Dynamics of brain-muscle networks reveal effects of age and somatosensory function on gait.

Walking is a complex motor activity that requires coordinated interactions between the sensory and motor systems. We used mobile EEG and EMG to investigate the brain-muscle networks involved in gait control during overground walking in young people, older people, and individuals with Parkinson's disease. Dynamic interactions between the sensorimotor cortices and eight leg muscles within a gait cycle were assessed using multivariate analysis. We identified three distinct brain-muscle networks during a gait cycle. These networks include a bilateral network, a left-lateralized network activated during the left swing phase, and a right-lateralized network active during the right swing. The trajectories of these networks are contracted in older adults, indicating a reduction in neuromuscular connectivity with age. Individuals with the impaired tactile sensitivity of the foot showed a selective enhancement of the bilateral network, possibly reflecting a compensation strategy to maintain gait stability. These findings provide a parsimonious description of interindividual differences in neuromuscular connectivity during gait.

A Quantum Model of Trust Calibration in Human-AI Interactions.

This exploratory study investigates a human agent's evolving judgements of reliability when interacting with an AI system. Two aims drove this investigation: (1) compare the predictive performance of quantum vs. Markov random walk models regarding human reliability judgements of an AI system and (2) identify a neural correlate of the perturbation of a human agent's judgement of the AI's reliability. As AI becomes more prevalent, it is important to understand how humans trust these technologies and how trust evolves when interacting with them. A mixed-methods experiment was developed for exploring reliability calibration in human-AI interactions. The behavioural data collected were used as a baseline to assess the predictive performance of the quantum and Markov models. We found the quantum model to better predict the evolving reliability ratings than the Markov model. This may be due to the quantum model being more amenable to represent the sometimes pronounced within-subject variability of reliability ratings. Additionally, a clear event-related potential response was found in the electroencephalographic (EEG) data, which is attributed to the expectations of reliability being perturbed. The identification of a trust-related EEG-based measure opens the door to explore how it could be used to adapt the parameters of the quantum model in real time.

Community-driven health research in the Torres Strait.

BACKGROUND: In July 2018, participants at a Waiben (Thursday Island) conference declared that it was time for a locally driven research agenda for the Torres Strait and Queensland Northern Peninsula Area. For decades, they felt exploited by outside researchers. They identified a lack of respect and consultation, with few benefits for their people. METHODS: In response, the Australian Institute of Tropical Health and Medicine (Waiben Campus-Ngulaigau Mudh) invited a consultative group of elders and senior health providers to develop a research program based on local cultural and health needs. The aim was to promote research skills through a learn-by-doing approach. Four workshops were conducted over 2019. Key financial and in-kind support was provided by the Australian Institute of Tropical Health and Medicine, Hot North, and Queensland Health's Torres and Cape Hospital and Health Service. RESULTS: The first workshop attracted 24 people; none had previous research experience. The workshop format evolved over 2019, mainly guided by the participants. Overall, feedback was positive, and participant research proposals remain in various stages of development. CONCLUSIONS: Although suspended during the COVID-19 pandemic, this is a long-term investment in community-driven research that seeks to translate health benefits to the people. This model may apply to other communities, especially in rural and remote Australia. Warning: This article contains the names and/or images of deceased Aboriginal and Torres Strait Islander peoples.

Rural patients highly satisfied with gynaecological oncology care via telehealth.

BACKGROUND: Introduction of telehealth for gynaecological oncology consultations aims to improve access to specialised care for rural and remote Queensland women with gynaecological malignancies. AIMS: This survey examines patient satisfaction with gynaecological oncology consultations via telehealth after introduction of the service in Far North Queensland in 2017. MATERIALS AND METHODS: Patients who accessed the gynaecological oncology telehealth service at Cairns Hospital from January 2019 to June 2020 were invited to participate in the study. Demographic details and results of a satisfaction survey were investigated. The questionnaire included 16 statements measured on a five-point Likert scale and three open-ended questions, which were coded into related responses and predominant themes developed. RESULTS: Fifty-three patients completed the study. The mean satisfaction score across all questions was 90.5% (standard deviation 8.7%). The lowest overall patient score was 77.5% and the highest was 100%. Themes emerging from the open questions were emotions experienced by women, communication, relationship building and acceptability of the service. CONCLUSIONS: Patients were highly satisfied with the telehealth service. Our findings encourage further development and research into telehealth care models for surgical disciplines such as gynaecological oncology.

Appendicitis in Far North Queensland: a new take on an old story.

