Aphasia predicts unfavorable outcome in mild ischemic stroke patients and prompts thrombolytic treatment

Abstract

Background: Patients with an acute ischemic stroke rated as mild, and for this reason not submitted to thrombolysis, have an unfavorable outcome in a non-negligible proportion. Whether selective presentation features help identify those at risk of bad outcome, and whether it could be recommended to treat only patients with such features, is poorly elucidated. We report our experience based on retrospective evaluation of a consecutive series of patients scoring 6 or less on baseline National Institutes of Health Stroke Scale (NIHSS), some of whom received thrombolysis.

Methods: From the prospective Careggi Hospital Stroke Registry, Florence, Italy, we selected a series of patients who fulfilled the following criteria: (1) screening for treatment within 3 hours of symptom onset; (2) mild symptoms, defined as a score of 6 or less on NIHSS, with or without rapid improvement; (3) no other reason for exclusion from thrombolysis; (4) no previous disability; and (5) admission to the stroke unit. We choose a modified Rankin scale score of less than 2 to define a good 3-month functional outcome. We studied as potential outcome predictors: age, baseline NIHSS score, isolated aphasia, motor impairment with or without aphasia, thrombolysis, previous stroke or transient ischemic attack, and interactions between each of these factors and thrombolysis.

Results: Between February 2004 and June 2011, 128 patients fulfilled the selection criteria: 47 (36.7%) received tissue plasminogen activator, 81 (63.3%) did not. At 3 months, of the 81 patients not receiving tissue plasminogen activator, 14 (17.3%) had an unfavorable outcome, compared with 6 (12.8%) among the 47 treated. Hemorrhagic complications or death occurred in neither group. Adjusting for major confounders and for thrombolysis, the presence of aphasia on early assessment proved the only independent predictor of worse outcome. NIHSS score variation showed no effect.

Conclusions: Aphasia is an early marker of unfavorable outcome in mild ischemic stroke patients. In these patients thrombolysis should be considered beyond the NIHSS scoring.

Keywords: Aphasia; ischemic stroke; mild symptoms; thrombolysis.