According to our 2013 AHA/ASA guidelines for the early management of patients with acute ischemic stroke, patients with “minor and isolated or rapidly improving neurologic signs” are defined as such:

“Minor and isolated symptoms are those that are not presently potentially disabling. Although most patients with potentially disabling symptoms will have NIHSS scores ≥4, certain patients, such as those with gait disturbance, isolated aphasia, or isolated hemianopia, may have potentially disabling symptoms although their NIHSS score is just 2.”


These guidelines are reasonable for everyday practice, as many acute strokes are mild and “minor and rapidly improving signs” is the most frequently cited reason to withhold tPA in patients with acute ischemic stroke who are otherwise eligible. However, there seems to be a fair amount of subjectivity in determining “disabling” deficits and there is nothing concrete about a NIHSS cutoff of 4. To continue what was said about minor symptoms in the guidelines:

“Several studies have now reported that approximately one third of patients who are not treated with intravenous rtPA because of mild or rapidly improving stroke symptoms
on hospital arrival have a poor final stroke outcome. A persistent large-artery occlusion on imaging, despite minor symptoms or clinical improvement, may identify patients at increased risk of subsequent deterioration. In light of these observations, the practice of withholding intravenous fibrinolytic therapy because of mild or rapidly improving symptoms has been questioned, which justifies further study.”

In light of this ambiguity, some SUNY and Tufts investigators conducted a survey of active urban academic neurologists as to how they make tPA decisions in the setting of minor acute ischemic stroke. The standardized survey was composed 110 clinical cases with permutations in NIHSS, symptom type, pattern of changes, and age/occupation.

The survey composition has its flaws and the makeup of the respondents, including only 43% of those invited, calls the generalizability into question but, NIHSS is not the only determinant of tPA provision, although it was a significant factor. Symptom type (language/neglect over motor and visual/sensory/ataxia) and age/occupation (35/violinist, 52/taxi driver, and 65/lawyer over 80/retired) were also significant predictors of tPA provision when controlling for NIHSS. These are the first quantitative data on tPA decision-making for minor acute stroke.

The findings of this survey are interesting if not unsurprising. It would be shortsighted to make tPA decisions based on NIHSS alone, but what of the symptom clusters separated them? Or are we reading too much into it because of the symptom clusters are not individual features as we discern at the bedside? And what about age? Is the withholding of tPA to the 80 year old retiree an acknowledgment of series suggesting lower tPA efficacy and higher bleed risk or ageism? As the investigators say, future similarly designed surveys (hopefully with acknowledged limitations addressed) cast additional light to better understand practice patterns in this controversial realm. That is an important step before we can constructively scrutinize “typical practice” and make recommendations for minor stroke.