Diaphragm pacing with the spinal cord stimulator

Area of Science:

• Neurology
• Respiratory Medicine
• Biomedical Engineering

Background:

• Diaphragm pacing using phrenic nerve stimulation is a known treatment for central hypoventilation syndrome.
• Device availability for phrenic nerve stimulation is limited in Japan.
• Spinal cord stimulators, typically used for pain management, were adapted for phrenic nerve stimulation.

Purpose of the Study:

• To evaluate the efficacy and feasibility of phrenic pacing using a modified approach with a spinal cord stimulator.
• To assess the potential of an adapted pain management device for respiratory support.

Main Methods:

• A spinal cord stimulator was implanted in five patients with chronic central hypoventilation.
• The stimulation electrode was positioned along the phrenic nerve in the neck.
• Cyclic stimulation mode was employed with specific parameters (1s ramp up, 2s on, 3s off, 150 µs pulse width, 21 Hz frequency), with amplitude adjusted for adequate tidal volume and PaCO2 levels around 40 mmHg.

Main Results:

• All five patients experienced stable and sufficient ventilation throughout the follow-up period (3-34 months, mean 23 months).
• No complications were reported during the study.
• The adapted device successfully maintained adequate respiratory function.

Conclusions:

• Diaphragm pacing utilizing a spinal cord stimulator is a feasible treatment for central hypoventilation syndrome.
• While longer follow-up is warranted, the initial results suggest this compromise method is effective.
• This approach offers a potential solution where standard diaphragm pacing devices are unavailable.