Evaluation of Wire Electrodes to Activate the Expiratory Muscles to Restore Cough
Phase: NA
Conditions: Spinal Cord Injuries, Spinal Cord Diseases, Paralysis, Central Nervous System Diseases, Cough
Sponsor: MetroHealth Medical Center

Evaluation of Wire Electrodes to Activate the Expiratory Muscles to Restore 
Cough / Sub-study to Spinal Cord Stimulation to Restore Cough  
 
 IRB08-00269/IRB98-00091 
 
 
 
 
 
 
Title of Document: Study Protocol   

Sub-study to Spinal Cord Stimulation to Restore Cough  
IRB sub-study#: IRB08-00269  
Date Approved: 7/21/2008 
 
 
Study Protocol 
Patients with cervical and thoracic spinal cord injuries often have paralysis of a major portion of 
their expiratory muscles and therefore, lack a normal cough mechanism (1). Consequently, most 
of these patients suffer from a markedly reduced ability to clear airway secretions, a factor which 
contributes to the development of recurrent respiratory tract infections (2,3). Since the spinal cord 
below the level of injury is intact in most patients, the motorneurons of the spinal cord and 
peripheral neuromuscular system innervating the expiratory muscles are intact. These muscles, 
therefore, can be electrically activated by electrical stimulation of the spinal roots to produce a 
functionally effective cough. 
  
We have demonstrated that lower thoracic spinal cord stimulation (SCS), using disc electrodes, 
(4,5) has resulted in the generation of large positive airway pressures and peak expiratory flow 
rates, characteristics of a normal cough. Animal studies (performed in our laboratory) indicate that 
a similar response can be achieved using wire electrodes. Wire electrodes can be placed by less 
invasive surgical procedures, thereby reducing the surgical risks and post-operative care associated 
with implant of the disc electrodes. This methodology, therefore, has the potential to reach a larger 
population of spinal cord injured patients.  
 
We plan to test the efficacy of temporary wire electrodes (6-8) in at least one and no more than 
eight study subjects enrolled in our current study ["Spinal Cord Stimulation to Restore Cough" 
(IRB98-00091)]. This will be done by temporarily placing the wire electrodes over the lower 
thoracic spinal cord. Stimulation will then be applied, and the degree of muscle contraction 
assessed by visual inspection and palpation over the abdominal wall and by recordings of 
expiratory airflow, expired volume and airway pressure. Since monopolar SCS with the disc leads, 
when applied in clinical trials, resulted in airway pressure generation that approximated pressures 
generated with a normal maximum cough, airway pressure generation achieved during SCS with 
these leads served as our gold standard to which all comparisons were made. If the response using 
the wire electrodes is similar to that of the disc electrodes, we can conclude that wire electrodes 
will offer an effective means of stimulation of the expiratory muscles to produce an effective 
cough. 
Primary Aims: 
To test the efficacy of wire electrodes to potentially replace disc electrodes currently being used 
under the IRB-approved study "Spinal Cord Stimulation to Restore Cough" (IRB98-00091). 
Secondary Aims: 
To determine if it is worthwhile to adapt the equipment currently in use under the IRB-approved 
study "Spinal Cord Stimulation to Restore Cough" (IRB98-00091) to mate with wire electrodes. 

Sub-study to Spinal Cord Stimulation to Restore Cough  
IRB sub-study#: IRB08-00269  
Date Approved: 7/21/2008 
 
REFERENCES 
1. 
DeVivo MJ, Kartus PL, Stover SL, Rutt RD, Fine PR. Cause of death for patients with 
spinal cord injuries. Arch Intern Med 149: 1761-1765, 1989. 
2. 
McMichan JC, Michel L, Westbrook PR. Pulmonary dysfunction following quadriplegia: 
recognition, prevention, and treatment. JAMA 243: 528-531, 1980. 
3. 
Bellamy R, Pitts FW, Stauffer ES. Respiratory complications in traumatic quadriplegia, 
analysis of 20 years' experience. J Neurosurgery 39: 596-600, 1973. 
4. 
DiMarco AF, Kowalski KE, Geertman RT, Hromyak DR. Spinal cord stimulation: A new 
method to produce cough in patients with spinal cord injury. Am J Respir Crit Care Med 
173: 1386-1389, 2006. 
 
5. 
DiMarco AF, Kowalski KE, Geertman RT, Hromyak DR, Frost FS, Creasey G. Muscle 
reconditioning for cough production in spinal cord injured patients. J Spinal Cord Med 
30:  405, 2007. 
6.    
North RB, Kidd DH, Olin JC, Sieracki JM. Spinal cord stimulation electrode design: 
prospective, randomized, controlled trial comparing percutaneous and laminectomy 
electrodes—Part I: Technical outcomes. Neurosurgery 51: 381-390, 2001.