Neurosciences Commons^™

Dose–Response Of Tdcs Effects On Motor Learning And Cortical Excitability: A Preregistered Study, Gavin Hsu, Zhenous Hadi Jafari, Abdelrahman Ahmed, Dylan J. Edwards, Leonardo G. Cohen, Lucas C. Parra

Research outputs 2022 to 2026

Multiple studies have demonstrated that transcranial direct current stimulation (tDCS) of the primary motor cortex (M1) can influence corticospinal excitability and motor skill acquisition. However, the evidence for these effects is inconsistent, and a common neural substrate for these effects has not been directly demonstrated. To address this, we hypothesized that higher tDCS intensities would produce more robust effects, and uncover their relationship. In this preregistered study, 120 participants engaged in a motor skill learning task while receiving tDCS with posterior-to-anterior currents through M1. We employed a double-blind, between-subjects design, with groups of 4 mA, 6 mA, or sham stimulation, …

Blood Biomarker Profiles In Young-Onset Neurocognitive Disorders: A Cohort Study, Oneil G. Bhalala, Jessica Beamish, Dhamidhu Eratne, Patrick Summerell, Tenielle Porter, Simon M. Laws, Matthew J.Y. Kang, Aamira J. Huq, Wei Hsuan Chiu, Claire Cadwallader, Mark Walterfang, Sarah Farrand, Andrew H. Evans, Wendy Kelso, Leonid Churilov, Rosie Watson, Nawaf Yassi, Dennis Velakoulis, Samantha M. Loi

Research outputs 2022 to 2026

Introduction: Young-onset neurocognitive symptoms result from a heterogeneous group of neurological and psychiatric disorders which present a diagnostic challenge. To identify such factors, we analysed the Biomarkers in Younger-Onset Neurocognitive Disorders cohort, a study of individuals < 65 years old presenting with neurocognitive symptoms for a diagnosis and who have undergone cognitive and biomarker analyses. Methods: Sixty-five participants (median age at assessment of 56 years, 45% female) were recruited during their index presentation to the Royal Melbourne Hospital Neuropsychiatry Centre, a tertiary specialist service in Melbourne, Australia, and categorized as either early-onset Alzheimer’s disease (n = 18), non-Alzheimer’s disease neurodegeneration (n = 23) or primary psychiatric disorders (n = 24). Levels of neurofilament light chain, glial fibrillary acidic protein …

Circulating Medium- And Long-Chain Acylcarnitines Are Associated With Plasma P-Tau181 In Cognitively Normal Older Adults, Tahmida Sharmin, Pratishtha Chatterjee, James D. Doecke, Nicholas J. Ashton, Kevin Huynh, Steve Pedrini, Hamid R. Sohrabi, Benjamin Heng, Shaun Eslick, Henrik Zetterberg, Kaj Blennow, Manohar Garg, Ralph N. Martins

Research outputs 2022 to 2026

Alzheimer's disease (AD) pathogenesis involves dysregulation in diverse biochemical processes. Nevertheless, plasma tau phosphorylated at threonine 181 (P-tau181), a recognised AD biomarker, has been described to reflect early-stage cortical amyloid-β (Aβ) deposition in cognitively normal (CN) adults. Therefore, identifying changes in plasma metabolites associated with plasma P-tau181 at the pre-clinical stage may provide insights into underlying biochemical mechanisms to better understand initial AD pathogenesis. In the current study, plasma P-tau181, quantified via single molecule array (Simoa) technology, and plasma metabolites, quantified via targeted-mass spectrometry, were investigated for associations in CN older adults and upon stratification by positron emission tomography (PET)-Aβ …

Sex Differences In The Association Between Episodic Memory Residual Reserve Index And Change In Executive Function, Cheyenne Chooi, Brandon E. Gavett, David Ames, Paul Maruff, Vincent Doré, Victor L. Villemagne, Pierrick Bourgeat, Ying Xia, Colin L. Masters, Ralph N. Martins, Kevin Taddei, Christopher C. Rowe, Michael Weinborn, Stephanie R. Rainey-Smith

Research outputs 2022 to 2026

Sex differences in cognitive reserve might contribute to females being disproportionately affected by Alzheimer's disease (AD). We investigated sex differences in the protective effects of cognitive reserve, and whether brain beta-amyloid accounts for differences. Older adults (n = 997 from the Australian Imaging, Biomarkers and Lifestyle Study of Ageing) diagnosed as Cognitively Normal, Mild Cognitive Impairment, or AD at baseline were assessed every 18 months for up to a maximum of seven visits. Cognitive reserve was calculated from the variance in episodic memory not explained by demographic or brain measures. Executive functioning (EF) intercept and slope were regressed onto the …

