Effects of withdrawal and re-application of spinal cord stimulation to restore cough.

Context: Paralysis of the expiratory muscles in cervical and high thoracic spinal cord injury (SCI) results in an impaired ability to clear airway secretions effectively and increases the risk of atelectasis and respiratory tract infections (RTI). Spinal cord stimulation (SCS) applied via the Cough Stimulation System (CSS) has been shown to restore an effective cough mechanism in subjects with SCI. In this study, we evaluated the specific impact of use of the CSS by one study participant with SCI, subsequent discontinuation of usage, and then re-institution of this modality.

Impact of the cough stimulation system on the care burden and life quality of caregivers of tetraplegics.

Objectives: To determine caregiver burden and quality of life of primary family caregivers of participants with cervical SCI before and after use of the cough stimulation system (CSS).

Design: Prospective assessment at four timepoints via questionnaire responses.

Setting: Out-patient hospital, United States.

Effects of restoration of cough via spinal cord stimulation on subject quality of life.

Objectives: To determine participant quality of life before and after use of the cough stimulation system (Cough System).

Design: Prospective assessment of life quality at 4 timepoints via questionnaire responses.

Setting: Out-patient hospital, United States.

Phrenic-to-intercostal reflex activity in response to high frequency spinal cord stimulation (HF-SCS).

Objective: HF-SCS is a novel technique of inspiratory muscle activation which results in coincident activation of the diaphragm and inspiratory intercostal muscles via spinal cord pathways and has the potential to provide respiratory support in ventilator dependent persons with spinal cord injury. The purpose of the present study was to examine the phrenic-to-intercostal reflex during HF-SCS.

Methods: In 5 anesthetized and C2 spinalized dogs, electrical stimulation was applied via a stimulating electrode located on the ventral surface of the upper thoracic spinal cord at the T2 level.

Model-Based Optimization of Spinal Cord Stimulation for Inspiratory Muscle Activation.

Objective: High-frequency spinal cord stimulation (HF-SCS) is a potential method to provide natural and effective inspiratory muscle pacing in patients with ventilator-dependent spinal cord injuries. Experimental data have demonstrated that HF-SCS elicits physiological activation of the diaphragm and inspiratory intercostal muscles via spinal cord pathways. However, the activation thresholds, extent of activation, and optimal electrode configurations (i.

Comparison of wire and disc electrodes to electrically activate the inspiratory muscles in dogs.

Objective: To compare the effectiveness of wire versus disc electrodes to activate the inspiratory muscles via high frequency spinal cord stimulation.

Design: Animal study.

Setting: Research laboratory.

Initial assessment and management of respiratory infections in persons with spinal cord injuries and disorders in the COVID-19 era.

As the COVID-19 pandemic unfolds, emergency department (ED) personnel will face a higher caseload, including those with special medical needs such as persons living with spinal cord injuries and disorders (SCI/D). Individuals with SCI/D who develop COVID-19 are at higher risk for rapid decompensation and development of acute respiratory failure during respiratory infections due to the combination of chronic respiratory muscle paralysis and autonomic dysregulation causing neurogenic restrictive/obstructive lung disease and chronic immune dysfunction. Often, acute respiratory infections will lead to significant mucus production in individuals with SCI/D, and aggressive secretion management is an important component of successful medical treatment.

Effects of Lower Thoracic Spinal Cord Stimulation on Bowel Management in Individuals With Spinal Cord Injury.

Objective: To systematically determine whether use of the spinal cord stimulation (SCS) system to restore cough may improve bowel management (BM) in individuals with spinal cord injury (SCI).

Design: Experimental studies (clinical trial).

Setting: Inpatient hospital setting for electrode insertion; outpatient setting for measurement of respiratory pressures; home setting for application of SCS.

Activation of the expiratory muscles via lower thoracic high frequency spinal cord stimulation in awake animals.

Lower thoracic spinal cord stimulation is an effective method of restoring an effective cough in participants with complete spinal cord injury. The high voltage requirements however significantly limits this application in subjects with intact lower chest wall sensation. In anesthetized animals, we have shown that the expiratory muscles can also be effectively activated with low stimulus currents (1 mA) but with high stimulus frequencies (HF-SCS -500 Hz).

Restoration of cough via spinal cord stimulation improves pulmonary function in tetraplegics.

Spinal cord injury (SCI) results in significant loss in pulmonary function secondary to respiratory muscle paralysis. Retention of secretions and atelectasis and, recurrent respiratory tract infections may also impact pulmonary function. To determine whether usage of lower thoracic spinal cord stimulation (SCS) to restore cough may improve spontaneous pulmonary function in individuals with chronic SCI.

High-frequency spinal cord stimulation in a subacute animal model of spinal cord injury.

High-frequency spinal cord stimulation (HF-SCS) applied at the T2 spinal level results in physiologic activation of the inspiratory muscles in C2 spinal-sectioned dogs. Although the bulbo-spinal fibers were cut, they likely survived the duration of acute experiments, and inspiratory muscle activation may have involved stimulation of these fibers. In two anesthetized, C2 paralyzed, intubated, and mechanically ventilated dogs, HF-SCS (300 Hz) was applied at the T2 level.

Neuromodulation for Functional Electrical Stimulation.

