Motor signs predict poor outcomes in Alzheimer disease

Predictors for survival in patients with Alzheimer's disease: a large comprehensive meta-analysis

The prevalence of Alzheimer's disease (AD) is increasing as the population ages, and patients with AD have a poor prognosis. However, knowledge on factors for predicting the survival of AD remains sparse. Here, we aimed to systematically explore predictors of AD survival. We searched the PubMed, Embase and Cochrane databases for relevant literature from inception to December 2022. Cohort and case-control studies were selected, and multivariable adjusted relative risks (RRs) were pooled by random-effects models. A total of 40,784 reports were identified, among which 64 studies involving 297,279 AD patients were included in the meta-analysis after filtering based on predetermined criteria. Four aspects, including demographic features (n = 7), clinical features or comorbidities (n = 13), rating scales (n = 3) and biomarkers (n = 3), were explored and 26 probable prognostic factors were finally investigated for AD survival. We observed that AD patients who had hyperlipidaemia (RR: 0.69) were at a lower risk of death. In contrast, male sex (RR: 1.53), movement disorders (including extrapyramidal signs) (RR: 1.60) and cancer (RR: 2.07) were detrimental to AD patient survival. However, our results did not support the involvement of education, hypertension, APOE genotype, Aβ42 and t-tau in AD survival. Our study comprehensively summarized risk factors affecting survival in patients with AD, provided a better understanding on the role of different factors in the survival of AD from four dimensions, and paved the way for further research.

Functional Connectivity Differences in Distinct Dentato-Cortical Networks in Alzheimer's Disease and Mild Cognitive Impairment

Recent research has implicated the cerebellum in Alzheimer's disease (AD), and cerebrocerebellar network connectivity is emerging as a possible contributor to symptom severity. The cerebellar dentate nucleus (DN) has parallel motor and non-motor sub-regions that project to motor and frontal regions of the cerebral cortex, respectively. These distinct dentato-cortical networks have been delineated in the non-human primate and human brain. Importantly, cerebellar regions prone to atrophy in AD are functionally connected to atrophied regions of the cerebral cortex, suggesting that dysfunction perhaps occurs at a network level. Investigating functional connectivity (FC) alterations of the DN is a crucial step in understanding the cerebellum in AD and in mild cognitive impairment (MCI). Inclusion of this latter group stands to provide insights into cerebellar contributions prior to diagnosis of AD. The present study investigated FC differences in dorsal (dDN) and ventral (vDN) DN networks in MCI and AD relative to cognitively normal participants (CN) and relationships between FC and behavior. Our results showed patterns indicating both higher and lower functional connectivity in both dDN and vDN in AD compared to CN. However, connectivity in the AD group was lower when compared to MCI. We argue that these findings suggest that the patterns of higher FC in AD may act as a compensatory mechanism. Additionally, we found associations between the individual networks and behavior. There were significant interactions between dDN connectivity and motor symptoms. However, both DN seeds were associated with cognitive task performance. Together, these results indicate that cerebellar DN networks are impacted in AD, and this may impact behavior. In concert with the growing body of literature implicating the cerebellum in AD, our work further underscores the importance of investigations of this region. We speculate that much like in psychiatric diseases such as schizophrenia, cerebellar dysfunction results in negative impacts on thought and the organization therein. Further, this is consistent with recent arguments that the cerebellum provides crucial scaffolding for cognitive function in aging. Together, our findings stand to inform future clinical work in the diagnosis and understanding of this disease.

Distinguishing features of depression in dementia from primary psychiatric disease

Depression is a common and devastating neuropsychiatric symptom in the elderly and in patients with dementia. In particular, nearly 80% of patients with Alzheimer's Disease dementia experience depression during disease development and progression. However, it is unknown whether the depression in patients with dementia shares the same molecular mechanisms as depression presenting as primary psychiatric disease or occurs and persists through alternative mechanisms. In this review, we discuss how the clinical presentation and treatment differ between depression in dementia and as a primary psychiatric disease, with a focus on major depressive disorder. Then, we hypothesize several molecular mechanisms that may be unique to depression in dementia such as neuropathological changes, inflammation, and vascular events. Finally, we discuss existing issues and future directions for investigation and treatment of depression in dementia.

Quantitative vestibular assessment: The development and validation of a novel, remote video head impulse test against in-clinic measurements

Objectives

To develop a novel remote head impulse test (rHIT), and to provide preliminary data validating the rHIT vestibular-ocular reflex (VOR) gains against the in-clinic vHIT.

Methods

A convenience sample of 10 patients referred for vestibular assessment at our institution was recruited. In-clinic vHIT was used to quantify lateral VOR gains. Patients subsequently underwent an rHIT protocol, whereby patients performed active, lateral head rotations while their eyes and heads were recorded using a laptop camera and video-conferencing software. The vHIT and rHIT VOR gains were compared using paired t-tests, and a Pearson correlation coefficient between the gains was calculated. Absolute accuracy, sensitivity, and specificity of the rHIT were additionally calculated.

Results

Of the 10 patients recruited, 4 were male, and the average ± standard deviation (SD) age was 61.4 ± 15.3 years. As determined by the vHIT, 2 patients had normal bilateral VOR gains, 6 with unilateral vestibular hypofunction, and 2 with bilateral vestibular hypofunction. The correlation between the rHIT and vHIT gains was 0.73 (p < .001). The rHIT exhibited an absolute accuracy of 75.0%, sensitivity of 70.0%, and specificity of 80.0%. When ears had a vHIT VOR gain less than 0.40, the rHIT exhibited 100.0% accuracy. Conversely, 60.0% of deficient ears with vHIT VOR gains greater than 0.40 were incorrectly categorized by the rHIT.

Conclusion

The rHIT may be better suited for detecting more severe vestibular deficiencies. Future iterations of the rHIT should aim to increase the video frame-rate capabilities to detect subtler VOR impairments.

Level of Evidence

4.

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.

Motor Symptoms in Early- versus Late-Onset Alzheimer's Disease

BACKGROUND

Age at onset was suggested as one possible risk factor for motor dysfunction in Alzheimer's disease (AD).

OBJECTIVE

We investigated the association of motor symptoms with cognition or neurodegeneration in patients with AD, and whether this association differs by the age at onset.

METHODS

We included 113 amyloid positive AD patients and divided them into early-onset AD (EOAD) and late-onset AD (LOAD), who underwent the Unified Parkinson's Disease Rating Scale (UPDRS)-Part III (=UPDRS) scoring, Mini-Mental State Examination (MMSE)/Clinical Deterioration Rating Sum-of-Boxes (CDR-SOB), and magnetic resonance image (MRI). Multiple linear regression was used to evaluate the association of UPDRS and MMSE/CDR-SOB or MRI neurodegeneration measures, and whether the association differs according to the group.

RESULTS

The prevalence of motor symptoms and their severity did not differ between the groups. Lower MMSE (β= -1.1, p < 0.001) and higher CDR-SOB (β= 2.0, p < 0.001) were significantly associated with higher UPDRS. There was no interaction effect between MMSE/CDR-SOB and AD group on UPDRS. Global or all regional cortical thickness and putaminal volume were negatively associated with UPDRS score, but the interaction effect of neurodegeneration and AD group on UPDRS score was significant only in parietal lobe (p for interaction = 0.035), which showed EOAD to have a more pronounced association between parietal thinning and motor symptoms.

CONCLUSION

Our study suggested that the severity of motor deterioration in AD is related to the severity of cognitive impairment itself rather than age at onset, and motor symptoms might occur through multiple mechanisms including cortical and subcortical atrophy.

