The Drivers of Conversations About Dementia Risk Reduction: A Qualitative Study

Dementia prevention is an area of health where public knowledge remains limited. A growing number of education initiatives are attempting to rectify this, but they tend to reach audiences of limited size and diversity, limiting intervention-associated health equity. However, initiative participants tend to discuss these initiatives and the information they contain with members of their social network, increasing the number and diversity of people receiving dementia risk reduction information. In this qualitative study, we sought to understand the drivers of this information sharing. We interviewed 39 people from Tasmania, Australia who completed the Preventing Dementia Massive Open Online Course in May 2020. We identified themes from responses to semi-structured interview questions using reflexive thematic analysis. We identified three key drivers of information sharing: participants' personal course experiences; participants finding information sharing opportunities with people they expected to be receptive; and conversation partners' responses to conversation topics. These drivers aligned with existing communication theories, with dementia-related stigma effecting both actual and perceived conversation partner receptivity. Understanding the drivers of information sharing may allow information about dementia risk reduction, and other preventative health behaviors, to be presented in ways that facilitate information diffusion, increasing equity in preventative health education.

Examination of the Feasibility, Acceptability, and Efficacy of the Online Personalised Training in Memory Strategies for Everyday (OPTIMiSE) Program for Older Adults: Results from a Single-Arm Pre-Post Trial (Preprint)

BACKGROUND

Memory strategy training for older adults helps maintain and improve cognitive health but is traditionally offered face-to-face, which is resource intensive, limits accessibility, and is challenging during a pandemic. Web-based interventions, such as the Online Personalised Training in Memory Strategies for Everyday (OPTIMiSE) program, may overcome such barriers.

OBJECTIVE

We report on OPTIMiSE's feasibility, acceptability, and efficacy.

METHODS

Australians aged ≥60 years reporting subjective cognitive decline participated in this single-arm pre-post web-based intervention. OPTIMiSE is a 6-module web-based program offered over 8-weeks with a 3-month booster. It has a problem-solving approach to memory issues, focusing on psychoeducation about memory and aging, knowledge and practice of compensatory memory strategies, and personalized content related to individual priorities. We examined the feasibility (recruitment, attrition, and data collection), acceptability (recommendation to others, suggestions for improvement, and withdrawal reasons), and efficacy (change in goal satisfaction, strategy knowledge and use, self-reported memory, memory satisfaction and knowledge, and mood; thematic content analysis of the most significant change; and the application of knowledge and strategies in daily life) of OPTIMiSE.

RESULTS

OPTIMiSE was feasible, demonstrated by strong interest (633 individuals screened), a satisfactory level of attrition (158/312, 50.6%), and minimal missing data from those completing the intervention. It was acceptable, with 97.4% (150/154) of participants agreeing they would recommend OPTIMiSE, the main suggestion for improvement being more time to complete modules, and withdrawal reasons similar to those in in-person interventions. OPTIMiSE was also efficacious, with linear mixed-effects analyses revealing improvements, of moderate to large effect sizes, across all primary outcomes (all P<.001): memory goal satisfaction (Cohen d after course=1.24; Cohen d at 3-month booster=1.64), strategy knowledge (Cohen d after course=0.67; Cohen d at 3-month booster=0.72) and use (Cohen d after course=0.79; Cohen d at 3-month booster=0.90), self-reported memory (Cohen d after course=0.80; Cohen d at 3-month booster=0.83), memory satisfaction (Cohen d after course=1.25; Cohen d at 3-month booster=1.29) and knowledge (Cohen d after course=0.96; Cohen d at 3-month booster=0.26), and mood (Cohen d after course=-0.35; nonsignificant Cohen d at booster). Furthermore, the most significant changes reported by participants (strategy use, improvements in daily life, reduced concern about memory, confidence and self-efficacy, and sharing and shame busting with others) reflected the course objectives and were consistent with themes arising from previous in-person interventions. At the 3-month booster, many participants reported continued implementation of knowledge and strategies in their daily lives.

CONCLUSIONS

This feasible, acceptable, and efficacious web-based program has the potential to enable access to evidence-based memory interventions for older adults worldwide. Notably, the changes in knowledge, beliefs, and strategy use continued beyond the initial program. This is particularly important for supporting the growing number of older adults living with cognitive concerns.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry ACTRN12620000979954; https://tinyurl.com/34cdantv.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

RR2-10.3233/ADR-200251.

Educating the masses to address a global public health priority: The Preventing Dementia Massive Open Online Course (MOOC)

Dementia is a global public health priority and risk reduction is an important pillar of the public health response. While 40% of cases are estimated to be attributable to modifiable health and lifestyle risk factors, public awareness of the evidence is low, limiting peoples’ opportunity to adopt risk-reducing behaviours. To address this gap, we designed, implemented, and evaluated an educational intervention, the Preventing Dementia Massive Open Online Course (PDMOOC). This mixed-methods study examined the reach and impact of the free and globally available PDMOOC, to assess its potential to provide effective dementia risk reduction education to a broad international audience. Over 100,000 individuals participated in the PDMOOC across seven iterations from 2016 to 2020, with 55,739 of these consenting to participate in research. Their mean age was 49 years (SD = 15), they came from 167 different countries, and the majority were female (86%), had completed post-secondary education (77%), lived in high-income countries (93%) and worked in health care and social assistance (63%). This demographic profile changed across time, with more men, people with higher education and people from low- and middle-income countries participating in recent course iterations. Two-thirds of participants completed the PDMOOC; completion was associated with being aged 50 to 70 years, residing in a high-income country, having tertiary education, and working in the health sector. Participants reported high levels of satisfaction with the PDMOOC, improved dementia risk reduction understanding and self-efficacy, increased motivation to maintain healthy lifestyles, and, importantly, application of their learning to health behaviour change with the potential to reduce their dementia risk. The PDMOOC educated a large global audience about dementia risk reduction, which contributed to participants making risk-reducing behaviour changes. This suggests MOOCs can be a successful public health strategy to improve dementia risk reduction understanding.

Interpersonal Communication May Improve Equity in Dementia Risk Education

ISSUE ADDRESSED

Encouraging people to adopt life-long habits that reduce dementia risk is necessary to manage the growing global prevalence of this condition and is, therefore, a global health priority. Current initiatives promoting risk-reducing behaviour primarily attract participants from a limited range of backgrounds, even if widely available. This may inadvertently increase health inequities, as the people who are most likely to develop dementia are the people who are least involved in risk-reduction initiatives. Interpersonal communication can effectively disseminate health messages to demographically diverse populations and may therefore broaden the reach of dementia risk reduction information.

