Fast and Slow Recovery Following Acute Ischemic Stroke

Abstract

OBJECTIVE: To investigate the variability in early recovery after hemiparetic stroke. BACKGROUND: Prior work suggests that most hemiparetic patients recover approximately 70% of their initial impairment by 3-months, but the speed of the recovery is unknown. METHODS: We assessed 30 patients with first-ever hemiparetic stroke using the Fugl-Meyer upper extremity score (max score=66) at 24-72 hours (FMInit), 1-week (FM1wk), and 3-months (FM3mo). Patients who did not demonstrate proportional recovery (0.70 x initial impairment) were excluded from analysis. The distribution of recovery at 7-days among the proportional recoverers was characterized and contrasted with recovery at 90-days using the Shapiro-Wilk test for normality and Sarle’s binomial coefficient. Cluster analysis was then used to assess the distribution of recovery rates at 7-days. Tests of differences and association were performed to assess if the early recovery-rate groups differed significantly in clinical and demographic characteristics. RESULTS: Twenty-six of the 30 initial patients were identified as proportional recovers, the other 4 were non-recoverers at 90-days. Among the proportional recoverers, there was a bimodal distribution of recovery at 7-days. Cluster analysis identified patients who achieved virtually all of their total recovery at 7-days (n=13, percent recovery=0.89±0.19; 95%CI:0.79-1.00) and patients who achieved virtually none their total recovery at 7-days (n=13, percent recovery=-0.23±0.77, 95%CI:-0.65-0.19), but went on to achieve the expected recovery at 90 days. Initial stroke severity was the only characteristic that showed a statistically significant correlation with early recovery group membership. SIGNIFICANCE: Patients who demonstrate proportional recovery over the first 3-months fall into 2 distinct early recovery groups, either achieving approximately 90% of their total recovery by 1-week or making little or no recovery early, and only later achieving their total expected recovery. Implications for treatment planning are profound.