Persisting cognitive impairment predicts functional dependence at 1 year after stroke and transient ischemic attack: a longitudinal, cohort study

OBJECTIVE: Minor stroke or transient ischemic attack (TIA) usually have mild and nondisabling symptoms, and these functional deficits may recover fully e.g., TIA, however, part of them still suffer from cognitive impairment and poor outcomes. We conducted a study to determine the relationship between cognition evaluated by Montreal Cognitive Assessment (MoCA) and poor functional outcomes assessed by the Modified Rankin Scale (mRS) (mRS ≥ 2) and Stroke Impact Scale (SIS)-16(SIS-16<25%). METHODS: The data of this study come from the impairment of cognition and Sleep (ICONS) after acute ischemic stroke or transient ischemic attack in Chinese patients study. A total of 1675 minor stroke patients and TIA patients were finally recruited. Patients’ cognition were evaluated by Montreal Cognitive Assessment (MoCA) scale at 2-week (2w), 3 months (3 m) and 1 year(1y). Cognitive impairment (CI) was defined as MoCA score ≤ 22. According to MoCA score, patients were divided into 4 groups: no PSCI group: with MoCA-2w>22 and MoCA-3 m>22; improved PSCI group: with MoCA-2w ≤ 2 and MoCA-3 m>22;delayed PSCI group: MoCA-2w>22 and MoCA-3 m ≤ 22; persisting PSCI group: with MoCA-2w ≤ 22 and MoCA-3 m ≤ 22. RESULTS: A total of 1675 stroke patients were recruited in this study. There were 818 patients (48.84%) who had PSCI at baseline. Of these, 123 patients (15%) had mRS ≥2 at 3 months. The persisting PSCI group was a significant predictor of functional dependence at 3 months and 1 year after stroke and when adjusted for covariates such as gender, age, history of stroke, depression and intracranial atherosclerotic stenosis, stroke subtype and acute infarction type. CONCLUSION: Persisting PSCI increased the risk of poor functional outcome after 3 months and 1 year follow-up. These high-risk individuals should be identified for targeted rehabilitation and counseling to improve longer-term post-stroke outcome. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12877-022-03609-z.