Stimulation of the Premotor Cortex Enhances Interhemispheric Functional Connectivity in Association with Upper Limb Motor Recovery in Moderate-to-Severe Chronic Stroke.

Transcranial direct current stimulation (tDCS) targeting the primary motor cortex is modestly effective for promoting upper-limb motor function following stroke. The premotor cortex (PMC) represents an alternative target based on its higher likelihood of survival and dense motor-network connections. The objective of this study was to determine whether ipsilesional PMC tDCS affects motor network functional connectivity (FC) in association with reduction in motor impairment, and to determine whether this relationship is influenced by baseline motor severity.

Myoelectric Arm Orthosis in Motor Learning-Based Therapy for Chronic Deficits After Stroke and Traumatic Brain Injury.

Background: Technologies that enhance motor learning-based therapy and are clinically deployable may improve outcome for those with neurological deficits. The MyoPro™ is a customized myoelectric upper extremity orthosis that utilizes volitionally generated weak electromyographic signals from paretic muscles to assist movement of an impaired arm. Our purpose was to evaluate MyoPro as a tool for motor learning-based therapy for individuals with chronic upper limb weakness.

Repetitive Transcranial Magnetic Stimulation of the Contralesional Dorsal Premotor Cortex for Upper Extremity Motor Improvement in Severe Stroke: Study Protocol for a Pilot Randomized Clinical Trial.

Up to 50% of stroke survivors have persistent, severe upper extremity paresis even after receiving rehabilitation. Repetitive transcranial magnetic stimulation (rTMS) can augment the effects of rehabilitation by modulating corticomotor excitability, but the conventional approach of facilitating excitability of the ipsilesional primary motor cortex (iM1) fails to produce motor improvement in stroke survivors with severe loss of ipsilesional substrate. Instead, the undamaged, contralesional dorsal premotor cortex (cPMd) may be a more suitable target.

Investigation of the Feasibility of Ventricular Delivery of Resveratrol to the Microelectrode Tissue Interface.

(1) Background: Intracortical microelectrodes (IMEs) are essential to basic brain research and clinical brain-machine interfacing applications. However, the foreign body response to IMEs results in chronic inflammation and an increase in levels of reactive oxygen and nitrogen species (ROS/RNS). The current study builds on our previous work, by testing a new delivery method of a promising antioxidant as a means of extending intracortical microelectrodes performance.

A Primary Care Provider's Guide to Pain After Spinal Cord Injury: Screening and Management.

Individuals with spinal cord injury (SCI) often experience chronic pain as a secondary complication. It can significantly impair mental health, sleep, mood, and overall quality of life. It is important for providers within a primary care setting to recognize the different types of pain such as nociceptive and neuropathic.

Investigating the Association between Motor Function, Neuroinflammation, and Recording Metrics in the Performance of Intracortical Microelectrode Implanted in Motor Cortex.

Long-term reliability of intracortical microelectrodes remains a challenge for increased acceptance and deployment. There are conflicting reports comparing measurements associated with recording quality with postmortem histology, in attempts to better understand failure of intracortical microelectrodes (IMEs). Our group has recently introduced the assessment of motor behavior tasks as another metric to evaluate the effects of IME implantation.

Stratifying chronic stroke patients based on the influence of contralesional motor cortices: An inter-hemispheric inhibition study.

Objective: A recent "bimodal-balance recovery" model suggests that contralesional influence varies based on the amount of ipsilesional reserve: inhibitory when there is a large reserve, but supportive when there is a low reserve. Here, we investigated the relationships between contralesional influence (inter-hemispheric inhibition, IHI) and ipsilesional reserve (corticospinal damage/impairment), and also defined a criterion separating subgroups based on the relationships.

Methods: Twenty-four patients underwent assessment of IHI using Transcranial Magnetic Stimulation (ipsilateral silent period method), motor impairment using Upper Extremity Fugl-Meyer (UEFM), and corticospinal damage using Diffusion Tensor Imaging and active motor threshold.

Adding Contralaterally Controlled Electrical Stimulation of the Triceps to Contralaterally Controlled Functional Electrical Stimulation of the Finger Extensors Reduces Upper Limb Impairment and Improves Reachable Workspace but not Dexterity: A Randomized Controlled Trial.

Objective: Different methods of neuromuscular electrical stimulation may be used for poststroke upper limb rehabilitation. This study evaluated the effects of contralaterally controlled functional electrical stimulation of the triceps and finger extensors.