Distinct Contributions Of Cerebrospinal Fluid Biomarkers To Cognitive Impairment And Neuropsychiatric Symptoms In Young-Onset Dementia, Wei Hsuan Chiu, Anita M.Y. Goh, Dhamidhu Eratne, Charles B. Malpas, Matthew J.Y. Kang, Wendy Kelso, Mark Walterfang, Dennis Velakoulis, Samantha M. Loi

Research outputs 2022 to 2026

Objective: Young-onset dementia (YOD), defined by symptom onset before age 65, encompasses diverse aetiologies and presents with prominent neuropsychiatric symptoms (NPS) that often accompany or exacerbate cognitive decline. However, the pathological mechanisms linking NPS, cognition, and biomarkers remain unclear. It was hypothesised that relationships between NPS and cognition would be mediated or moderated by cerebrospinal fluid (CSF) biomarker levels in individuals with YOD. Methods: This retrospective, cross-sectional study included 46 participants with YOD (24 with Alzheimer's disease [AD], 22 with non-AD dementias) diagnosed at the Neuropsychiatry Centre, Royal Melbourne Hospital. NPS were measured using the Depression Anxiety and Stress Scale …

Developing, Implementing, And Evaluating The First National Memory And Cognition Clinic Guidelines In Australia, Inga Mehrani, Matthew Paradise, Lee Fay Low, Sue Kurrle, Valerie Arsenova, Gemma Jahn, Katrina Fyfe, Johannes C. Michaelian, Katharine Salmon, Jane Alty, Sharon L. Naismith, Perminder S. Sachdev

Research outputs 2022 to 2026

Introduction: A lack of national consensus on the roles and responsibilities of Australian memory and cognition clinics contributes to the large variability seen across services. The introduction of guidelines and a quality assessment framework could facilitate greater harmonization and quality improvements.

Methods: We used a modified Delphi process to develop the guidelines. Pilot clinics completed a self-assessment, case-note audit, and review meeting to evaluate their service against the guidelines.

Results: The final guidelines included 160 standards on 14 different topics. Standards around maximum waiting times for an assessment and minimum post-diagnostic care responsibilities were particularly controversial. Seven clinics participated in …

Exploring Non-Invasive Brain Stimulation Effects On Physical Outcomes In People With Parkinson’S Disease: An Umbrella Evidence Mapping Review With Meta-Analyses, Dale M. Harris, Christopher Latella, Nicholas Tripodi, Steven J. O’Bryan

Research outputs 2022 to 2026

Background: Non-invasive brain stimulation (NIBS) is sometimes used alongside medication to alleviate motor symptoms in people with Parkinson’s disease (PD). However, the evidence supporting NIBS’s effectiveness for improving motor function in PD patients is uncertain.

Objective: This umbrella review aims to synthesize recent systematic reviews and meta-analyses that have evaluated the effectiveness of NIBS in improving motor function in people with PD, with a key focus being to examine the quality of the evidence presented. Methods: The review protocol was registered in PROSPERO (CRD42022380544) and conducted per Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The search strategy was …

Exploring The Relationship Between Melanopsin Gene Variants, Sleep, And Markers Of Brain Health, Ayeisha Milligan Armstrong, Eleanor O'Brien, Tenielle Porter, Vincent Dore, Pierrick Bourgeat, Paul Maruff, Christopher C. Rowe, Victor L. Villemagne, Stephanie R. Rainey-Smith, Simon M. Laws

Research outputs 2022 to 2026

INTRODUCTION: Melanopsin is a photopigment with roles in mediating sleep and circadian-related processes, which are often disrupted in Alzheimer's disease (AD). Melanopsin also impacts cognition and synaptogenesis. This study investigated the associations between melanopsin genetic variants, sleep, and markers of brain health. METHODS: Linear regression analyses examined the relationship of single-nucleotide polymorphisms (SNPs) within the melanopsin gene (OPN4), with cortical amyloid beta (Aβ), cognition, brain volumes, and self-reported sleep traits in cognitively unimpaired older adults. Further analyses assessed whether sleep traits x OPN4 SNP interactions were associated with markers of brain health. RESULTS: OPN4 SNPs rs2355009 and rs3740334 were associated …

