Distinguishing reflex from non-reflex responses elicited by transcutaneous spinal stimulation targeting the lumbosacral cord in healthy individuals.

Transcutaneous spinal stimulation (TSS) studies rely on the depolarization of afferent fibers to provide input to the spinal cord; however, this has not been routinely ascertained. Thus, we aimed to characterize the types of responses evoked by TSS and establish paired-pulse ratio cutoffs that distinguish posterior root reflexes, evoked by stimulation of afferent nerve fibers, from motor responses, evoked by stimulation of efferent nerve fibers. Twelve neurologically intact participants (six women) underwent unipolar TSS (cathode over T11-12 spinal processes, anode paraumbilically) while resting supine.

Pendulum test parameters are useful for detecting knee muscle hypertonia and quantifying response to an intrathecal baclofen bolus injection.

Our objective was to determine which pendulum test parameters are useful for detecting hypertonia in the knee muscles and assessing the group and individual responses to intrathecal baclofen (ITB) bolus injection among prospective pump recipients. We included 15 neurological patients with lower limb hypertonia (mainly spinal cord injury, n  = 7) and collected data the day before (baseline), and 2.5 and 5.

The contribution of walking speed versus recent stroke to temporospatial gait variability.

Background: Inconsistent results have been reported for temporospatial gait variability after stroke. Given the large differences in gait speed across stroke subjects and relative to healthy controls, it is not clear which changes in temporospatial gait variability can be ascribed to the walking speed during gait evaluation versus the consequences of stroke.

Research Questions: Does temporospatial gait variability differ between (1) stroke subjects grouped in clinically-relevant functional ambulation classes, (2) the paretic and non-paretic legs within each class, and (3) stroke and healthy subjects after controlling for gait speed?

Methods: Stroke subjects were evaluated at their comfortable speed < 2 months post-onset and classified into the household (<40 cm/s, n = 38), limited-community (40-80 cm/s, n = 35), and full-community (>80 cm/s, n = 14) walkers.

Neuromodulation with transcutaneous spinal stimulation reveals different groups of motor profiles during robot-guided stepping in humans with incomplete spinal cord injury.

Neuromodulation via spinal stimulation has been investigated for improving motor function and reducing spasticity after spinal cord injury (SCI) in humans. Despite the reported heterogeneity of outcomes, few investigations have attempted to discern commonalities among individual responses to neuromodulation, especially the impact of stimulation frequencies. Here, we examined how exposure to continuous lumbosacral transcutaneous spinal stimulation (TSS) across a range of frequencies affects robotic torques and EMG patterns during stepping in a robotic gait orthosis on a motorized treadmill.

Reply to Daly, J.J. Comment on "Chow, J.W.; Stokic, D.S. Longitudinal Changes in Temporospatial Gait Characteristics during the First Year Post-Stroke. . 2021, , 1648".

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Longitudinal Changes in Temporospatial Gait Characteristics during the First Year Post-Stroke.

Given the paucity of longitudinal data in gait recovery after stroke, we compared temporospatial gait characteristics of stroke patients during subacute (<2 months post-onset, T0) and at approximately 6 and 12 months post-onset (T1 and T2, respectively) and explored the relationship between gait characteristics at T0 and the changes in gait speed from T0 to T1. Forty-six participants were assessed at T0 and a subsample of twenty-four participants were assessed at T2. Outcome measures included Fugl-Meyer lower-extremity motor score, 14 temporospatial gait parameters, and symmetry indices of 5 step parameters.

Perception and predictors of health locus of control at rehabilitation discharge and 1 year after traumatic spinal cord injury.

This retrospective study examined the perception and predictors of health locus of control (LOC) in 71 individuals with a spinal cord injury (SCI) at discharge from inpatient rehabilitation (average age 39 years, 77% male, 54% black, 51% cervical SCI, 51% incomplete SCI and average time post-SCI 20 days). We also determined if health LOC beliefs and predictors change over the 1st year after SCI in a representative subsample of 36 individuals. The participants completed surveys regarding the health LOC, self-esteem and depression whereas demographic and SCI information were retrieved from medical records.

Characteristics of rectus femoris activation and rectus femoris-hamstrings coactivation during force-matching isometric knee extension in subacute stroke.

The spectral properties of surface electromyographic (EMG) signal in the rectus femoris (RF) and the coactivation in the medial hamstrings (MH) were investigated in 45 stroke subjects (22 ± 12 days post-onset) and 30 age-matched healthy controls who performed unilateral knee extensions at maximum effort (100% MVC) and during 5-s force-matching tasks (10, 30, 50% MVC). The spectral properties were obtained through a power spectrum analysis based on Fast Fourier Transform. The coactivation was measured as the MH amplitude (%max) and MH/RF amplitude ratio.

Providing unloading by exoskeleton improves shoulder flexion performance after stroke.

Robotic devices can be engaged actively or passively to unload arm weight or impose additional loading. The conditions of variable loading and unloading offer an opportunity to investigate motor performance of the arm affected by a stroke. The objective of this study was to investigate the interactive effects of the proximal arm impairment and passive weight compensation on shoulder flexion performance in the sagittal plane after stroke.

Relations between knee and ankle muscle coactivation and temporospatial gait measures in patients without hypertonia early after stroke.

It is unclear whether muscle coactivation during gait is altered early after stroke and among which muscles. We sought to characterize muscle coactivation during gait in subacute stroke subjects without hypertonia and explore the relationship with temporospatial parameters. In 70 stroke (23 ± 12 days post-onset) and 29 age-matched healthy subjects, surface electromyography signals were used to calculate coactivation magnitude and duration between rectus femoris and medial hamstring (knee antagonistic coactivation), tibialis anterior and medial gastrocnemius (ankle antagonistic coactivation), and rectus femoris and medial gastrocnemius (extensor synergistic coactivation) during early double-support (DS1), early single-support (SS1), late single-support (SS2), late double-support (DS2), and swing (SW).

