From Entropy to Outcome: Multimodal Digital Biomarkers in Stroke — NEURO-PERSIST Study Protocol (v0.5)

NEURO-PERSIST is a pre-registered clinical study protocol for predicting 90-day functional outcome after ischemic or hemorrhagic stroke using interpretable multimodal digital biomarkers. The proposed biomarker domains include heart-rate-variability entropy, prosody stability, gait and motor microvariability, and baseline imaging/radiomics features. The protocol defines the modified Rankin Scale at 90 days (mRS-90d) as the primary outcome, analysed both ordinally and dichotomously (mRS 0-2 vs. 3-6). It introduces the Persistence Score C (PS_C), a replication-oriented feature robustness framework across centres, devices, time, and missingness. The planned sample size is N=300 with an assumed poor-outcome rate of…