Abstract 202: The NIH Stroke Scale Can Miss Improvement After IV tPA For Acute Ischemic Stroke
Background and Objective: The National Institute of Health Stroke Scale (NIHSS) is the most commonly used metric to evaluate stroke severity and improvement following intervention. Despite its advantages as a rapid, reproducible screening tool, it may be too insensitive to adequately capture functional improvement following treatment. We evaluated the difference in rate of improvement by previously accepted criteria (change of ≥4 NIHSS points) versus physician documentation in patients receiving IV tissue plasminogen activator (tPA) for acute ischemic stroke.
Methods: Prospectively collected data on all patients receiving IV tPA over a 15 month period were retrospectively reviewed. NIHSS 24 hours post-treatment and on discharge were extrapolated based on examination and compared to NIHSS on presentation. NIHSS scores at post-discharge follow-up were also recorded. Two reviewers evaluated the medical record and determined improvement based on physician documentation. Using tests of proportion, ‘significant improvement’ by NIHSS was compared to physician documentation at each time point.
Results: Forty-one patients were treated with IV tPA. The mean admission NIHSS was 8.6 and improved to 6.4 24 hours post-tPA. Twenty-nine of 41 patients (79%) were “better” by documentation; however only 11/41 (27%) met NIHSS criteria for improvement (p compared to documentation <0.001). On discharge, 20/41 patients (49%) met NIHSS criteria for improvement; however a significant difference between physician documentation remained (p=0.04). The mean post-discharge follow-up NIHSS score was 2.0. 20/21 patients (95%) were “better” compared to 16/21 (76%) meeting NIHSS criteria (p=0.08).
Conclusion: The NIHSS may inadequately capture functional improvement post-treatment, especially in the days immediately following intervention.
Author Disclosures: E.B. Marsh: None. E. Lawrence: None. R.H. Llinas: None.
- © 2015 by American Heart Association, Inc.