Transcutaneous auricular vagus nerve stimulation modifies cortical excitability in middle-aged and older adults.

There is a growing interest in the clinical application of transcutaneous auricular vagus nerve stimulation (taVNS). However, its effect on cortical excitability, and whether this is modulated by stimulation duration, remains unclear. We evaluated whether taVNS can modify excitability in the primary motor cortex (M1) in middle-aged and older adults and whether the stimulation duration moderates this effect. In addition, we evaluated the blinding efficacy of a commonly reported sham method. In a double-blinded randomized cross-over sham-controlled study, 23 healthy adults (mean age 59.91 ± 6.87 years) received three conditions: active taVNS for 30 and 60 min and sham for 30 min. Single and paired-pulse transcranial magnetic stimulation was delivered over the right M1 to evaluate motor-evoked potentials. Adverse events, heart rate and blood pressure measures were evaluated. Participant blinding effectiveness was assessed via guesses about group allocation. There was an increase in short-interval intracortical inhibition (F = 7.006, p = .002) and a decrease in short-interval intracortical facilitation (F = 4.602, p = .014) after 60 min of taVNS, but not 30 min, compared to sham. taVNS was tolerable and safe. Heart rate and blood pressure were not modified by taVNS (p > .05). Overall, 96% of participants detected active stimulation and 22% detected sham stimulation. taVNS modifies cortical excitability in M1 and its effect depends on stimulation duration in middle-aged and older adults. taVNS increased GABAAergic inhibition and decreased glutamatergic activity. Sham taVNS protocol is credible but there is an imbalance in beliefs about group allocation.

White Matter Integrity and Chronic Poststroke Upper Limb Function: An ENIGMA Stroke Recovery Analysis.

BACKGROUND: Integrity of the corticospinal tract (CST) is an important biomarker for upper limb motor function following stroke. However, when structurally compromised, other tracts may become relevant for compensation or recovery of function. METHODS: We used the ENIGMA Stroke Recovery data set, a multicenter, retrospective, and cross-sectional collection of patients with upper limb impairment during the chronic phase of stroke to test the relevance of tracts in individuals with less and more severe (laterality index of CST fractional anisotropy ≥0.25) CST damage in an observational study design. White matter integrity was quantified using fractional anisotropy for the CST, the superior longitudinal fascicle, and the callosal fibers interconnecting the primary motor cortices between hemispheres. Optic radiations served as a control tract as they have no a priori relevance for the motor system. Pearson correlation was used for testing correlation with upper limb motor function (Fugl-Meyer upper extremity). RESULTS: From 1235 available data sets, 166 were selected (by imaging, Fugl-Meyer upper extremity, covariates, stroke location, and stage) for analyses. Only individuals with severe CST damage showed a positive association of fractional anisotropy in both callosal fibers interconnecting the primary motor cortices (r[21]=0.49; P=0.025) and superior longitudinal fascicle (r[21]=0.51; P=0.018) with Fugl-Meyer upper extremity. CONCLUSIONS: Our data support the notion that individuals with more severe damage of the CST depend on residual pathways for achieving better upper limb outcome than those with less affected CST.

A scoping review of resting-state brain functional alterations in Type 2 diabetes.

Resting-state functional magnetic resonance imaging (rs-fMRI) has been actively used in the last decade to investigate brain functional connectivity alterations in Type 2 Diabetes Mellitus (T2DM) to understand the neuropathophysiology of T2DM in cognitive degeneration. Given the emergence of new analysis techniques, this scoping review aims to map the rs-fMRI analysis techniques that have been applied in the literature and reports the latest rs-fMRI findings that have not been covered in previous reviews. Graph theory, the contemporary rs-fMRI analysis, has been used to demonstrate altered brain topological organisations in people with T2DM, which included altered degree centrality, functional connectivity strength, the small-world architecture and network-based statistics. These alterations were correlated with T2DM patients' cognitive performances. Graph theory also contributes to identify unbiased seeds for seed-based analysis. The expanding rs-fMRI analytical approaches continue to provide new evidence that helps to understand the mechanisms of T2DM-related cognitive degeneration.

Sex Differences in Spatiotemporal Gait Parameters of Transtibial Amputees.

