While theNIH Stroke Scale (NIHSS) may be relatively cumbersome and quite comprehensive, it is an extremely important tool that must not be ignored; it serves as a "common language" between emergency physicians and neurologists and often significantly shapes the management of acute ischemic stroke patients.
Its prognostic usefulness (i.e. in cases wherein treatment is not initiated) has been validated and should be applied in emergent settings to determine optimal patient candidates for tPA treatment.
For example,NIHSS > 20 in patients over 75 years old = 45% mortality; NIHSS >17 in patients with atrial fibrillation = positive predictive value for poor outcome of 96%; NIHSS of 6 or less = good spontaneous recovery.
An abbreviated version of the NIHSS has been validated and assesses those components which are the best indicators of prognosis. Therefore, when unable to perform a full NIHSS, one should strongly consider using this tool rather than not performing a stroke scale assessment at all.
This abbreviated version consists of only 5 categories which assess ability to see (1. best gaze; 2. best visual), walk (3. motor function of left leg; 4. motor function of right leg), and talk (5. best language). Can patient "see, walk, and talk?" This scale is scored from 0 to 16, with 16 representing the worst prognosis. (see attached abbreviated NIHSS).
References
The National Institute of Neurological Disorders and Stroke rt-PA Stroke Study Group. Tissue plasminogen activator for acute ischemic stroke. N Engl J Med 333:1581-1587, 1995.
Tirschwell, et al. "Shortening the NIH Stroke Scale for Use in the Prehospital Setting." Stroke 2002; 33: 2801-2806.
