Assess rate of hematoma expansion (HE) among patient diagnosed with intracranial hemorrhage (ICH) on Mobile Stroke Unit (MSU).

Early HE is independently associated with poor functional outcomes and mortality in ICH patients. However, we lack data on HE rates within first 2 hrs from symptom onset. MSU provides a unique opportunity to track early ICH expansion.

Retrospective review of patients diagnosed with ICH on MSU from May 2018 to December 2019 was conducted. Patient demographics, Glasgow coma scale (GCS) were recorded. Hematoma volumes were tracked on head imaging obtained on MSU and after hospital admission. ABC/2 formula was used to calculate hematoma volumes. Intraventricular hemorrhage score (IVHS) was recorded.

17 patients were diagnosed with ICH on MSU. Mean age was 63 years, 77% male, and 82% black. 35% (n= 6) patient were diagnosed within 1 hr of symptom onset on MSU of whom 17% (1/6) had HE (20% ICH volume increase; IVHS decline by ≥2; GCS decline ≥ 2) between MSU and first hour imaging in emergency department (ED). 52% (n=9) were diagnosed with ICH within 2 hrs of symptom onset of whom 11% (2/9) had HE (ICH volume increase 11-20%, IVHS decline ≥ 2; GCS decline ≥ 2) between MSU and first hour imaging in ED. Overall, total expansion rate (early + late) was 33% for patients presenting within 1 hr and 22% within 2 hrs from symptom onset.

IVHS decline drives hematoma expansion in patients presenting within very early time window with ICH. Although limited by small sample size, our study provides an estimate of very early ICH expansion that have not been reported before. Analysis with large sample size by pooling data from different MSUs is recommended to confirm HE rates and correlation with functional outcome.