This article describes the application of neuromodulation in different ways to motor recovery, to replace lost function, or to improve function of organ systems for those who have experienced spinal cord injury or stroke. Multiple devices have been developed and are currently available for use whereas others are still in the experimental stage. Multiple uses of neuromodulation are described.

Inspiratory muscle activation via ventral lower thoracic high-frequency spinal cord stimulation.

In animals, high-frequency spinal cord stimulation (HF-SCS) applied on the ventral epidural surface at the T level results in negative airway pressure generation consistent with inspiratory muscle activation. In the present study, in anesthetized dogs, we found that ventral HF-SCS (500 Hz) applied at all thoracic levels resulted in negative airway pressure generation. In the region of the lower thoracic spinal cord, negative airway pressure generation was most pronounced at the T level.

Complete Restoration of Respiratory Muscle Function in Three Subjects With Spinal Cord Injury: Pilot Interventional Clinical Trial.

Objectives: The aim of this study was to assess the safety and efficacy of complete restoration of respiratory muscle function in subjects with spinal cord injury.

Methods: This was an interventional study investigating three subjects maintained on a diaphragm pacing system who were implanted with the spinal cord stimulation system to restore cough. Peak expiratory airflow and airway pressure generation were the primary physiologic outcome measures; an assessment of the degree of difficulty in raising secretions was the primary clinical outcome measure.

Diaphragm Pacing.

Diaphragm pacing (DP) is a useful and cost-effective alternative to mechanical ventilation in patients with ventilator-dependent spinal cord injury and central hypoventilation syndrome. Patients with SCI should be carefully screened to assess the integrity of their phrenic nerves. In eligible patients, DP improves mobility, speech, olfaction, and quality of life.

Economic Consequences of an Implanted Neuroprosthesis in Subjects with Spinal Cord Injury for Restoration of an Effective Cough.

To determine if an implanted neuroprosthesis for restoration of an effective cough is less costly than conventional methods of respiratory management. Nonrandomized clinical trial of participants ( = 14) with spinal cord injury (SCI) using the Cough Stimulator device in the inpatient hospital setting for Cough Stimulator implantation and outpatient hospital or residence for follow-up. A neuroprosthesis was implanted for restoration of an effective cough.

Case report: Minimally invasive method to activate the expiratory muscles to restore cough.

Context: Spinal cord stimulation (SCS) via disc electrodes surgically placed via laminotomy incisions has been shown to restore an effective cough in subjects with spinal cord injury (SCI). The purpose of this study was to evaluate a new method of expiratory muscle activation utilizing spinal cord wire leads, which can be implanted with minimally invasive techniques.

Methods: In a subject with SCI, parallel wire leads with two electrode contacts were inserted percutaneously through a needle, advanced to the T9, T11 spinal levels and connected to an implanted radiofrequency receiver.

Bifurcation of the respiratory response to lung inflation in anesthetized dogs.

Numerous studies have demonstrated the effect of lung volume on prolongation of duration of expiration (TE) with limited understanding of the TE shortening and termination of expiration as observed in newborn. In 14 dogs, the effects of varied onset of lung inflation during expiration on the TE were evaluated. When lung inflation was applied in the first part of expiration (20-60% of TE) TE was lengthened.

Safety assessment of epidural wire electrodes for cough production in a chronic pig model of spinal cord injury.

Background: It is our hypothesis that high intensity spinal cord stimulation (SCS) to restore an effective cough mechanism using wire leads, will result in significant activation of target neurons without tissue injury or electrode corrosion.

Methods: Adult mini-pigs underwent chronic spinal cord compression, followed by implantation of parallel wire leads on the dorsal epidural surface of the spinal cord, with stimulation contacts at the T9 and T12, and control electrode contacts at the T2 and T5 levels. After 3 months of daily SCS, airway pressure generation (P), tissue in the area of the stimulating and control electrodes and electrode leads were examined.

Electrical activation to the parasternal intercostal muscles during high-frequency spinal cord stimulation in dogs.

High-frequency spinal cord stimulation (HF-SCS) is a novel technique of inspiratory muscle activation involving stimulation of spinal cord pathways, which may have application as a method to provide inspiratory muscle pacing in ventilator-dependent patients with spinal cord injury. The purpose of the present study was to compare the spatial distribution of motor drive to the parasternal intercostal muscles during spontaneous breathing with that occurring during HF-SCS. In nine anesthetized dogs, HF-SCS was applied at the T2 spinal level.

Functional electrical stimulation and spinal cord injury.

Spinal cord injuries (SCI) can disrupt communications between the brain and the body, resulting in loss of control over otherwise intact neuromuscular systems. Functional electrical stimulation (FES) of the central and peripheral nervous system can use these intact neuromuscular systems to provide therapeutic exercise options to allow functional restoration and to manage medical complications following SCI. The use of FES for the restoration of muscular and organ functions may significantly decrease the morbidity and mortality following SCI.

Diaphragmatic pacing in spinal cord injury.

After cervical spinal cord injuries, many patients are unable to sustain independent ventilation because of a disruption of diaphragm innervation and respiratory functioning. If phrenic nerve function is preserved, the patient may be able to tolerate exogenous pacing of the diaphragm via electrical stimulation. Previously this was accomplished by stimulation directly to the phrenic nerves, but may be accomplished less invasively by percutaneously stimulating the diaphragm itself.