Spinal Neuromodulation for Respiratory Rehabilitation in Patients with Post-Acute COVID-19 Syndrome

(1) Background: Neurological deficits associated with coronavirus disease (COVID-19) exacerbate respiratory dysfunction, necessitating rehabilitation strategies that address both. Previous studies have demonstrated that spinal cord transcutaneous stimulation (scTS) can facilitate the excitation of respiratory spinal neural networks in patients with post-COVID-19 syndrome. This study evaluates the efficacy of combining scTS with respiratory training (RT) to improve respiratory function in individuals with post-COVID-19 pulmonary deficits; (2) Methods: In this before-after, case-controlled clinical trial, five individuals with post-acute COVID-19 respiratory deficits participated in two interventional programs: 10 daily sessions of respiratory training (RT), followed by 10 daily sessions of scTS combined with RT (scTS + RT). Forced vital capacity (FVC), peak inspiratory flow (PIF), peak expiratory flow (PEF), time-to-peak inspiratory flow (tPIF), and time-to-peak expiratory flow (tPEF) were assessed at baseline and after each program; (3) Results: Compared to RT alone, the scTS + RT intervention resulted in an average effect size that was twice as large, with significant increases in FVC and PEF, and a significant decrease in tPEF; (4) Conclusions: The scTS-induced activation of respiratory neuronal networks, when combined with respiratory training, offers a promising therapeutic approach for treating persistent respiratory deficits in patients with post-acute COVID-19 syndrome.