title: Hematoma Expansion Following Intracerebral Hemorrhage: Mechanisms Targeting the Coagulation Cascade and Platelet Activation.
abstract: Hematoma expansion (HE), defined as a greater than 33% increase in intracerebral hemorrhage (ICH) volume within the first 24 hours, results in significant neurological deficits, and enhancement of ICH-induced primary and secondary brain injury. An escalation in the use of oral anticoagulants has led to a surge in the incidences of oral anticoagulation-associated ICH (OAT-ICH), which has been associated with a greater risk for HE and worse functional outcomes following ICH. The oral anticoagulants in use include vitamin K antagonists, and direct thrombin and factor Xa inhibitors. Fibrinolytic agents are also frequently administered. These all act via differing mechanisms and thus have varying degrees of impact on HE and ICH outcome. Additionally, antiplatelet medications have also been increasingly prescribed, and result in increased bleeding risks and worse outcomes after ICH. Aspirin, thienopyridines, and GPIIb/IIIa receptor blockers are some of the most common agents in use clinically, and also have different effects on ICH and hemorrhage growth, based on their mechanisms of action. Recent studies have found that reduced platelet activity may be more effective in predicting ICH risk, hemorrhage expansion, and outcomes, than antiplatelet agents, and activating platelets may thus be a novel target for ICH therapy. This review explores how dysfunctions or alterations in the coagulation and platelet cascades can lead to, and/or exacerbate, hematoma expansion following intracerebral hemorrhage, and describe the mechanisms behind these effects and the drugs that induce them. We also discuss potential future therapy aimed at increasing platelet activity after ICH.
authors.affiliation: Department of Physiology, Loma Linda University School of Medicine, Loma Linda CA, USA.|Center for Neuroscience Research, Loma Linda University School of Medicine, Loma Linda, CA, USA.
authors.forename: Sherrefa R
authors.initials: SR
authors.lastname: Burchell
authors.affiliation: Department of Physiology, Loma Linda University School of Medicine, Loma Linda CA, USA.|Center for Neuroscience Research, Loma Linda University School of Medicine, Loma Linda, CA, USA.
authors.forename: Jiping
authors.initials: J
authors.lastname: Tang
authors.affiliation: Department of Physiology, Loma Linda University School of Medicine, Loma Linda CA, USA.|Center for Neuroscience Research, Loma Linda University School of Medicine, Loma Linda, CA, USA.|Department of Anesthesiology, Loma Linda University School of Medicine, Loma Linda CA, USA.
authors.forename: John H
authors.initials: JH
authors.lastname: Zhang
mesh_terms: D000925:Anticoagulants / Q000008:administration & dosage / Q000009:adverse effects*; D002543:Cerebral Hemorrhage / Q000139:chemically induced / Q000150:complications / Q000188:drug therapy*; D065427:Factor Xa Inhibitors / Q000008:administration & dosage / Q000009:adverse effects; D005343:Fibrinolytic Agents / Q000008:administration & dosage / Q000494:pharmacology; D006406:Hematoma / Q000209:etiology* / Q000517:prevention & control; D006801:Humans; D015539:Platelet Activation / Q000187:drug effects; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage / Q000494:pharmacology; D013917:Thrombin / Q000008:administration & dosage / Q000009:adverse effects; D014812:Vitamin K / Q000037:antagonists & inhibitors
chemical_list: D000925:Anticoagulants; D065427:Factor Xa Inhibitors; D005343:Fibrinolytic Agents; D010975:Platelet Aggregation Inhibitors; D014812:Vitamin K; D013917:Thrombin
keywords: Ctype
  lectin-like receptor 2; Hematoma expansion; anticoagulant; antiplatelet; intracerebral hemorrhage; oral-anticoagulant-associated ICH; platelet activation