Lower Thoracic Spinal Cord Stimulation to Restore Cough in Patients With Spinal Cord Injury: Results of a National Institutes of Health–Sponsored Clinical Trial. Part II: Clinical Outcomes

Presented in part to the Congress of Neurological Surgeons, October 7–12, 2006, Chicago, IL; the American Spinal Injury Association, May 30–June 2, 2007, Tampa, FL; the International Spinal Cord Society, June 27–July 1, 2007, Reykjavik, Iceland; the American Paraplegia Society, August 27–29, 2007, Orlando, FL; the American Academy of Physical Medicine and Rehabilitation, September 27–30, 2007, Boston, MA; the American Thoracic Society, May 16–21, 2008, Toronto, ON, Canada; and the American Spinal Injury Association, August 8–11, 2008, Orlando, FL.

Abstract

DiMarco AF, Kowalski KE, Geertman RT, Hromyak DR, Frost FS, Creasey GH, Nemunaitis GA. Lower thoracic spinal cord stimulation to restore cough in patients with spinal cord injury: results of a National Institutes of Health–sponsored clinical trial. Part II: clinical outcomes.

Objective

To evaluate the clinical effects of spinal cord stimulation (SCS) to restore cough in subjects with cervical spinal cord injury.

Design

Clinical trial assessing the clinical outcomes and side effects associated with the cough system.

Setting

Outpatient hospital or residence.

Participants

Subjects (N=9; 8 men, 1 woman) with cervical spinal cord injury.

Interventions

SCS was performed at home by either the subjects themselves or caregivers on a chronic basis and as needed for secretion management.

Main Outcome Measures

Ease in raising secretions, requirement for trained caregiver support related to secretion management, and incidence of acute respiratory tract infections.

Results

The degree of difficulty in raising secretions improved markedly, and the need for alternative methods of secretion removal was virtually eliminated. Subject life quality related to respiratory care improved, with subjects reporting greater control of breathing problems and enhanced mobility. The incidence of acute respiratory tract infections fell from 2.0±0.5 to 0.7±0.4 events/subject year (P<.01), and mean level of trained caregiver support related to secretion management measured over a 2-week period decreased from 16.9±7.9 to 2.1±1.6 and 0.4±0.3 times/wk (P<.01) at 28 and 40 weeks after implantation of the device, respectively. Three subjects developed mild hemodynamic effects that abated completely with continued SCS. Subjects experienced mild leg jerks during SCS, which were well tolerated. There were no instances of bowel or bladder leakage.

Conclusions

Restoration of cough via SCS is safe and efficacious. This method improves life quality and has the potential to reduce the morbidity and mortality associated with recurrent respiratory tract infections in this patient population.

Key Words: Cough, Electric stimulation, Quadriplegia, Rehabilitation, Respiratory muscles, Spinal cord injuries

List of Abbreviations: QOL, quality of life, SCI, spinal cord injury, SCS, spinal cord stimulation

a Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, OH

b Department of Neurological Surgery, Case Western Reserve University, Cleveland, OH

c Division of Neurological Surgery, MetroHealth Medical Center, Cleveland, OH

d Department of Physical Medicine and Rehabilitation, MetroHealth Medical Center, Cleveland, OH

Correspondence to Anthony F. DiMarco, MD, MetroHealth Medical Center, Rammelkamp Center for Education and Research, 2500 MetroHealth Dr, Cleveland, OH 44109

Supported by the National Institute of Neurological Disorders and Stroke (grant no. R01 NS049516) and the National Center for Research Resources (grant no. M01 RR00080 and UL1 RR024989).

Clinical Trial Registration Number: NCT00116337.

We certify that we have affiliations with or financial involvement (eg, employment, consultancies, honoraria, stock ownership or options, expert testimony, grants and patents received or pending, royalties) with an organization or entity with a financial interest in, or financial conflict with, the subject matter or materials discussed in the article. Dr. DiMarco is a Founder of and has a significant financial interest in Synapse BioMedical, Inc, a manufacturer of diaphragm pacing systems.

Reprints are not available from the author.

PII: S0003-9993(09)00124-5

doi:10.1016/j.apmr.2008.11.014

7 of 32