Long-term follow-up of spinal cord stimulation to restore cough in subjects with spinal cord injury

Abstract

Objective

To determine the long-term effects of the cough stimulation system.

Design

Nonrandomized clinical trial of subjects using the study device well beyond the period of close follow-up.

Setting

Use of the study device in the home setting.

Participants

Subjects (N = 10) implanted with the device for a minimum of 2 years (mean 4.6 ± 0.6 years).

Interventions

Application of daily stimulation.

Outcome measures

Airway pressure generation and other clinical assessments including ease in raising secretions, life quality, caregiver support, and incidence of respiratory tract infections were measured at 1 year and mean 4.6 years after implantation.

Results

Each subject continued to use the device on a regular basis. During SCS, mean maximum airway pressures were 103.1 ± 20.4 and 107.7 ± 23.0 cmH₂O at the 1-year and mean 4.6-year follow-up points, respectively (P < 0.05 compared with pre-implant and not significantly different (NS) compared with 1-year follow-up). Benchmarks related to ease in raising secretions and improvements in life quality related to respiratory care were maintained at the mean 4.6 year follow-up. The need for trained caregivers to provide other means of secretion management remained significantly below the pre-implant values (P < 0.05). The incidence of acute respiratory tract infections remained low at 0.2 ± 0.1 events/year, which is significantly below the pre-implant value of 1.4 ± 0.3 events/year (P < 0.05).

Conclusion

Subjects continued to use the system on a long-term basis beyond the period of close follow-up and to continued derive significant clinical benefits.

Keywords:

• Cough
• Expiratory muscles
• Spinal cord stimulation

Acknowledgment

The authors gratefully acknowledge the technical assistance in data analysis of statistician, Charles Thomas, B.A.