Gait dysfunction in Alzheimer disease

Alzheimer's disease (AD) is the most common cause of age-associated dementia and will exponentially rise in prevalence in the coming decades, supporting the parallel development of the early stage detection and disease-modifying strategies. While primarily considered as a cognitive disorder, AD also features motor symptoms, primarily gait dysfunction. Such gait abnormalities can be phenotyped across classic clinical syndromes as well as by quantitative kinematic assessments to address subtle dysfunction at preclinical and prodromal stages. As such, certain measures of gait can predict the future cognitive and functional decline. Moreover, cross-sectional and longitudinal studies have associated gait abnormalities with imaging, biofluid, and genetic markers of AD across all stages. This suggests that gait assessment is an important tool in the clinical assessment of patients across the AD spectrum, especially to help identify at-risk individuals.

Association between Cerebral Coordination Functions and Clinical Outcomes of Alzheimer's Dementia

Background: Alzheimer’s dementia (AD) is a degenerative disease that impairs cognitive function, initially, and then motor or other function, eventually. Motor coordination function impairment usually accompanies cognition impairment but it is seldom examined whether it can reflect the clinical outcomes of AD. Methods: 113 clinically diagnosed AD patients with a mean age of 78.9 ± 6.9 years underwent an annual neuropsychological assessment using the Mini-Mental State Examination (MMSE), the Cognitive Abilities Screening Instrument (CASI), the Sum of Boxes of Clinical Dementia Rating (CDR-SB), and the CDR. The cerebral coordination function was evaluated through correlations among 15 joints with a kinetic depth sensor annually. An intra-individual comparison of both cognitive and motor coordination functions was performed to examine their correlations. Results: The changes in coordination function in the lower limbs can significantly reflect the clinical outcomes, MMSE (p < 0.001), CASI (p = 0.006), CDR (p < 0.001), and CDR-SB (p < 0.001), but the changes in upper limbs can only reflect the clinical outcome in CDR (p < 0.001). Conclusions: The use of a kinetic depth sensor to determine the coordination between joints, especially in lower limbs, can significantly reflect the global functional and cognitive outcomes in AD. Such evaluations could be another biomarker used to evaluate non-cognitive outcomes in AD for clinical and research purposes.

Association between Motor Signs and Cognitive Performance in Cognitively Unimpaired Older Adults: A Cross-Sectional Study Using the NACC Database

Aiming to examine whether specific motor signs are associated with worse performance in specific cognitive domains among cognitively unimpaired (CU) individuals, we performed a cross-sectional analysis of data from the baseline evaluations of older, CU participants from the National Alzheimer's Coordinating Center (NACC) Uniform Data Set. In total, 8149 CU (≥60 years) participants were included. Of these, 905 individuals scored ≥ 2 on at least one of the motor domains of the Unified Parkinson's Disease Rating Scale part III (UPDRSIII). Cognitively impaired individuals, participants with psychiatric disorders and/or under treatment with antipsychotic, anxiolytic, sedative or hypnotic agents were excluded. Nine motor signs were examined: hypophonia, masked facies, resting tremor, action/postural tremor, rigidity, bradykinesia, impaired chair rise, impaired posture/gait and postural instability. Their association with performance on episodic memory, semantic memory, language, attention, processing speed or executive function was assessed using crude and adjusted linear regression models. Individuals with impaired chair rise had worse episodic memory, semantic memory, processing speed and executive function, while those with bradykinesia had worse language, processing speed and executive function. Sensitivity analyses, by excluding participants with cerebrovascular disease or PD, or other Parkinsonism, produced similar results with the exception of the relationship between bradykinesia and language performance.

Falling Short: The Contribution of Central Insulin Receptors to Gait Dysregulation in Brain Aging

Insulin resistance, which manifests as a reduction of insulin receptor signaling, is known to correlate with pathological changes in peripheral tissues as well as in the brain. Central insulin resistance has been associated with impaired cognitive performance, decreased neuronal health, and reduced brain metabolism; however, the mechanisms underlying central insulin resistance and its impact on brain regions outside of those associated with cognition remain unclear. Falls are a leading cause of both fatal and non-fatal injuries in the older population. Despite this, there is a paucity of work focused on age-dependent alterations in brain regions associated with ambulatory control or potential therapeutic approaches to target these processes. Here, we discuss age-dependent alterations in central modalities that may contribute to gait dysregulation, summarize current data supporting the role of insulin signaling in the brain, and highlight key findings that suggest insulin receptor sensitivity may be preserved in the aged brain. Finally, we present novel results showing that administration of insulin to the somatosensory cortex of aged animals can alter neuronal communication, cerebral blood flow, and the motivation to ambulate, emphasizing the need for further investigations of intranasal insulin as a clinical management strategy in the older population.

Vestibular therapy to reduce falls in people with Alzheimer's disease: study protocol for a pilot randomized controlled trial

BACKGROUND

Falls are highly common in patients with Alzheimer's disease (AD); around two-thirds of AD patients fall annually. Fall events are major drivers of injury, early institutionalization, and shorter survival. Balance and mobility impairment are among the most important fall risk factors in AD patients. Vestibular therapy (VT) is an effective rehabilitation intervention in improving balance and fall risk through vestibular function, but not often used in AD. We want to evaluate the feasibility of using VT to reduce falls and improve balance function in patients with AD and drive use of an existing, potentially beneficial therapy in a patient population whose high level of vestibular deficits is currently unaddressed.

METHODS

The proposed pilot clinical trial will be a parallel-group randomized controlled trial. Patients with a diagnosis of mild-moderate AD, age ≥ 60, and the presence of a caregiver will be recruited from the Johns Hopkins Memory and Alzheimer's Treatment Center. Eligible patients will be offered vestibular testing. Patients with vestibular loss will be offered participation in the VT trial. One-hundred AD patients with vestibular loss will be enrolled and randomized 1:1 into the control and intervention arms of the trial. All patients will undergo baseline balance and cognitive assessment, followed by 8 weeks of active control therapy or VT, consisting of ~25-min office sessions with a vestibular therapist. Patients will be tracked for falls and undergo follow-up balance and cognitive assessment at 8 and 52 weeks (1 year) to assess the potential short-term and longer-term effects, respectively, of VT on balance and cognition. The main outcomes of this trial are falls, balance (using the Berg Balance Scale and the Timed Up and Go test), and cognition (using the clock drawing test, the Card Rotations test, the Money Road Map test, and the triangle completion task).

DISCUSSION

As the population ages and the number of individuals with AD in the US grows to a projected 14 million in 2050, managing falls in AD will continue to grow as a critical public health concern; this trial assesses feasibility of a potential solution.

TRIAL REGISTRATION

ClinicalTrial.Gov identifier - NCT03799991 . Registered 01 August 2019.

Structural MRI Reveals Cervical Spinal Cord Atrophy in the P301L Mouse Model of Tauopathy: Gender and Transgene-Dosing Effects

In primary tauopathies, the deposition of tau neurofibrillary tangles and threads as well as neurodegenerative changes have been found within the brain and spinal cord. While degenerative changes have been intensively studied in the brain using structural magnetic resonance imaging (MRI), MRI studies investigating the spinal cord are still scarce. In the present study, we acquired ex vivo high resolution structural MRI of the cervical spinal cord of 8.5–9 month old hemizygous and homozygous P301L mice and non-transgenic littermates of both genders. We assessed the total cross-sectional area, and the gray and white matter anterior-posterior width and left-right width that are established imaging marker of spinal cord degeneration. We observed significant tissue-specific reductions in these parameters in female P301L mice that were stronger in homozygous than in hemizygous P301L mice, indicating both an effect of gender and transgene expression on cervical spinal cord atrophy. Moreover, atrophy was stronger in the gray matter than in the white matter. Immunohistochemical analysis revealed neurodegenerative and neuroinflammatory changes in the cervical spinal cord in both the gray and white matter of P301L mice. Collectively, our results provide evidence for cervical spinal cord atrophy that may directly contribute to the motor signs associated with tauopathy.

Oxyphylla A ameliorates cognitive deficits and alleviates neuropathology via the Akt-GSK3β and Nrf2-Keap1-HO-1 pathways in vitro and in vivo murine models of Alzheimer's disease

Introduction

Alzheimer’s disease (AD) is a progressive brain disorder, and one of the most common causes of dementia and amnesia. Due to the complex pathogenesis of AD, the underlying mechanisms remain unclear. Although scientists have made increasing efforts to develop drugs for AD, no effective therapeutic agents have been found.

