Encephalopathy only stroke codes (EoSC) do not result in rt-PA treatments

BACKGROUND: Isolated mental status changes as a presenting sign (EoSC+), are not uncommon stroke code triggers. As stroke alerts, they still require the same intensive resources be applied. We previously showed that EoSC+ strokes (EoSC+ Stroke+) account for 0.1–0.2% of all codes. Whether these result in thrombolytic treatment (rt-PA), and the characteristics/ risk factor profiles of EoSC+ Stroke+ patients, have not been reported. METHODS: Retrospective analysis of stroke codes from an IRB approved registry, from 2004 to 2018, was performed. EoSC+ was defined as a NIHSS>0 for Q1a, 1b, or 1c with remaining elements scored 0. Characteristics and risk factors were compared for EoSC+, EoSC−, EoSC+ Stroke+, and rt-PA (EoSC+ Stroke+TPA+) patients. RESULTS: EoSC+ occurred in 55/2982 (1.84%) of all stroke codes. EoSC+ Stroke+ occurred in 8/55 (14.5%) of EoSC+ codes and 8/2982 (0.27%) of all stroke codes. 6/8 (75%) of EoSC+ Stroke+ scored NIHSS=1. When comparing EoSC++versus EoSC−, Hispanic ethnicity (p=0.009), hypertension (p=0.02), and history of stroke/TIA (p=0.002) were less common in EoSC+. No demographic/risk factor differences were noted for EoSC+ Stroke+ vs. EoSC+ Stroke−. No cases of rt-PA eligibility/treatment were noted. In EoSC+ Stroke+ analysis, imaging positive stroke/intracranial hemorrhage was noted on only 3 cases (3/2982=0.10% of all stroke codes) and none were posterior stroke. CONCLUSIONS: EoSC+ rarely results in stroke/TIA (0.27%) or stroke (0.10%), and in our analysis never (0%) resulted in rt-PA. Sub-analysis did not show missed rt-PA or posterior strokes. Understanding characteristics, and knowing that EoSC+ Stroke+ patients are unlikely to receive rt-PA, may help triage stroke resources.