Related Experiment Video
Updated: Aug 16, 2026

Intrastriatal Injection of Autologous Blood or Clostridial Collagenase as Murine Models of Intracerebral Hemorrhage
Published on: July 3, 2014
Hematoma Expansion in Intracerebral Hemorrhage With Unclear Onset
Andrea Morotti1, Gregoire Boulouis2, Andreas Charidimou2
1From UO Neurologia (A.M.), Azienda Socio-Sanitaria Territoriale (ASST) Valcamonica, Esine, Italy; Neuroradiology Department (G. Boulouis), Centre Hospitalier Sainte-Anne, Paris, France; J.P. Kistler Stroke Research Center, Department of Neurology (A. Charidimou, Q.L., A.D.W., C.D.A., M.E.G., A.B., A.V., S.M.G., J.R., J.N.G.), Massachusetts General Hospital Stroke Research Center, Harvard Medical School, Boston; Dipartimento di Scienze Cliniche e Sperimentali, Clinica Neurologica (L.P., A. Pezzini, A. Padovani), Università degli Studi di Brescia; UO di Neurologia (P.C.), Istituto Clinico Fondazione Poliambulanza, Brescia; UOC Neurologia (V.D.G.), ASST Cremona; UC Malattie Cerebrovascolari e Stroke Unit (E.L., F.M., A. Cavallini) and UC Neurologia d'Urgenza (E.L., F.M., G.M.), IRCCS Fondazione Mondino, Pavia; Dipartimento di Dipartimento di Scienze Biomediche, Sperimentali e Cliniche, Neuroradiologia, Università degliStudi di Firenze (G. Busto, E.F.), and Stroke Unit (F.A., A.Z.), Ospedale Universitario Careggi, Firenze; UOC Neurologia e Rete Stroke, Metropolitana (L.B., S.G.), and Unità di Neuroradiologia (L.S.), IRCCS Istituto delle Scienze Neurologiche di Bologna, Ospedale Maggiore; Clinica Neurologica, Dipartimento di Scienze Biomediche e Chirurgico Specialistiche (M.L., I.C.), Università degli studi diFerrara, Ospedale Universitario S. Anna, Ferrara; Neurologia e Stroke Unit (E.C.), Ospedale di Circolo, ASST Settelaghi, Varese; Stroke Unit (M.G., M.M.), Neurologia Vascolare, ASST Spedali Civili, Brescia, Italy; Division of Neurocritical Care and Emergency Neurology, Department of Neurology (C.D.A., J.R., J.N.G.), Harvard Medical School, Henry and Allison McCance Center for Brain Health (C.D.A., J.R., J.N.G.), and Department of Emergency Medicine (J.N.G.), Massachusetts General Hospital, Boston. andrea.morotti85@gmail.com.
Objective:
To investigate the prevalence, predictors, and prognostic effect of hematoma expansion (HE) in patients with intracerebral hemorrhage (ICH) with unclear symptom onset (USO).
Methods:
We performed a retrospective analysis of patients with primary spontaneous ICH admitted at 5 academic medical centers in the United States and Italy. HE (volume increase >6 mL or >33% from baseline to follow-up noncontrast CT [NCCT]) and mortality at 30 days were the outcomes of interest. Baseline NCCT was also analyzed for presence of hypodensities (any hypodense region within the hematoma margins). Predictors of HE and mortality were explored with multivariable logistic regression.
Results:
We enrolled 2,165 participants, 1,022 in the development cohort and 1,143 in the replication cohort, of whom 352 (34.4%) and 407 (35.6%) had ICH with USO, respectively. When compared with participants having a clear symptom onset, patients with USO had a similar frequency of HE (25.0% vs 21.9%, p = 0.269 and 29.9% vs 31.5%, p = 0.423). Among patients with USO, HE was independently associated with mortality after adjustment for confounders (odds ratio [OR] 2.64, 95% confidence interval [CI] 1.43-4.89, p = 0.002). This finding was similar in the replication cohort (OR 3.46, 95% CI 1.86-6.44, p < 0.001). The presence of NCCT hypodensities in patients with USO was an independent predictor of HE in the development (OR 2.59, 95% CI 1.27-5.28, p = 0.009) and replication (OR 2.43, 95% CI 1.42-4.17, p = 0.001) population.
Conclusion:
HE is common in patients with USO and independently associated with worse outcome. These findings suggest that patients with USO may be enrolled in clinical trials of medical treatments targeting HE.
Related Concept Videos
Hemorrhagic Stroke l: Introduction
Hemorrhagic Stroke ll: Pathophysiology
Increased Intracranial Pressure l: Introduction
Increased Intracranial Pressure ll: Pathophysiology
Cerebral Edema l: Introduction
Cerebral Edema ll: Pathophysiology