Design: This is a randomized controlled trial of 67 participants who were less than 2 yrs poststroke and assigned to the following: (a) arm + hand contralaterally controlled functional electrical stimulation, (b) hand contralaterally controlled functional electrical stimulation, or (c) arm + hand cyclic neuromuscular electrical stimulation.

A review of methods for achieving upper limb movement following spinal cord injury through hybrid muscle stimulation and robotic assistance.

Individuals with tetraplegia, typically attributed to spinal cord injuries (SCI) at the cervical level, experience significant health care costs and loss of independence due to their limited reaching and grasping capabilities. Neuromuscular electrical stimulation (NMES) is a promising intervention to restore arm and hand function because it activates a person's own paralyzed muscles; however, NMES sometimes lacks the accuracy and repeatability necessary to position the limb for functional tasks, and repeated muscle stimulation can lead to fatigue. Robotic devices have the potential to restore function when used as assistive devices to supplement or replace limited or lost function of the upper limb following SCI.

Predicting functional force production capabilities of upper extremity functional electrical stimulation neuroprostheses: a proof of concept study.

Objective: This study's goal was to demonstrate person-specific predictions of the force production capabilities of a paralyzed arm when actuated with a functional electrical stimulation (FES) neuroprosthesis. These predictions allow us to determine, for each hand position in a person's workspace, if FES activated muscles can produce enough force to hold the arm against gravity and other passive forces, the amount of force the arm can potentially exert on external objects, and in which directions FES can move the arm.

Approach: We computed force production predictions for a person with high tetraplegia and an FES neuroprosthesis used to activate muscles in her shoulder and arm.

Ability of people with post-stroke hemiplegia to self-administer FES-assisted hand therapy video games at home: An exploratory case series.

Introduction: This article describes the development and initial clinical testing of an innovative home-based treatment for upper extremity hemiplegia that integrates contralaterally controlled functional electrical stimulation with hand therapy video games.

Methods: We explored the ability of seven participants with moderate-to-severe hand impairment to self-administer 12 weeks of contralaterally controlled functional electrical stimulation video game therapy at home for 10 h/week and in-lab with a therapist for four h/week. Clinical suitability was assessed by device usage logs, qualitative surveys, and clinical motor and cognitive outcomes.

Bilateral Contralaterally Controlled Functional Electrical Stimulation Reveals New Insights Into the Interhemispheric Competition Model in Chronic Stroke.

Upper-limb chronic stroke hemiplegia was once thought to persist because of disproportionate amounts of inhibition imposed from the contralesional on the ipsilesional hemisphere. Thus, one rehabilitation strategy involves discouraging engagement of the contralesional hemisphere by only engaging the impaired upper limb with intensive unilateral activities. However, this premise has recently been debated and has been shown to be task specific and/or apply only to a subset of the stroke population.

Exercise intensity affects acute neurotrophic and neurophysiological responses poststroke.

Aerobic exercise may acutely prime the brain to be more responsive to rehabilitation, thus facilitating neurologic recovery from conditions like stroke. This aerobic priming effect could occur through multiple mechanisms, including upregulation of circulating brain-derived neurotrophic factor (BDNF), increased corticospinal excitability, and decreased intracortical inhibition. However, optimal exercise parameters for targeting these mechanisms are poorly understood.

Convergent Validity and Responsiveness of the SULCS.

Objective: To evaluate the convergent validity and responsiveness of the Stroke Upper Limb Capacity Scale (SULCS) in comparison to the Arm Motor Ability Test (AMAT), the Box and Blocks Test (BBT), and the upper limb Fugl-Meyer Assessment (FMA). The SULCS is a relatively new measure that was designed to be easier to score and less time consuming than some existing measures.

Design: Prospective repeated-measures design.

Block of motor nerve conduction via transcutaneous application of direct current.

Aims: Nerve conduction block using implanted electrodes is being used increasingly for clinical applications. Alternatively, non-invasive electrical nerve block would be beneficial for applications including pain block and muscle spasticity. Here we developed a novel means of non-invasive electrical nerve conduction blockade - transcutaneous direct current block (tDCB) - that produces direct block of nerve conduction.

Fully Implantable Peripheral Nerve Stimulation for Hemiplegic Shoulder Pain: A Multi-Site Case Series With Two-Year Follow-Up.