METHODS

Coding reliability thematic analysis was used to categorise reports of information sharing provided by participants from one global online dementia risk education initiative, the [course - name removed for blinding]. These reports of information sharing were provided in response to the feedback question: "If you have already applied your [course] learning, please tell us how".

RESULTS

Information was reportedly shared with a wide range of people, including those from demographic groups that are under-represented among [course] participants. Information about specific risk factors was shared, along with general information about the course and/or dementia risk reduction. Some participants also reported that the people they shared information with were initiating risk-reducing behaviours.

CONCLUSION

Interpersonal communication has the potential to disseminate dementia risk reduction information to, and promote behaviour change among, a broad group of people at risk of dementia, thereby increasing equity in dementia risk education.

Island Study Linking Aging and Neurodegenerative Disease (ISLAND) Targeting Dementia Risk Reduction: Protocol for a Prospective Web-Based Cohort Study

Background

Up to 40% of incident dementia is considered attributable to behavioral and lifestyle factors. Given the current lack of medical treatments and the projected increase in dementia prevalence, a focus on prevention through risk reduction is needed.

Objective

We aim to increase dementia risk knowledge and promote changes in dementia risk behaviors at individual and population levels.

Methods

The Island Study Linking Aging and Neurodegenerative Disease (ISLAND) is a long-term prospective, web-based cohort study with nested interventions that will be conducted over a 10-year period. Target participants (n=10,000) reside in Tasmania and are aged 50 years or over. Survey data on knowledge, attitudes, and behaviors related to modifiable dementia risk factors will be collected annually. After each survey wave, participants will be provided with a personalized dementia risk profile containing guidelines for reducing risk across 9 behavioral and lifestyle domains and with opportunities to engage in educational and behavioral interventions targeting risk reduction. Survey data will be modeled longitudinally with intervention engagement indices, cognitive function indices, and blood-based biomarkers, to measure change in risk over time.

Results

In the initial 12 months (October 2019 to October 2020), 6410 participants have provided baseline data. The study is ongoing.

Conclusions

Recruitment targets are feasible and efforts are ongoing to achieve a representative sample. Findings will inform future public health dementia risk reduction initiatives by showing whether, when, and how dementia risk can be lowered through educational and behavioral interventions, delivered in an uncontrolled real-world context.

International Registered Report Identifier (IRRID)

DERR1-10.2196/34688

Family carers of people living with dementia and discussion board engagement in the Understanding Dementia Massive Open Online Course

OBJECTIVES

This study compared discussion board involvement between family carers and non-carers in the Understanding Dementia Massive Open Online Course (UD-MOOC).

METHODS

A mixed methods observational cohort study of family carers and non-carers was undertaken over the February-April 2020 UD-MOOC. Discussion board engagement was measured as number of posts and replies and examined longitudinally using mixed models. Discussion topics were explored through structural topic models (STM). Subsequently, thematic analysis of STM derived-topic exemplars was conducted to contextualise these discussions.

RESULTS

Family carers were (n = 2320) found to post (p < 0.001) and reply (p = 0.029) significantly more often than non-carers (n = 2392). Of the 32-STM derived-topics, meaningful activities (mean Δ = 0.007, 95% CrI [0.005-0.100]), personal stories of diagnosis (mean Δ = 0.007, 95% CrI [0.005-0.009]), and family history of dementia (mean Δ = 0.006, 95% CrI [0.004-0.008]) were discussed significantly more frequently by family carers compared to non-carers.

CONCLUSION

These results may reflect underlying motivational differences and circumstantial relevance. Perhaps the greater engagement by family carers is related to a sense of having inadequate relevant offline social resources, where engagement in the UD-MOOC discussion boards may serve as means to share experiences with others.

Invasive experimental brain surgery for dementia: Ethical shifts in clinical research practices?

The increasing dementia prevalence worldwide is driving the testing of novel therapeutic approaches, such as invasive brain technologies, despite limited clinical evidence and the risk of accelerating cognitive decline. Our manuscript (a) reviews the NIH Clinicaltrials.gov database for deep brain stimulation, stem cell implantation, and gene therapy trials on people with dementia; (b) discusses issues on beneficence, nonmaleficence, and autonomy associated with these trials; and (c) proposes nine recommendations that build on elements from the Declaration of Helsinki. We found 49 preregistered high-risk trials from nine countries planning to or involving 11,801 people with Alzheimer's or Lewy body dementia or dementia secondary to Parkinson's or Huntington's disease. Most of the people with Alzheimer's who are in these trials are from North America and East Asia. There is substantial heterogeneity in the enrolment criteria, even for trials recruiting only those with Alzheimer's disease. Although most trials enrol people in mild to moderate stages of Alzheimer's disease, trials in China enrol people who have severe Alzheimer's. Our findings highlight a pressing need to review and refine the enrolment criteria for invasive neural trials in people with dementia, considering risks, potential benefits, and capacity for informed consent. As a multidisciplinary team from Australia, the USA, Canada, and Germany with expertise in neurology, neuroscience, and ethics, we examine how it is essential to balance the risks of invasive neural research in a vulnerable population with limited capacity to provide informed consent to help advance the body of knowledge regarding a disease with limited therapeutic options.

Evaluating Course Completion, Appropriateness, and Burden in the Understanding Multiple Sclerosis Massive Open Online Course: Cohort Study

Background

Massive open online course (MOOC) research is an emerging field; to date, most research in this area has focused on participant engagement.

Objective

The aim of this study is to evaluate both participant engagement and measures of satisfaction, appropriateness, and burden for a MOOC entitled Understanding Multiple Sclerosis (MS) among a cohort of 3518 international course participants.

Methods

We assessed the association of key outcomes with participant education level, MS status, caregiver status, sex, and age using summary statistics, and 2-tailed t tests, and chi-square tests.

Results

Of the 3518 study participants, 928 (26.37%) were people living with MS. Among the 2590 participants not living with MS, 862 (33.28%) identified as formal or informal caregivers. Our key findings were as follows: the course completion rate among study participants was 67.17% (2363/3518); the course was well received, with 96.97% (1502/1549) of participants satisfied, with an appropriate pitch and low burden (a mean of 2.2 hours engagement per week); people living with MS were less likely than those not living with MS to complete the course; and people with a recent diagnosis of MS, caregivers, and participants without a university education were more likely to apply the material by course completion.

