Abstract
Post-COVID-19 condition involves persistent symptoms after acute infection, often linked to dysautonomia, which affects heart rate variability, pain perception, fatigue, and sleep. Superficial neuromodulation has been proposed as a treatment. Objective: To assess the effects of superficial neuromodulation on symptoms, sleep quality, and autonomic function in post-COVID-19 condition patients. Methods: A pilot study was conducted based on a triple-blind randomized controlled trial methodology involving 16 female participants. The experimental group received neuromodulation, while the control group used a placebo device. The intervention spanned 15 sessions over two months. Primary outcomes included heart rate variability, pain threshold, cortisol levels, fatigue, sleep quality, and quality of life, analyzed using repeated-measures ANOVA. Results: Both groups improved over time. Heart rate variability (SDNN) increased in the experimental group (30.42 to 39.11 ms) but decreased in controls (31.88 to 28.73 ms) (p < 0.05). Pain threshold at C5-C6 improved in the experimental group (2.1 to 3.5 kg/cm(2)) but remained stable in controls (p = 0.032). Fatigue decreased significantly in both groups (p = 0.002). Sleep quality improved, with Pittsburgh Sleep Quality Index scores decreasing similarly in both groups. Cortisol levels increased, with a non-significant trend favoring controls. Conclusions: While improvements were seen, both groups benefited, suggesting a possible placebo effect. Superficial neuromodulation appears safe, but further studies with larger samples are needed to confirm efficacy.