Whole body angular momentum characterizes reactive balance adaptations and perturbation intensity.

Identifying measures which accurately quantify reactive balance adaptation during walking is essential to understand how emerging perturbation-based gait paradigms impact stability over the course of an intervention. These perturbation paradigms have shown promise in reducing falls for numerous clinical populations, however tracking progress in objective terms throughout an intervention remains challenging. Whole body angular momentum (H) may be particularly suited to detect subtle adaptations in the reactive balance response and is applicable within numerous perturbation environments.

F wave analysis based on the compound muscle action potential scan.

Introduction/aims: Conventional F wave analysis involves a relatively uniform physiological environment induced by supramaximal stimulations. The F wave characteristics in a dynamic physiological condition, however, are rarely investigated. This study aimed to improve understanding of F wave properties in the more dynamic process by introducing a novel method to analyze F waves based on the compound muscle action potential (CMAP) scan technique.

Altered Cortical Activity during a Finger Tap in People with Stroke.

This study describes electroencephalography (EEG) measurements during a simple finger movement in people with stroke to understand how temporal patterns of cortical activation and network connectivity align with prolonged muscle contraction at the end of a task. We investigated changes in the EEG temporal patterns in the beta band (13-26 Hz) of people with chronic stroke (N = 10, 7 F/3 M) and controls (N = 10, 7 F/3 M), during and after a cued movement of the index finger. We quantified the change in beta band EEG power relative to baseline as activation at each electrode and the change in task-based phase-locking value (tbPLV) and beta band task-based coherence (tbCoh) relative to baseline coherence as connectivity between EEG electrodes.

Noninvasive estimation of skeletal muscle oxygen consumption rate and microvascular reactivity in chronic stroke survivors using near-infrared spectroscopy.

Understanding post-stroke changes in skeletal muscle oxidative metabolism and microvascular reactivity could help create therapeutic targets that optimize rehabilitative interventions. Due to disuse atrophy, we hypothesized that basal muscle oxygen consumption rate and microvascular endothelial function would be impaired in the tibialis anterior (TA) muscle of the affected leg of chronic stroke survivors compared with the nonaffected leg and versus matched controls. Fifteen chronic stroke survivors (10 females) and 15 matched controls (9 females) completed this study.

People with degenerative cervical myelopathy have impaired reactive balance during walking.

Background: People with degenerative cervical myelopathy are known to have impaired standing balance and walking abilities, but less is known about balance responses during walking.

Research Question: The aim of this project was to assess reactive balance impairments during walking in people with degenerative cervical myelopathy (PwDCM). We hypothesized that center of mass motion following perturbations would be larger in PwDCM and gluteus medius electromyographic amplitude responses would be decreased in PwDCM.

Cervical spinal cord angiography and vessel-selective perfusion imaging in the rat.

Arterial spin labeling (ASL) has been widely used to evaluate arterial blood and perfusion dynamics, particularly in the brain, but its application to the spinal cord has been limited. The purpose of this study was to optimize vessel-selective pseudocontinuous arterial spin labeling (pCASL) for angiographic and perfusion imaging of the rat cervical spinal cord. A pCASL preparation module was combined with a train of gradient echoes for dynamic angiography.

Longitudinal changes in diffusion tensor imaging in hemodialysis patients.

Introduction: Hemodialysis patients have increased white matter and gray matter pathology in the brain relative to controls based on MRI. Diffusion tensor imaging is useful in detecting differences between hemodialysis and controls but has not identified the expected longitudinal decline in hemodialysis patients. In this study we implemented specialized post-processing techniques to reduce noise to detect longitudinal changes in diffusion tensor imaging parameters and evaluated for any association with changes in cognition.

Cortical effects of wrist tendon vibration during an arm tracking task in chronic stroke survivors: An EEG study.

The purpose of this study was to characterize changes in cortical activity and connectivity in stroke survivors when vibration is applied to the wrist flexor tendons during a visuomotor tracking task. Data were collected from 10 chronic stroke participants and 10 neurologically-intact controls while tracking a target through a figure-8 pattern in the horizontal plane. Electroencephalography (EEG) was used to measure cortical activity (beta band desynchronization) and connectivity (beta band task-based coherence) with movement kinematics and performance error also being recorded during the task.

Reduced oxygen desaturation in the vastus lateralis of chronic stroke survivors during graded muscle contractions.

Background: Few studies have examined changes in skeletal muscle physiology post-stroke. This study examined changes in tissue oxygen saturation (StO) of the vastus lateralis (VL) muscle of stroke survivors and age-matched control participants during maximal and submaximal isometric contractions of the knee extensor muscles.

Objectives: We hypothesized that tissue oxygen desaturation (ΔStO) during knee extensor muscle contractions would be less in the VL in the paretic vs.

Cerebrovascular Function is Altered in Hemodialysis Patients.

Key Points: Hemodialysis patients have impaired cerebrovascular reactivity. Hemodialysis patients have cerebral structural deficits.

Background: Hemodialysis patients have declines in cerebral blood flow (CBF) and cerebral oxygenation during hemodialysis that may lead to ischemic brain injury.

Quantifying Hand Strength and Isometric Pinch Individuation Using a Flexible Pressure Sensor Grid.

Modulating force between the thumb and another digit, or isometric pinch individuation, is critical for daily tasks and can be impaired due to central or peripheral nervous system injury. Because surgical and rehabilitative efforts often focus on regaining this dexterous ability, we need to be able to consistently quantify pinch individuation across time and facilities. Currently, a standardized metric for such an assessment does not exist.

Assembly-style making: How structured making serves as an on-ramp to creativity and engineering design.