Conclusions

The Understanding MS MOOC is fit for purpose; it presents information in a way that is readily understood by course participants and is applicable in their lives.

Implementing dementia risk reduction in primary care: views of enrollees in the Preventing Dementia Massive Open Online Course

There is a push for greater promotion of dementia risk reduction (DRR) by primary care practitioners (PCPs). The aims of this study were to understand the views of non-medically trained Australian contributors in a Massive Open Online Course (MOOC) about dementia prevention regarding the role of PCPs in promoting DRR and to consider the implications of those views for developing implementation strategies. Discussion board posts of MOOC enrollees were analysed regarding the actions that organisations, communities and/or governments should take to help people work towards DRR. Of the 1641 eligible contributors to the discussion, 160 (10%) indicated that PCPs had a role in promoting DRR. This subset of participants particularly wanted earlier identification of risk by PCPs and a discussion about DRR. Some participants thought PCPs did not currently prioritise DRR, lacked knowledge about DRR and faced Medicare and resource restrictions to promoting DRR. We suggest that PCPs need: better publicity for their role in promoting DRR; to prioritise DRR; knowledge about DRR; and to take advantage of existing opportunities to promote DRR quickly. The findings of this study should be considered when attempting to implement DRR guidelines in primary care.

Assessing the Impact of Online Health Education Interventions From 2010-2020: A Systematic Review of the Evidence

OBJECTIVE

Systematically review the evaluation and impact of online health education interventions: assess approaches used, summarize main findings, and identify knowledge gaps.

DATA SOURCE

We searched the following databases: EMBASE, ERIC, MEDLINE, and Web of Science.

STUDY INCLUSION AND EXCLUSION CRITERIA

Studies were included if (a) published in English between 2010-2020 in a peer-reviewed journal (b) reported an online health education intervention aimed at consumers, caregivers, and the public (c) evaluated implementation OR participant outcomes (d) included ≥ 100 participants per study arm.

DATA EXTRACTION

Two authors extracted data using a standardized form.

DATA SYNTHESIS

Data synthesis was structured around the primary outcomes of the included studies.

RESULTS

26 studies met the inclusion criteria. We found substantial heterogeneity in study population, design, intervention, and primary outcomes, and significant methodological issues that resulted in moderate to high risk of bias. Overall, interventions that were available to all (e.g., on YouTube) consistently attained a large global reach, and knowledge was consistently improved. However, the impact on other outcomes of interest (e.g., health literacy, health behaviors) remains unclear.

CONCLUSION

Evidence around the impacts of the type of online health education interventions assessed in this review is sparse. A greater understanding of who online interventions work for and what outcomes can be achieved is crucial to determine, and potentially expand, their place in health education.

A novel cognitive-motor exercise program delivered via a tablet to improve mobility in older people with cognitive impairment - StandingTall Cognition and Mobility

BACKGROUND

Evidence-based interventions to improve mobility in older people include balance, strength and cognitive training. Digital technologies provide the opportunity to deliver tailored and progressive programs at home. However, it is unknown if they are effective in older people, especially in those with cognitive impairment.

OBJECTIVE

The aim of this study was to examine the efficacy of a novel tablet-delivered cognitive-motor program on mobility in older people with cognitive impairment.

METHODS

This was a 6-month single-blind randomised controlled trial of older people living in the community with subjective and/or objective cognitive impairment. Participants randomised to the intervention were asked to follow a 120 min per week balance, strength and cognitive training program delivered via an app on an iPad. Both the intervention and control group received monthly phone calls and health fact sheets. The primary outcome measure was gait speed. Secondary measures included dual-task gait speed, balance (step test, FISCIT-4), 5 sit to stand test, cognition (executive function, memory, attention), mood and balance confidence. Adherence, safety, usability and feedback were also measured.

RESULTS

The planned sample size of 110 was not reached due to COVID-19 restrictions. A total of 93 (mean age 72.8 SD 7.0 years) participants were randomised to the two groups. Of these 77 participants returned to the follow-up clinic. In intention-to-treat analysis for gait speed, there was a non-significant improvement favouring the intervention group (β 0.04 m/s 95% CI -0.01, 0.08). There were no significant findings for secondary outcomes. Adherence was excellent (84.5%), usability of the app high (76.7% SD 15.3) and no serious adverse events were reported. Feedback on the app was positive and included suggestions for future updates.

CONCLUSION

Due to COVID-19 the trial was under powered to detect significant results. Despite this, there was a trend towards improvement in the primary outcome measure. The excellent adherence and positive feedback about the app suggest a fully powered trial is warranted.

Change in modifiable dementia risk factors during COVID-19 lockdown: The experience of over 50s in Tasmania, Australia

INTRODUCTION

Containment measures implemented to minimize the spread of coronavirus disease 2019 (COVID-19) are reported to be negatively affecting mental health, diet, and alcohol consumption. These factors, as well as poor cardiometabolic health and insufficient physical and cognitive activity, are known to increase the risk of developing dementia. COVID-19 "lockdown" measures may have exacerbated these dementia risk factors among people in mid-to-later life.

METHODS

We compared longitudinal data from before (October 2019) and during (April-June 2020) the first COVID-19 lockdown period in Tasmania, Australia. Participants (n = 1671) were 50+ years of age and engaged in a public health program targeting dementia risk reduction, with one-third participating in the Preventing Dementia Massive Open Online Course (PD-MOOC). Regression models were used to assess changes in smoking, alcohol use, body mass index (BMI), diet, physical exercise, cognitive and social activity, anxiety and depression, and management of cholesterol, diabetes, and blood pressure. Where significant changes were noted, the moderating influence of being in current employment, living with others, and completing the PD-MOOC was tested.

RESULTS

Although friend networks contracted marginally during lockdown, no detrimental effects on modifiable dementia risk factors were noted. Anxiety levels and alcohol consumption decreased, there was no change in depression scores, and small but significant improvements were observed in cognitive and physical activity, smoking, diet, and BMI. Stronger improvements in cognitive activity were observed among people who were cohabiting (not living alone) and both cognitive activity and adherence to the MIND diet (Mediterranean-DASH diet Intervention for Neurological Delay) improved more for people who participated in the PD-MOOC.

DISCUSSION

Longitudinal data did not show widespread negative effects of COVID-19 lockdown on modifiable dementia risk factors in this sample. The results counter the dominant narratives of universal pandemic-related distress and suggest that engaging at-risk populations in proactive health promotion and education campaigns during lockdown events could be a protective public health strategy.