Objectives

Natural products and their constituents have shown promise for treating neurodegenerative diseases, including AD. Thus, in-depth study of medical plants, and the main active ingredients thereof against AD, is necessary to devise therapeutic agents.

Methods

In this study, N2a/APP cells and SAMP8 mice were employed as in vitro and in vivo models of AD. Multiple molecular biological methods were used to investigate the potential therapeutic actions of oxyphylla A, and the underlying mechanisms.

Results

Results showed that oxyphylla A, a novel compound extracted from Alpinia oxyphylla, could reduce the expression levels of amyloid precursor protein (APP) and amyloid beta (Aβ) proteins, and attenuate cognitive decline in SAMP8 mice. Further investigation of the underlying mechanisms showed that oxyphylla A exerted an antioxidative effect through the Akt-GSK3β and Nrf2-Keap1-HO-1 pathways.

Conclusions.

Taken together, our results suggest a new horizon for the discovery of therapeutic agents for AD.

Predictors of Life Expectancy in Autopsy-Confirmed Alzheimer's Disease

BACKGROUND

Life expectancy (LE) following Alzheimer's disease (AD) is highly variable. The literature to date is limited by smaller sample sizes and clinical diagnoses.

OBJECTIVE

No study to date has evaluated predictors of AD LE in a retrospective large autopsy-confirmed sample, which was the primary objective of this study.

METHODS

Participants (≥50 years old) clinically and neuropathologically diagnosed with AD were evaluated using National Alzheimer's Coordinating Center (N = 1,401) data. Analyses focused on 21 demographic, medical, neuropsychiatric, neurological, functional, and global cognitive predictors of LE at AD dementia diagnosis. These 21 predictors were evaluated in univariate analyses. Variables found to be significant were then entered into a forward multiple regression. LE was defined as months between AD diagnosis and death.

RESULTS

Fourteen predictors were significant in univariate analyses and entered into the regression. Seven predictors explained 27% of LE variance in 764 total participants. Mini-Mental State Examination (MMSE) score was the strongest predictor of LE, followed by sex, age, race/ethnicity, neuropsychiatric symptoms, abnormal neurological exam results, and functional impairment ratings. Post-hoc analyses revealed correlations of LE were strongest with MMSE ≤12.

CONCLUSION

Global cognitive functioning was the strongest predictor of LE following diagnosis, and AD patients with severe impairment had the shortest LE. AD patients who are older, male, white, and have more motor symptoms, functional impairment, and neuropsychiatric symptoms were also more likely have shorter LE. While this model cannot provide individual prognoses, additional studies may focus on these variables to enhance predictions of LE in patients with AD.

Peripheral reaching in Alzheimer's disease and mild cognitive impairment

Recent evidence has implicated areas within the posterior parietal cortex (PPC) as among the first to show pathophysiological changes in Alzheimer's disease (AD). Focal brain damage to the PPC can cause optic ataxia, a specific deficit in reaching to peripheral targets. The present study describes a novel investigation of peripheral reaching ability in AD and mild cognitive impairment (MCI), to assess whether this deficit is common among these patient groups. Individuals with a diagnosis of mild-to-moderate AD, or MCI, and healthy older adult controls were required to reach to targets presented in central vision or in peripheral vision using two reaching tasks; one in the lateral plane and another presented in radial depth. Pre-registered case–control comparisons identified 1/10 MCI and 3/17 AD patients with significant peripheral reaching deficits at the individual level, but group-level comparisons did not find significantly higher peripheral reaching error in either AD or MCI by comparison to controls. Exploratory analyses showed significantly increased reach duration in both AD and MCI groups relative to controls, accounted for by an extended Deceleration Time of the reach movement. These findings suggest that peripheral reaching deficits like those observed in optic ataxia are not a common feature of AD. However, we show that cognitive decline is associated with a generalised slowing of movement which may indicate a visuomotor deficit in reach planning or online guidance.

Single-Task or Dual-Task? Gait Assessment as a Potential Diagnostic Tool for Alzheimer's Dementia

Background:

A person’s gait performance requires the integration of sensorimotor and cognitive systems. Therefore, a person’s gait may be influenced by concurrent cognitive load such as simultaneous talking. Although it has been known that gait performance of people with Alzheimer’s dementia (AD) is compromised when they attempt a dual-task walking task, it is unclear if using a dual-task gait performance during an AD assessment yields higher diagnostic accuracy.

Objective:

This study was designed to compare the predictive power for AD of dual-task gait performance in an AD assessment to that of single-task gait performance.

Methods:

Participants (14 with AD and 15 healthy controls) walked across the GAITRite© Portable Walkway mat under three different cognitive load conditions: no simultaneous cognitive load, walking while counting numbers by ones, and walking while completing category naming.

Results:

Multiple logistic regression revealed that the gait performance under a dual-task condition (i.e., concurrent counting or category naming) increased the proportion of variance explained by the FAP, SL, and DST, of the incidence of AD.

Conclusion:

Dual-task walking and talking may be a more effective diagnostic feature than single-task walking in a comprehensive AD diagnostic assessment.

Parkinsonism and dementia

The aim of the present review is to summarize literature data on dementia in parkinsonian disorders. Cognitive decline and the gradual development of dementia are considered to be key features in the majority of parkinsonian conditions. The burden of dementia in everyday life of parkinsonian patients and their caregivers is vast and can be even more challenging to handle than the motor component of the disease. Common pathogenetic mechanisms involve the aggregation and spreading of abnormal proteins like alpha-synuclein, tau or amyloid in cortical and subcortical regions with subsequent dysregulation of multiple neurotransmitter systems. The degree of cognitive deterioration in these disorders is variable and ranges from mild cognitive impairment to severe cognitive dysfunction. There is also variation in the number and type of affected cognitive domains which can involve either a single domain like executive or visuospatial function or multiple ones. Novel genetic, biological fluid or imaging biomarkers appear promising in facilitating the diagnosis and staging of dementia in parkinsonian conditions. A significant part of current research in Parkinson's disease and other parkinsonian syndromes is targeted towards the cognitive aspects of these disorders. Stabilization or amelioration of cognitive outcomes represents a primary endpoint in many ongoing clinical trials for novel disease modifying treatments in this field. This article is part of the Special Issue "Parkinsonism across the spectrum of movement disorders and beyond" edited by Joseph Jankovic, Daniel D. Truong and Matteo Bologna.

Mild Parkinsonian Signs: A Systematic Review of Clinical, Imaging, and Pathological Associations

Mild parkinsonian signs (MPS) have been widely studied during the past 3 decades and proposed as a risk marker for neurodegenerative disease. This systematic review explores the epidemiology, clinical and prognostic associations, radiological features, and pathological findings associated with MPS in older adults free from neurodegenerative disease. We find that MPS as currently defined are strongly associated with increasing age and increased risk of development of Parkinson's disease (PD), all-cause dementia, disability, and death. Positive associations with later PD are found mainly in younger populations and those with other features of prodromal PD. There are currently no consistent radiological findings for MPS, and pathological studies have shown that MPS, at least in the oldest old, are often underpinned by mixed neuropathologies, including those associated with Alzheimer's disease, cerebrovascular disease, nigral neuronal loss, and Lewy bodies. Different subcategories of MPS appear to convey varying risk and specificity for PD and other outcomes. MPS overall are not specific for parkinsonian disorders and, although associated with increased risk of PD, can reflect multiple pathologies, particularly in older individuals. "Mild motor signs" appears a more appropriate term to avoid prognostic and pathological implications, and larger future studies to prospectively examine outcomes and associations of specific MPS subcategories are required. © 2021 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Rehabilitation in Dementia

Dementia is an eurodegenerative disorder, which causes significant disability, especially among the elderly population worldwide. The affected person shows a progressive cognitive decline, which interferes with the independence in performing the activities of daily living. Other than the cognitive domain, the patient tends to have neuropsychiatric, behavioral, sensorimotor, speech, and language-related issues. It is expected that the global burden of the disease will rise with more people entering the geriatric age group. By 2050 close, to 140 million people will be living with one or the other type of dementia. Alzheimer's disease contributes to more than 60% of cases worldwide, followed by vascular dementia. Pharmacotherapy has a limited role to play in the treatment, and at present, no drug is available, which can halt or reverse the progress of the disease. World Health Organization has mandated rehabilitation as a core recommendation in the global action plan on the public health response to dementia. Rehabilitation services are widely recognized as a practical framework to maximize independence and community participation in dementia care. The rehabilitation program is customized to achieve the desired goals, as each person has different experiences, preferences, motivations, strengths, and requirements based on type, course, and severity of the illness. It is an interdisciplinary-team approach with the involvement of several health care professionals. This article reviews the existing literature and outlines the effective rehabilitation strategies concisely in dementia care.