Research addressing lower limb amputee gait and prosthetic design often focuses on men, despite female lower limb amputees having different risk factors and lower success with their prosthetics overall. It is widely agreed that sex differences exist in able-bodied gait, but research analyzing sex differences in amputee gait is rare. This study compared male and female transtibial amputee gait to ascertain potential sex differences. Forty-five transtibial amputees were asked to walk at their self-selected speed, and spatiotemporal gait data were obtained. Both the mean and variability metric of parameters were analyzed for 10 male and 10 female participants. For all participants, amputated limbs had a shorter stance time, longer swing time, and larger step length. Females had a 10% shorter stance time and 26% larger normalized step and stride length than males. Female participants also walked over 20% faster than male participants. Finally, significant interactions were found in the mean and variability metric of stride velocity, indicating greater variability in women. These findings suggest that sex differences exist in transtibial amputee gait, offering possible explanations for the different comorbidities experienced by female lower limb amputees. These results have major implications for female amputees and for sex-specific research, rehabilitation, and prosthetic design.

Can body awareness training improve recovery following stroke: A study to assess feasibility and preliminary efficacy.

BACKGROUND: Impairments in body awareness are common after stroke and are associated with decreased participation and performance in everyday activities. OBJECTIVES: To explore the feasibility and safety of a body awareness program after stroke, and identify the preliminary efficacy of class-based lessons compared to home-based lessons on sensation, body awareness, motor impairment and quality of life. METHODS: A two-armed pilot randomized controlled trial with a nested qualitative descriptive study was conducted. Individuals with a diagnosis of stroke (at least three months post injury) were randomized to either class-based face-to-face body awareness lessons or home-based individually performed body awareness lessons. Outcome measures were safety, feasibility, sensation, body awareness, motor impairment, self-efficacy and quality of life. Semi-structured interviews were used to allow greater exploration and understanding of participants' experience of the program. RESULTS: Twenty participants were randomized, 16 participants completed the program. Feasibility was greater in the class-based group. No adverse events were detected. The class-based group led to improvement in body awareness (p = 0.002), quality of life (p = 0.002), and the arm (p = 0.025) and leg (p = 0.005) motor impairment scores. Qualitative data similarly indicated that the class-based group experienced a stronger sense of awareness, achievement and connection than the home-based group. CONCLUSIONS: Body awareness training was safe, feasible and acceptable in people with stroke. Individuals in the class-based group showed greater benefit compared to those receiving home-based therapy.

Revisiting dose and intensity of training: Opportunities to enhance recovery following stroke.

PURPOSE: Stroke is a global leading cause of adult disability with survivors often enduring persistent impairments and loss of function. Both intensity and dosage of training appear to be important factors to help restore behavior. However, current practice fails to achieve sufficient intensity and dose of training to promote meaningful recovery. The purpose of this review is to propose therapeutic solutions that can help achieve a higher dose and/or intensity of therapy. Raising awareness of these intensive, high-dose, treatment strategies might encourage clinicians to re-evaluate current practice and optimize delivery of stroke rehabilitation for maximal recovery. METHODS: Literature that tested and evaluated solutions to increase dose or intensity of training was reviewed. For each therapeutic strategy, we outline evidence of clinical benefit, supporting neurophysiological data (where available) and discuss feasibility of clinical implementation. RESULTS: Possible therapeutic solutions included constraint induced movement therapy, robotics, circuit therapy, bursts of training, gaming technologies, goal-oriented instructions, and cardiovascular exercise. CONCLUSION: Our view is that clinicians should evaluate current practice to determine how intensive high-dose training can be implemented to promote greater recovery after stroke.

Cognitive Reserve Modifies the Relationship Between Neural Function, Neural Injury and Upper-Limb Recovery After Stroke.