Online Personalised Training in Memory Strategies for Everyday (OPTIMiSE) Program for Older Adults with Cognitive Concerns: Pilot Study Protocol

Memory interventions for older adults with cognitive concerns result in improved memory performance and maintenance of cognitive health. These programs are typically delivered face-to-face, which is resource intensive and creates access barriers, particularly for those with reduced mobility, limited transportation, and living in rural or remote areas. The COVID-19 pandemic has created an additional access barrier, given the increased risk this disease poses to older adults. Internet-based interventions seek to overcome these barriers. This paper describes the protocol of a pilot study that aims to evaluate the feasibility, acceptability, and efficacy of one such internet-based intervention: the Online Personalised Training in Memory Strategies for Everyday (OPTIMiSE) program. OPTIMiSE focuses on improving knowledge regarding memory and providing training in effective memory strategies for everyday life. The pilot study described in this protocol will be a single-arm pre-post study of 8 weeks duration, with a single maintenance session 3 months post-intervention. Participants will be Australian adults aged ≥60 years reporting cognitive changes compared with 10 years ago. Primary outcome measures will address feasibility, acceptability, and efficacy. Secondary outcome measures assessing sense of community and self-efficacy will be administered at the 8-week and 3-month timepoints. Data collection will conclude mid-2021, and results will be presented in a subsequent publication. Translation of memory interventions to internet-based delivery has the potential to remove many access barriers for older adults; however, the acceptability and feasibility of this modality needs investigation. OPTIMiSE is the initial step in what could be an important program enabling access to an evidence-based memory intervention for older adults worldwide. Trial registration: Australian New Zealand Clinical Trials Registry (ANZCTR), ACTRN12620000979954.

Quantitative MRI in myositis patients: comparison with healthy volunteers and radiological visual assessment

AIM

To assess whether magnetic resonance imaging (MRI)-based measurements of T2, fat fraction, diffusion tensor imaging, and muscle volume can detect differences between the muscles of myositis patients and healthy controls, and to identify how they compare with semi-quantitative MRI diagnosis.

MATERIALS AND METHODS

Sixteen myositis patients and 16 age- and gender-matched healthy controls underwent MRI of their thigh. Quantitative MRI measurements and radiologists' semi-quantitative scores were assessed. Strength was assessed using an isokinetic dynamometer.

RESULTS

Fat fraction and T2 values were higher in myositis patients whereas muscle volume was lower compared to healthy controls. There was no difference in diffusion. Muscle strength was lower in myositis patients compared to healthy controls. In a subgroup of eight patients, scored as unaffected by radiologists, T2 values were still significantly higher in myositis patients.

CONCLUSIONS

Quantitative MRI measurements can detect differences between myositis patients and healthy controls. Changes in the muscles of myositis patients, undetected by visual, semi-quantitative scoring, can be detected using quantitative T2 measurements. This suggests that MRI T2 values may be useful for the management of myositis patients.

THU0522 DIFFERENCES IN MUSCLE PROPERTIES IN GCA PATIENTS COMPARED TO HEALTHY CONTROLS AS ASSESSED BY QUANTITATIVE MRI

Background:

Giant cell arteritis (GCA) is a systemic inflammatory vasculitis that often presents with headaches and visual symptoms. It is a medical emergency as it can lead to permanent sight loss. Prompt treatment with high doses of glucocorticoid therapy are often required. However, it has been shown that GCA patients on glucocorticoid therapy develop muscle weakness, known as glucocorticoid induced myopathy (1).

Quantitative MRI may be sensitive to detect the differences in muscle parameters between newly diagnosed GCA patients compared to healthy controls. MRI T2 is sensitive to fluid related to physiological changes at the molecular level, and is regarded as an indirect measure of muscle inflammation (2). MRI muscle fat fraction (FF) is useful for identifying myosteatosis (3). Diffusion tensor imaging (DTI) is sensitive to changes in muscle microstructure and may be useful in identifying changes to muscle fibres (4).

Objectives:

To obtain preliminary estimates of the extent to which quantitative MRI-based measurements of muscle T2, FF, DTI and volume differ between newly diagnosed GCA patients and healthy controls (HC) and how the muscle changes over 3- and 6-month intervals following glucocorticoid therapy.

Methods:

MRI of the mid-thigh were acquired using Dixon imaging to assess FF, Stimulated Echo Acquisition Mode echo planar imaging (STEAM-EPI) to measure diffusion, and a fat-suppressed multi-echo spin-echo to measure T2. Regions of interest were drawn around the quadriceps and hamstrings. All participants had knee extension and flexion torque measured on an isokinetic dynamometer, and isometric dynamometer to measure grip strength.

Results:

20 GCA patients (68.2±8.3 years, 14/20 female, mean ESR 26.9mm/h, mean CRP 39.6mg/L) were enrolled within 14 days of starting glucocorticoids: 15 returned at 3 months (mean ESR 17mm/h, mean CRP 5.7mg/L); 8 returned at 6 months (mean ESR 18 mm/h, mean CRP 6mg/L). 20 directly age- and gender-matched HC also were recruited. T2 and FF were higher and muscle volume lower in the GCA patients at baseline compared to HC (fig. 1 and 2). Within the hamstrings, the mean differences between GCA patients and HC for T2, FF and muscle volume were 2.2ms (95% CI 1, 4; p=0.09), 3.8% (95% 2, 5; p<0.001), and -166cm3 (95% CI 110, 210; p<0.001) respectively. There was no substantive difference in mean diffusivity or fractional anisotropy. Results in the quadriceps followed a similar trend. Following glucocorticoid treatment, there were no substantive changes in MRI measurements. Knee flexion/extension and handgrip strength were lower in the GCA patients at baseline compared to HC, with differences of -5.3Nm (95% CI -32.6, -7.4; p=0.003) and -4.4Nm (95% CI -56.7, -1.3; p=0.04) for flexion and extension respectively. Muscle strength did not change following glucocorticoid treatment.

Figure 1.

Quantitative MRI measurements of GCA patients and healthy controls in the hamstrings.

Conclusion:

This pilot study suggests for the first time that muscle health may be affected in newly diagnosed GCA patients compared to age and gender matched HC, as demonstrated by higher T2 and FF, and lower muscle volume and muscle strength. These preliminary results show that muscle changes may occur in the early stages of GCA and persist throughout the disease duration. If these findings are confirmed, it will be important to consider interventions to improve muscle health in the treatment pathway for GCA.