Longitudinal Timed Up and Go Assessment in Amyotrophic Lateral Sclerosis: A Pilot Study

Progressive loss of walking ability in amyotrophic lateral sclerosis (ALS) has been scarcely studied as a potential predictive factor for survival in motor neuron disease. We aimed to assess the progression of gait decline and its association with mortality in ALS using the Timed Up and Go test (TUG). Patients were followed up prospectively at the Centre for ALS and Related Disorders in Geneva University Hospitals between 2012 and 2016. The TUG was performed at baseline and subsequent evaluations occurred every 3 months. At inclusion, patients were classified as unable to perform the TUG, "slow TUG" (>10.6 s), and "fast TUG" (≤10.6 s). In total, 68 patients with ALS (mean ± SD age: 68.6 ± 11.9 years; 50% female) were included. Baseline TUG was negatively correlated with the total ALSFRS-R score (r = -0.63, p < 0.001). At baseline, ALS patients with bulbar onset performed the TUG faster (9.9 ± 3.7 s) than the non-bulbar ones (17.3 ± 14.9 s, p = 0.008). Thirty of 68 (44%) patients died by the end of the follow-up period. The TUG performance at the first visit did not predict mortality. While we did not find any association with mortality in ALS and gait quantification, the TUG was feasible in a majority of ALS patients, was correlated with functional status, and could be of interest in the follow-up of non-bulbar ALS patients.

Emerging concepts on bradykinesia in non-parkinsonian conditions

BACKGROUND AND PURPOSE

Bradykinesia is one of the cardinal motor symptoms of Parkinson's disease. However, clinical and experimental studies indicate that bradykinesia may also be observed in various neurological diseases not primarily characterized by parkinsonism. These conditions include hyperkinetic movement disorders, such as dystonia, chorea, and essential tremor. Bradykinesia may also be observed in patients with neurological conditions that are not seen as "movement disorders," including those characterized by the involvement of the cerebellum and corticospinal system, dementia, multiple sclerosis, and psychiatric disorders.

METHODS

We reviewed clinical reports and experimental studies on bradykinesia in non-parkinsonian conditions and discussed the major findings.

RESULTS

Bradykinesia is a common motor abnormality in non-parkinsonian conditions. From a pathophysiological standpoint, bradykinesia in neurological conditions not primarily characterized by parkinsonism may be explained by brain network dysfunction.

CONCLUSION

In addition to the pathophysiological implications, the present paper highlights important terminological issues and the need for a new, more accurate, and more widely used definition of bradykinesia in the context of movement disorders and other neurological conditions.

Perspective: Treatment for Disease Modification in Chronic Neurodegeneration

Symptomatic treatments are available for Parkinson's disease and Alzheimer's disease. An unmet need is cure or disease modification. This review discusses possible reasons for negative clinical study outcomes on disease modification following promising positive findings from experimental research. It scrutinizes current research paradigms for disease modification with antibodies against pathological protein enrichment, such as α-synuclein, amyloid or tau, based on post mortem findings. Instead a more uniform regenerative and reparative therapeutic approach for chronic neurodegenerative disease entities is proposed with stimulation of an endogenously existing repair system, which acts independent of specific disease mechanisms. The repulsive guidance molecule A pathway is involved in the regulation of peripheral and central neuronal restoration. Therapeutic antagonism of repulsive guidance molecule A reverses neurodegeneration according to experimental outcomes in numerous disease models in rodents and monkeys. Antibodies against repulsive guidance molecule A exist. First clinical studies in neurological conditions with an acute onset are under way. Future clinical trials with these antibodies should initially focus on well characterized uniform cohorts of patients. The efficiency of repulsive guidance molecule A antagonism and associated stimulation of neurogenesis should be demonstrated with objective assessment tools to counteract dilution of therapeutic effects by subjectivity and heterogeneity of chronic disease entities. Such a research concept will hopefully enhance clinical test strategies and improve the future therapeutic armamentarium for chronic neurodegeneration.

Motor signs in Alzheimer's disease and vascular dementia: Detection through natural language processing, co-morbid features and relationship to adverse outcomes

BACKGROUND

Motor signs in patients with dementia are associated with a higher risk of cognitive decline, institutionalisation, death and increased health care costs, but prevalences differ between studies. The aims of this study were to employ a natural language processing pipeline to detect motor signs in a patient cohort in routine care; to explore which other difficulties occur co-morbid to motor signs; and whether these, as a group and individually, predict adverse outcomes.

METHODS

A cohort of 11,106 patients with dementia in Alzheimer's disease, vascular dementia or a combination was assembled from a large dementia care health records database in Southeast London. A natural language processing algorithm was devised in order to establish the presence of motor signs (bradykinesia, Parkinsonian gait, rigidity, tremor) recorded around the time of dementia diagnosis. We examined the co-morbidity profile of patients with these symptoms and used Cox regression models to analyse associations with survival and hospitalisation, adjusting for twenty-four potential confounders.

RESULTS

Less than 10% of patients were recorded to display any motor sign, and tremor was most frequently detected. Presence of motor signs was associated with younger age at diagnosis, neuropsychiatric symptoms, poor physical health and higher prescribing of psychotropics. Rigidity was independently associated with a 23% increased mortality risk after adjustment for confounders (p = 0.014). A non-significant trend for a 15% higher risk of hospitalisation was detected in those with a recorded Parkinsonian gait (p = 0.094).

CONCLUSIONS

With the exception of tremor, motor signs appear to be under-recorded in routine care. They are part of a complex clinical picture and often accompanied by neuropsychiatric and functional difficulties, and thereby associated with adverse outcomes. This underlines the need to establish structured examinations in routine clinical practice via easy-to-use tools.

Deterioration, Compensation and Motor Control Processes in Healthy Aging, Mild Cognitive Impairment and Alzheimer's Disease

Aging is associated with modifications of several brain structures and functions. These modifications then manifest as modified behaviors. It has been proposed that some brain function modifications may compensate for some other deteriorated ones, thus maintaining behavioral performance. Through the concept of compensation versus deterioration, this article reviews the literature on motor function in healthy and pathological aging. We first highlight mechanistic studies that used paradigms, allowing us to identify precise compensation mechanisms in healthy aging. Subsequently, we review studies investigating motor function in two often-associated neurological conditions, i.e., mild cognitive impairment and Alzheimer's disease. We point out the need to expand the knowledge gained from descriptive studies with studies targeting specific motor control processes. Teasing apart deteriorated versus compensating processes represents precious knowledge that could significantly improve the prevention and rehabilitation of age-related loss of mobility.

Extrapyramidal signs and Alzheimer's disease prognosis in a multiethnic, community-based sample of demented elders

INTRODUCTION

Extrapyramidal signs (EPS) are a common feature of Alzheimer's disease associated with worse outcomes in observational studies of dementia. Less research has been conducted on ethnic minority and non-clinic-based populations.