Makerspaces, workspaces where families can explore materials and tools collaboratively, can provide an opportunity for creative expression and early engineering learning in community spaces. The present study examined a cardboard-focused museum makerspace that included an assembly-style activity. Assembly-style making uses instructions to support makers.

Characterization of diffusion MRI using the mean apparent propagator model in hemodialysis patients: A pilot study.

To better understand documented cognitive decline in hemodialysis (HD) patients, diffusion MRI (dMRI) has been used to characterize brain anatomical deficits relative to controls. Studies to this point have primarily used diffusion tensor imaging (DTI) to model the three-dimensional diffusion of water in HD patients, with DTI parameters reflecting underlying microstructural changes of brain tissue. Since DTI has some limitations in characterizing tissue microstructure, some of which may be complicated by HD, we explored the use of the mean apparent propagator (MAP) model to describe diffusion in HD patients.

Quantitative assessments of finger individuation with an instrumented glove.

Background: In clinical and research settings, hand dexterity is often assessed as finger individuation, or the ability to move one finger at a time. Despite its clinical importance, there is currently no standardized, sufficiently sensitive, or fully objective platform for these evaluations.

Methods: Here we developed two novel individuation scores and tested them against a previously developed score using a commercially available instrumented glove and data collected from 20 healthy adults.

Synchronization of kinetic and kinematic hand tasks with electrocorticography and cortical stimulation during awake craniotomies.

Awake craniotomies provide unique and invaluable scientific opportunities for neurophysiological experimentation in consenting human subjects. While such experimentation carries a long history, rigorous reporting of methodologies focusing on synchronizing data across multiple platforms is not universally reported and often not translatable to across operating rooms, facilities, or behavioral tasks. Therefore, here we detail an intraoperative data synchronization methodology designed to work across multiple commercially available platforms to collect behavioral and surgical field videos, electrocorticography, brain stimulation timing, continuous finger joint angles, and continuous finger force production.

Radiology and radiation oncology considerations for transgender and intersex patients: A qualitative study.

Introduction: In this qualitative study, we explored experiences of radiologists and radiation oncologists in providing clinical care to transgender, gender diverse (TGD), and intersex patients by asking about comfort level, relevant past training and training gaps, and clinical recommendations for TGD and intersex patient care.

Methods: A purposive sample of radiology and radiation oncology professionals (n = 16) from diverse practice settings were interviewed on a videoconferencing platform. Transcripts were auto-populated and checked manually for accuracy.

Comparison and optimization of pCASL and VSASL for rat thoracolumbar spinal cord MRI at 9.4 T.

Purpose: To evaluate pseudo-continuous arterial spin labeling (pCASL) and velocity-selective arterial spin labeling (VSASL) for quantification of spinal cord blood flow (SCBF) in the rat thoracolumbar spinal cord.

Methods: Labeling efficiency (LE) was compared between pCASL and three VSASL variants in simulations and both phantom and in vivo experiments at 9.4 T.

Spectrum of injuries with "less-lethal" beanbag weapons: pictorial essay.

Beanbag weapons are gaining popularity with increasing daily use as a non-lethal or less-lethal alternative to traditional firearms. While these are considered "less-lethal," these are associated with a spectrum of serious injuries. We present a pictorial essay of these injuries ranging from mild skin contusions to more severe solid organ injuries.

Changes in Cortical Activity in Stroke Survivors Undergoing Botulinum Neurotoxin Therapy for Treatment of Focal Spasticity.

Botulinum NeuroToxin-A (BoNT-A) relieves muscle spasticity and increases range of motion necessary for stroke rehabilitation. Determining the effects of BoNT-A therapy on brain neuroplasticity could help physicians customize its use and predict its outcome. The purpose of this study was to investigate the effects of Botulinum Toxin-A therapy for treatment of focal spasticity on brain activation and functional connectivity.

Visual oscillation effects on dynamic balance control in people with multiple sclerosis.

Background: People with multiple sclerosis (PwMS) have balance deficits while ambulating through environments that contain moving objects or visual manipulations to perceived self-motion. However, their ability to parse object from self-movement has not been explored. The purpose of this research was to examine the effect of medial-lateral oscillations of the visual field and of objects within the scene on gait in PwMS and healthy age-matched controls using virtual reality (VR).

The Relationship between Cerebrovascular Reactivity and Cerebral Oxygenation during Hemodialysis.

Background: Patients with kidney failure treated with hemodialysis (HD) may be at risk for cerebral hypoperfusion due to HD-induced BP decline in the setting of impaired cerebral autoregulation. Cerebrovascular reactivity (CVR), the cerebrovascular response to vasoactive stimuli, may be a useful indicator of cerebral autoregulation in the HD population and identify those at risk for cerebral hypoperfusion. We hypothesize that CVR combined with intradialytic BP changes will be associated with declines in cerebral oxygenation saturation (ScO) during HD.

Acute Magnetic Resonance Imaging Predictors of Chronic Motor Function and Tissue Sparing in Rat Cervical Spinal Cord Injury.

Predicting functional outcomes from spinal cord injury (SCI) at the acute setting is important for patient management. This work investigated the relationship of early magnetic resonance imaging (MRI) biomarkers in a rat model of cervical contusion SCI with long-term functional outcome and tissue sparing. Forty rats with contusion injury at C5 at either the spinal cord midline (bilateral) or over the lateral cord (unilateral) were examined using multi-modal quantitative MRI at 1 day post-injury.

Degenerative cervical myelopathy delays responses to lateral balance perturbations regardless of predictability.

The aim of this study was to quantify balance impairments in standing in people with degenerative cervical myelopathy (PwDCM) in response to external perturbations. PwDCM have damage to their spinal cord due to degeneration of the cervical vertebral column, but little is known about balance. Balance was quantified by capturing kinetics, kinematic, and electromyographic data during standing in response to lateral waist pulls.