References:

[1]Proven A, et al. Arthritis and rheumatism. 2003;49(5):703-8.

[2]Maillard SM, et al. 2004;43(5):603-8.

[3]Grimm A, et al. The Journal of Frailty & Aging. 2018.

[4]Ran J, et al. 2016;263(7):1296-302.

Figure 2.

Quantitative muscle volume and muscle strength measurements of GCA patients and healthy controls.

Disclosure of Interests:

Matt Farrow: None declared, John Biglands: None declared, Steven Tanner: None declared, Elizabeth Hensor: None declared, Sarah Mackie Grant/research support from: Roche (attendance of EULAR 2019; co-applicant on research grant), Consultant of: Sanofi, Roche/Chugai (monies paid to my institution not to me), Paul Emery Grant/research support from: AbbVie, Bristol-Myers Squibb, Merck Sharp & Dohme, Pfizer, Roche (all paid to employer), Consultant of: AbbVie (consultant, clinical trials, advisor), Bristol-Myers Squibb (consultant, clinical trials, advisor), Lilly (clinical trials, advisor), Merck Sharp & Dohme (consultant, clinical trials, advisor), Novartis (consultant, clinical trials, advisor), Pfizer (consultant, clinical trials, advisor), Roche (consultant, clinical trials, advisor), Samsung (clinical trials, advisor), Sandoz (clinical trials, advisor), UCB (consultant, clinical trials, advisor), Ai Lyn Tan: None declared

OP0332 MUSCLE DETERIORATION DUE TO RHEUMATOID ARTHRITIS: ASSESSMENT BY QUANTITATIVE MRI AND STRENGTH TESTING

Background:

As well as joint damage, rheumatoid arthritis (RA) is also associated with altered body composition known as rheumatoid cachexia (RC). RC is characterised by reduced skeletal muscle and increased (white) fat mass and decreased strength. RC is associated with increased disease severity and disability (1). It is unknown at what stage muscle involvement begins in RA, and if the muscle damage is modifiable when patients achieve disease control.

Quantitative MRI (qMRI) can measure the biomarkers associated with RC. MRI T2 is sensitive to fluid related to physiological changes at the molecular level, and is regarded as an indirect measure of muscle inflammation (2). MRI muscle fat fraction (FF) measurements are useful for identifying myosteatosis (3).

Objectives:

To obtain preliminary estimates of the extent to which muscle imaging phenotype differs between RA and healthy controls (HC); and to describe the RA phenotype at different levels of disease activity.

Methods:

39 RA patients (comprising three groups) and 13 age and gender directly matched HC had a MRI scan of their dominant thigh. The RA groups were:

[1]13 ‘New RA’ - newly diagnosed, treatment naïve

[2]13 ‘Active RA’ - diagnosed >1 year, persistent DAS28 >3.2 for >1 year

[3]13 ‘Remission RA’ - diagnosed >1 year, persistent DAS28 <2.6 for >1 year

MR images of the mid-thigh were acquired using Dixon imaging to assess FF and a fat-suppressed multi-echo spin-echo to measure T2. Regions of interest were drawn around the quadriceps and hamstrings. All participants had knee extension and flexion torque measured on an isokinetic dynamometer, and isometric dynamometer to measure grip strength. One-Way ANOVA with Dunnett’s post-hoc analysis provided preliminary indication of potential differences between T2, FF, muscle volume and strength measurements between the disease stages.

Results:

39 RA patients were recruited: 13 new RA (mean age [years] 63 ± 15, DAS28 5.2 ± 3), 13 active RA (mean age [years] 65 ± 10, DAS28 4.8 ± 3), 13 remission RA (mean age [years] 67 ± 19, DAS28 1.7 ± 0.7) and also 13 HC. T2 and FF were higher in RA patients compared to HC (fig. 1). Within the hamstrings for T2, the mean differences between HC versus new, active and remission patients were 4.5ms (95% CI 2.5, 6.4; p<0.001), 3ms (95% CI 1.1, 4.9; p=0.001), and 5.0ms (95% CI 3.0, 6.4; p<0.001) respectively. Quadriceps results were similar. For muscle volume, the mean differences between HC versus new, active and remission patients were -517.3cm3(95% CI -751, -283; p<0.001), -370.5cm3(95% CI -605, -136; p=0.001), and -312.3cm3(95% CI -546. -77; p=0.006) respectively (fig. 2). Knee flexion/extension and handgrip strength were lower in all 3 groups of RA patients compared to HC. For knee flexion, the mean differences between HC versus new, active and remission patients were 18.4Nm (95% CI -35, -1; p=0.03), 10.1Nm (95% CI -27, 7; p=0.3), and 13.3Nm (95% CI -33, 0; p=0.1) respectively.

Figure 1.

Quantitative T2 and FF MRI of RA patients and healthy controls

Conclusion:

This pilot study suggests muscle health may be adversely affected in RA patients compared to matched HC. Our results suggest that muscle changes occur in the earliest stages of RA and persist throughout the disease duration, even in clinical remission. If confirmed, these data imply the need for adjunctive muscle intervention to current RA treatment strategies in order to improve patient outcomes.

References:

[1]Giles JT, et al. Arthritis Care & Research. 2008

[2]Maillard SM, et al. Rheumatology (Oxford, England). 2004

[3]Grimm A, et al. The Journal of Frailty & Aging. 2018.

Figure 2.

MRI muscle volume in RA patients and healthy controls

Disclosure of Interests:

Matt Farrow: None declared, John Biglands: None declared, Steven Tanner: None declared, Elizabeth Hensor: None declared, Maya H Buch Grant/research support from: Pfizer, Roche, and UCB, Consultant of: Pfizer; AbbVie; Eli Lilly; Gilead Sciences, Inc.; Merck-Serono; Sandoz; and Sanofi, Paul Emery Grant/research support from: AbbVie, Bristol-Myers Squibb, Merck Sharp & Dohme, Pfizer, Roche (all paid to employer), Consultant of: AbbVie (consultant, clinical trials, advisor), Bristol-Myers Squibb (consultant, clinical trials, advisor), Lilly (clinical trials, advisor), Merck Sharp & Dohme (consultant, clinical trials, advisor), Novartis (consultant, clinical trials, advisor), Pfizer (consultant, clinical trials, advisor), Roche (consultant, clinical trials, advisor), Samsung (clinical trials, advisor), Sandoz (clinical trials, advisor), UCB (consultant, clinical trials, advisor), Ai Lyn Tan: None declared

Exercise and dementia prevention

Ageing, genetic, medical and lifestyle factors contribute to the risk of Alzheimer’s disease and other dementias. Around a third of dementia cases are attributable to modifiable risk factors such as physical inactivity, smoking and hypertension. With the rising prevalence and lack of neuroprotective drugs, there is renewed focus on dementia prevention strategies across the lifespan. Neurologists encounter many people with risk factors for dementia and are frequently asked whether lifestyle changes may help. Exercise has emerged as a key intervention for influencing cognition positively, including reducing the risk of age-related cognitive decline and dementia. This article focuses on the current evidence for physical inactivity as a modifiable dementia risk factor and aims to support neurologists when discussing risk reduction.

