Cross-Sectional Study Evaluating the Role of Autonomic Nervous System Functional Diagnostics in Differentiating Post-Infectious Syndromes: Post-COVID Syndrome, Chronic Fatigue Syndrome, and Lyme Disease.
Level 4 - case-series / case-control
Cross-sectional observational study comparing clinical cohorts
PubMed 40002769 · doi:10.3390/biomedicines13020356
What was done
This cross-sectional study evaluated autonomic nervous system function across 758 patients divided into four groups: Post-COVID syndrome, Chronic Fatigue Syndrome (CFS) following Post-COVID syndrome, CFS unrelated to COVID-19, and late-stage Lyme disease. Autonomic function was assessed via cardiovascular reflex tests, the Head-Up Tilt Test, beat-to-beat analysis, 5-minute electrocardiograms, 24-hour Holter monitoring, and 24-hour ambulatory blood pressure monitoring to compare sympathetic and parasympathetic parameters.
What was found
Patients with late-stage Lyme disease demonstrated distinct autonomic patterns, notably a 53.4% prevalence of orthostatic hypotension and heart rate variability changes during tilt testing indicative of adrenergic failure. Lyme disease patients also showed reduced baroreceptor sensitivity and diminished frequency-domain heart rate variability responses during orthostatic stress, with less prevalent parasympathetic dysfunction. The Post-COVID and CFS groups showed more pronounced general autonomic imbalances, though exact numerical values and effect sizes for these groups were not reported in the abstract.
Why it matters
Post-infectious syndromes often present with overlapping symptoms like fatigue and orthostatic intolerance. These findings indicate that functional autonomic testing may differentiate late-stage Lyme disease from Post-COVID and CFS based on distinct adrenergic and hemodynamic failure patterns.
Limits
The study is cross-sectional and cannot determine whether autonomic abnormalities are causal or progressive. The abstract provides no healthy control group comparison, lacks numerical values and statistical test metrics for the non-Lyme cohorts, and does not detail disease duration or medication confounding.
Cited by
- partial Postural orthostatic tachycardia syndrome (POTS) and dysautonomia occur in 40% to 50% of chronic Lyme and tick-borne disease patients.