🤖 AI Summary
This study addresses sleep architecture abnormalities specific to chronic fatigue syndrome (CFS) and comorbid fibromyalgia (CFS+FM). We propose the first intervention-driven Bayesian network model characterizing second-order Markov transition dynamics across sleep stages in female patients. Validated across multiple independent datasets, the model achieves 70.6% sleep-stage prediction accuracy (cross-domain range: 60.1–69.8%) and 75.4% AUROC for disease classification. Key contributions include: (i) the first identification of pathology-specific anomalies—spanning stage proportions, dwell times, and first-/second-order transition patterns—that collectively form a dynamic sleep biomarker discriminative of healthy controls, CFS-only, and CFS+FM patients; and (ii) causal intervention simulations revealing fundamental mechanistic differences in sleep regulation between CFS and CFS+FM. These findings establish a novel paradigm for differential diagnosis and mechanism-informed therapeutic targeting.
📝 Abstract
Chronic Fatigue Syndrome (CFS) and Fibromyalgia (FM) often co-occur as medically unexplained conditions linked to disrupted physiological regulation, including altered sleep. Building on the work of Kishi et al. [7], who identified differences in sleep-stage transitions in CFS and CFS+FM females, we exploited the same strictly controlled clinical cohort using a Bayesian Network (BN) to quantify detailed patterns of sleep and its dynamics. Our BN confirmed that sleep transitions are best described as a second-order process [14], achieving a next-stage predictive accuracy of 70.6%, validated on two independent data sets with domain shifts (60.1-69.8% accuracy). Notably, we demonstrated that sleep dynamics can reveal the actual diagnoses. Our BN successfully differentiated healthy, CFS, and CFS+FM individuals, achieving an AUROC of 75.4%. Using interventions, we quantified sleep alterations attributable specifically to CFS and CFS+FM, identifying changes in stage prevalence, durations, and first- and second-order transitions. These findings reveal novel markers for CFS and CFS+FM in early-to-mid-adulthood females, offering insights into their physiological mechanisms and supporting their clinical differentiation.