Ischemic Signatures in Acute Intracerebral Hemorrhage

Abstract

Introduction: Acute blood pressure (BP) reduction is among the few treatments options available in the acute management of intracerebral hemorrhage (ICH). Recent observational studies have demonstrated the presence of lesions suggestive of ischemia on diffusion-weighted sequences (DWI) on MRI. We hypothesized that DWI lesions in ICH are independent from acute BP reduction and hypoperfusion. Methods: Patients with spontaneous ICH undergoing MR imaging were retrospectively enrolled in the first part of the study. In the second part of the study, ICH patients who underwent MRI with perfusion-weighted imaging were prospectively enrolled. Perilesional cerebral blood flow (CBF) was calculated on post-processed calibrated perfusion maps. Results: One hundred-seventeen patients were enrolled in the first substudy. DWI lesions in regions remote to the hematoma were found in 17 (14.7%) patients. Maximal SBP drop at 24 hours was similar in patients with (-20.5(51) mmHg) and without remote DWI lesions (-27(33.5) mmHg, p=0.96). Nineteen patients were enrolled in the second substudy. On baseline MRI, 3 DWI hyperintensities remote to the hematoma were found in 2 patients and 1 subsequent remote DWI hyperintensity was found in one patient on day 7 MRI. Mean absolute perilesional CBF was 37.6 ± 17.2 ml/100g/min with a perilesional rCBF of 1.1 ± 0.1. Mean absolute internal borderzone (BZ) CBF was slightly lower in patients with DWI lesions (18.8 ± 1.8 ml/100g per minute) than patients without DWI lesions (22.6 ± 8.0 ml/100g, p=0.29); however, mean rCBF in the internal BZ regions did not differ between groups (0.96 ± 0.01 and 1.0 ± 0.2, respectively, p=0.37). Conclusion: DWI lesions remote to the hematoma region are commonly observed in sponatneous ICH. Remote DWI lesions are not associated with acute 24-hour BP reduction nor do they appear to be associated with perilesional or borderzone hypoperfusion. These data do not support a hemodynamic mechanism of ischemic injury after spontaneous ICH.