METHODS

One hundred and forty-two multiethnic community-dwelling participants with dementia were selected. Adjusted Cox models were fitted for mortality, cognitive (Mini Mental State Examination ≤10), functional (Blessed Dementia Rating Scale ≥10), and dependency (needs full-time care) endpoints with baseline EPS as predictor.

RESULTS

Thirty-seven participants (26.06%) had EPS at baseline. EPS predicted more rapid time to death (hazard ratio [HR] = 2.76, 95% confidence interval [CI] = 1.49, 5.42), and functional endpoint (HR = 3.88, 95% CI = 1.75, 8.62) but not cognitive and dependency endpoints. No evidence of interaction by ethnicity, age, sex, education, or apolipoprotein E ε4 polymorphism was found.

DISCUSSION

Our results partially confirm previous studies on predominantly White, clinic-based samples. Further research is needed to better understand the etiological role of EPS in AD.

Variáveis psicomotoras, cognitivas e funcionais em idosas saudáveis e com doença de Alzheimer

RESUMO A teoria da retrogênese descreve os declínios apresentados na doença de Alzheimer a partir dos estágios do desenvolvimento neuropsicomotor de Piaget. O objetivo deste estudo transversal é avaliar e descrever aspectos psicomotores, cognitivos e quedas, investigando a relação de dependência entre essas variáveis de acordo com a teoria da retrogênese. A amostra foi composta por 45 idosas (27 saudáveis e 18 com Alzheimer fase leve), residentes em São Paulo entre 2016 e 2017. Para a avaliação foram utilizados: anamnese, Escala de Depressão Geriátrica de Yesavage (GDS-30), Montreal Cognitive Assessment (MoCA), Cambridge Cognitive Exam-Revised (CAMCOG-R), Escala de Equilíbrio de Berg (EEB), timed up and go test (TUGT), Avaliação Direta do Estado Funcional (DAFS-BR), teste U de Mann-Whitney, coeficiente de correlação de Spearman e análise de regressão múltipla com p<0,05. Observou-se ordem de perda semelhante à sugerida pela teoria da retrogênese nos dois grupos estudados. Quanto menor o índice CAMCOG-R, maior o número de quedas (p=0,03). Itens praxia (p<0,00) e funções executivas (p<0,00) do CAMCOG-R mostraram-se altamente correlacionados com o TUGT e a EEB. Sugere-se relação de dependência entre funcionalidade e cognição e equilíbrio e cognição, bem como correlação entre risco de queda e desempenho cognitivo nos dois grupos estudados. As perdas observadas estão de acordo com o que a teoria da retrogênese propõe, mas com diferentes intensidades entre os grupos. Estudos longitudinais são necessários, com uso de exames de imagem para validar a teoria nos padrões de perda em idosos com e sem doença de Alzheimer.

CD33 rs3865444 as a risk factor for Parkinson's disease

BACKGROUND

Alzheimer's (AD) and Parkinson's diseases (PD) share a few elements of their clinical, pathological and genetic backgrounds. The CD33 rs3865444 has emerged as a strong genetic locus associated with AD through genome-wide association study (GWAS). However, little is known for its role in PD.

OBJECTIVE

To assess the role of CD33 rs3865444 on PD risk.

METHODS

We genotyped 358 patients with PD and 358 healthy controls for theCD33 rs3865444. Odds ratios (ORs) with the respective 95% confidence intervals (CIs)], were calculated with the SNPStats software, assuming five genetic models (co-dominant, dominant, recessive, over-dominant and log-additive), with the G allele as the reference allele.

RESULTS

The CD33 rs3865444 was associated with decreased PD risk in the dominant [GG vs GT + TT; OR (95% CI) = 0.61 (0.45-0.82), p = 0.001], the over-dominant [GG + TT vs GT; OR (95% CI) = 0.65 (0.48-0.89), p = 0.0061], log-additive [OR (95% CI) = 0.67 (0.52-0.86), p = 0.0014], and co-dominant [with overall p = 0.0043, and OR (95% CI) = 0.62 (0.45-0.84) for the TG genotype compared to the GG], modes of inheritance.

CONCLUSIONS

The CD33 rs3865444 is associated with decreased PD risk, and larger studies investigating the role of CD33 rs3865444 on PD are needed.

Different patterns of β-amyloid deposition in patients with Alzheimer's disease according to the presence of mild parkinsonism

This study aimed to compare the patterns of β-amyloid deposition between patients with early-stage Alzheimer's disease (AD) with mild parkinsonism and those without parkinsonism. Sixty-one patients with early-stage AD (Clinical Dementia Rating [CDR], 0.5 or 1) who underwent ¹⁸F-florbetaben (¹⁸F-FBB) PET scans were enrolled. We performed comparative analyses of regional FBB uptake in the frontal, parietal, lateral temporal, medial temporal, occipital, anterior cingulate, and posterior cingulate cortices and in the precuneus, striatum, and thalamus between AD patients with mild parkinsonism (AD-p+; n = 23) and those without parkinsonism (AD-p-; n = 38). There was no significant difference in age, sex, years of education, Mini-Mental State Examination score, and white matter hyperintensity severity between groups. The AD-p+ group had lower composite scores in frontal/executive function domain than the AD-p- group. The AD-p+ group had a higher FBB uptake in the occipital cortex, but not in other cortical regions, than the AD-p- group. Our findings suggest that additional β-amyloid deposition in the occipital region is associated with mild parkinsonism in early-stage AD.

Deterioration in Motor Function Over Time in Older Adults With Type 2 Diabetes is Associated with Accelerated Cognitive Decline

OBJECTIVE

Type 2 diabetes (T2D) is associated with motor impairments and a higher dementia risk. The relationships of motor decline with cognitive decline in T2D older adults has rarely been studied. Using data from the Israel Diabetes and Cognitive Decline study (N = 892), we examined associations of decline in motor function with cognitive decline over a 54-month period.

METHODS

Motor function measures were strength (handgrip) and gait speed (time to walk 3 m). Participants completed a neuropsychologic battery of 13 tests transformed into z-scores, summarized into 4 cognitive domains: episodic memory, attention/working memory, executive functions, and language/semantic categorization. The average of the 4 domains' z-scores defined global cognition. Motor and cognitive functions were assessed in 18-months intervals. A random coefficients model delineated longitudinal relationships of cognitive decline with baseline and change from baseline in motor function, adjusting for sociodemographic, cardiovascular, and T2D-related covariates.

RESULTS

Slower baseline gait speed levels were significantly associated with more rapid decline in global cognition (P = .004), language/semantic categorization (P = .006) and episodic memory (P = .029). Greater decline over time in gait speed was associated with an accelerated rate of decline in global cognition (P = .050), attention/working memory (P = .047) and language/semantic categorization (P<.001). Baseline strength levels were not associated with cognitive decline but the rate of declining strength was associated with an accelerated decline in executive functions (P = .025) and language/semantic categorization (P = .006).

CONCLUSION

In T2D older adults, the rate of decline in motor function, beyond baseline levels, was associated with accelerated cognitive decline, suggesting that cognitive and motor decline share common neuropathologic mechanisms in T2D.

Modifiable, Non-Modifiable, and Clinical Factors Associated with Progression of Alzheimer's Disease

There is an extensive literature relating to factors associated with the development of Alzheimer's disease (AD), but less is known about factors which may contribute to its progression. This review examined the literature with regard to 15 factors which were suggested by PubMed search to be positively associated with the cognitive and/or neuropathological progression of AD. The factors were grouped as potentially modifiable (vascular risk factors, comorbidities, malnutrition, educational level, inflammation, and oxidative stress), non-modifiable (age at clinical onset, family history of dementia, gender, Apolipoprotein E ɛ4, genetic variants, and altered gene regulation), and clinical (baseline cognitive level, neuropsychiatric symptoms, and extrapyramidal signs). Although conflicting results were found for the majority of factors, a positive association was found in nearly all studies which investigated the relationship of six factors to AD progression: malnutrition, genetic variants, altered gene regulation, baseline cognitive level, neuropsychiatric symptoms, and extrapyramidal signs. Whether these or other factors which have been suggested to be associated with AD progression actually influence the rate of decline of AD patients is unclear. Therapeutic approaches which include addressing of modifiable factors associated with AD progression should be considered.

