Advances in understanding spontaneous intracerebral hemorrhage: insights from neuroimaging

Abstract

Spontaneous (non-traumatic) symptomatic intracerebral hemorrhage is a devastating form of stroke, with very high overall mortality and morbidity. Even with the best current medical or surgical treatment, outcomes still remain poor. By contrast with ischemic stroke, the incidence of intracerebral hemorrhage is not decreasing. Indeed, the incidence of intracerebral hemorrhage related to antithrombotic drugs, including oral anticoagulants, has increased in recent decades. Despite the clear unmet research need for both prevention and acute treatment, there has, until recently, been limited progress in understanding the pathogenesis of this disease. New advances, especially related to neuroimaging biomarkers, are rapidly increasing our understanding of the spectrum of mechanisms of brain injury in intracerebral hemorrhage. The aim of this article is to review recent insights from neuroimaging studies into the pathophysiology and causes of intracerebral hemorrhage, focusing on MRI. We also discuss some of the current and future challenges facing clinicians in understanding and treating intracerebral hemorrhage.

Keywords::

• cerebral amyloid angiopathy
• cerebral microbleeds
• cortical superficial siderosis
• hypertensive arteriopathy
• intracerebral hemorrhage
• leukoaraiosis
• MRI

Financial & competing interests disclosure

A Charidimou receives research support from the Greek State Scholarship Foundation, the Stroke Association and the British Heart Foundation. DJ Werring and D Wilson receive research support from the Stroke Association and the British Heart Foundation. This research was funded by the Stroke Association and the British Heart Foundation and supported by researchers at the National Institute for Health Research University College London Hospitals Biomedical Research Centre. The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending or royalties.

No writing assistance was utilized in the production of this manuscript.

Key issues

• There is no single ‘cause’ of most cases of intracerebral hemorrhage (ICH), but rather an interplay between genetic and environmental factors.

• Cerebral small vessel disease underpins most cases of spontaneous ICH. MRI is the most effective method to image the consequences of small vessel disease (SVD). Lack of evidence of SVD on advanced imaging should arouse suspicion of a ‘secondary’ cause for ICH, although evidence for this approach remains limited.

• The topography of cerebral microbleeds (CMBs) is useful in determining SVD pathology. Strictly lobar CMBs (as described in the Boston criteria) have high specificity for pathology-proven cerebral amyloid angiopathy (CAA). However, further studies are needed to determine whether incorporating other MRI findings (e.g., perivascular spaces) could usefully increase the sensitivity of the Boston criteria.

• CMB are the most studied prognostic marker in ICH survivors, and are associated with an increased risk of both ischemic stroke and ICH. Although their clinical relevance remains undetermined, multiple strictly lobar CMBs suggesting CAA should lead to caution in using antithrombotic agents, particularly anticoagulants.

• The presence of cortical superficial siderosis is a promising indicator of future incident hemorrhage in CAA, but further studies are required.

Notes