Intracranial Hemorrhage

Updated: Oct 13, 2017
  • Author: David S Liebeskind, MD, FAAN, FAHA, FANA; Chief Editor: Helmi L Lutsep, MD  more...
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Overview

Background

Intracranial hemorrhage (ie, the pathological accumulation of blood within the cranial vault) may occur within brain parenchyma or the surrounding meningeal spaces. Hemorrhage within the meninges or the associated potential spaces, including epidural hematoma, subdural hematoma, and subarachnoid hemorrhage, is covered in detail in other articles. Intracerebral hemorrhage (ICH) and extension of parenchymal bleeding into the ventricles (ie, intraventricular hemorrhage [IVH]) are detailed here.

Intracerebral hemorrhage accounts for 8-13% of all strokes and results from a wide spectrum of disorders. Intracerebral hemorrhage is more likely to result in death or major disability than ischemic stroke or subarachnoid hemorrhage. Intracerebral hemorrhage and accompanying edema may disrupt or compress adjacent brain tissue, leading to neurological dysfunction. Substantial displacement of brain parenchyma may cause elevation of intracranial pressure (ICP) and potentially fatal herniation syndromes.

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Pathophysiology

Nontraumatic intracerebral hemorrhage most commonly results from hypertensive damage to blood vessel walls (eg, hypertension, eclampsia, drug abuse), but it also may be due to autoregulatory dysfunction with excessive cerebral blood flow (eg, reperfusion injury, hemorrhagic transformation, cold exposure), rupture of an aneurysm or arteriovenous malformation (AVM), arteriopathy (eg, cerebral amyloid angiopathy, moyamoya), altered hemostasis (eg, thrombolysis, anticoagulation, bleeding diathesis), hemorrhagic necrosis (eg, tumor, infection), or venous outflow obstruction (eg, cerebral venous thrombosis).

Nonpenetrating and penetrating cranial trauma are also common causes of intracerebral hemorrhage.Patients who experience blunt head trauma and subsequently receive warfarin or clopidogrel are considered at increased risk for traumatic intracranial hemorrhage. According to one study, patients receiving clopidogrel have a significantly higher prevalence of immediate traumatic intracranial hemorrhage compared with patients receiving warfarin. Delayed traumatic intracranial hemorrhage is rare and occurred only in patients receiving warfarin. [1]

Chronic hypertension produces a small vessel vasculopathy characterized by lipohyalinosis, fibrinoid necrosis, and development of Charcot-Bouchard aneurysms, affecting penetrating arteries throughout the brain including lenticulostriates, thalamoperforators, paramedian branches of the basilar artery, superior cerebellar arteries, and anterior inferior cerebellar arteries.

Predilection sites for intracerebral hemorrhage include the basal ganglia (40-50%), lobar regions (20-50%), thalamus (10-15%), pons (5-12%), cerebellum (5-10%), and other brainstem sites (1-5%).

Intraventricular hemorrhage occurs in one third of intracerebral hemorrhage cases from extension of thalamic ganglionic bleeding into the ventricular space. Isolated intraventricular hemorrhage frequently arise from subependymal structures including the germinal matrix, AVMs, and cavernous angiomas.

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Epidemiology

Frequency

United States

Each year, intracerebral hemorrhage affects approximately 12-15 per 100,000 individuals, including 350 hypertensive hemorrhages per 100,000 elderly individuals. The overall incidence of intracerebral hemorrhage has declined since the 1950s.

International

Asian countries have a higher incidence of intracerebral hemorrhage than other regions of the world.

Mortality/Morbidity

Annually, more than 20,000 individuals in the United States die of intracerebral hemorrhage. Intracerebral hemorrhage has a 30-day mortality rate of 44%. Pontine or other brainstem intracerebral hemorrhage has a mortality rate of 75% at 24 hours. Hallevi et al reviewed the charts and CT scans of patients with intraventricular hemorrhage (IVH) to determine if the extension of the hemorrhage could be measured. Clinical outcome was determined by the modified Rankin Scale (mRS). IVH was also classified with an IVH score. The IVH score allowed rapid estimate of IVH volume by the practitioner and increased predictability for outcome. [2]

Race

Intracerebral hemorrhage has a higher incidence among populations with a higher frequency of hypertension, including African Americans. A higher incidence of intracerebral hemorrhage has been noted in Chinese, Japanese, and other Asian populations, possibly due to environmental factors (eg, a diet rich in fish oils) and/or genetic factors.

Sex

Intracerebral hemorrhage has a slight male predominance, though study results have been conflicting.

Cerebral amyloid angiopathy may be more common among women.

Phenylpropanolamine use has been associated with intracerebral hemorrhage in young women. [3]

Age

Incidence of intracerebral hemorrhage increases in individuals older than 55 years and doubles with each decade until age 80 years. The relative risk of intracerebral hemorrhage is greater than 7 in individuals older than 70 years.

In individuals younger than 45 years, lobar hemorrhage is the most common site of and frequently is associated with AVMs.

Subependymal hemorrhage or germinal matrix hemorrhage is primarily seen in premature infants.

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