Sleep regularity fails to improve after stroke, linked to depression and quality of life
Stroke survivors have severely disrupted sleep-wake schedules that do not improve on their own after hospital discharge, according to a new longitudinal study published in the Journal of the American Heart Association. The irregularity is associated with higher depression scores and lower quality of life, suggesting that sleep rhythm should be a target in post-stroke rehabilitation.
Researchers led by Dr. George Fulk, Professor and Interim Chair of the Department of Rehabilitation Medicine at Emory University School of Medicine, followed 71 stroke survivors and measured their sleep regularity using wrist-worn actigraphy at 10, 60, and 90 days after their stroke. The key metric was the Sleep Regularity Index (SRI), a score from 0 (completely irregular) to 100 (perfectly regular) that captures how consistently a person is in the same sleep or wake state at the same clock time on consecutive days.
What they found
SRI scores were low at the first measurement point 10 days post-stroke, averaging 32.68 on the 0–100 scale — indicating highly irregular sleep-wake patterns. At 60 days the average rose slightly to 34.01, and at 90 days to 38.44, but neither change was statistically significant (P = 0.41 and P = 0.42, respectively). In other words, stroke survivors’ sleep regularity did not meaningfully improve in the first three months of recovery.
The study also found that lower SRI scores were significantly associated with higher scores on the Patient Health Questionnaire 9, a standard measure of depression severity (P = 0.05), and with lower scores on the Stroke Impact Scale, which measures quality of life after stroke (P = 0.04). The only predictor of SRI improvement over time was the initial SRI itself — participants who started with more regular sleep tended to stay more regular, while those with irregular patterns remained irregular.
Why it matters
Sleep-wake disruption has long been recognized as a common consequence of stroke, but most research has focused on sleep duration or efficiency — how much or how well someone sleeps. The Sleep Regularity Index captures a different dimension: the day-to-day consistency of the sleep-wake cycle. An SRI of 32 means that a person’s sleep and wake times fluctuate substantially from one day to the next, a pattern that has been linked in large epidemiological studies to cardiovascular risk, metabolic dysfunction, and cognitive decline.
The finding that sleep regularity does not recover spontaneously in the weeks after a stroke is clinically significant. It means that current rehabilitation protocols, which focus on motor function, speech, and activities of daily living, may be missing an important modifiable factor. If irregular sleep contributes to post-stroke depression, fatigue, and reduced quality of life, interventions that target sleep scheduling — such as bright light therapy, melatonin timing, or behavioral sleep hygiene — could become a standard component of stroke rehabilitation.
The study is part of a larger ongoing clinical trial (NCT05012605) exploring the impact of sleep disorders on stroke recovery, funded through Emory University.
Limits
The study included 71 participants, a modest sample size that limits subgroup analyses. SRI was calculated from actigraphy, which estimates sleep-wake state based on movement rather than the gold standard of polysomnography. The observational design cannot establish whether poor sleep regularity causes worse outcomes or whether more severe strokes both disrupt sleep and worsen depression independently. The study also did not test any sleep intervention, so the potential benefit of improving SRI after stroke remains theoretical.
Bottom line
Sleep regularity is severely disrupted early after stroke and does not improve naturally over the first three months of recovery. Lower regularity is linked to higher depression and poorer quality of life. The findings suggest that sleep schedule consistency deserves attention as a potential target in post-stroke rehabilitation.
Source
Fulk GD, Bell R, Batts K, Klingman K, Peterson E. “Sleep Regularity Index After Stroke: Change Over Time and Its Association With Recovery: A Longitudinal Observational Study.” Journal of the American Heart Association, 2026; e048392. DOI: 10.1161/JAHA.125.048392. PMID: 42261959.