Patients with cervical and thoracic spinal cord injuries often have paralysis of a major portion of their expiratory muscles — the muscles responsible for coughing — and therefore, lack a normal cough mechanism. 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 such as pneumonia and bronchitis. Expiratory muscles can be activated by electrical stimulation of the spinal roots to produce a functionally effective cough.

The purpose of this trial is to determine if electrical stimulation of the expiratory muscles is capable of producing an effective cough on demand. According to the trial researchers, if successful, this technique will prevent the need for frequent patient suctioning — which often requires the constant presence of trained personnel. It will also allow spinal cord injured patients to clear their secretions more readily, thereby reducing the incidence of respiratory complications and associated illness and death.

In the trial, researchers will study 18 adults (18-65 years old) with spinal injuries (T5 level or higher), at least 18 months following the date of injury. After an evaluation of medical history, a brief physical examination, and initial testing, participants will have small electrodes (metal discs) placed — by a routine surgical procedure — over the surface of their spinal cords on the lower back to stimulate the expiratory muscles and restore cough.

Inclusion Criteria:

• Stable spinal cord injury T5 level or higher
• Expiratory muscle weakness

Exclusion Criteria:

• Significant cardiovascular disease
• Active lung disease
• Brain disease
• Scoliosis, chest wall deformity, or obesity