Association Between Early Psychotic Symptoms and Alzheimer's Disease Prognosis in a Community-Based Cohort

BACKGROUND

Psychotic symptoms are an important and increasingly recognized aspect of Alzheimer's disease (AD). They have been shown to contribute to faster disease progression in clinic-based, demographically homogenous samples with high educational attainment.

OBJECTIVE

We studied the association between baseline psychotic symptoms and disease progression among individuals with incident AD or 'at risk' of developing AD, from a demographically heterogenous, community-based cohort with minimal educational attainment.

METHODS

212 participants received the Columbia University Scale of Psychopathology in Alzheimer's Disease scale. Participants had psychotic symptoms with any of: visual illusions, delusions, hallucinations, or agitation/aggression. Disease progression was measured yearly and defined by meeting cognitive (≤10 on the Folstein MMSE) or functional endpoints (≥10 on the Blessed Dementia Rating Scale or ≥4 on the Dependence Scale).

RESULTS

The mean age was 85 years old. The cohort was 78.3% female, 75.9% Hispanic, and had a mean 6.96 years of education. Within the follow-up period (mean: 3.69 years), 24 met the cognitive endpoint, 59 met the functional endpoint, and 132 met the cutoff for dependence. The presence of at least one psychotic symptom was initially associated with an increased risk of reaching the functional endpoint (HR 3.12, 95% CI 1.67-5.86, p < 0.001) and the endpoint of dependence (HR = 1.498, 95% CI 1.05-2.13, p = 0.03). However, these associations were attenuated and non-significant when adjusted for baseline functional status. Psychotic symptoms were not associated with the cognitive endpoint.

CONCLUSION

Psychotic symptoms may predict functional decline in patients of non-Caucasian ethnicity and with lower educational attainment.

Phenotype-Agnostic Molecular Subtyping of Neurodegenerative Disorders: The Cincinnati Cohort Biomarker Program (CCBP)

Ongoing biomarker development programs have been designed to identify serologic or imaging signatures of clinico-pathologic entities, assuming distinct biological boundaries between them. Identified putative biomarkers have exhibited large variability and inconsistency between cohorts, and remain inadequate for selecting suitable recipients for potential disease-modifying interventions. We launched the Cincinnati Cohort Biomarker Program (CCBP) as a population-based, phenotype-agnostic longitudinal study. While patients affected by a wide range of neurodegenerative disorders will be deeply phenotyped using clinical, imaging, and mobile health technologies, analyses will not be anchored on phenotypic clusters but on bioassays of to-be-repurposed medications as well as on genomics, transcriptomics, proteomics, metabolomics, epigenomics, microbiomics, and pharmacogenomics analyses blinded to phenotypic data. Unique features of this cohort study include (1) a reverse biology-to-phenotype direction of biomarker development in which clinical, imaging, and mobile health technologies are subordinate to biological signals of interest; (2) hypothesis free, causally- and data driven-based analyses; (3) inclusive recruitment of patients with neurodegenerative disorders beyond clinical criteria-meeting patients with Parkinson's and Alzheimer's diseases, and (4) a large number of longitudinally followed participants. The parallel development of serum bioassays will be aimed at linking biologically suitable subjects to already available drugs with repurposing potential in future proof-of-concept adaptive clinical trials. Although many challenges are anticipated, including the unclear pathogenic relevance of identifiable biological signals and the possibility that some signals of importance may not yet be measurable with current technologies, this cohort study abandons the anchoring role of clinico-pathologic criteria in favor of biomarker-driven disease subtyping to facilitate future biosubtype-specific disease-modifying therapeutic efforts.

The continuum between neurodegeneration, brain plasticity, and movement: a critical appraisal

While the “physiological” aging process is associated with declines in motor and cognitive features, these changes do not significantly impair functions and activities of daily living. Differently, motor and cognitive impairment constitute the most common phenotypic expressions of neurodegeneration. Both manifestations frequently coexist in the same disease, thus making difficult to detect “pure” motor or cognitive conditions. Movement disorders are often characterized by cognitive disturbances, and neurodegenerative dementias often exhibit the occurrence of movement disorders. Such a phenotypic overlap suggests approaching these conditions by highlighting the commonalities of entities traditionally considered distinct. In the present review, we critically reappraised the common clinical and pathophysiological aspects of neurodegeneration in both animal models and patients, looking at motricity as a trait d’union over the spectrum of neurodegeneration and focusing on synaptopathy and oscillopathy as the common pathogenic background. Finally, we discussed the possible role of movement as neuroprotective intervention in neurodegenerative conditions, regardless of the etiology. The identification of commonalities is critical to drive future research and develop novel possible disease-modifying interventions.

Relationship Between Balance, Gait, and Activities of Daily Living in Older Adults With Dementia

Introduction:

Gait characteristics are closely associated with executive functions including basic and high-level cognitive processes such as attention, working memory, decision-making, and problem-solving. Impaired cognitive function resulting from dementia is associated with loss of balance and poor activities of daily living (ADLs). If associations between gait parameters, balance, and ADLs are observed, then quantitative gait analysis may be optimal for reinforcing balance and ADL assessments in people with dementia. This study aimed to determine the association between balance, gait, and ADLs in older adults with dementia.

Materials and Methods:

A cross-sectional study was conducted in 46 older adults who have been diagnosed with dementia. Measurements including the Mini-Mental Statement Examination-Korean version (MMSE-K), Berg Balance Scale (BBS), 10-meter walk test (10MWT), Modified Barthel index (MBI), and GAITRite were used to assess cognitive function, balance, walking speed, ADLs, and gait parameters, respectively. The Pearson product correlation coefficient (r) was used for correlation analysis.

Results and Discussion:

Among the gait parameters, velocity was positively associated with the BBS, 10MWT, and MBI (r = 0.341-0.516, P > .05). Step length (r = 0.301-0.586, P > .05), stride length (r = 0.329-0.580, P > .05), and walk ratio (r = 0.324-0.556, P > .05) were positively associated with the MMSE-K, BBS, 10MWT, and MBI. A moderate positive association between single support time and MBI was observed (r = 0.308, P = .039). Additionally, a moderate negative association between double support time and the MBI was observed (r = −0.349, P = .019). This study presents the first empirical evidence on the association between balance, gait, and ADLs in older adults with dementia.

Conclusions:

This study identified important associations between balance, gait, and ADL assessments in people with dementia. Further studies involving targeted interventions addressing gait parameters and improving balance and functional performance in people with dementia are required in the future.

Protein-protein interactions underlying the behavioral and psychological symptoms of dementia (BPSD) and Alzheimer's disease

Alzheimer’s Disease (AD) is a devastating neurodegenerative disorder currently affecting 45 million people worldwide, ranking as the 6^th highest cause of death. Throughout the development and progression of AD, over 90% of patients display behavioral and psychological symptoms of dementia (BPSD), with some of these symptoms occurring before memory deficits and therefore serving as potential early predictors of AD-related cognitive decline. However, the biochemical links between AD and BPSD are not known. In this study, we explored the molecular interactions between AD and BPSD using protein-protein interaction (PPI) networks built from OMIM (Online Mendelian Inheritance in Man) genes that were related to AD and two distinct BPSD domains, the Affective Domain and the Hyperactivity, Impulsivity, Disinhibition, and Aggression (HIDA) Domain. Our results yielded 8 unique proteins for the Affective Domain (RHOA, GRB2, PIK3R1, HSPA4, HSP90AA1, GSK3beta, PRKCZ, and FYN), 5 unique proteins for the HIDA Domain (LRP1, EGFR, YWHAB, SUMO1, and EGR1), and 6 shared proteins between both BPSD domains (APP, UBC, ELAV1, YWHAZ, YWHAE, and SRC) and AD. These proteins might suggest specific targets and pathways that are involved in the pathogenesis of these BPSD domains in AD.

