Impact of Time on Improvement of Outcome After Stroke

TLDR

Longitudinal studies show that neurologic and functional recovery is fastest in the first weeks after stroke. The study aimed to quantify how the passage of time influences improvements in motor strength, synergisms, and daily activities during the first 16 weeks poststroke. A prospective cohort of 101 first‑ever ischemic middle cerebral artery stroke patients was followed for 16 weeks, with biweekly intervals used as an independent covariate in a first‑order longitudinal regression model linking time to changes in Fugl‑Meyer, Motricity Index, letter‑cancellation, Functional Ambulation Categories, Action Research Arm test, and Barthel Index scores. Time alone explained 16–42 % of the observed gains in motor function, walking, dexterity, and activities of daily living during the first 6–10 weeks, with comparable effects on upper‑ and lower‑limb measures and a 16 % reduction in visuospatial inattention, and these associations persisted after adjusting for age, gender, stroke characteristics, and interventions.

Abstract

Background and Purpose— Longitudinal conducted studies show that neurologic and functional recovery show faster recovery in the first weeks poststroke. The aim of the present study was to study the effects of progress of time on observed improvements in motor strength, synergisms, and activities during the first 16 weeks poststroke. Methods— Based on data from a previous study, 101 patients with first-ever ischemic middle cerebral artery strokes were prospectively investigated during the first 16 weeks after stroke. Progress of time was categorized into 8 biweekly time intervals and was used as the independent covariate in a first-order longitudinal regression model. The biweekly time change (progress of time) was related to improvement in upper and lower limb motor recovery assessed with Fugl-Meyer score and Motricity Index, reduction in visuospatial inattention based on the letter cancellation task, and improvement in walking ability, dexterity, and activities of daily living measured with the Functional Ambulation Categories, Action Research Arm test, and Barthel Index. Results— Time explained a significant change of 8.4 (42%) measurement units on the Barthel Index for the first 10 weeks poststroke, 1.1 (22%) measurement units on Functional Ambulation Categories, and 19% on the Action Research Arm test for the first 6 and 8 weeks poststroke. Approximately 25% (for Fugl-Meyer-arm) to 26% (for Motricity Index-arm) of the significant change in measurements units was explained by time alone for the upper limb compared with 33% for Fugl-Meyer-leg and 39% for Motricity Index-leg of the lower limb. Time accounted for a reduction of 16% in the letter cancellation task. Observed associations did not change after controlling for covariates such as age, gender, hemisphere of stroke, type of stroke, or intervention. Conclusion— Progress of time is an independent covariate that reflects spontaneous recovery of body functions and activities explaining &16% to 42% of the observed improvements in the first 6 to 10 weeks after stroke onset.