OBJECTIVE: To investigate whether cognitive reserve modifies the relationship between functional connectivity, lesion volume, stroke severity and upper-limb motor impairment and recovery in stroke survivors. METHODS: Ten patients with first-ever ischemic middle cerebral artery stroke completed the Cognitive Reserve Index Questionnaire at baseline. Upper-limb motor impairment and functional connectivity were assessed using the Fugl-Meyer Assessment and electroencephalography respectively at baseline and 3-months post-stroke. A debiased weighted phase lag index was computed to estimate functional connectivity between electrodes. Partial least squares (PLS) regression identified a connectivity model that maximally predicted variance in the degree of upper-limb impairment. Regression models were generated to determine whether cognitive reserve modified the relationship between neural function (functional connectivity), neural injury (lesion volume), stroke severity (National Institutes of Health Stroke Scale) and upper-limb motor impairment at baseline and recovery at 3-months (Fugl-Meyer Assessment). RESULTS: The addition of cognitive reserve to a regression model with a dependent variable of upper-limb motor recovery and independent variables of functional connectivity between the ipsilesional motor cortex and parietal cortex, stroke severity and lesion volume improved model efficiency (∆BIC=-7.07) despite not reaching statistical significance (R2=0.90, p=0.07). Cognitive reserve did not appear to improve regression models examining motor impairment at baseline. CONCLUSIONS: Preliminary observations suggest cognitive reserve might modify the relationship between neural function, neural injury, stroke severity and upper-limb motor recovery. Further investigation of cognitive reserve in motor recovery post-stroke appears warranted.

Do Adults with Stroke have Altered Interhemispheric Inhibition? A Systematic Review with Meta-Analysis.

OBJECTIVE: Interhemispheric inhibition is an important cortical mechanism to support motor control. Altered interhemispheric inhibition has been the target of neuromodulation interventions. This systematic review investigated the evidence for altered interhemispheric inhibition in adults with unilateral neurological conditions: stroke, amyotrophic lateral sclerosis, cerebral palsy, complex regional pain syndrome, traumatic brain injury, and cerebral palsy METHODS: We pre-registered the protocol and followed PRISMA guidelines. Five databases were systematically searched to identify studies reporting interhemispheric inhibition measures in unilateral neurological conditions and healthy controls. Data were grouped according to the measure (ipsilateral silent period and dual-coil), stimulated hemisphere, and stage of the condition (subacute and chronic). RESULTS: 1372 studies were identified, of which 14 were included (n = 226 adults with stroke and 161 age-matched controls). Ipsilateral silent period-duration was longer in people with stroke than in controls (stimulation of dominant hemisphere) regardless of stroke stage. Motor evoked potential was less suppressed in people with sub-acute stroke (stimulation of the unaffected hemisphere) than controls (stimulation of dominant hemisphere) and this reversed in chronic stroke. CONCLUSION: Detection of altered interhemispheric inhibition appears to be dependent on the measure of interhemispheric inhibition and the stage of recovery. SIGNIFICANCE: Rebalancing interhemispheric inhibition using neuromodulation is considered a promising line of treatment for stroke rehabilitation. Our results did not find compelling evidence to support consistent alterations in interhemispheric inhibition in adults with stroke.

Implication of the ipsilateral motor network in unilateral voluntary muscle contraction: the cross-activation phenomenon.

Voluntary force production requires that the brain produces and transmits a motor command to the muscles. It is widely acknowledged that motor commands are executed from the primary motor cortex (M1) located in the contralateral hemisphere. However, involvement of M1 located in the ipsilateral hemisphere during moderate to high levels of unilateral muscle contractions (>30% of the maximum) has been disclosed in recent years. This phenomenon has been termed cross-activation. The activation of the ipsilateral M1 relies on complex inhibitory and excitatory interhemispheric interactions mediated via the corpus callosum and modulated according to the contraction level. The regulatory mechanisms underlying these interhemispheric interactions, especially excitatory ones, remain vague, and contradictions exist in the literature. In addition, very little is known regarding the possibility that other pathways could also mediate the cross-activation. In the present review, we will therefore summarize the concept of cross-activation during unilateral voluntary muscle contraction and explore the associated mechanisms and other nervous system pathways underpinning this response. A broader knowledge of these mechanisms would consequently allow a better comprehension of the motor system as a whole, as distant brain networks working together to produce the motor command.

Strategies to implement and monitor in-home transcranial electrical stimulation in neurological and psychiatric patient populations: a systematic review.

