Disordered descent into sleep: microstructural divergence across arousal-linked conditions

Biabani, Nazanin;Birdseye, Adam;Gnoni, Valentina;Tauman, Riva;Ilic, Katarina;Drakatos, Panagis;Nesbitt, Alexander;Puligheddu, Monica;O'Regan, David;Leech, Robert;Goadsby, Peter J.;Rosenzweig, Ivana

2026-01-01

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Abstract

Sleep onset is an unstable transition whose microstructure may distinguish clinical phenotypes. Using Hori 4-second microstaging in patients with narcolepsy type 1, idiopathic REM sleep behaviour disorder, NREM parasomnia and an exploratory fibromyalgia cohort, each with matched controls (n = 48 pairs), we quantified timing, entropy, hemispheric laterality and sequence ordering. Narcolepsy showed compressed, irregular onset, fibromyalgia prolonged divergent onset, and the remaining groups near-normative trajectories, suggesting disorder-specific signatures of arousal instability.