Bipolar transcutaneous spinal stimulation evokes short-latency reflex responses in human lower limbs alike standard unipolar electrode configuration.

Noninvasive electrical stimulation targeting the posterior lumbosacral roots has been applied recently in reflexes studies and as a neuromodulation intervention for modifying spinal cord circuitry after an injury. Here, we characterized short-latency responses evoked by four bipolar electrode configurations placed longitudinally over the spinal column at different vertebral levels from L1 to T9. They were compared with the responses evoked by the standard unipolar (aka monopolar) electrode configuration (cathode at T11/12, anode over the abdominal wall).

The utility of the single-subject method for comparison of temporal-spatial gait changes between a microprocessor and non-microprocessor prosthetic knees.

Background: Despite increasing knowledge about the potential benefits of advanced user-controlled technology, the decision about switching an individual prosthesis user from a non-microprocessor prosthetic knee to a microprocessor prosthetic knee is mainly based on clinician's experience rather than empirical evidence.

Objectives: To demonstrate the utility of single-subject design and data analysis for evaluating changes in temporal-spatial gait characteristics between walking with a non-microprocessor prosthetic knee and microprocessor prosthetic knee.

Study Design: Single-subject ABA/BAB design.

Knee Muscle Stretch Reflex Responses After an Intrathecal Baclofen Bolus in Neurological Patients With Moderate-to-Severe Hypertonia.

Objectives: To examine the prevalence, onset threshold, and response magnitude of stretch reflex response (SRR) in the knee extensors and flexors before and after an intrathecal baclofen (ITB) bolus injection in patients with moderate-to-severe hypertonia.

Materials And Methods: SRRs were elicited by reciprocal passive knee extension/flexion movements at preset angular velocities of 5, 60, 120, 180, 240, and 300°/s using an isokinetic dynamometer and recorded with surface electromyographic (EMG) electrodes placed over the knee extensors and flexors in 53 neurologic patients before and at 2.5 and 5 hours after an ITB injection via lumbar puncture.

Electrically induced cycling and nutritional counseling for counteracting obesity after spinal cord injury: A pilot study.

The purpose of this pilot study was to determine the preliminary efficacy of interval functional electrical stimulation (FES) cycling combined with nutritional counseling in obese adults with SCI. Community-based individuals with chronic SCI. Ten participants with chronic SCI.

Safety and preliminary efficacy of functional electrical stimulation cycling in an individual with cervical cord injury, autonomic dysreflexia, and a pacemaker: Case report.

Functional electric stimulation (FES) cycling is a commonly used therapeutic exercise modality after spinal cord injury (SCI); however, additional precautions must be taken in certain situations. The purpose of this study was to develop and apply a safety monitoring protocol for autonomic dysreflexia (AD) during FES cycling and to determine if an interval-FES cycling program can be safe and beneficial to an individual with cervical SCI, a history of AD, and a non-dependent cardiac pacemaker.The participant was a 36-year-old male with C6 AIS-C SCI sustained 9 years earlier, intermittent AD, and implanted cardiac pacemaker.

Exteroceptive suppression of voluntary activity in thenar muscles by cutaneous stimulation: How many trials should be averaged?

Objective: To determine a minimum number of trials that preserve input-output (I-O) properties of duration and magnitude of exteroceptive EMG suppression (eEMGs).

Patients And Methods: eEMGs was recorded in 16 healthy subjects from thenar muscles following index finger stimulation at 2.5, 5, 10, and 20 times sensory threshold (xST).

The Effect of Electrically Induced Cycling and Nutritional Counseling on Cardiometabolic Health in Upper and Lower Motor Neuron Chronic Spinal Cord Injury: Dual Case Report.

Introduction: Various therapies have been utilized to improve cardiometabolic health after spinal cord injury (SCI), including Functional Electrical Stimulation (FES) cycling. Typically, FES is used in SCI cases resulting from Upper Motor Neuron Injury (UMN-SCI). However, it has been reported that FES may improve muscle torque and functional mobility in individuals with Lower Motor Neuron Injuries (LMN-SCI) but potential effects on cardiometabolic health have not been studied before.

Differential Expression of Genes Related to Innate Immune Responses in Ex Vivo Spinal Cord and Cerebellar Slice Cultures Infected with West Nile Virus.

West Nile virus (WNV) infection results in a spectrum of neurological symptoms, ranging from a benign fever to severe WNV neuroinvasive disease with high mortality. Many who recover from WNV neuroinvasive infection present with long-term deficits, including weakness, fatigue, and cognitive problems. While neurons are a main target of WNV, other cell types, especially astrocytes, play an important role in promoting WNV-mediated central nervous system (CNS) damage.

Gait Impairments in Patients Without Lower Limb Hypertonia Early Poststroke Are Related to Weakness of Paretic Knee Flexors.

Objective: To describe gait characteristics of patients without clinical evidence of lower limb hypertonia within 2 months of stroke and explore the relationship between gait and residual motor function.

Design: Cohort study.

Setting: Motion analysis laboratory in a tertiary-care free-standing rehabilitation hospital.

Comparison of mobility and user satisfaction between a microprocessor knee and a standard prosthetic knee: a summary of seven single-subject trials.

Insufficient evidence of the benefits provided by costlier microprocessor knees (MPKs) over nonmicroprocessor knees (NMPKs) often causes concern when considering MPK prescription. Thus, more studies are needed to demonstrate differences between MPKs and NMPKs and define sensitive outcomes to guide MPK prescription. The aim of this study was to evaluate the impact of switching from NMPK to MPK on measures of mobility and preference.