Determination of Oxytetracycline/Oxytetracycline Hydrochloride in Animal Feed, Fish Feed, and Veterinary Medicinal Products by Liquid Chromatography with Fluorescence Detection: Collaborative Study

A method for determining oxytetracycline (OTC) in animal feed, fish feed, and veterinary medicinal products at medicated use and contamination levels was collaboratively studied. The method is applicable to the analysis of animal feeds and mineral premixes containing levels 2 mg/kg, and fish feed containing levels 10 mg/kg. Oxytetracycline hydrochloride (OTC.HCl) is extracted from ground feed material in acidmethanol solution using mechanical agitation. After centrifugation for 5 min at 1230 g, an aliquot of the extract is diluted with water and/or acidmethanol so that the concentration of OTC.HCl is approximately the same as that in the working standard, and the solutions contain at least 50 water. Injectable veterinary medicinal materials (also called animal remedy materials) are diluted with water and/or extractant to reach the target concentration. The extracts are filtered and analyzed by reversed-phase liquid chromatography with fluorescence detection with excitation at 390 nm and emission at 512 nm. Twenty-eight test samples of medicated feeds, supplements, and drug premixes, including 4 test samples for trace-level analysis, were sent to 17 collaborators in Canada, The Netherlands, and the United States. Results were received from 11 laboratories. The RSDr values (within-laboratory repeatability) ranged from 1.26 to 9.21; RSDR values (among-laboratory reproducibility) ranged from 2.14 to 12.9, and HorRat values ranged from 0.54 to 3.02. It is recommended that this method be adopted AOAC Official First Action.

Continuous performance task in ADHD: Is reaction time variability a key measure?

OBJECTIVE

To compare the use of the Continuous Performance Task (CPT) reaction time variability (intraindividual variability or standard deviation of reaction time), as a measure of vigilance in attention-deficit hyperactivity disorder (ADHD), and stimulant medication response, utilizing a simple CPT X-task vs an A-X-task.

METHOD

Comparative analyses of two separate X-task vs A-X-task data sets, and subgroup analyses of performance on and off medication were conducted.

RESULTS

The CPT X-task reaction time variability had a direct relationship to ADHD clinician severity ratings, unlike the CPT A-X-task. Variability in X-task performance was reduced by medication compared with the children's unmedicated performance, but this effect did not reach significance. When the coefficient of variation was applied, severity measures and medication response were significant for the X-task, but not for the A-X-task.

CONCLUSION

The CPT-X-task is a useful clinical screening test for ADHD and medication response. In particular, reaction time variability is related to default mode interference. The A-X-task is less useful in this regard.

First-Dose Methylphenidate-Induced Changes in Brain Functional Connectivity Are Correlated With 3-Month Attention-Deficit/Hyperactivity Disorder Symptom Response

BACKGROUND

Attention-deficit/hyperactivity disorder (ADHD) symptoms are most commonly treated with stimulant medication such as methylphenidate (MPH); however, approximately 25% of patients show little or no symptomatic response. We examined the extent to which initial changes in brain functional connectivity (FC) associated with the first MPH dose in boys newly diagnosed with ADHD predict MPH-associated changes in ADHD inattentiveness and hyperactivity symptoms at 3 months.

METHODS

Brain FC was estimated using steady-state visual evoked potential partial coherence before and 90 minutes after the administration of the first MPH dose to 40 stimulant drug-naïve boys newly diagnosed with ADHD while they performed the AX version of the continuous performance task. The change in parent-rated inattention and hyperactivity scores over the first 3 months of MPH medication was correlated with the initial 90-minute MPH-mediated FC changes.

RESULTS

Hyperactivity improvements at 3 months were associated with first-dose MPH-mediated FC reductions restricted to frontal-prefrontal sites following the appearance of the "A" and at frontal and right temporal sites during the appearance of the "X." Corresponding 3-month inattention score improvement was associated with initial MPH-mediated FC reductions restricted to occipitoparietal sites following the appearance of the "A."

CONCLUSIONS

These findings are discussed in the context of MPH effects on the default mode network and the possible role of the default mode network in MPH-mediated improvements in inattention and hyperactivity symptom scores.

MAXCOG-Maximizing Cognition: A Randomized Controlled Trial of the Efficacy of Goal-Oriented Cognitive Rehabilitation for People with Mild Cognitive Impairment and Early Alzheimer Disease

OBJECTIVES

To review the efficacy of a home-based four-session individualized face-to-face cognitive rehabilitation (MAXCOG) intervention for clients with mild cognitive impairment (MCI) or early dementia and their close supporters.

DESIGN

Randomized controlled trial comparing the intervention group (MAXCOG) with treatment as usual (control).

PARTICIPANTS

A total of 55 client-supporter dyads were enrolled in the study and 40 completed; 25 client-supporter dyads completed MAXCOG and 15 completed treatment as usual. Both MAXCOG and control groups included more MCI cases than dementia (22 versus 3 and 12 versus 3, respectively).

INTERVENTION

Four weekly individual sessions of MAXCOG consisting of personalized interventions to address individually relevant goals, supported by the provision of the MAXCOG information resource.

MEASURES

The primary outcomes were goal performance and satisfaction, assessed using the Canadian Occupational Performance Measure (COPM). Questionnaires assessing mood, illness adjustment, quality of life, and carer burden were also administered.

RESULTS

The intervention group displayed significantly higher performance and satisfaction with primary goals on the COPM post-intervention than the control group, using a per-protocol analysis.

CONCLUSIONS

The MAXCOG intervention is effective in improving goal performance and satisfaction in clients with MCI and early dementia.

Dopaminergic modulation of default mode network brain functional connectivity in attention deficit hyperactivity disorder

INTRODUCTION

Recent evidence suggests that attention deficit hyperactivity disorder (ADHD) is associated with a range of brain functional connectivity abnormalities, with one of the most prominent being reduced inhibition of the default mode network (DMN) while performing a cognitive task. In this study, we examine the effects of a methylphenidate dose on brain functional connectivity in boys diagnosed with ADHD while they performed a cognitive task.

