# Study on the sleep–wake circadian rhythm and phenotypic characteristics in the acute phase of hemorrhagic stroke

## TL;DR

This study found that patients with acute hemorrhagic stroke experience disrupted sleep patterns and weakened circadian rhythms, which could affect recovery and require targeted interventions.

## Contribution

The study identifies specific sleep-wake rhythm disruptions and their associations in acute hemorrhagic stroke patients.

## Key findings

- ICH patients showed significantly reduced circadian rhythm indices (IS, IV, RA) compared to controls.
- Sleep architecture in ICH patients included prolonged light and deep sleep, and reversed sleep-wake cycles.
- Reduced interdaily stability was significantly linked to reversed sleep-wake cycles in ICH patients.

## Abstract

To investigate the sleep–wake circadian rhythm and phenotypic characteristics in patients with acute intracerebral hemorrhage (ICH), and to explore the relationship and potential mechanisms between sleep–wake phenotypes and circadian rhythm disruption.

A retrospective analysis was conducted on 100 patients with acute ICH admitted to Kailuan General Hospital between January 2020 and December 2024, along with 67 age- and sex-matched hospitalized controls. Sleep parameters during the daytime (06:00–18:00) and nighttime (18:00–06:00) were collected using a mattress-based sleep monitoring system. Circadian rhythm indices—including interdaily stability (IS), intradaily variability (IV), and relative amplitude (RA)—as well as sleep phenotypic features were evaluated.

Compared with the control group, patients with ICH exhibited significantly disrupted circadian rhythms, characterized by reductions in IS, IV, and RA (all p < 0.05). Significant alterations in sleep–wake states were observed in both daytime and nighttime periods among ICH patients. These included prolonged/increased durations and proportions of light sleep, deep sleep, NREM sleep, REM sleep, and sleep efficiency, along with shortened/decreased sleep latency, REM latency, and proportion of NREM sleep (all p < 0.05). Phenotypic analysis revealed a significantly higher prevalence of excessive daytime sleep, increased total sleep across 24 h, and reversed sleep–wake cycles in the ICH group (all p < 0.05). Regression analysis indicated that reduced IS was significantly associated with reversed sleep–wake cycles (OR = −5.831; 95% CI,: −12.577 ~ −1.350).

Acute hemorrhagic stroke is associated with excessive sleepiness, disrupted sleep architecture, and weakened circadian rhythms. These disturbances may impair recovery and long-term outcomes, underscoring the need for rhythm-based biomarkers and individualized interventions.