Neural Noise- Theta-tACS modulates brain-heart interplay and improves sleep in insomnia patients.1
- The study highlights tACS for sleep disorders and the brain-heart axis as a novel target.1 1
Weekly enrichment (2026-07-20)
- The study enrolled 44 patients with insomnia disorder and 32 healthy controls, recording synchronous EEG and ECG to quantify bidirectional brain–heart interplay (BHI) using a synthetic data generation (SDG) model.2
- Insomnia patients showed significantly higher BHI in both top-down (brain-to-heart) and bottom-up (heart-to-brain) directions than controls, extending the hyperarousal theory of insomnia to the brain–heart axis.2
- Theta-tACS was delivered to the F3 (left dorsolateral prefrontal) site for 10 consecutive days using high-definition tACS hardware (Soterix Medical), with EEG/ECG collected before and after treatment.2
- Pittsburgh Sleep Quality Index (PSQI) scores correlated with top-down BHI, while Hamilton Anxiety Rating Scale (HAMA) scores correlated with bottom-up BHI, linking distinct BHI directions to sleep versus anxiety symptoms.2
- Theta-tACS modulated the abnormal BHI, and baseline top-down BHI at Fz predicted and mediated post-treatment improvements in sleep quality and depression, positioning BHI as a candidate biomarker of treatment response.2
- A companion published report (Shao et al., Sleep Medicine 133, 106606, 2025) frames the same intervention as theta-tACS modulating brain–heart interplay to enhance sleep in insomnia disorder.3
- A 2026 meta-analysis of four RCTs (n = 247) found tACS significantly reduced sleep onset latency at 2 weeks (MD = −56.90 min; 95% CI −74.44 to −39.36) and 4 weeks (MD = −52.20 min), improved PSQI (MD = −5.73), and increased total sleep time (MD = +85.29 min; p = 0.0013).4
- In that meta-analysis, tACS response rates strongly favored active over sham (RR = 11.21; 95% CI 3.20–39.23; p = 0.0002) with no significant adverse events (RR = 1.06), though mood benefits were not sustained beyond 8 weeks and heterogeneity was moderate-to-high.4