The Role Of Glial Fibrillary Acidic Protein In The Neuropathology Of Alzheimer’S Disease And Its Potential As A Blood Biomarker For Early Diagnosis And Progression, Ekanayaka M.S. Bandara, Prita R. Asih, Steve Pedrini, Eugene Hone, Warnakulasuriya Mary Ann Dipika Binosha Fernando, Ralph N. Martins

Research outputs 2022 to 2026

Alzheimer’s disease (AD) is a neurodegenerative disease characterised by neuropathological hallmarks, including extracellular amyloid plaques and neurofibrillary tangles. The disease is clinically defined by cognitive dysfunction, including learning, memory deficits, and behavioural changes. With the rising global prevalence of AD, early diagnosis is critical for implementing effective interventions before irreversible neuronal damage occurs. Biomarkers correlating amyloid deposition, tau pathology, neuroinflammation, and neurodegeneration are currently being investigated using cerebrospinal fluid analysis and positron emission tomography imaging. These methods are invasive or costly, limiting their widespread clinical utility. Blood-based biomarkers offer a promising alternative due to accessibility, cost-effectiveness, and feasibility for large-scale …

Motor Cortex Inhibition And Facilitation Changes Within Two Weeks Of Anterior Cruciate Ligament Reconstruction (Aclr): A Case Series, Colin Sylvester, Ann Maree Vallence, Casey Whife, Peter D'Alessandro, Christopher Latella, Ebonie Rio, Myles C. Murphy

Research outputs 2022 to 2026

Purpose: Anterior cruciate ligament reconstruction (ACLR) can cause arthrogenic muscle inhibition (AMI) or persistent muscle weakness that impairs physical function and return to sport. Deficits in voluntary activation (one method to measure AMI) are thought to contribute to AMI, however, the specific neurophysiological underpinnings remain inconclusive. The primary objective of this study was to explore changes in intracortical excitability (inhibition and facilitation) of the quadriceps representation in the primary motor cortex pre- and post-ALCR. Our secondary objective was to explore changes in hamstrings intracortical excitability pre- and post-ALCR. Methods: Prospective case-series pre-post-ACLR. Single- and paired-pulse transcranial magnetic stimulation (TMS) was …

Association Of High-Sensitivity Cardiac Troponin I Levels Below The Sex-Specific 99th Percentile With Late-Life Dementia: The Perth Longitudinal Study Of Ageing Women, Carlos J. Toro-Huamanchumo, Abadi Kahsu Gebre, Tiago Pecanha, Craig Sale, Wai Lim, Elizabeth Byrnes, Ee Mun Lim, Simon Laws, Kun Zhu, Carl Schultz, Richard L. Prince, Blossom C.M. Stephan, Mario Siervo, Joshua R. Lewis, Marc Sim

Research outputs 2022 to 2026

Background: Elevated high-sensitivity cardiac troponin (hs-cTn) levels are linked with cardiovascular disease and cognitive impairment, both of which are strong risk factors for late-life dementia (LLD). This study examined the association between hs-cTnI levels below the sex-specific 99th percentile for myocardial injury and the incidence of LLD in older women. Methods: 986 community-dwelling women aged ≥70 years without prior LLD and with hs-cTnI < 15.6 ng/L (stratified into quartiles) were included from the Perth Longitudinal Study of Ageing Women. The primary outcome was incident LLD events, including LLD hospitalisation or death, over 14.5 years obtained from linked health records. Associations between hs-cTnI and LLD outcomes were explored using multivariable-adjusted Cox models, as part of restricted cubic splines. Results: At baseline, participants' mean (±SD) age was 75.2±2.7 years. Over 14.5 years of follow-up, LLD events (n=174, 17.7%), hospitalisations (n=155, 15.7%) and deaths (n=68, 6.9%) were recorded. Compared with those in the lowest quartile (Q1, median 3.1 ng/L), women in the highest quartile of hs-cTnI (Q4, median 7.3 ng/L) had a greater risk of developing LLD-related events (adjusted HR: 1.88, 95% CI: 1.22 to 2.91), hospitalisation (adjusted HR: 1.65, 95% CI: 1.04 to 2.64) and death (adjusted HR: 2.27, 95% CI: 1.13 to 4.59), after adjusting for established cardiovascular and dementia risk factors, including apolipoprotein E (APOE) genotype. Conclusion: Among older women, hs-cTnI levels below the sex-specific 99th percentile for myocardial injury were associated with an increased risk of LLD events over 14.5 years. These findings suggest that hs-cTnI may identify older women at higher risk of LLD, capturing both cardiovascular and brain health vulnerability in older age.

