Naoki Mori, Yohei Otaka, Kaoru Honaga, Daisuke Matsuura, Kunitsugu Kondo, Meigen Liu, Tetsuya Tsuji
Department of Rehabilitation Medicine, Keio University School of Medicine, Tokyo, Japan.
DOI: 10.2340/16501977-2859

Objective: To elucidate the characteristics of subacute stroke survivors with post-stroke cognitive impairment, and examine the factors associated with cognitive recovery.
Design: Retrospective cohort study.
Participants: A total of 218 consecutive stroke survivors, who were admitted to a rehabilitation hospital between April 2014 and March 2015, were included.
Methods: The prevalence of post-stroke cognitive impairment, defined as having a Mini-Mental State Examination (MMSE) score < 24 was investigated. Among those with post-stroke cognitive impairment, the characteristics of patients with clinically significant improvement in MMSE scores (change ≥ 4) were explored. Univariable and multivariable regression analyses were performed to examine the relationship between Functional Independence Measure (FIM) items and improvement in post-stroke cognitive impairment.
Results: Post-stroke cognitive impairment occurred in 47. 7% of participants. The mean improvement in their MMSE scores was 3. 43. Participants who showed improvement had significantly higher FIM scores at discharge than those who did not show improvement. Regarding FIM items, eating (odds ratio 1. 3; 95% confidence interval 1. 0–1. 7; p = 0. 041) and social interaction (odds ratio 1. 5, 95% CI 1. 1–2. 1, p = 0. 010) were associated with cognitive improvement.
Conclusion: Approximately half of subacute stroke survivors have post-stroke cognitive impairment. Eating and social interaction are significantly associated with cognitive improvement.

Cognitive impairments after stroke inhibit the effectiveness of rehabilitation and limit the activities of daily living. Therefore, it is very important to take measures against cognitive impairments early on. Previous studies have shown that cognitive function improves to some extent after a stroke. However, there is a lack of knowledge on the improvement of cognitive function during subacute phase and its associate factors. We investigated the cognitive function of 218 patients with subacute stroke admitted to a rehabilitation hospital. As a result, we found that approximately half of the patients showed cognitive impairments on admission and approximately half of those eventually improved during hospitalisation. Furthermore, we found that the ability of eating and social interaction in daily life on admission were associated with cognitive improvement.