Background and purpose: Improvement in the National Institutes of Health Stroke Scale (NIHSS) 24 hours after stroke has been associated with subsequent neurological deterioration. We hypothesized that a similar association would be apparent for events occurring after 7 days, when acute changes from edema and herniation are less common. We evaluated the degree of NIHSS improvement at 7 days (recovery) as a predictor of subsequent neurological deterioration from day 7 to day 90.
Methods: We studied all patients of the Glycine Antagonist (gavestinel) In Neuroprotection (GAIN) International Trial with ischemic stroke alive at day 7, excluding patients with hemorrhagic events and deaths from nonstroke-related causes. The GAIN International Trial was a randomized, double-blind, placebo-controlled, and parallel-group trial; because the study drug had no effect on stroke outcome, treatment groups were combined for this analysis. Neurological deterioration was assessed by the combined measure, including: (1) stroke-related events recorded as "serious adverse events," (2) recurrent stroke recorded on a separate case report form, and (3) any NIHSS worsening.
Results: Among 1187 patients included, 25% had >65% recovery. Deterioration was more prevalent in the group with >65% early recovery (15.5% versus 10.3%; P=0.01). Logistic regression modeling indicated that recovery was associated with subsequent neurological deterioration (odds ratio, 1.2; 95% CI, 1.1 to 1.3, per 10% recovery) after adjusting for age, NIHSS at 7 days, and stroke subtype.
Conclusions: Substantial neurological recovery at 7 days is associated with subsequent neurological deterioration.