Cyp1b1-Rmdn2 Alzheimer’S Disease Endophenotype Locus Identified For Cerebral Tau Pet, Kwangsik Nho, Shannon L. Risacher, Liana G. Apostolova, Paula J. Bice, Jared R. Brosch, Rachael Deardorff, Kelley Faber, Martin R. Farlow, Tatiana Foroud, Sujuan Gao, Thea Rosewood, Jun Pyo Kim, Kelly Nudelman, Meichen Yu, Paul Aisen, Reisa Sperling, Basavaraj Hooli, Sergey Shcherbinin, Diana Svaldi, Clifford R. Jack, William J. Jagust, Susan Landau, Aparna Vasanthakumar, Tenielle Porter, Vincent Doré, Simon M. Laws

Research outputs 2022 to 2026

Determining the genetic architecture of Alzheimer’s disease pathologies can enhance mechanistic understanding and inform precision medicine strategies. Here, we perform a genome-wide association study of cortical tau quantified by positron emission tomography in 3046 participants from 12 independent studies. The CYP1B1-RMDN2 locus is associated with tau deposition. The most significant signal is at rs2113389, explaining 4.3% of the variation in cortical tau, while APOE4 rs429358 accounts for 3.6%. rs2113389 is associated with higher tau and faster cognitive decline. Additive effects, but no interactions, are observed between rs2113389 and diagnosis, APOE4, and amyloid beta positivity. CYP1B1 expression is upregulated in AD. …

Pain Prevalence, Intensity, And Association With Neuropsychiatric Symptoms Of Dementia In Immigrant And Non-Immigrant Aged Care Residents In Australia, Pelden Chejor, Mustafa Atee, Patricia Cain, Daniel Whiting, Thomas Morris, Davina Porock

Research outputs 2022 to 2026

Pain recognition for culturally diverse people is complex as pain experience is subjective and influenced by cultural background. We compared the prevalence, intensity, and association of pain with neuropsychiatric symptoms (NPS) between immigrants and non-immigrants living with dementia in residential aged care homes (RACHs) who were referred to two Dementia Support Australia programs. Immigrant status was defined by the documented country of birth. Pain and NPS were assessed using PainChek® and the Neuropsychiatric Inventory, respectively. Subgroup analyses were also completed for English-speaking and non-English-speaking immigrants. A total of 17,637 referrals [immigrants, n = 6340; non-immigrants, n = 11,297] from 2792 …

Clearance And Transport Of Amyloid Β By Peripheral Monocytes Correlate With Alzheimer’S Disease Progression, Xin Huang, Chris Fowler, Yihan Li, Qiao Xin Li, Jiaqi Sun, Yijun Pan, Liang Jin, Keyla A. Perez, Céline Dubois, Yen Y. Lim, Candace Drysdale, Rebecca L. Rumble, Holly R. Chinnery, Christopher C. Rowe, Ralph N. Martins, Paul Maruff, James D. Doecke, Yong Lin, Abdel A. Belaidi, Kevin J. Barnham, Colin L. Masters, Ben J. Gu

Research outputs 2022 to 2026

Impaired clearance of amyloid β (Aβ) in late-onset Alzheimer’s disease (AD) affects disease progression. The role of peripheral monocytes in Aβ clearance from the central nervous system (CNS) is unclear. We use a flow cytometry assay to identify Aβ-binding monocytes in blood, validated by confocal microscopy, Western blotting, and mass spectrometry. Flow cytometry immunophenotyping and correlation with AD biomarkers are studied in 150 participants from the AIBL study. We also examine monocytes in human cerebrospinal fluid (CSF) and their migration in an APP/PS1 mouse model. The assay reveals macrophage-like Aβ-binding monocytes with high phagocytic potential in both the periphery and …

Detection And Staging Of Alzheimer's Disease By Plasma Ptau217 On A High Throughput Immunoassay Platform, Azadeh Feizpour, James David Doecke, Vincent Doré, Natasha Krishnadas, Kun Huang, Pierrick Bourgeat, Simon Matthew Laws, Christopher Fowler, Joanne Robertson, Lucy Mackintosh, Scott Ayton, Ralph Martins, Stephanie Ruth Rainey-Smith, Kevin Taddei, Larry Ward, Eddie Stage, Anthony Wilson Bannon, Colin Louis Masters, Jurgen Fripp, Victor Luis Villemagne, Christopher Cleon Rowe