BACKGROUND: Transcranial electrical stimulation is a promising technique to facilitate behavioural improvements in neurological and psychiatric populations. Recently there has been interest in remote delivery of stimulation within a participant's home. OBJECTIVE: The purpose of this review is to identify strategies employed to implement and monitor in-home stimulation and identify whether these approaches are associated with protocol adherence, adverse events and patient perspectives. METHODS: MEDLINE, Embase Classic + Embase, Emcare and PsycINFO databases and clinical trial registries were searched to identify studies which reported primary data for any type of transcranial electrical stimulation applied as a home-based treatment. RESULTS: Nineteen published studies from unique trials and ten on-going trials were included. For published data, internal validity was assessed with the Cochrane risk of bias assessment tool with most studies exhibiting a high level of bias possibly reflecting the preliminary nature of current work. Several different strategies were employed to prepare the participant, deliver and monitor the in-home transcranial electrical stimulation. The use of real time videoconferencing to monitor in-home transcranial electrical stimulation appeared to be associated with higher levels of compliance with the stimulation protocol and greater participant satisfaction. There were no severe adverse events associated with in-home stimulation. CONCLUSIONS: Delivery of transcranial electrical stimulation within a person's home offers many potential benefits and appears acceptable and safe provided appropriate preparation and monitoring is provided. Future in-home transcranial electrical stimulation studies should use real-time videoconferencing as one of the approaches to facilitate delivery of this potentially beneficial treatment.

Transcranial Magnetic Stimulation-EEG Biomarkers of Poststroke Upper-Limb Motor Function.

BACKGROUND: Motor evoked potentials obtained with transcranial magnetic stimulation (TMS) can provide valuable information to inform stroke neurophysiology and recovery but are difficult to obtain in all stroke survivors due to high stimulation thresholds. OBJECTIVE: To determine whether transcranial magnetic stimulation evoked potentials (TEPs) evoked using a lower stimulus intensity, below that necessary for recording motor evoked potentials, could serve as a marker of poststroke upper-limb motor function and were different compared to healthy adults. METHODS: Eight chronic stroke survivors (66 ± 21 years) and 15 healthy adults (53 ± 10 years) performed a motor function task using a customized grip-lift manipulandum. TMS was applied to the lesioned motor cortex, with TEPs recorded using simultaneous high-definition electroencephalography (EEG). RESULTS: Stroke participants demonstrated greater hold ratio with the manipulandum. Cluster-based statistics revealed larger P30 amplitude in stroke participants, with significant clusters over frontal (P = .016) and parietal-occipital electrodes (P = .023). There was a negative correlation between the N45 peak amplitude and hold ratio in stroke participants (r = -.83, P = .02), but not controls. CONCLUSIONS: TEPs can be recorded using lower stimulus intensities in chronic stroke. The global P30 TEP response differed between stroke participants and healthy controls, with results suggesting that the TEP can be used as a biomarker of upper-limb behavior.

Simulation of electromyographic recordings following transcranial magnetic stimulation.

Transcranial magnetic stimulation (TMS) is a technique that enables noninvasive manipulation of neural activity and holds promise in both clinical and basic research settings. The effect of TMS on the motor cortex is often measured by electromyography (EMG) recordings from a small hand muscle. However, the details of how TMS generates responses measured with EMG are not completely understood. We aim to develop a biophysically detailed computational model to study the potential mechanisms underlying the generation of EMG signals following TMS. Our model comprises a feed-forward network of cortical layer 2/3 cells, which drive morphologically detailed layer 5 corticomotoneuronal cells, which in turn project to a pool of motoneurons. EMG signals are modeled as the sum of motor unit action potentials. EMG recordings from the first dorsal interosseous muscle were performed in four subjects and compared with simulated EMG signals. Our model successfully reproduces several characteristics of the experimental data. The simulated EMG signals match experimental EMG recordings in shape and size, and change with stimulus intensity and contraction level as in experimental recordings. They exhibit cortical silent periods that are close to the biological values and reveal an interesting dependence on inhibitory synaptic transmission properties. Our model predicts several characteristics of the firing patterns of neurons along the entire pathway from cortical layer 2/3 cells down to spinal motoneurons and should be considered as a viable tool for explaining and analyzing EMG signals following TMS. NEW & NOTEWORTHY A biophysically detailed model of EMG signal generation following transcranial magnetic stimulation (TMS) is proposed. Simulated EMG signals match experimental EMG recordings in shape and amplitude. Motor-evoked potential and cortical silent period properties match experimental data. The model is a viable tool to analyze, explain, and predict EMG signals following TMS.