The Proteome of the Dentate Terminal Zone of the Perforant Path Indicates Presynaptic Impairment in Alzheimer Disease

Synaptic dysfunction is an early pathogenic event in Alzheimer disease (AD) that contributes to network disturbances and cognitive decline. Some synapses are more vulnerable than others, including the synapses of the perforant path, which provides the main excitatory input to the hippocampus. To elucidate the molecular mechanisms underlying the dysfunction of these synapses, we performed an explorative proteomic study of the dentate terminal zone of the perforant path. The outer two-thirds of the molecular layer of the dentate gyrus, where the perforant path synapses are located, was microdissected from five subjects with AD and five controls. The microdissected tissues were dissolved and digested by trypsin. Peptides from each sample were labeled with different isobaric tags, pooled together and pre-fractionated into 72 fractions by high-resolution isoelectric focusing. Each fraction was then analyzed by liquid chromatography-mass spectrometry. We quantified the relative expression levels of 7322 proteins, whereof 724 showed significantly altered levels in AD. Our comprehensive data analysis using enrichment and pathway analyses strongly indicated that presynaptic signaling, such as exocytosis and synaptic vesicle cycle processes, is severely disturbed in this area in AD, whereas postsynaptic proteins remained unchanged. Among the significantly altered proteins, we selected three of the most downregulated synaptic proteins; complexin-1, complexin-2 and synaptogyrin-1, for further validation, using a new cohort consisting of six AD and eight control cases. Semi-quantitative analysis of immunohistochemical staining confirmed decreased levels of complexin-1, complexin-2 and synaptogyrin-1 in the outer two-thirds of the molecular layer of the dentate gyrus in AD. Our in-depth proteomic analysis provides extensive knowledge on the potential molecular mechanism underlying synaptic dysfunction related to AD and supports that presynaptic alterations are more important than postsynaptic changes in early stages of the disease. The specific synaptic proteins identified could potentially be targeted to halt synaptic dysfunction in AD.

Parkinsonism in genetic and sporadic Alzheimer's disease

Alzheimer disease (AD) is a neurodegenerative disease characterized by deposition of pathologically aggregated amyloid-β in the extracellular space and pathologically aggregated tau protein in the intracellular space. Mainly affected brain areas are the temporal and the parietal lobe, which cause the classical AD phenotype consisting of increasing forgetfulness and difficulties to orientate. However, AD pathology is not restricted to these brain areas and spreads through the brain as the disease progresses, which can lead to a number of additional symptoms and to atypical presentations. Motor symptoms in AD are the topic of this chapter. Even though motor symptoms are usually not severe and seldomly treated, motor symptoms are quite frequent and can be observed in the majority of AD cases. Motor symptoms are especially frequent in cases with early onset and long disease duration, for example in Apolipoprotein E e4 carriers and in familial early onset AD. In severe cases treatment with pharmacological approaches might be considered. However, treatment strategies largely rely on expert opinions. Due to potential positive impact on prognosis non-pharmacological treatment and exercise might be considered in less advanced cases.

Presynaptic dopaminergic function in early-onset Alzheimer's disease: an FP-CIT image study

We aimed to investigate whether amyloid-β (Aβ) positive early-onset Alzheimer's disease (EOAD) patients have presynaptic dopaminergic deficits on in vivo ¹⁸F-FP-CIT PET imaging. We enrolled 34 EOAD patients and 9 cognitively normal controls (NC), all of whom underwent ¹⁸F-florbetaben and ¹⁸F-FP-CIT PET at Samsung Medical Center. We assessed motor symptoms using Unified Parkinson's Disease Rating Scale (UPDRS) and divided the EOAD patients into 2 groups using a UPDRS cutoff of 10. We compared regional florbetaben and FP-CIT uptake across the NC and the 2 EOAD groups with lower and higher UPDRS and investigated the associations between regional florbetaben or FP-CIT uptake and UPDRS in EOAD patients. Among the 30 EOAD patients who were Aβ positive on florbetaben PET, the higher UPDRS (>10) group (n = 9) had a longer disease duration (7.2 ± 3.3 vs. 4.1 ± 1.8, p = 0.002), and had a tendency to have lower Mini-Mental State Examination (9.6 ± 7.9 vs. 15.0 ± 6.0, p = 0.052) than the lower UPDRS (≤10) group (n = 21). Across the NC and the 2 EOAD groups, there were no significant differences in FP-CIT uptake in caudate (p = 0.122) and putamen (p = 0.685) or florbetaben uptake in midbrain (p = 0.890). Finally, regression analyses showed that UPDRS was not associated with FP-CIT uptake in caudate (p = 0.913) or putamen (p = 0.407), or with florbetaben PET uptake in caudate (p = 0.553), putamen (p = 0.617), midbrain (p = 0.843), or global cortex (p = 0.658). This study showed that parkinsonian signs in EOAD patients may be related with mechanisms other than presynaptic dopaminergic deficit. Our finding is clinically important because it suggests that L-dopa treatment in EOAD with parkinsonian signs may not improve motor symptoms.

Key factors for the assessment of mobility in advanced dementia: A consensus approach

INTRODUCTION

Loss of mobility is common in advanced dementia and has important negative consequences related to fall risk, loss of independence, and lack of participation in meaningful activities. The causes of decline are multifactorial, including disease-specific changes in motor function, behavior, and cognition. To optimize clinical management of mobility, there is a need to better characterize capacity for safe and independent mobility. This study aimed to identify key factors that impact on mobility in dementia.

METHODS

Expert input was gathered using a modified Delphi consensus approach. The primary criterion for participation was specialist knowledge in mobility or dementia, either as a clinician or a researcher. Participants rated elements of mobility for importance and feasibility of assessment in advanced dementia and prioritized items for inclusion in a mobility staging tool. Descriptive statistics and qualitative content analysis were used to summarize responses.

RESULTS

Thirty-six experts completed the first survey with an 80% retention rate over three rounds. One-third of 61 items reached consensus for being both important and feasible to assess, representing five categories of elements. Items reaching agreement for a staging tool included walking, parkinsonism, gait, impulsivity, fall history, agitation, transfers, and posture control.

DISCUSSION

This study highlights the need for a multidimensional, dementia-specific approach to mobility assessment. Results have implications for development of assessment methods and management guidelines to support the clinical care of mobility impairment in people with dementia.

Linking late life depression and Alzheimer's disease: mechanisms and resilience

Purpose of Review

This review summarizes recent literature linking Alzheimer's disease (AD) and late life depression (LLD). It describes shared neurobiological features associated with both conditions, as well as factors that may increase resilience to onset and severity of cognitive decline and AD. Finally, we pose a number of future research directions toward improving detection, management, and treatment of both conditions.

Recent Findings

Epidemiological studies have consistently shown a significant relationship between LLD and AD, with support for depression as a prodromal feature of AD, a risk factor for AD, and observation of some shared risk factors underlying both disease processes. Three major neurobiological features shared by LLD and AD include neurodegeneration, disruption to cerebrovascular functioning, and increased levels of neuroinflammation. There are also potentially modifiable factors that can increase resilience to AD and LLD, including social support, physical and cognitive engagement, and cognitive reserve.

Summary

We propose that, in the context of depression, neurobiological events, such as neurodegeneration, cerebrovascular disease, and neuroinflammation result in a brain that is more vulnerable to the consequences of the pathophysiological features of AD, lowering the threshold for the onset of the behavioral presentation of AD (i.e., cognitive decline and dementia). We discuss factors that can increase resilience to AD and LLD, including social support, physical and cognitive engagement, and cognitive reserve. We conclude with a discussion of future research directions.

Pneumonia-associated death in patients with dementia: A systematic review and meta-analysis

BACKGROUND

Pneumonia is a serious disease associated with mortality among patients with dementia. However, the reported frequency of pneumonia as a cause of death in patients with dementia varies, the reason for which has not been fully elucidated.