Research outputs 2022 to 2026

Background: Plasma phospho-tau 217 (pTau217) assays can accurately detect Alzheimer's disease (AD) pathology, but clinical application is limited by the need for specialised equipment. This study tests the performance of a plasma pTau217 assay performed on the Lumipulse-G® platform, that is in widespread clinical use, for selecting patients for therapy based on β-amyloid (Aβ) status and tau staging. Methods: Participants included 388 individuals with 18F-NAV4694 Aβ-PET and 18F-MK6240 tau-PET. Association of pTau217 with PET was examined using Spearman's correlation. Discriminative performance for Aβ and tau PET status as well as tau staging was assessed using Receiver Operating Characteristic analysis. Findings: …

Persistent Inward Currents In Tibialis Anterior Motoneurons Can Be Reliably Estimated Within The Same Session, Thomas Lapole, Ricardo N.O. Mesquita, Stéphane Baudry, Robin Souron, Eleanor K. O'Brien, Callum G. Brownstein, Vianney Rozand

Research outputs 2022 to 2026

The response of spinal motoneurons to synaptic input greatly depends on the activation of persistent inward currents (PICs), the contribution of which can be estimated through the paired motor unit technique. Yet, the intra-session test–retest reliability of this measurement remains to be fully established. Twenty males performed isometric triangular dorsiflexion contractions to 20 and 50 % of maximal torque at baseline and after a 15-min resting period. High-density electromyographic signals (HD-EMG) of the tibialis anterior were recorded with a 64-electrode matrix. HD-EMG signals were decomposed, and motor units tracked across time points to estimate the contribution of PICs to motoneuron …

Apolipoprotein Ε4 Is Associated With Increased Risk Of Fall- And Fracture-Related Hospitalization: The Perth Longitudinal Study Of Ageing Women, Jedd Pratt, Jack Dalla Via, Craig Sale, Abadi K. Gebre, Blossom C.M. Stephan, Simon Laws, Kun Zhu, Wai H. Lim, Richard L. Prince, Joshua R. Lewis, Marc Sim

Research outputs 2022 to 2026

Apolipoprotein ε4 (APOE ε4) may be a genetic risk factor for reduced bone mineral density (BMD) and muscle function, which could have implications for fall and fracture risk. We examined the association between APOE ε4 status and long-term fall- and fracture-related hospitalization risk in older women. A total of 1 276 community-dwelling women from the Perth Longitudinal Study of Aging Women (mean age ± SD = 75.2 ± 2.7 years) were included. At baseline, women underwent APOE genotyping and detailed phenotyping for covariates including prevalent falls and fractures, as well as health and lifestyle factors. The association between APOE ε4 …

Investigating Genetic Overlap Between Alzheimer’S Disease, Lipids, And Coronary Artery Disease: A Large-Scale Genome-Wide Cross Trait Analysis, Artika Kirby, Tenielle Porter, Emmanuel O. Adewuyi, Simon M. Laws

Research outputs 2022 to 2026

There is evidence to support a link between abnormal lipid metabolism and Alzheimer’s disease (AD) risk. Similarly, observational studies suggest a comorbid relationship between AD and coronary artery disease (CAD). However, the intricate biological mechanisms of AD are poorly understood, and its relationship with lipids and CAD traits remains unresolved. Conflicting evidence further underscores the ongoing investigation into this research area. Here, we systematically assess the cross-trait genetic overlap of AD with 13 representative lipids (from eight classes) and seven CAD traits, leveraging robust analytical methods, well-powered large-scale genetic data, and rigorous replication testing. Our main analysis demonstrates a significant …

Resting State Electrophysiological Profiles And Their Relationship With Cognitive Performance In Cognitively Unimpaired Older Adults: A Systematic Review, Brenda Chino, David López-Sanz, Sandra Doval, Lucía Torres-Simón, Jaisalmer De Frutos Lucas, Lydia Giménez-Llort, Jonathan Zegarra-Valdivia, Fernando Maestú