Neuroplasticity and network connectivity of the motor cortex following stroke: A transcranial direct current stimulation study.

Transcranial direct current stimulation (tDCS) is a noninvasive brain stimulation technique that has potential for clinical utility in neurorehabilitation. However, recent evidence indicates that the responses to tDCS are highly variable. This study investigated whether electroencephalographic (EEG) measures of functional connectivity of the target network were associated with the response to ipsilesional anodal tDCS in stroke survivors. Ten chronic stroke patients attended two experimental sessions in a randomized cross-over trial and received anodal or sham tDCS. Single-pulse transcranial magnetic stimulation was used to quantify change in corticospinal excitability following tDCS. At the beginning of each session, functional connectivity was estimated using the debiased-weighted phase lag index from EEG recordings at rest. Magnetic resonance imaging identified lesion location and lesion volume. Partial least squares regression identified models of connectivity which maximally accounted for variance in anodal tDCS responses. Stronger connectivity of a network with a seed approximating the stimulated ipsilesional motor cortex, and clusters of electrodes approximating the ipsilesional parietal cortex and contralesional frontotemporal cortex in the alpha band (8-13 Hz) was strongly associated with a greater increase of corticospinal excitability following anodal tDCS. This association was not observed following sham stimulation. Addition of a structural measure(s) of injury (lesion volume) provided an improved model fit for connectivity between the seed electrode and ipsilesional parietal cortex, but not the contralesional frontotemporal cortex. TDCS has potential to greatly assist stroke rehabilitation and functional connectivity appears a robust and specific biomarker of response which may assist clinical translation of this therapy.

Resting state functional connectivity measures correlate with the response to anodal transcranial direct current stimulation.

Responses to non-invasive brain stimulation are highly variable between subjects. Resting state functional connectivity was investigated as a marker of plasticity induced by anodal transcranial direct current stimulation (tDCS). Twenty-six healthy adults (15 male, 26.4 ± 6.5 years) were tested. Experiment 1 investigated whether functional connectivity could predict modulation of corticospinal excitability following anodal tDCS. Experiment 2 determined test-retest reliability of connectivity measures. Three minutes of electroencephalography was recorded and connectivity was quantified with the debiased weighted phase lag index. Anodal (1 mA, 20 min) or sham tDCS was applied to the left primary motor cortex (M1), with a change in motor evoked potential amplitude recorded from the right first dorsal interosseous used as a marker of tDCS response. Connectivity in the high beta frequency (20-30 Hz) between an electrode approximating the left M1 (C3) and electrodes overlying the left parietal cortex was a strong predictor of tDCS response (cross-validated R2  = 0.69). Similar relationships were observed for alpha (8-13 Hz; R2  = 0.64), theta (4-7 Hz; R2  = 0.53), and low beta (14-19 Hz; R2  = 0.58) frequencies, however, test-retest reliability of connectivity measures was strongest for the high beta frequency model (ICC = 0.65; good reliability). Further investigation of the high beta model found that greater connectivity between C3 and a cluster of electrodes approximately overlying the left parietal cortex was associated with stronger responses to anodal (rho = 0.61, P = 0.03), but not sham tDCS (rho = 0.43, P = 0.14). Functional connectivity is a strong predictor of the neuroplastic response to tDCS and may be one important characteristic to assist targeted tDCS application.

An investigation of cortical neuroplasticity following stroke in adults: is there evidence for a critical window for rehabilitation?

BACKGROUND: Evidence in animal stroke models suggests that neuroplasticity takes place maximally in a specific time window after an ischaemic lesion, which may coincide with the optimal time to intervene with rehabilitation. The aim of this study is to investigate neurophysiological evidence for a "critical window" of enhanced neuroplasticity in patients following ischaemic stroke, and establish its duration. We will also investigate changes in cortical inhibition following stroke, and the influence this has on functional recovery. METHODS/DESIGN: We will recruit participants recently admitted to the Stroke Unit of major metropolitan hospitals who have had a stroke and can provide informed consent. Participants will be excluded if they have any contraindications to Transcranial Magnetic Stimulation. We will compare neurophysiological outcomes in an age-matched healthy control group. We conservatively hypothesise a 5% increase in neuroplasticity at the optimal timing following stroke, compared to control participants, and require 43 patients following stroke to detect a significant difference with 80% power. The primary outcome is the change in the motor evoked potential (MEP) amplitude in a hand muscle, after the administration of a plasticity-inducing paradigm to the affected hemisphere. Secondary outcomes include measures of cortical excitability, intracortical inhibition and arm function. DISCUSSION: The data from this trial will clarify whether there is a critical window for neuroplastic change in the brain following stroke. If so, intensive rehabilitation during this period could be more effective, reducing long-term disability and the cost burden of stroke.

