Brain-Hand Function Relationships Based on Level of Grasp Function in Chronic Left-Hemisphere Stroke.

Background And Objective: The biomarkers of hand function may differ based on level of motor impairment after stroke. The objective of this study was to determine the relationship between resting state functional connectivity (RsFC) and unimanual contralesional hand function after stroke and whether brain-behavior relationships differ based on level of grasp function.

Methods: Sixty-two individuals with chronic, left-hemisphere stroke were separated into three functional levels based on Box and Blocks Test performance with the contralesional hand: Low (moved 0 blocks), Moderate (moved >0% but <90% of blocks relative to the ipsilesional hand), and High (moved ≥90% of blocks relative to the ipsilesional hand).

Effect of positive social comparative feedback on the resting state connectivity of dopaminergic neural pathways: A preliminary investigation.

Positive social comparative feedback is hypothesized to generate a dopamine response in the brain, similar to reward, by enhancing expectancies to support motor skill learning. However, no studies have utilized neuroimaging to examine this hypothesized dopaminergic mechanism. Therefore, the aim of this preliminary study was to investigate the effect of positive social comparative feedback on dopaminergic neural pathways measured by resting state connectivity.

Effects of positive social comparative feedback on motor sequence learning and performance expectancies.

Introduction: Positive social comparative feedback indicates to the learner that they are performing better than others. While this type feedback supports motor skill learning in some tasks, the effect of social comparative feedback on implicit motor sequence learning remains unknown. The aim of this study was to determine the effect of positive social comparative feedback on the learning of and expectancies for a motor sequence task.

Using whole-brain diffusion tensor analysis to evaluate white matter structural correlates of delayed visuospatial memory and one-week motor skill retention in nondemented older adults: A preliminary study.

Skill retention is important for motor rehabilitation outcomes. Recent work has demonstrated that delayed visuospatial memory performance may predict motor skill retention in older and neuropathological populations. White matter integrity between parietal and frontal cortices may explain variance in upper-extremity motor learning tasks and visuospatial processes.

Low normal FMR1 genotype in older adult women: Psychological well-being and motor function.

The FMR1 gene plays a key role in adult neurogenesis and neuroplasticity, and thus may contribute to age-related health in the population. The current study focused on the "low normal" FMR1 genotype, defined by lower-than-typical numbers of FMR1 CGG repeats (<26), as a potential genetic determinant of age-related health. We characterized the effect of the low normal FMR1 genotype on psychological well-being and motor function in a racially diverse non-clinical sample of older adult women.

Effect of behavioural practice targeted at the motor action selection network after stroke.

Motor action selection engages a network of frontal and parietal brain regions. After stroke, individuals activate a similar network, however, activation is higher, especially in the contralesional hemisphere. The current study examined the effect of practice on action selection performance and brain activation after stroke.

Observational Study of Neuroimaging Biomarkers of Severe Upper Limb Impairment After Stroke.

Background And Objectives: It is difficult to predict poststroke outcome for individuals with severe motor impairment because both clinical tests and corticospinal tract (CST) microstructure may not reliably indicate severe motor impairment. Here, we test whether imaging biomarkers beyond the CST relate to severe upper limb (UL) impairment poststroke by evaluating white matter microstructure in the corpus callosum (CC). In an international, multisite hypothesis-generating observational study, we determined if (1) CST asymmetry index (CST-AI) can differentiate between individuals with mild-moderate and severe UL impairment and (2) CC biomarkers relate to UL impairment within individuals with severe impairment poststroke.

Task-Based Functional Connectivity and Blood-Oxygen-Level-Dependent Activation During Within-Scanner Performance of Lumbopelvic Motor Tasks: A Functional Magnetic Resonance Imaging Study.

There are a limited number of neuroimaging investigations into motor control of the lumbopelvic musculature. Most investigation examining motor control of the lumbopelvic musculature utilize transcranial magnetic stimulation (TMS) and focus primarily on the motor cortex. This has resulted in a dearth of knowledge as it relates to how other regions of the brain activate during lumbopelvic movement.

Upper and Lower Limb Motor Function Correlates with Ipsilesional Corticospinal Tract and Red Nucleus Structural Integrity in Chronic Stroke: A Cross-Sectional, ROI-Based MRI Study.

Background: Structural integrity of the ipsilesional corticospinal tract (CST) is important for upper limb motor recovery after stroke. However, additional neuromechanisms associated with motor function poststroke are less well understood, especially regarding the lower limb.

Objective: To investigate the neural basis of upper/lower limb motor deficits poststroke by correlating measures of motor function with diffusion tensor imaging-derived indices of white matter integrity (fractional anisotropy (FA), mean diffusivity (MD)) in primary and secondary motor tracts/structures.

Scaling of Joint Motion and Muscle Activation for 3-Dimensional Control of Reach Extent.

This study investigated the scaling of upper arm kinematics, joint motion, and muscle activation for three-dimensional (3D) reaches to targets of increasing distance. Fifteen participants completed 108 total reaches to targets placed 7, 14, and 21 cm across midline. Peak velocity, acceleration, and time to peak velocity scaled to both target and movement distance.

Physical Activity in De Novo Parkinson Disease: Daily Step Recommendation and Effects of Treadmill Exercise on Physical Activity.

Objective: People with Parkinson disease (PD) have low physical activity (PA) levels and are at risk for cardiovascular events. The 3 purposes of this study were to determine a step threshold that corresponds to meeting aerobic PA guidelines, determine effects of treadmill exercise on PA, and quantify the relationship between changes in daily steps and fitness.

Methods: This was a secondary analysis of the Study in Parkinson's Disease of Exercise trial, which randomized participants to high-intensity treadmill exercise, moderate-intensity treadmill exercise, or usual care for 6 months.