Research outputs 2022 to 2026

Background: Aging is a complex and natural process. The physiological decline related to aging is accompanied by a slowdown in cognitive processes, which begins shortly after individuals reach maturity. These changes have been sometimes interpreted as a compensatory sign and others as a fingerprint of deterioration. Objective: In this context, our aim is to uncover the mechanisms that underlie and support normal cognitive functioning in the brain during the later stages of life. Methods: With this purpose, a systematic literature search was conducted using PubMed, Scopus, and Web of Science databases, which identified 781 potential articles. After applying inclusion and …

The Relationship Between Diet, Depression, And Alzheimer's Disease: A Narrative Review, Hilal Salim Said Al Shamsi, Stephanie R. Rainey-Smith, Samantha L. Gardener, Hamid R. Sohrabi, Rodrigo Canovas, Ralph N. Martins, Warnakulasuriya Mary Ann Dipika Binosha Fernando

Research outputs 2022 to 2026

Purpose of Review: This narrative review evaluates the role of diet in the relationship between depression and Alzheimer's disease (AD). Recent Findings: AD and depression are often comorbid, and depression appears to independently increase the future risk of AD. Evidence suggests diet influences the risk of both conditions directly and indirectly. Diet impacts neurochemical and biological processes that may affect the development and progression of depression and cognitive dysfunction. The dietary components offering the greatest protection against depression and AD are yet to be determined. Current evidence highlights the importance of polyphenolic compounds, folate, B vitamins, and polyunsaturated fatty acids, …

The Crosstalk Between Amyloid-Β, Retina, And Sleep For The Early Diagnosis Of Alzheimer's Disease: A Narrative Review, Isaiah Lorenzo De Guia, Shaun Eslick, Sharon L. Naismith, Swathi Kanduri, Tejal M. Shah, Ralph N. Martins

Research outputs 2022 to 2026

Alzheimer's disease (AD) is the most common type of dementia, which is characterised by progressive memory loss and accumulation of hallmark markers amyloid-β (Aβ) and neurofibrillary tangles in the diseased brain. The current gold standard diagnostic methods have limitations of being invasive, costly, and not easily accessible. Thus, there is a need for new avenues, such as imaging the retina for early AD diagnosis. Sleep disruption is symptomatically frequent across preclinical and AD subjects. As circadian activity, such as the sleep-wake cycle, is linked to the retina, analysis of their association may be useful additions for achieving predictive AD diagnosis. …

Association Of Basal Forebrain Atrophy With Cognitive Decline In Early Alzheimer Disease, Ying Xia, Vincent Dore, Jurgen Fripp, Pierrick Bourgeat, Simon M. Laws, Christopher J. Fowler, Stephanie R. Rainey-Smith, Ralph N. Martins, Christopher Rowe, Colin L. Masters, Elizabeth J. Coulson, Paul Maruff

Research outputs 2022 to 2026

Background and Objectives: In early Alzheimer disease (AD), β-amyloid (Aβ) deposition is associated with volume loss in the basal forebrain (BF) and cognitive decline. However, the extent to which Aβ-related BF atrophy manifests as cognitive decline is not understood. This study sought to characterize the relationship between BF atrophy and the decline in memory and attention in patients with early AD.

Methods: Participants from the Australian Imaging, Biomarkers and Lifestyle (AIBL) study who completed Aβ-PET imaging and repeated MRI and cognitive assessments were included. At baseline, participants were classified based on their clinical dementia stage and Aβ status, yielding groups …

Non-Invasive Brain Stimulation As Treatment For Motor Impairment In People With Parkinson's Disease: Protocol For An Umbrella Review, Dale M. Harris, Steven J. O'Bryan, Christopher Latella

Research outputs 2022 to 2026

Background Parkinson's disease (PD) is a progressive neurodegenerative disorder that predominantly affects movement and currently has no cure. Alongside medication, non-invasive brain stimulation (NIBS) may be used as an adjunct therapy to attenuate the motor symptoms experienced by people with PD. However, there is considerable heterogeneity in the evidence exploring the effects of NIBS for improving aspects of physical function in people with PD. Therefore, this protocol paper will outline the objectives, structure and procedure of a proposed umbrella review which will comprehensively summarise and map the current body evidence on the effectiveness of NIBS for improving physical function in …

