factor for YOPD; conversely, the prolonged sporting life represented a protective factor. HTs can favor PD onset, even as YOPD. Sport-related HT resulted a risk factor for YOPD, although the longer sporting practice delayed PD onset, protecting from YOPD. Tauopathy may underlie the overall association between HT and PD. Additional mechanisms could be instead implicated in HT contribution to YOPD onset.

Freezing of saccades in dopa-responsive parkinsonian syndrome

Purpose

Ocular motor abnormalities such as abnormal saccades are common in idiopathic Parkinson's disease (PD) and atypical parkinsonian syndrome, such as progressive supranuclear palsy (PSP) and corticobasal degeneration (CBD). In this study, we describe a case of patient with PD and show a video illustrating severe delay of reflexive saccades.

Observations

A 68-year-old Caucasian woman with diagnosis of PD presented for evaluation of diplopia. Neuro-ophthalmic examination revealed good visual acuity in both eyes and normal optic nerves but prominent ocular motor abnormalities, including hypometric saccades, impaired smooth pursuit, and convergence insufficiency causing diplopia at near. Despite treatment with carbidopa-levodopa three times per day, she exhibited episodic, severe delay of reflexive saccades. During these episodes, the patient appeared frozen and unable to initiate reflexive saccades for 20 s or longer. This freezing of reflexive saccades was variable and occurred suddenly during exam but could be interrupted by smooth pursuit. There was no gait freezing, eyelid apraxia, or prominent exacerbation of other motor symptoms. Freezing of saccades dramatically resolved after increasing dosage of carbidopa-levodopa.

Conclusions and Importance

We describe a patient with dopa-responsive parkinsonian syndrome with intermittent difficulty initiating reflexive saccades mimicking ocular motor apraxia. Resolution of saccadic freezing with higher carbidopa-levodopa is consistent with ocular motor impairment as a result of degeneration and dysfunction of the dopaminergic pathways in supranuclear ocular motor control.

Amyloid-β42/Neurogranin Ratio as a Potential Index for Cognitive Impairment in Parkinson's Disease

BACKGROUND

Synaptopathy is critical in pathophysiology of Parkinson's disease (PD). Cerebrospinal fluid (CSF) levels of neurogranin (NG) and amyloid-β42 (Aβ42) are considered markers of synaptic dysfunction in neurodegenerative diseases.

OBJECTIVE

To evaluate the CSF synaptopathy-related biomarkers, especially the novel Aβ42/NG ratio, in PD, establishing possible associations with cognitive level and other clinical parameters.

METHODS

Levels of NG, Aβ42, amyloid-β40, total and phosphorylated tau, and Aβ42/NG ratio were measured in 30 PD patients and 30 controls and correlated with cognitive and motor parameters. The accuracy in distinguishing the cognitive status was determined.

RESULTS

NG and Aβ42 were significantly reduced in PD, with higher NG levels in patients with worse cognition. The Aβ42/NG ratio showed a direct correlation with Mini-Mental State Examination, independently from age and sex, and differentiated cognitively impaired patients with 92% sensitivity and 71.4% specificity, accuracy higher than NG alone. No correlations resulted with motor disturbances or therapy.

CONCLUSIONS

The novel Aβ42/NG ratio couples either presynaptic or postsynaptic markers of synaptic dysfunction, representing a potential global index of synaptopathy, useful to track cognitive functions in PD.

Design of an Innovative Methodology for Cerebrospinal Fluid Analysis: Preliminary Results

Cerebrospinal fluid (CSF) analysis supports diagnosis of neurodegenerative diseases (NDs), however a number of issues limits its potentialities in clinical practice. Here, a newly developed technique for fluid voltammetry, relying on a simple sensor (BIOsensor-based multisensorial system for mimicking Nose, Tongue and Eyes, BIONOTE), was used to test the applicability for CSF analysis. BIONOTE was initially calibrated on an artificial CSF-like solution and then applied on human CSF, either immediately after collection or after refrigerated storage. Following optimization, it was used to evaluate 11 CSF samples correlating the electrochemical dataset with CSF routine parameters and biomarkers of neurodegeneration. Multivariate data analysis was performed for model elaboration and calibration using principal component analysis and partial least squares discriminant analysis. BIONOTE presented a high capacity to predict both physiological and pathological constituents of artificial CSF. It differentiated distinct fresh human CSF samples well but lost accuracy after refrigerated storage. The electrochemical analysis-derived data correlated with either CSF routine cytochemical indexes or a biomarker of neurodegeneration. BIONOTE resulted as being a reliable system for electrochemical analysis of CSF. The CSF fingerprint provided by the sensor has shown itself to be sensitive to CSF modification, thus it is potentially representative of CSF alteration. This result opens the way to its testing in further study addressed at assessing the clinical relevance of the methodology. Because of its advantages due to the ease and rapidity of the methodology, a validation study is now required to translate the technique into clinical practice and improve diagnostic workup of NDs.

How Comorbidity Reflects on Cerebrospinal Fluid Biomarkers of Neurodegeneration in Aging

Systemic comorbidity precipitates the risk for dementia. To comprehend the underlying mechanisms into a therapeutic perspective, we analyzed how comorbidity affects neurodegeneration-related cerebrospinal fluid (CSF) biomarkers of 55 cognitively intact subjects. The Charson Comorbidity Index (CCI) was correlated with CSF amyloid-β42 (Aβ42), amyloid-β40, total-tau, 181-phosphorylated-tau (p-tau), the Aβ42/p-tau ratio, neurogranin, and lactate. The age-related brain lesions at imaging were also considered. CCI had a raw association with Aβ42/p-tau and p-tau, and a stronger, age-independent correlation with lactate. These preliminary findings suggested that, in normal subjects, systemic comorbidity might increase CNS oxidative stress and, together with aging, contribute to develop an Alzheimer's disease-like biochemical profile.

Weaker Braking Force, A New Marker of Worse Gait Stability in Alzheimer Disease

Background: Braking force is a gait marker associated with gait stability. This study aimed to determine the alteration of braking force and its correlation with gait stability in Alzheimer disease (AD).

Methods: A total of 32 AD patients and 32 healthy controls (HCs) were enrolled in this study. Gait parameters (braking force, gait variability, and fall risk) in the walking tests of Free walk, Barrier, and Count backward were measured by JiBuEn^® gait analysis system. Gait variability was calculated by the coefficient of variation (COV) of stride time, stance time, and swing time.

Results: The braking force of AD was significantly weaker than HCs in three walking tests (P < 0.001, P < 0.001, P = 0.007). Gait variability of AD showed significant elevation than HCs in the walking of Count backward (COV_stride: P = 0.013; COV_swing: P = 0.006). Fall risk of AD was significantly higher than HCs in three walking tests (P = 0.001, P = 0.001, P = 0.001). Braking force was negatively associated with fall risks in three walking tests (P < 0.001, P < 0.001, P < 0.001). There were significant negative correlations between braking force and gait variability in the walking of Free walk (COV_stride: P = 0.018; COV_swing: P = 0.013) and Barrier (COV_stride: P = 0.002; COV_swing: P = 0.001), but not Count backward (COV_stride: P = 0.888; COV_swing: P = 0.555).

Conclusion: Braking force was weaker in AD compared to HCs, reflecting the worse gait stability of AD. Our study suggests that weakening of braking force may be a new gait marker to indicate cognitive and motor impairment and predict fall risk in AD.