Isolated Anisocoria As a Presenting Stroke Code Symptom is Unlikely to Result in Alteplase Administration

Background: Acute stroke codes may be activated for anisocoria, but how often these codes lead to a final stroke diagnosis or alteplase treatment is unknown. The purpose of this study was to assess the frequency of anisocoria in stroke codes that ultimately resulted in alteplase administration.

Methods: We retrospectively assessed consecutive alteplase-treated patients from a prospectively-collected stroke registry between February 2015 and July 2018. Based on the stroke code exam, patients were categorized as having isolated anisocoria [A+(only)], anisocoria with other findings [A+(other)], or no anisocoria [A-]. Baseline demographics, stroke severity, alteplase time metrics, and outcomes were also collected.

Results: Ninety-six patients received alteplase during the study period. Of the 94 who met inclusion criteria, there were 0 cases of A+(only). There were 9 cases of A+(other) (9.6%). A+(other) exhibited higher baseline National Institutes of Health (NIH) Stroke Scale scores compared to A- (17 versus 7; P = .0003), and no additional differences in demographics or alteplase time metrics. Final stroke diagnosis and other outcome measures were no different between A+(other) and A-. Of the A+ patients without pre-existing anisocoria, 5 of 6 (83%) had posterior circulation events or diffuse subarachnoid hemorrhage.

Conclusions: In this exploratory analysis, zero patients with isolated anisocoria received alteplase treatment. Anisocoria as a part of the neurologic presentation occurred in 10% of alteplase patients, and was strongly associated with a posterior circulation event. Therefore, we conclude that anisocoria has a higher likelihood of leading to alteplase treatment when identified in the presence of other neurologic deficits.