Prevention Of Dementia Using Mobile Phone Applications (Prodemos): A Multinational, Randomised, Controlled Effectiveness–Implementation Trial, Eric P.Moll Van Charante, Marieke P. Hoevenaar-Blom, Manshu Song, Sandrine Andrieu, Linda Barnes, Cindy Birck, Rachael Brooks, Nicola Coley, Esmé Eggink, Jean Georges, Melanie Hafdi, Willem A. Van Gool, Ron Handels, Haifeng Hou, Jihui Lyu, Yixuan Niu, Libin Song, Wenzhi Wang, Youxin Wang, Anders Wimo, Yueyi Yu, Jinxia Zhang, Wei Zhang, Carol Brayne, Wei Wang, Edo Richard

Research outputs 2022 to 2026

Background: The expected increase of dementia prevalence in the coming decades will mainly be in low-income and middle-income countries and in people with low socioeconomic status in high-income countries. This study aims to reduce dementia risk factors in underserved populations at high-risk using a coach-supported mobile health (mHealth) intervention. Methods: This open-label, blinded endpoint, hybrid effectiveness–implementation randomised controlled trial (RCT) investigated whether a coach-supported mHealth intervention can reduce dementia risk in people aged 55–75 years of low socioeconomic status in the UK or from the general population in China with at least two dementia risk factors. The primary effectiveness outcome …

Sorghum Grain Polyphenolic Extracts Demonstrate Neuroprotective Effects Related To Alzheimer’S Disease In Cellular Assays Sorghum Grain Polyphenolic Extracts Demonstrate Neuroprotective Effects Related To Alzheimer’S Disease In Cellular Assays, Nasim Rezaee, Eugene Hone, Hamid R. Sohrabi, Stuart Johnson, Leizhou Zhong, Prakhar Chatur, Stuart Gunzburg, Ralph N. Martins, W. M.A.D.Binosha Fernando

Research outputs 2022 to 2026

Sorghum grain contains high levels and a diverse profile of polyphenols (PPs), which are antioxidants known to reduce oxidative stress when consumed in the diet. Oxidative stress leading to amyloid-β (Aβ) aggregation, neurotoxicity, and mitochondrial dysfunction is implicated in the pathogenesis of Alzheimer’s disease (AD). Thus, PPs have gained attention as possible therapeutic agents for combating AD. This study aimed to (a) quantify the phenolic compounds (PP) and antioxidant capacities in extracts from six different varieties of sorghum grain and (b) investigate whether these PP extracts exhibit any protective effects on human neuroblastoma (BE(2)-M17) cells against Aβ- and tau-induced toxicity, …

Cognitive And Neuroscientific Perspectives Of Healthy Ageing, Jon B. Prince, Helen L. Davis, Jane Tan, Katrina Muller-Townsend, Shaun Markovic, David M. G. Lewis, Brianne Hastie, Matthew B. Thompson, Peter D. Drummond, Hakuei Fujiyama, Hamid R. Sohrabi

Research outputs 2022 to 2026

With dementia incidence projected to escalate significantly within the next 25 years, the United Nations declared 2021–2030 the Decade of Healthy Ageing, emphasising cognition as a crucial element. As a leading discipline in cognition and ageing research, psychology is well-equipped to offer insights for translational research, clinical practice, and policy-making. In this comprehensive review, we discuss the current state of knowledge on age-related changes in cognition and psychological health. We discuss cognitive changes during ageing, including (a) heterogeneity in the rate, trajectory, and characteristics of decline experienced by older adults, (b) the role of cognitive reserve in age-related cognitive decline, …

Intensity-Dependent Effects Of Tdcs On Motor Learning Are Related To Dopamine, Li Ann Leow, Jiaqin Jiang, Samantha Bowers, Yuhan Zhang, Paul E. Dux, Hannah L. Filmer

Research outputs 2022 to 2026

Non-invasive brain stimulation techniques, such as transcranial direct current stimulation (tDCS), are popular methods for inducing neuroplastic changes to alter cognition and behaviour. One challenge for the field is to optimise stimulation protocols to maximise benefits. For this to happen, we need a better understanding of how stimulation modulates cortical functioning/behaviour. To date, there is increasing evidence for a dose-response relationship between tDCS and brain excitability, however how this relates to behaviour is not well understood. Even less is known about the neurochemical mechanisms which may drive the dose-response relationship between stimulation intensities and behaviour. Here, we examine the effect …

Healing Right Way Randomised Control Trial Enhancing Rehabilitation Services For Aboriginal People With Brain Injury In Western Australia: Translation Principles And Activities, Neil Drew, Meaghan Mcallister, Juli Coffin, Melanie Robinson, Judith Katzenellenbogen, Elizabeth Armstrong

