Diaphragm pacing and independent breathing in individuals with severe Pompe disease.

Only six implanted subjects were analysed, and nine were enrolled, so the study is too small to show whether pacing works. There was no control group, so changes over time cannot be separated from natural disease course, enzyme replacement therapy, ventilatory support, and respiratory care. Participants varied in age, disease onset, ventilation type, feeding support, and comorbidities, which made comparisons difficult. Follow-up was incomplete and irregular because travel, health, and enrollment timing limited measurements. Some subjects enrolled after implantation at outside institutions, so early data were not available for all participants. Patient-reported outcomes were not measured systematically, so functional benefits were anecdotal. Lead breaks and caregiver support interrupted pacing in several subjects. Diaphragm electrical activity changes were not significant, and direct paced versus unpaced breathing comparisons were not significant. The study did not show whether pacing prevents disease progression or reverses existing diaphragm or phrenic nerve damage.

The project was funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development (Grant R21HD090752). Early pilot work was supported by the Acid Maltase Deficiency Association. The paper does not report author conflicts of interest.

Do not conclude that diaphragm pacing causes ventilator weaning in Pompe disease. The study had no control group, included only six implanted subjects, and all were also receiving enzyme replacement therapy and positive-pressure ventilation, so pacing cannot be separated from other treatments. Also, direct paced versus unpaced breathing measurements did not show significant increases in tidal volume or minute ventilation.