Differences in Circadian Rhythmicity of Activity Levels by Functional Stroke Severity: A Cosinor Analysis
Faculty Mentor
Elena Crooks
Presentation Type
Poster
Start Date
4-14-2026 9:00 AM
End Date
4-14-2026 11:00 AM
Location
PUB NCR
Primary Discipline of Presentation
Physical Therapy
Abstract
BACKGROUND & PURPOSE: Neurobiological mechanisms of sleep-wake regulation hypothesize that greater neurological involvement post-stroke yields greater dysfunction in circadian rhythmicity; however, this has not yet been studied. This study compares circadian rhythmicity of motor activity by stroke severity. METHODS: Seventeen participants (aged 72.09 ± 12.69, 13.73 ± 6.47 days post-stroke) attending inpatient rehabilitation (IR) completed the study. Near IR admission, participants completed the Functional Independence Measure (FIM) and were categorized as having functional impairment of mild severity (MSev; FIM score >61) or severe severity (SSev; FIM score ≤61). Wrist actigraphy continuously measured activity counts (Philips Respironics, Actiware 6.3), averaged into 5-minute bins during baseline (BL; first 48 hours) and discharge (DC; final 48 hours, 6 days later). Nonlinear mixed-effects cosinor regression (SAS 9.4) compared circadian rhythmicity of activity for each stroke severity (MSev vs SSev), study period (BL vs DC) and their interaction. RESULTS: Cosinor analyses confirmed significant 24-hour rhythmicity at BL and DC for both severity groups (p< 0.001). There was a significant interaction of stroke severity by study period (p< 0.001). Amplitude showed no change for MSev (p=0.51), and significantly increased for SSev (p< 0.01) from BL to DC. There were no significant changes in acrophase. CONCLUSIONS: This is the first report to determine circadian rhythmicity in activity by stroke functional severity level. There was a significant 24-hour rhythm in motor activity at BL and DC for both MSev and SSev. Amplitude increased in SSev and not MSev, and there were no changes in peak activity across time.
Recommended Citation
Zanze, John, "Differences in Circadian Rhythmicity of Activity Levels by Functional Stroke Severity: A Cosinor Analysis" (2026). 2026 Symposium. 51.
https://dc.ewu.edu/srcw_2026/ps_2026/p1_2026/51
Creative Commons License

This work is licensed under a Creative Commons Attribution-NonCommercial-No Derivative Works 4.0 International License.
Differences in Circadian Rhythmicity of Activity Levels by Functional Stroke Severity: A Cosinor Analysis
PUB NCR
BACKGROUND & PURPOSE: Neurobiological mechanisms of sleep-wake regulation hypothesize that greater neurological involvement post-stroke yields greater dysfunction in circadian rhythmicity; however, this has not yet been studied. This study compares circadian rhythmicity of motor activity by stroke severity. METHODS: Seventeen participants (aged 72.09 ± 12.69, 13.73 ± 6.47 days post-stroke) attending inpatient rehabilitation (IR) completed the study. Near IR admission, participants completed the Functional Independence Measure (FIM) and were categorized as having functional impairment of mild severity (MSev; FIM score >61) or severe severity (SSev; FIM score ≤61). Wrist actigraphy continuously measured activity counts (Philips Respironics, Actiware 6.3), averaged into 5-minute bins during baseline (BL; first 48 hours) and discharge (DC; final 48 hours, 6 days later). Nonlinear mixed-effects cosinor regression (SAS 9.4) compared circadian rhythmicity of activity for each stroke severity (MSev vs SSev), study period (BL vs DC) and their interaction. RESULTS: Cosinor analyses confirmed significant 24-hour rhythmicity at BL and DC for both severity groups (p< 0.001). There was a significant interaction of stroke severity by study period (p< 0.001). Amplitude showed no change for MSev (p=0.51), and significantly increased for SSev (p< 0.01) from BL to DC. There were no significant changes in acrophase. CONCLUSIONS: This is the first report to determine circadian rhythmicity in activity by stroke functional severity level. There was a significant 24-hour rhythm in motor activity at BL and DC for both MSev and SSev. Amplitude increased in SSev and not MSev, and there were no changes in peak activity across time.
Comments
Authors:
Elena Crooks, PT, DPT, PhDa, Kirsie R Lundholm, MSb, Amanda A. Higa, SPTa, John K. Zanze SPTa, Brieann C Satterfield, PhDb
aDepartment of Physical Therapy, Eastern Washington University, Spokane, WA
bDepartment of Translational Medicine and Physiology; Sleep and Performance Research Center, Washington State University, Spokane, WA