Assessing gait variability in transtibial amputee fallers based on spatial-temporal gait parameters normalized for walking speed.

OBJECTIVE: To determine whether normalizing spatial-temporal gait data for walking speed obtained from multiple walking trials leads to differences in gait variability parameters associated with a history of falling in people with transtibial amputations. DESIGN: Cross-sectional study. SETTING: Rehabilitation center. PARTICIPANTS: People with unilateral transtibial amputations (N=45; mean age ± SD, 60.5±13.7y; 35 men [78%]) were recruited. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Participants completed 10 consecutive walking trials using an instrumented walkway system. Primary gait parameters were walking speed and step-length, step-width, step-time, and swing-time variability. A retrospective 12-month fall history was obtained from participants. RESULTS: Sixteen amputees (36%) were classified as fallers. Variation in gait speed across the 10 walking trials was 2.9% (range, 1.1%-12.1%). Variability parameters of normalized gait data were significantly different from variability parameters of nonnormalized data (all P<.01). For nonnormalized data, fallers had greater amputated limb step-time (P=.02), step-length (P=.02), swing-time (P=.05), and step-width (P=.03) variability and nonamputated limb step-length (P=.04) and step-width (P=.01) variability. For normalized data, only 3 variability parameters were significantly greater for fallers. These were amputated limb step-time (P=.05), step-length (P=.02), and step-width (P=.01) variability. CONCLUSIONS: Normalizing spatial-temporal gait data for walking speed before calculating gait variability parameters may aid in discerning variability parameters related to falls histories in people with transtibial amputations. This may help focus on the initial rehabilitation efforts of amputees with a fall history.

Ipsilateral corticomotor excitability is associated with increased gait variability in unilateral transtibial amputees.

Ipsilateral primary motor cortex (M1) reorganisation after unilateral lower-limb amputation may degrade function of the amputated limb. We hypothesised unilateral lower-limb amputees would have a bilateral increase in corticomotor excitability, and increased excitability of ipsilateral M1 would be associated with increased step-time variability during gait. Twenty transtibial amputees (16 male) aged 60.1 years (range 45-80 years), and 20 age- and gender-matched healthy adult controls were recruited. Single-pulse transcranial magnetic stimulation assessed corticomotor excitability. Two indices of corticomotor excitability were calculated. An index of corticospinal excitability (ICE) determined relative excitability of ipsilateral and contralateral corticomotor projections to alpha-motoneurons innervating the quadriceps muscle (QM) of the amputated limb. A laterality index (LI) assessed relative excitability of contralateral projections from each hemisphere. Spatial-temporal gait analysis was performed to calculate step-time variability. Amputees had lower ICE values, indicating relatively greater excitability of ipsilateral corticomotor projections than controls (P = 0.04). A lower ICE value was associated with increased step-time variability for amputated (P = 0.04) and non-amputated limbs (P = 0.02). This association suggests corticomotor projections from ipsilateral M1 to alpha-motoneurons innervating the amputated limb QM may interfere with gait. Cortical excitability in amputees was not increased bilaterally, contrary to our hypothesis. There was no difference in excitability of contralateral M1 between amputees and controls (P = 0.10), and no difference in LI (P = 0.71). It appears both hemispheres control one QM, with predominance of contralateral corticomotor excitability in healthy adults. Following lower-limb amputation, putative ipsilateral corticomotor excitability is relatively increased in some amputees and may negatively impact on function.

Use of an activity monitor and GPS device to assess community activity and participation in transtibial amputees.