Research outputs 2022 to 2026

Background: This report provides the theory, method and practice of culturally secure translation and knowledge exchange in the Healing Right Way Clinical Trial (2017–2022), outlining activities to date. Healing Right Way was a stepped wedge cluster randomised controlled trial conducted in Western Australia, aimed at enhancing rehabilitation services and quality of life for Aboriginal Australians following acquired brain injury. The trial translation plan was aspirational and action-oriented, with its implementation iterative and ongoing. Translational activities aimed to inform service and research planning for Aboriginal people with brain injury. Situated in the intercultural space, the work guards against undertaking activities that …

The Australian Multidomain Approach To Reduce Dementia Risk By Protecting Brain Health With Lifestyle Intervention Study (Au-Arrow): A Study Protocol For A Single-Blind, Multi-Site, Randomized Controlled Trial, Samantha L. Gardener, Stephanie J. Fuller, Sharon L. Naismith, Laura Baker, Miia Kivipelto, Victor L. Villemagne, Stuart M. Grieve, Paul Yates, Stephanie R. Rainey-Smith, Juliana Chen, Belinda Thompson, Nicola J. Armstrong, Malika G. Fernando, Carolina B. Castro, Silochna Meghwar, Rema Raman, Andrew Gleason, Catriona Ireland, Roger Clarnette, Kaarin J. Anstey, Kevin Taddei, Manohar Garg, Hamid R. Sohrabi, Ralph N. Martins

Research outputs 2022 to 2026

Introduction: The Finnish Geriatric Intervention Study (FINGER) led to the global dementia risk reduction initiative: World-Wide FINGERS (WW-FINGERS). As part of WW-FINGERS, the Australian AU-ARROW study mirrors aspects of FINGER, as well as US-POINTER.

Method: AU-ARROW is a randomized, single-blind, multisite, 2-year clinical trial (n = 600; aged 55–79). The multimodal lifestyle intervention group will engage in aerobic exercise, resistance training and stretching, dietary advice to encourage MIND diet adherence, BrainHQ cognitive training, and medical monitoring and health education. The Health Education and Coaching group will receive occasional health education sessions. The primary outcome measure is the change in a …

Suboptimal Self-Reported Sleep Efficiency And Duration Are Associated With Faster Accumulation Of Brain Amyloid Beta In Cognitively Unimpaired Older Adults, Louise N. Pivac, Belinda M. Brown, Kelsey R. Sewell, James D. Doecke, Victor L. Villemagne, Vincent Doré, Michael Weinborn, Hamid R. Sohrabi, Samantha L. Gardener, Romola S. Bucks, Simon M. Laws, Kevin Taddei, Paul Maruff, Colin L. Masters, Christopher Rowe, Ralph N. Martins, Stephanie R. Rainey-Smith

Research outputs 2022 to 2026

Introduction: This study investigated whether self-reported sleep quality is associated with brain amyloid beta (AB) accumulation. METHODS: Linear mixed effect model analyses were conducted for 189 cognitively unimpaired (CU) older adults (mean ± standard deviation 74.0 ± 6.2; 53.2% female), with baseline self-reported sleep data, and positron emission tomography-determined brain AB measured over a minimum of three time points (range 33.3–72.7 months). Analyses included random slopes and intercepts, interaction for apolipoprotein E (APOE) 4 allele status, and time, adjusting for sex and baseline age.

Results: Sleep duration < 6 hours, in APOE 4 carriers, and sleep efficiency < 65%, in the whole sample and APOE 4 non-carriers, is associated with faster accumulation of brain AB. DISCUSSION: These findings suggest a role for self-reported suboptimal sleep efficiency and duration in the accumulation of Alzheimer's disease (AD) neuropathology in CU individuals. Additionally, poor sleep efficiency represents a potential route via which individuals at lower genetic risk may progress to preclinical AD. Highlights: In cognitively unimpaired older adults self-report sleep is associated with brain amyloid beta (AB) accumulation. Across sleep characteristics, this relationship differs by apolipoprotein E (APOE) genotype. Sleep duration < 6 hours is associated with faster brain AB accumulation in APOE 4 carriers. Sleep efficiency < 65% is associated with faster brain AB accumulation in APOE 4 non-carriers. Personalized sleep interventions should be studied for potential to slow AB accumulation.