Functional Recovery in Patients with Acute Stroke and Pre-Existing Disability: A Natural History Study

Abstract

Objectives: We aimed to determine which factors influence recovery in stroke patients with pre-existing disability, as these patients are often excluded from acute treatment trials.

Materials and methods: A prospective stroke center registry of admitted patients from 2019-2021 with acute stroke was queried for patients with pre-stroke modified Rankin Scale (mRS) of 0-4. Multivariable logistic regression was used to estimate odds of functional recovery at 90 days (mRS 0-2, or return to pre-stroke mRS).

Results: Of 1228 patients, 856 (70%) included patients had pre-stroke mRS 0-4 and 90-day follow-up mRS. The median age was 68y (IQR 59-78), with a median National Institutes of Health Stroke Scale (NIHSS) of 5 (IQR 2-17). Compared to those with mRS 0-1 (n = 596), patients with pre-stroke mRS of 2 (n = 126), 3 (n = 96), or 4 (n = 38) were less likely to achieve functional recovery in univariate analysis. After multivariable adjustment, odds of functional recovery were significantly lower for patients with pre-stroke mRS of 2 (adjusted odds ratio [OR_adj] 0.45, 95% confidence interval [CI] 0.28-0.72), but not those with pre-stroke mRS of 3 (OR_adj 1.14, 95%CI 0.66-1.97) or 4 (OR_adj 0.50, 95%CI 0.21-1.19). Older age (OR_adj per year 0.97, 95%CI 0.95-0.97) and higher NIHSS (OR_adj per point 0.89, 95%CI 0.88-0.91) were associated with lower odds of functional recovery, while thrombolysis (OR_adj 2.43, 95%CI 1.42-4.15) and a cryptogenic stroke mechanism (OR_adj 1.57, 95%CI 1.07-2.31) were protective.

Conclusions: Recovery of patients with pre-existing disability was driven by age and stroke severity. Thrombolysis remained predictive of recovery irrespective of age, stroke severity, and pre-stroke disability.

Keywords: Acute ischemic stroke; Pre-stroke disability; Stroke recovery; Thrombolysis.