Binary Classification of Consciousness Using Cerebral Blood Flow and EEG Features.

BACKGROUND/OBJECTIVES: Assessing consciousness at the bedside in the neurocritical care unit is complicated by sedation and other treatment effects. While electroencephalogram (EEG) is commonly used, it offers a limited view of the neurovascular unit. We evaluated whether combining cerebral blood flow (CBF) features with EEG improves binary classification of consciousness in patients with severe brain injury. METHODS: We retrospectively analyzed 26 adults who underwent multimodal neuromonitoring. Signals were segmented into 30-min windows after each probe recalibration. We used parameters including CBF low-frequency bands (band IV 0.027-0.073 Hz, band V 0.01-0.027 Hz, and band all 0-0.5 Hz) and EEG band powers (delta-beta), alpha-delta ratio (ADR), alpha/(delta + theta) (ADTR), total power. A random forest (RF) model trained using K-fold cross-validation achieved optimal classification. Highly correlated features (r > 0.8) were excluded from simultaneous use. Performance was summarized with receiver operating characteristic-area under the curve (ROC-AUC) and accuracy, with confusion matrices shown for the best combinations. RESULTS: Multimodal feature combinations significantly improved classification compared with EEG features alone. The best-performing combination (EEG ADR, total EEG power, and CBF B and V) achieved a ROC-AUC of 0.86 and an accuracy of 82%, outperforming EEG-only models. In two exploratory cases with noninvasive diffuse correlation spectroscopy (DCS) monitoring, the same feature framework produced predictions concordant with those obtained using invasive CBF features. CONCLUSIONS: Combining EEG and CBF metrics, particularly low-frequency oscillations in perfusion fluctuations, enhances classification of consciousness in critically ill patients and may support future bedside tools for real-time neurovascular monitoring and decision making about treatment and rehabilitation.