This study characterized measures of community activity and participation of transtibial amputees based on combined data from separate accelerometer and GPS devices. The relationship between community activity and participation and standard clinical measures was assessed. Forty-seven participants were recruited (78% male, mean age 60.5 years). Participants wore the accelerometer and GPS devices for seven consecutive days. Data were linked to assess community activity (community based step counts) and community participation (number of community visits). Community activity and participation were compared across amputee K-level groups. Forty-six participants completed the study. On average each participant completed 16,645 (standard deviation (SD) 13,274) community steps and 16 (SD 10.9) community visits over seven days. There were differences between K-level groups for measures of community activity (F(2,45) = 9.4, p < 0.001) and participation (F(2,45) = 6.9, p = 0.002) with lower functioning K1/2 amputees demonstrating lower levels of community activity and participation than K3 and K4 amputees. There was no significant difference between K3 and K4 for community activity (p = 0.28) or participation (p = 0.43). This study demonstrated methodology to link accelerometer and GPS data to assess community activity and participation in a group of transtibial amputees. Differences in K-levels do not appear to accurately reflect actual community activity or participation in higher functioning transtibial amputees.

Effect of weekend physiotherapy provision on physiotherapy and hospital length of stay after total knee and total hip replacement.

OBJECTIVE: The aim of the present study was to investigate a change in physiotherapy provision from a 5- to 7-days-a-week service on both physiotherapy and hospital length of stay (LOS) after total knee (TKR) and total hip (THR) replacement. METHODS: A retrospective analysis of a clinical database was conducted for patients who received either a TKR or THR between July 2010 and June 2012 in one regional hospital. RESULTS: There was a significant decrease in physiotherapy LOS from 5.0 days (interquartile range (IQR) 5.0-6.0 days) for a 5-day physiotherapy service, to 5.0 days (IQR 4.0-5.0 days) for 7-day physiotherapy service (U=1443.5, z=-4.62, P=0.001). However, hospital LOS was not reduced (P=0.110). For TKR, physiotherapy LOS decreased significantly by 1 day with a 7-day physiotherapy service (U=518.0, z=-4.20, P=0.001). However, hospital LOS was again no different (P=0.309). For THR there was no difference in physiotherapy LOS (P=0.060) or hospital LOS (P=0.303) between the 5- and 7-day physiotherapy services. Where physiotherapy LOS was less than hospital LOS, delayed discharge was due primarily to non-medical issues (72%) associated with hospital organisational aspects. CONCLUSIONS: Increasing the provision of physiotherapy service after TKR provides an increase in physiotherapy sessions and has the potential to reduce hospital LOS. To be effective this must align with other administrative aspects of hospital discharge.

Virtual Reality Action Observation and Motor Imagery to Enhance Neuroplastic Capacity in the Human Motor Cortex: A Pilot Double-blind, Randomized Cross-over Trial.

Neuroplasticity is important for learning, development and recovery from injury. Therapies that can upregulate neuroplasticity are therefore of interest across a range of fields. We developed a novel virtual reality action observation and motor imagery (VR-AOMI) intervention and evaluated whether it could enhance the efficacy of mechanisms of neuroplasticity in the human motor cortex of healthy adults. A secondary question was to explore predictors of the change in neuroplasticity following VR-AOMI. A pre-registered, pilot randomized controlled cross-over trial was performed. Twenty right-handed adults (13 females; mean age: 23.0 ± 4.53 years) completed two experimental conditions in separate sessions; VR-AOMI and control. We used intermittent theta burst stimulation (iTBS) to induce long term potentiation-like plasticity in the motor cortex and recorded motor evoked potentials at multiple timepoints as a measure of corticospinal excitability. The VR-AOMI task did not significantly increase the change in MEP amplitude following iTBS when compared to the control task (Group × Timepoint interaction p = 0.17). However, regression analysis identified the change in iTBS response following VR-AOMI was significantly predicted by the baseline iTBS response in the control task. Specifically, participants that did not exhibit the expected increase in MEP amplitude following iTBS in the control condition appear to have greater excitability following iTBS in the VR-AOMI condition (r = -0.72, p < 0.001). Engaging in VR-AOMI might enhance capacity for neuroplasticity in some people who typically do not respond to iTBS. VR-AOMI may prime the brain for enhanced neuroplasticity in this sub-group.