Abstract: Background: The National Institutes of Health Stroke Scale (NIHSS)
has been criticized for limited representation of cognitive dysfunction and
bias towards dominant hemisphere functions. Patients may therefore receive a
low NIHSS score despite a fairly large stroke. A broader scale including simple
cognitive tests would improve the clinical and research utility of the NIHSS. Methods: We studied 200 patients with acute non-dominant hemispheric
stroke who underwent cognitive testing and had MRI with diffusion-weighted
imaging (DWI) within 5 days of presentation. We measured DWI volumes and
retrospectively calculated NIHSS scores. We used linear regression to determine
the role of selected cognitive tests, when added to the NIHSS, in predicting
DWI volume. Results: The NIHSS predicted DWI volume in a univariate
analysis, as did total line cancellation and a visual perception task. In a
multivariate model, using log-transformed variables, the NIHSS (p=0.0002),
line cancellation errors (p=0.02) and visual perception (p=0.004) each
improved prediction of total infarct volume. Conclusion: The addition of
line cancellation and visual perception tasks significantly adds to the model
of NIHSS alone in predicting DWI volume. We propose that these two cognitive
tests, which together can be completed in 2–3 minutes, could be combined with
the NIHSS to create an "NIHSS-plus" that more accurately represents a
patient's ischemic tissue volume after a stroke. This scale requires further
validation in a prospective study.
Keywords: Stroke, stroke scales, diffusion-weighted imaging, neglect, diagnosis and treatment of acute stroke (ischemia)