Comparison of corticospinal tract integrity measures extracted from standard versus native space in chronic stroke.

Background: Fractional anisotropy (FA) and mean diffusivity (MD) are measures derived from diffusion-weighted imaging that represent the integrity of the corticospinal tract (CST) after stroke. Some studies of the motor system after stroke extract FA and MD from native space while others extract from standard space making comparison across studies challenging.

New Method: The purpose was to compare CST integrity measures extracted from standard versus native space in individuals with chronic stroke.

Feasibility of integrating survivors of stroke into cardiac rehabilitation: A mixed methods pilot study.

Background: Survivors of stroke are often deconditioned and have limited opportunities for exercise post-rehabilitation. Cardiac Rehabilitation (CR), a structured exercise program offered post-cardiac event in the United States (U.S.

Predictors of Daily Steps at 1-Year Poststroke: A Secondary Analysis of a Randomized Controlled Trial.

Background And Purpose: Walking has the potential to improve endurance and community participation after stroke. Obtaining ≥6000 daily steps can decrease subsequent stroke risk. Early identification of those prone to low daily steps could facilitate interventions that lead to increased walking and improved health.

Integrating Survivors of Stroke Into Exercise-Based Cardiac Rehabilitation Improves Endurance and Functional Strength.

Background Cardiac rehabilitation (CR) is a structured exercise program prevalent in the United States for people with cardiovascular disease that has been shown to increase cardiovascular endurance and improve quality of life. Despite similar cardiovascular risk factors, stroke is not among the covered diagnoses for CR. The purpose of this study was to examine the participant impact of integrating survivors of stroke into the exercise portion of an existing hospital-based CR program through measures of physical function and other health impacts and through qualitative evaluation of participant perception.

Perceived effort for reaching is associated with self-reported fatigue.

Perceived effort for goal-directed reaching may be impacted by the level of self-reported fatigue, however, the relationship between self-reported fatigue and perceived effort has not been examined. We examined how perceived effort changed under varied reach conditions and the relationship between fatigue, perceived effort and reach performance. Twenty-three young adults performed reach actions toward 9 different targets on a digitizing tablet.

Neural correlates of within-session practice effects in mild motor impairment after stroke: a preliminary investigation.

While the structural integrity of the corticospinal tract (CST) has been shown to support motor performance after stroke, the neural correlates of within-session practice effects are not known. The purpose of this preliminary investigation was to examine the structural brain correlates of within-session practice effects on a functional motor task completed with the more impaired arm after stroke. Eleven individuals with mild motor impairment (mean age 57.

Targeted Engagement of the Action Selection Network during Task-Oriented Arm Training after Stroke.

Action selection (AS), or selection of an action from a set of alternatives, is an important movement preparation process that engages a frontal-parietal network. The addition of AS demands to arm training after stroke could be used to engage this motor planning process and the neural network that supports it. The purpose of this case series is to describe the feasibility and outcomes associated with task-oriented arm training aimed at engaging the AS behavioral process and the related neural network in three individuals with chronic stroke.

Effect of Standing on a Standardized Measure of Upper Extremity Function.

Although many daily activities that require the upper extremity are performed in standing, arm motor function is generally measured in sitting. The purpose of this study was to examine the effect of standing on a measure of upper extremity function, the Jebsen Hand Function Test (JHFT). Twelve nondisabled adults (26.

Test-retest reliability and minimal detectable change of corticospinal tract integrity in chronic stroke.

Diffusion tensor imaging (DTI) can be used to index white matter integrity of the corticospinal tract (CST) after stroke; however, the psychometric properties of DTI-based measures of white matter integrity are unknown. The purpose of this study was to examine test-retest reliability as determined by intraclass correlation coefficients (ICC) and calculate minimal detectable change (MDC) of DTI-based measures of CST integrity using three different approaches: a Cerebral Peduncle approach, a Probabilistic Tract approach, and a Tract Template approach. Eighteen participants with chronic stroke underwent DTI on the same magnetic resonance imaging scanner 4 days apart.

Stepping After Stroke: Walking Characteristics in People With Chronic Stroke Differ on the Basis of Walking Speed, Walking Endurance, and Daily Steps.

Background: What contributes to free-living walking after stroke is poorly understood. Studying the characteristics of walking may provide further details that guide interventions.

Objective: The objectives of this study were to examine how the walking characteristics of bouts per day, median steps per bout, maximum steps per bout, and time spent walking differ in individuals with various walking speeds, walking endurance, and daily steps and to identify cutoffs for differentiating ambulators who were active versus inactive.

The six-minute walk test as a fall risk screening tool in community programs for persons with stroke: a cross-sectional analysis.

: Persons with stroke have increased risk for recurrent stroke. Group exercise programs like cardiac rehabilitation might reduce this risk. These programs commonly use the six-minute walk test to measure aerobic capacity.

Poststroke Fatigue Is Related to Motor and Cognitive Performance: A Secondary Analysis.

Background And Purpose: Poststroke fatigue (PSF) is a common debilitating and persistent symptom after stroke. The relationship between PSF and motor and cognitive function remains inconclusive partly due to lack of control for effects of depression and use of insensitive measures. We examined the relationship between PSF and motor and cognitive performance using a comprehensive set of behavioral measures and excluding individuals with depression.

The Neurological Exercise Training (NExT) program: A pilot study of a community exercise program for survivors of stroke.

Background: Many survivors of stroke face chronic disability and increased risk for recurrent stroke. Regular physical activity can reduce these risk factors and improve cardiovascular fitness. Most survivors of stroke face barriers to exercise, including lack of access to programs; as a result, most are sedentary.