METHODS

We conducted a systematic search in PubMed and the Cochrane Database of Systematic Reviews (inception to December 2016). Two authors independently determined the suitability of studies and potential bias and extracted the data. The primary outcome was frequency of pneumonia-associated death in patients with dementia. Stratified subgroup analysis was conducted among studies grouped according to type of mortality cause (immediate or underlying), information source of mortality cause (autopsy or death certificate), and study setting (clinic, hospital, or nursing home).

RESULTS

We included 7 studies reporting the cause of death among patients with dementia and 12 studies comparing the cause of death among patients with and without dementia. The frequency of pneumonia-associated death among 19 eligible studies was 29.69% (95% confidence interval [CI], 25.86-33.53). Those frequencies differed according to whether the source for information about cause of death was an autopsy confirmation (49.98%; 95% CI, 43.75-56.71) or death certificate (19.65%; 95% CI, 15.48-23.83) and according to whether the type of mortality cause was an indirect cause of death (13.96%; 95% CI, 9.42-18.51) or direct cause of death (44.45%; 95% CI, 29.81-50.10). The risk of pneumonia-associated death in patients with dementia was twice as high as among those without dementia (odds ratio, 2.15; 95% CI, 1.63-2.83; p < 0.001).

CONCLUSION

The various frequencies of pneumonia-associated death in patients with dementia were associated with the information source, type of mortality cause, and study setting. Patients with dementia in the terminal stages urgently require careful clinical management of pneumonia, to maximize patient life expectancy and quality.

Effect of grip strength on mental health

BACKGROUND

This study is to longitudinally investigate the association between grip strength and mental health disorders in middle aged and aged population from the Korean Longitudinal Study of Aging.

METHODS

Data from the Korean Longitudinal Study of Aging (KLoSA) from 2006 to 2016 was assessed using longitudinal data analysis and out of the 9279 research subjects gathered 1549 (16.7%) participants were reported as Q1 group and 2074 (22.4%) participants were reported as Q5 group. To analyze the association between grip strength and mental health disorders, generalized estimating equation (GEE) model was used.

RESULTS

The association between grip strength and cognitive decline was statistically significant, with the following Odds ratio (OR) predicting decreased cognitive decline: OR = 4.99 (p < .0001) for Q1 group vs. Q5 group. The association between grip strength and MMSE and CESD was also statistically significant, with the following estimate (B) predicting decreased MMSE score: B = -0.12 (p < .0001) for Q1 group vs. Q5 group. In terms of CESD, CESD score was higher for Q1 group (B = 0.34, p < .0001) compared to Q5 group.

CONCLUSION

This study shows a significant association between grip strength and risk of mental illness in Korean middle aged and aged population. Therefore, grip strength should be given more focus in terms of resistance training programs.

Quantitative Measurements of Motor Function in Alzheimer's Disease, Frontotemporal Dementia, and Dementia with Lewy Bodies: A Proof-of-Concept Study

BACKGROUND

This study examines the efficacy of using quantitative measurements of motor dysfunction, compared to clinical ratings, in Alzheimer's disease (AD), frontotemporal dementia (FTD), and dementia with Lewy bodies (DLB).

METHODS

In this cross-sectional study, 49 patients with a diagnosis of AD (n = 17), FTD (n = 19), or DLB (n = 13) were included and underwent cognitive testing, clinical motor evaluation, and quantitative motor tests: pronation/supination hand tapping, grasping and lifting, and finger and foot tapping.

RESULTS

Our results revealed significantly higher Q-Motor values in pronation/supination and in grip lift force assessment in AD, FTD, and DLB compared to healthy controls (HC). Q-Motor values detected significant differences between AD and HC, while clinical ratings did not.

CONCLUSION

Our results suggest that quantitative measurements provide more objective and sensitive measurements of motor dysfunction in dementia.

The Diagnostic and Prognostic Value of a Dual-Tasking Paradigm in a Memory Clinic

BACKGROUND

Daily living requires the ability to perform dual-tasking. As cognitive skills decrease in dementia, performing a cognitive and motor task simultaneously become increasingly challenging and subtle gait abnormalities may even be present in pre-dementia stages. Therefore, a dual-tasking paradigm, such as the Timed Up and Go-Dual Task (TUG-DT), may be useful in the diagnostic assessment of mild cognitive impairment (MCI).

OBJECTIVE

To investigate the diagnostic and prognostic ability of a dual-tasking paradigm in patients with MCI or mild Alzheimer's disease (AD) and to evaluate the association between the dual-tasking paradigm and cerebrospinal fluid (CSF) AD biomarkers.

METHODS

The study is a prospective cohort study conducted in a clinical setting in two memory clinics. Eighty-six patients were included (28 MCI, 17 AD, 41 healthy controls (HC)). The ability to perform dual-tasking was evaluated by the TUG-DT. Patients underwent a standardized diagnostic assessment and were evaluated to determine progression yearly.

RESULTS

ROC curve analysis illustrated a high discriminative ability of the dual-tasking paradigm in separating MCI patients from HC (AUC: 0.78, AUC: 0.82) and a moderate discriminative ability in separating MCI from AD (AUC: 0.73, AUC: 0.55). Performance discriminated clearly between all groups (p < 0.01). Logistic regression analyses revealed a low prognostic value of the dual-tasking paradigm for progression and rate of cognitive decline. A moderately strong correlation between the dual-tasking paradigm and CSF AD biomarkers was observed.

CONCLUSION

In our study, we found that patients with MCI and mild AD have increasing difficulties in dual-tasking compared to healthy elderly. Hence, the dual-tasking paradigm may be a potential complement in the diagnostic assessment in a typical clinical setting.

Gait and dementia

Cognitive decline and neurodegenerative disease have been implicated in gait dysfunction via disturbance of top-down control mechanisms. Gait velocity decreases, variability increases, and ability to multitask while walking is impaired as cognition declines. Changes in gait can be used to predict incident mild cognitive impairment states as well as dementia. Slow gait velocity together with a cognitive complaint, the Motoric Cognitive Risk syndrome, can serve as a clinical biomarker for high risk of neurologic decline. While patients with Alzheimer's disease typically have quantitative gait impairment, those with other forms of dementia often manifest more overt, qualitative changes to walking. A variety of interventions may be useful to improve gait, including physical and cognitive rehabilitation, treatment of specific underlying causes of gait problems, and treatment of the dementia itself. Understanding the relationship between gait and dementia can elucidate pathology and improve patient care.

Dysfunction of Neuromuscular Synapses in the Genetic Model of Alzheimer's Disease

The function of synaptic transmission and presynaptic vesicular cycle in the neuromuscular synapses of the diaphragm was studied in transgenic APP/PS1 mice (Alzheimer's disease model). The decrease in the quantal content of end-plate potential, intense depression of the amplitude of terminal plate potentials under conditions of lasting high frequency stimulation (50 Hz), a drastic prolongation of the synaptic vesicle recycling time in APP/PS1 mice in comparison with wild type mice were detected. Manifest dysfunction of the neuromuscular synapses, caused by disordered neurosecretion and recycling of the synaptic vesicles in the presynaptic nerve endings, was detected in the Alzheimer's disease model on transgenic APP/PS1 mice. The study supplemented the notions on the pathogenesis of Alzheimer's disease as a systemic disease, while the detected phenomena could just partially explain the development of motor disorders in this disease.

Cognitive predictors of sequential motor impairments in children with dyslexia and/or attention deficit/hyperactivity disorder

This study examined cognitive predictors of sequential motor skills in 215 children with dyslexia and/or attention deficit/hyperactivity disorder (ADHD). Visual working memory and math fluency abilities contributed significantly to performance of sequential motor abilities in children with dyslexia (N = 67), ADHD (N = 66) and those with a comorbid diagnosis (N = 82), generally without differentiation between groups. In addition, primary diagnostic features of each disorder, such as reading and inattention, did not contribute to the variance in motor skill performance of these children. The results support a unifying framework of motor impairment in children with neurodevelopmental disorders such as dyslexia and ADHD.