Abstract 2220: Fast Versus Slow Recoverers Following Acute Ischemic Stroke
INTRODUCTION: Prior work has identified that the majority of acute hemiparetic patients recover a very predictable (adjusted R2=0.85) 70% of their maximum potential recovery on the Fugl-Meyer Upper Extremity Motor exam (FM) at 3-months. We examined these data to investigate whether the early recovery trajectory was uniform among these patients at 3 months. Among first-time acute stroke patients who recover motor function at 3 months, we assessed the hypothesis that the rate of recovery will be variable at one week after stroke.
METHODS: We examined 30 patients with first-ever unilateral hemiparetic stroke using the FM score (max score=66) at 24-72 hours (FMinit), 1 week (FM1wk), and 3-months (FM3mo). Initial impairment was defined as 66 - FMinit. Recovery was defined as the change in FM over 3 months (FM3mo - FMinit). A Pearson correlation coefficient was calculated for predicted vs. observed change to assess how well (0.70 x initial impairment) predicted 3-month recovery, as well as to identify the subgroup of non-recoverers. A histogram was plotted for the recoverers to examine the distribution of patients based on the proportion of the 3-month recovery that had been achieved by 1-week.
RESULTS: A strong correlation (R2=0.96) was demonstrated of predicted vs. observed recoveries, with non-recoverers (n=4) removed. Among recoverers, there was a bimodal distribution of patients by the proportion of 3-month recovery achieved at 1-week-- those who achieved >50% of 3-month recovery (fast to recover-- FTR, N=14) vs. those who achieved <50% of 3-month recovery (slow to recover--STR, N=12). The difference in the proportions of recovery achieved at 1-week for FTR (0.93,95% CI, 0.75-1.11) vs. STR (-0.07,95% CI, -0.30-0.16) patients was highly significant (p<0.001).
CONCLUSION: Patients who recover over the first 3 months follow distinct trajectories, either achieving approximately 90% of their total recovery by 1 week or making marginal recovery early, and only later achieving their total expected recovery (Fig). These findings have important implications for rehabilitation and predicting recovery after stroke. Future work must address the biological correlates of this dichotomy.
- © 2012 by American Heart Association, Inc.