BACKGROUND: Appendicitis is a leading cause of surgical hospital admission. To date, there have been no published epidemiological studies describing appendicitis in tropical and remote Australia and none specifically documenting appendicitis in Indigenous Australians. This descriptive study used available state data to investigate appendicitis across Far North Queensland (FNQ). METHODS: Queensland Health hospital admission data for FNQ was analysed to explore appendicitis epidemiology and outcomes in FNQ, 2012-2018. Population data for the same time period provided rates. RESULTS: Over the study period, 3458 hospital presentations for appendicitis were available for analysis. Mean incidence was 178 per 100 000/yr. Median age was 27 years with 50.1% female patients. The annual rate of appendicitis was higher in the Indigenous population. Most patients had a laparoscopic procedure with a low rate of conversion to open surgery (2.6%). More than 80% of patients were discharged from hospital in less than 3 days. Intensive care (ICU) admission rate was low overall (1.1%) although higher for Indigenous people (2.4%). Following discharge, the hospital re-admission rate was 3.8% and all-cause mortality was 0.03%. CONCLUSION: The incidence of appendicitis in FNQ is higher than that reported in the rest of Australia in both Indigenous and non-Indigenous populations. Despite logistical challenges of health care, clinical outcomes are in line with best practice across the country. Clinicians in FNQ should maintain a high index of suspicion for diagnosing appendicitis in rural and remote settings.

Using a validated tool to assess whole-body cadaveric simulation course on open general and emergency surgery.

BACKGROUND: The Anatomy of Surgical Exposure (ASE) is a cadaver-based operative surgery simulation course that aims to teach techniques and exposures commonly used in open surgical operations. In this study, we used a validated tool to determine efficacy of assessing skills acquisition in the simulated environment. Our aims were to investigate if the ASE course improves the candidates' surgical performance, and to assess if the validated Objective Structured Assessment of Technical Skill (OSATS) template could be a useful tool for assessing technical skills. METHODS: Participants (n = 33) undertook supervised assessment of specific procedures at 10 cadaveric stations over a 2-year period; performance was marked using the OSATS template. This template utilizes a seven-item score to assess general and specific surgical techniques and knowledge using a 5-point Likert scale. Experienced tutors assessed each surgery for each participant; individual and comparative data over the 3-day course was used to provide each participant specific feedback at course completion. RESULTS: Average OSATS scores did not improve significantly over the 3-day OSATS course. There was a significant positive correlation observed between surgical trainees and OSATS total scores (P = 0.001, r = 0.747), number of years of post-graduation, and total OSATS scores (P = 0.001, r = 0.527). CONCLUSIONS: Our findings indicate that those on the surgical training pathway and those who had graduated earlier, had an overall higher score than those not yet on surgical training. The template was able to provide on-site specific candidate feedback by the end of the course, identifying areas of improvement of technical surgical skills.

Corticomuscular control of walking in older people and people with Parkinson's disease.

Changes in human gait resulting from ageing or neurodegenerative diseases are multifactorial. Here we assess the effects of age and Parkinson's disease (PD) on corticospinal activity recorded during treadmill and overground walking. Electroencephalography (EEG) from 10 electrodes and electromyography (EMG) from bilateral tibialis anterior muscles were acquired from 22 healthy young, 24 healthy older and 20 adults with PD. Event-related power, corticomuscular coherence (CMC) and inter-trial coherence were assessed for EEG from bilateral sensorimotor cortices and EMG during the double-support phase of the gait cycle. CMC and EMG power at low beta frequencies (13-21 Hz) was significantly decreased in older and PD participants compared to young people, but there was no difference between older and PD groups. Older and PD participants spent shorter time in the swing phase than young individuals. These findings indicate age-related changes in the temporal coordination of gait. The decrease in low-beta CMC suggests reduced cortical input to spinal motor neurons in older people during the double-support phase. We also observed multiple changes in electrophysiological measures at low-gamma frequencies during treadmill compared to overground walking, indicating task-dependent differences in corticospinal locomotor control. These findings may be affected by artefacts and should be interpreted with caution.

Effects of Dance on Gait, Cognition, and Dual-Tasking in Parkinson's Disease: A Systematic Review and Meta-Analysis.

Dance-based interventions have been proposed for the management of Parkinson's disease (PD) symptoms. This review critically appraises and synthesises the research on the effects of dance interventions on gait, cognition and dual-tasking in PD, through a meta-analysis of peer-reviewed literature from seven databases. Eligible studies included people with PD, used a parallel-group or cohort design with a dance-based intervention, reported outcome measures of gait, cognition or dual-tasking, and were published in English up until September 2017. Of the initial 1079 articles, 677 articles were reviewed for eligibility, and 25 articles were retained. Only 12 articles had sufficient common assessment items for meta-analysis. Two independent reviewers extracted the data and assessed the risk of bias of each study using the Cochrane risk-of-bias tool. Based on pre-post change scores, gait speed, Timed Up and Go (TUG) test performance, freezing of gait questionnaire, and six-minute walk test times significantly improved after a dance intervention compared to controls. Global cognition assessed with Montreal Cognitive Assessment, and cognitive dual-tasking measured using dual-task TUG, also exhibited greater improvement in dance groups. There was limited evidence to determine the most effective intensity, frequency, duration of dance interventions or the most beneficial music. Findings must be interpreted cautiously because of the lack of randomised control trials, and the moderate to high risk of bias of studies. However, the results of papers with level-I and level-II.1 evidence suggest that dance may have the potential to ameliorate PD symptoms, particularly gait, global cognition and cognitive dual-tasking.

Melanopsin-mediated pupil function is impaired in Parkinson's disease.