METHOD

Brain functional connectivity was estimated using steady-state visual evoked potential partial coherence before and 90 min after the administration of a methylphenidate dose to 42 stimulant drug-naïve boys newly diagnosed with ADHD while they performed the A-X version of the continuous performance task (CPT A-X).

RESULTS

Methylphenidate robustly reversed the transient functional connectivity increase in the A-X interval seen premedication to a postmedication decrease during this interval. In addition, methylphenidate-induced reductions in individual reaction time were correlated with corresponding reductions in functional connectivity.

CONCLUSION

These findings suggest that methylphenidate suppresses the increased functional connectivity observed in ADHD and that such suppression is associated with improved performance. Our findings support the suggestion that the increased functional connectivity we have observed in ADHD is associated with abnormal DMN activity. In addition, we comment on the significance of specific frequency channels mediating top-down communication within the cortex and the extent to which our findings are selectively sensitive to top-down intracortical communication.

Brain functional connectivity abnormalities in attention-deficit hyperactivity disorder

INTRODUCTION

Recent evidence suggests that attention-deficit hyperactivity disorder (ADHD) is associated with brain functional connectivity (FC) abnormalities.

METHODS

In this study, we use steady-state visually evoked potential event-related partial coherence as a measure of brain FC to examine functional connectivity differences between a typically developing (TD) group of 25 boys and an age/IQ-matched group of 42 drug naive boys newly diagnosed with ADHD (ADHD group). Functional connectivity was estimated while both groups performed a low-demand reference task and the A-X version of the continuous performance task (CPT A-X).

RESULTS

While the TD and ADHD groups exhibited similar prefrontal FC increases prior to the appearance of the target in the reference task, these groups demonstrated significant FC differences in the interval preceding the appearance of the target in the CPT A-X task. Specifically, the ADHD group exhibited robust prefrontal and parieto-frontal FC increases that were not apparent in the TD group.

CONCLUSION

The FC differences observed in the ADHD group are discussed in the context of inadequate suppression of cortical networks that may interfere with task performance.

Alzheimer's disease cerebrospinal fluid biomarkers are not influenced by gravity drip or aspiration extraction methodology

Introduction

Cerebrospinal fluid (CSF) biomarkers, although of established utility in the diagnostic evaluation of Alzheimer’s disease (AD), are known to be sensitive to variation based on pre-analytical sample processing. We assessed whether gravity droplet collection versus syringe aspiration was another factor influencing CSF biomarker analyte concentrations and reproducibility.

Methods

Standardized lumbar puncture using small calibre atraumatic spinal needles and CSF collection using gravity fed collection followed by syringe aspirated extraction was performed in a sample of elderly individuals participating in a large long-term observational research trial. Analyte assay concentrations were compared.

Results

For the 44 total paired samples of gravity collection and aspiration, reproducibility was high for biomarker CSF analyte assay concentrations (concordance correlation [95%CI]: beta-amyloid1-42 (Aβ42) 0.83 [0.71 - 0.90]), t-tau 0.99 [0.98 - 0.99], and phosphorylated tau (p-tau) 0.82 [95 % CI 0.71 - 0.89]) and Bonferroni corrected paired sample t-tests showed no significant differences (group means (SD): Aβ42 366.5 (86.8) vs 354.3 (82.6), p = 0.10; t-tau 83.9 (46.6) vs 84.7 (47.4) p = 0.49; p-tau 43.5 (22.8) vs 40.0 (17.7), p = 0.05). The mean duration of collection was 10.9 minutes for gravity collection and <1 minute for aspiration.

Conclusions

Our results demonstrate that aspiration of CSF is comparable to gravity droplet collection for AD biomarker analyses but could considerably accelerate throughput and improve the procedural tolerability for assessment of CSF biomarkers.

Randomized Comparison of Mobile and Web-Tools to Provide Dementia Risk Reduction Education: Use, Engagement and Participant Satisfaction

BACKGROUND

Encouraging middle-aged adults to maintain their physical and cognitive health may have a significant impact on reducing the prevalence of dementia in the future. Mobile phone apps and interactive websites may be one effective way to target this age group. However, to date there has been little research investigating the user experience of dementia risk reduction tools delivered in this way.

OBJECTIVE

The aim of this study was to explore participant engagement and evaluations of three different targeted smartphone and Web-based dementia risk reduction tools following a four-week intervention.

METHODS

Participants completed a Web-based screening questionnaire to collect eligibility information. Eligible participants were asked to complete a Web-based baseline questionnaire and were then randomly assigned to use one of the three dementia risk reduction tools for a period of four weeks: (1) a mobile phone application; (2) an information-based website; and (3) an interactive website. User evaluations were obtained via a Web-based follow-up questionnaire after completion of the intervention.

RESULTS

Of 415 eligible participants, 370 (89.16%) completed the baseline questionnaire and were assigned to an intervention group; 200 (54.05%) completed the post-intervention questionnaire. The average age of participants was 52 years, and 149 (75%) were female. Findings indicated that participants from all three intervention groups reported a generally positive impression of the tools across a range of domains. Participants using the information-based website reported higher ratings of their overall impression of the tool, F2,191=4.12, P=.02; how interesting the information was, F2,189=3.53, P=.03; how helpful the information was, F2,192=4.15, P=.02; and how much they learned, F2,188=3.86, P=.02. Group differences were significant between the mobile phone app and information-based website users, but not between the interactive website users and the other two groups. Additionally, participants using the information-based website reported significantly higher scores on their ratings of the ease of navigation, F2,190=4.20, P=.02, than those using the mobile phone app and the interactive website. There were no significant differences between groups on ratings of ease of understanding the information, F2,188=0.27, P=.76. Most participants from each of the three intervention groups indicated that they intended to keep using the dementia risk reduction eHealth tool.

CONCLUSIONS

Overall, results indicated that while participants across all three intervention groups reported a generally positive experience with the targeted dementia risk reduction tools, participants using the information-based website provided a more favorable evaluation across a range of areas than participants using the mobile phone app. Further research is required to investigate whether targeted dementia risk reduction tools, in the form of interactive websites and mobile apps, can be improved to provide benefits above those gained by providing static information alone.