Objective: To explore the feasibility and safety of a single-lead, fully implantable peripheral nerve stimulation system for the treatment of chronic shoulder pain in stroke survivors.

Participants: Participants with moderate to severe shoulder pain not responsive to conservative therapies for six months.

Methods: During the trial phase, which included a blinded sham introductory period, a percutaneous single-lead peripheral nerve stimulation system was implanted to stimulate the axillary nerve of the affected shoulder.

The Effect of Peripheral Nerve Stimulation on Shoulder Biomechanics: A Randomized Controlled Trial in Comparison to Physical Therapy.

Objective: To establish the effects on shoulder biomechanics from a peripheral nerve stimulation (PNS) treatment compared to physical therapy (PT) in stroke survivors with chronic hemiplegic shoulder pain.

Design: Single-site, pilot, randomized controlled trial for adults with chronic shoulder pain after stroke. Participants were randomized to receive a 3-week treatment of single-lead PNS or physical therapy (PT).

Neurostimulation for Postsurgical Analgesia: A Novel System Enabling Ultrasound-Guided Percutaneous Peripheral Nerve Stimulation.

While neurostimulation-stimulation of the nervous system using electrical current-has been used to treat chronic pain, its use treating postsurgical pain has been limited. Here, we report on the clinical application of a novel investigational lead to provide analgesia following total knee arthroplasty. In 5 subjects, leads were inserted percutaneously using ultrasound guidance within 0.

Infection Rates of Electrical Leads Used for Percutaneous Neurostimulation of the Peripheral Nervous System.

Background: Percutaneous neurostimulation of the peripheral nervous system involves the insertion of a wire "lead" through an introducing needle to target a nerve/plexus or a motor point within a muscle. Electrical current may then be passed from an external generator through the skin via the lead for various therapeutic goals, including providing analgesia. With extended use of percutaneous leads sometimes greater than a month, infection is a concern.

Contralaterally Controlled Functional Electrical Stimulation Improves Hand Dexterity in Chronic Hemiparesis: A Randomized Trial.

Background And Purpose: It is unknown whether one method of neuromuscular electrical stimulation for poststroke upper limb rehabilitation is more effective than another. Our aim was to compare the effects of contralaterally controlled functional electrical stimulation (CCFES) with cyclic neuromuscular electrical stimulation (cNMES).

Methods: Stroke patients with chronic (>6 months) moderate to severe upper extremity hemiparesis (n=80) were randomized to receive 10 sessions/wk of CCFES- or cNMES-assisted hand opening exercise at home plus 20 sessions of functional task practice in the laboratory for 12 weeks.

Upper Extremity Assessment in Tetraplegia: The Importance of Differentiating Between Upper and Lower Motor Neuron Paralysis.

Scientific advances are increasing the options for improved upper limb function in people with cervical level spinal cord injury (SCI). Some of these interventions rely on identifying an aspect of paralysis that is not uniformly assessed in SCI: the integrity of the lower motor neuron (LMN). SCI can damage both the upper motor neuron and LMN causing muscle paralysis.

Hemiparetic Gait.

The most common pattern of walking impairment poststroke is hemiparetic gait, which is characterized by asymmetry associated with an extensor synergy pattern of hip extension and adduction, knee extension, and ankle plantar flexion and inversion. There are characteristic changes in the spatiotemporal, kinematic and kinetic parameters, and dynamic electromyography patterns in hemiparesis, which may be assessed most accurately in a motion studies laboratory. An understanding of normal human gait is necessary to assess the complex interplay of motor, sensory, and proprioceptive loss; spasticity; and/or ataxia on hemiparetic gait.

Velocity neurons improve performance more than goal or position neurons do in a simulated closed-loop BCI arm-reaching task.

Brain-Computer Interfaces (BCIs) that convert brain-recorded neural signals into intended movement commands could eventually be combined with Functional Electrical Stimulation to allow individuals with Spinal Cord Injury to regain effective and intuitive control of their paralyzed limbs. To accelerate the development of such an approach, we developed a model of closed-loop BCI control of arm movements that (1) generates realistic arm movements (based on experimentally measured, visually-guided movements with real-time error correction), (2) simulates cortical neurons with firing properties consistent with literature reports, and (3) decodes intended movements from the noisy neural ensemble. With this model we explored (1) the relative utility of neurons tuned for different movement parameters (position, velocity, and goal) and (2) the utility of recording from larger numbers of neurons-critical issues for technology development and for determining appropriate brain areas for recording.