Parkinson's disease (PD) is characterised by non-motor symptoms including sleep and circadian disruption. Melanopsin-expressing intrinsically photosensitive Retinal Ganglion Cells (ipRGC) transmit light signals to brain areas controlling circadian rhythms and the pupil light reflex. To determine if non-motor symptoms observed in PD are linked to ipRGC dysfunction, we evaluated melanopsin and rod/cone contributions to the pupil response in medicated participants with PD (n = 17) and controls (n = 12). Autonomic tone was evaluated by measuring pupillary unrest in darkness. In the PD group, there is evidence for an attenuated post-illumination pupil response (PIPR) amplitude and reduced pupil constriction amplitude, and PIPR amplitudes did not correlate with measures of sleep quality, retinal nerve fibre layer thickness, disease severity, or medication dosage. Both groups exhibited similar pupillary unrest. We show that melanopsin- and the rod/cone-photoreceptor contributions to the pupil control pathway are impaired in people with early-stage PD who have no clinically observable ophthalmic abnormalities. Given that ipRGCs project to brain targets involved in arousal, sleep and circadian rhythms, ipRGC dysfunction may underpin some of the non-motor symptoms observed in PD.

Dynamics of corticospinal motor control during overground and treadmill walking in humans.

Increasing evidence suggests cortical involvement in the control of human gait. However, the nature of corticospinal interactions remains poorly understood. We performed time-frequency analysis of electrophysiological activity acquired during treadmill and overground walking in 22 healthy, young adults. Participants walked at their preferred speed (4.2, SD 0.4 km/h), which was matched across both gait conditions. Event-related power, corticomuscular coherence (CMC), and intertrial coherence (ITC) were assessed for EEG from bilateral sensorimotor cortices and EMG from the bilateral tibialis anterior (TA) muscles. Cortical power, CMC, and ITC at theta, alpha, beta, and gamma frequencies (4-45 Hz) increased during the double support phase of the gait cycle for both overground and treadmill walking. High beta (21-30 Hz) CMC and ITC of EMG was significantly increased during overground compared with treadmill walking, as well as EEG power in theta band (4-7 Hz). The phase spectra revealed positive time lags at alpha, beta, and gamma frequencies, indicating that the EEG response preceded the EMG response. The parallel increases in power, CMC, and ITC during double support suggest evoked responses at spinal and cortical populations rather than a modulation of ongoing corticospinal oscillatory interactions. The evoked responses are not consistent with the idea of synchronization of ongoing corticospinal oscillations but instead suggest coordinated cortical and spinal inputs during the double support phase. Frequency-band dependent differences in power, CMC, and ITC between overground and treadmill walking suggest differing neural control for the two gait modalities, emphasizing the task-dependent nature of neural processes during human walking. NEW & NOTEWORTHY We investigated cortical and spinal activity during overground and treadmill walking in healthy adults. Parallel increases in power, corticomuscular coherence, and intertrial coherence during double support suggest evoked responses at spinal and cortical populations rather than a modulation of ongoing corticospinal oscillatory interactions. These findings identify neurophysiological mechanisms that are important for understanding cortical control of human gait in health and disease.

Effects of Resistance Training on Measures of Muscular Strength in People with Parkinson's Disease: A Systematic Review and Meta-Analysis.

OBJECTIVE: The aim of this systematic review and meta-analysis was to determine the overall effect of resistance training (RT) on measures of muscular strength in people with Parkinson's disease (PD). METHODS: Controlled trials with parallel-group-design were identified from computerized literature searching and citation tracking performed until August 2014. Two reviewers independently screened for eligibility and assessed the quality of the studies using the Cochrane risk-of-bias-tool. For each study, mean differences (MD) or standardized mean differences (SMD) and 95% confidence intervals (CI) were calculated for continuous outcomes based on between-group comparisons using post-intervention data. Subgroup analysis was conducted based on differences in study design. RESULTS: Nine studies met the inclusion criteria; all had a moderate to high risk of bias. Pooled data showed that knee extension, knee flexion and leg press strength were significantly greater in PD patients who undertook RT compared to control groups with or without interventions. Subgroups were: RT vs. control-without-intervention, RT vs. control-with-intervention, RT-with-other-form-of-exercise vs. control-without-intervention, RT-with-other-form-of-exercise vs. control-with-intervention. Pooled subgroup analysis showed that RT combined with aerobic/balance/stretching exercise resulted in significantly greater knee extension, knee flexion and leg press strength compared with no-intervention. Compared to treadmill or balance exercise it resulted in greater knee flexion, but not knee extension or leg press strength. RT alone resulted in greater knee extension and flexion strength compared to stretching, but not in greater leg press strength compared to no-intervention. DISCUSSION: Overall, the current evidence suggests that exercise interventions that contain RT may be effective in improving muscular strength in people with PD compared with no exercise. However, depending on muscle group and/or training dose, RT may not be superior to other exercise types. Interventions which combine RT with other exercise may be most effective. Findings should be interpreted with caution due to the relatively high risk of bias of most studies.