Effects of Age on Long-Term Functional Recovery in Patients with Stroke

Abstract

Background and objectives: Age might be a determinant that limits functional recovery in patients with stroke. Here, we investigated the effect of age on functional recovery within 30 months after stroke onset. Materials and Methods: This retrospective longitudinal study enrolled 111 patients with first-ever stroke. Functional recovery was assessed at 2 weeks and at 1, 6, and 30 months after stroke onset using the modified Barthel Index (MBI), modified Rankin Score (mRS), functional ambulation category (FAC), muscle strength, and Mini-Mental State Examination (MMSE). A generalized estimating equation analysis was performed. Results: With the MBI, function improved until 6 months after stroke onset in patients aged <70 years and until 1 month after stroke onset in patients ≥70 years. At 30 months after stroke, there was no significant change of MBI in patients aged <70 years, whereas there was a significant decline in older patients. With the mRS and FAC, function improved until 30 months after stroke onset in patients aged <70 years and until 1 month after stroke onset in older patients. Motor deficit, assessed using the Medical Research Council (MRC), improved significantly until 6 months after stroke onset in patients aged <70 years. There was a significant improvement in cognition (assessed using the MMSE) until 6 months after stroke onset in patients aged <70 years and until 1 month after stroke onset in older patients. Conclusions: Long-term functional recovery occurred for up to 30 months after stroke. Patients aged ≥70 years showed functional decline between 6 and 30 months after onset. These findings could be useful when measuring functional recovery after stroke.

Keywords: age effect; functional recovery; outcome; stroke.

Figure 1

Time course of MBI scores for (A) two and (B) four age groups at 2 weeks, 1 month, 6 months, and 30 months. Data are expressed as the mean (95% confidence interval). MBI, Modified Barthel Index. MBI scores increased significantly within 6 months after stroke onset and did not change significantly between 6 and 30 months after stroke onset in patients aged <70 years. Patients aged ≥70 years exhibited significant increases in MBI scores until 1 month after stroke onset and a decline between 6 and 30 months after stroke onset. * Adjusted p-value < 0.05 for within-patient time effect; pairwise comparison with former score for time. † Adjusted p-value < 0.05 for between-patients group effect; pairwise comparison with adjacent score for age group.

Figure 2

Time course of functional assessment scores for two age groups at 2 weeks, 1 month, 6 months, and 30 months. Data are expressed as the mean (95% confidence interval). (A) mRS, modified Rankin Scale; (B) FAC, functional ambulation category; (C) MRC_UF, sum of MRC scores for elbow and wrist flexion of the affected arm; (D) MRC_LE, sum of MRC scores for hip and knee extension of the affected leg; (E) MMSE, Mini-Mental State Examination. mRS and FAC scores continued to increase significantly until 30 months after stroke onset in patients aged <70 years, and until 1 month after stroke onset in older patients. There was no significant change between 1 and 30 months after stroke onset in patients aged ≥70 years. MRC scores of the affected upper and lower extremities showed that motor deficit improved significantly until 6 months after stroke onset and did not change significantly between 6 and 30 months after stroke onset in patients aged <70 years. No significant changes in MRC scores were observed at any time in older patients. MMSE scores increased significantly until 6 months after stroke onset in patients aged <70 years, and until 1 month after stroke onset in older patients. There were no significant changes at any other time. * Adjusted p-value < 0.05 for within-patient time effect; pairwise comparison with former score for time. † Adjusted p-value < 0.05 for between-patients group effect; pairwise comparison with adjacent score for age group.