1. Lower HRV during sleep may signal early neurodegeneration.
2. Study involved 17 patients with iRBD and 102 controls.
3. Significant HRV differences found in sleep metrics.
4. 3 of 17 patients later diagnosed with Parkinson's.
5. Higher nocturnal heart rates observed in patients who converted.
6. Autonomic dysfunction could precede neurodegenerative diseases.
7. Larger trials needed to validate findings.

Source: European Journal of Neurology