Characterizing the developmental profile of effort-induced motor overflow across a timed trial

Motor overflow is overt involuntary movement that accompanies voluntary movement. This study investigated the change in overflow production across a timed trial and the factors that affected this profile. Seventeen children (aged 8-11 years), 17 young adults (aged 18-35 years), and 17 older adults (aged 60-80 years) performed a 5-s finger pressing task by exerting 33% or 66% of their maximal force output using either index finger. Overflow was recorded as force from the alternative index finger. Young adult overflow remained stable over the 5 s. The rate of overflow increase over time was significantly greater for children than young adults. There was also a tendency for a greater overflow increase in older adults than in young adults. This overflow gradient was also greater in the right hand, particularly for children. These findings indicate that the neurological processes underlying overflow production are age dependent. Overflow progressed in a dynamic fashion over the course of a trial in children and older adults, probably because of increased bilateral cortical activation and the facilitation of motor task performance. This study is unique in quantitatively capturing the dynamic profile of overflow production in healthy participants across the life span.

User perceptions of a dementia risk reduction website and its promotion of behavior change

Background

Several modifiable health and lifestyle factors are consistently associated with dementia risk and it is estimated that significantly fewer people would develop dementia if the incidence of risk factors could be reduced. Despite this, Australians’ awareness of the health and lifestyle factors associated with dementia risk is low. Within a national community education campaign, Alzheimer’s Australia developed a dementia risk reduction website providing information about modifiable risk or protective factors for dementia.

Objective

This study aimed to assess the usefulness of the website content in improving knowledge and enabling adoption of recommended strategies, and to examine what additional resources consumers need.

Methods

Visitors to the website over a 3 month period were invited to complete an online survey, which asked them to rate their knowledge of dementia risk reduction before and after visiting the site, how important monitoring their health related behavior was to them before and after visiting the site, their current behavior related to health and lifestyle factors associated with dementia risk, their intentions to change behavior, and the usefulness of potential additional resources to help them do so.

Results

For this study, 123 Australian adults responded to the survey. 44.7% (55/122) were aged over 60 and 82.1% (98/119) were female. Respondents’ ratings and comments indicated they generally found the content interesting, informative, and helpful to them. Respondents’ ratings of their knowledge about the links between health and lifestyle factors and dementia risk significantly increased after visiting the website (P<.001). Their ratings of how important monitoring what they do in relation to their health and lifestyle factors were also significantly increased after visiting the website (P<.001). Average ratings for how well respondents felt they were doing at the time in relation to specific risk or protective factors were generally high, suggesting many website visitors already had high levels of health motivation and healthy lifestyle behaviors. 55.6% (45/81) said that after visiting the website their intention to make lifestyle changes was strong. Only 27.1% (22/81) said their intention to visit their doctor to discuss dementia risk reduction was strong. Potential additional resources that would help people assess and address their personal dementia risk factors were rated as more helpful than general information resources.

Conclusions

A dementia risk reduction website providing information about the current evidence and practical strategies was of interest and was useful to the Australian community. Benefits for visitors included increased knowledge and increased motivation to address relevant behaviors. Many visitors to the site were already health conscious, indicating that more needs to be done to get dementia risk reduction messages to the wider community. More interactive and personalized resources in future interventions may offer additional benefits to individuals.

Relative or absolute? Implications and consequences of the measures adopted to investigate motor overflow

Motor overflow is involuntary overt movement or covert muscle activity that cooccurs with voluntary movement. Overflow is present in several pathological conditions, as well as in neurologically healthy children and older adults, and can be induced in healthy young adults under effortful conditions. This motor phenomenon may provide insight into the underlying mechanisms and kinetic characteristics of voluntary and involuntary motor control in various populations. Although often measured behaviorally using force transduction techniques, different methods of calculating and presenting such overflow data have resulted in seemingly contradictory findings, with limited discussion of the advantages and limitations of different approaches. In this article, the authors examined the relevant literature to highlight significant methodological considerations for authors and readers conducting or appraising this type of research. Issues regarding the interpretation and reporting of findings are also discussed. Researchers are encouraged to continue using behavioral measures to create well-defined variables that enable the study of the kinematic characteristics of overflow, as these may offer promising new ways forward in better characterizing and understanding this intriguing movement phenomenon.

Neurological soft signs in schizophrenia: investigating motor overflow

Investigation of neurological soft signs (NSSs) in schizophrenia may allow for a greater understanding of its underlying pathology. Motor overflow, involuntary movement occurring during voluntary movement, is a NSS thought to occur to a greater degree in schizophrenia. The aim of the current study was to replicate the only objective investigation which found enhanced motor overflow in schizophrenia and to further characterise its properties in a more systematic manner than previous research. The current study involved examining motor overflow production in 30 participants (15 with schizophrenia, 15 controls). Participants exerted 25 and 75% of their maximal force output, while overflow was monitored in the passive hand using linear variable differential transformer (LVDT) units. Patients with schizophrenia not only exhibited a significantly greater degree of motor overflow, compared to controls, they also exhibited a differential pattern of overflow production. Direct investigation of the cortical processes leading to motor overflow may provide a more complete understanding of the pathological relevance of motor overflow, and by extension NSSs, in schizophrenia.

A longitudinal diffusion tensor imaging study in symptomatic Huntington's disease

OBJECTIVE

The striatum and its projections are thought to be the earliest sites of Huntington's disease (HD) pathology. This study aimed to investigate progression of striatal pathology in symptomatic HD using diffusion tensor imaging.

METHOD

Diffusion weighted images were acquired in 18 HD patients and in 17 healthy controls twice, 1 year apart. Mean diffusivity (MD) was calculated in the caudate, putamen, thalamus and corpus callosum, and compared between groups. In addition, caudate width was measured using T1 high resolution images and correlated with caudate MD. Correlation analyses were also performed in HD between caudate/putamen MD and clinical measures.

RESULTS

MD was significantly higher in the caudate and putamen bilaterally for patients compared with controls at both time points although there were no significant MD differences in the thalamus or corpus callosum. For both groups, MD did not change significantly in any region from baseline to year 1. There was a significant negative correlation between caudate width and MD in patients at baseline but no correlation between these parameters in controls. There was also a significant negative correlation between Mini-Mental State Examination scores and caudate MD and putamen MD at both time points in HD.

CONCLUSIONS

It appears that microstructural changes influence cognitive status in HD. Although MD was significantly higher in HD compared with controls at both time points, there were no longitudinal changes in either group. This finding does not rule out the possibility that MD could be a sensitive biomarker for detecting early change in preclinical HD.