Intracranial hemorrhage

Intracranial hemorrhage (ICH) is bleeding within the skull. It can result from trauma, vascular abnormalities, hypertension, or other medical conditions. ICH is broadly categorized into several subtypes based on the location of the bleed: intracerebral hemorrhage (including intraparenchymal and intraventricular hemorrhages), subarachnoid hemorrhage, epidural hemorrhage, and subdural hematoma. Each subtype has distinct causes, clinical features, and treatment approaches.

Epidemiology

Acute, spontaneous intracranial hemorrhage (ICH) is the second most common form of stroke, affecting approximately 2 million people worldwide each year. In the United States, intracranial hemorrhage accounts for about 20% of all cerebrovascular accidents, with an incidence of approximately 20 cases per 100,000 people annually. Intracranial hemorrhages is diagnosed more frequently in men and individuals over the age of 55, with incidence increasing with age. This can be followed by bleeding extension, cerebral edema formation, and increased intracranial pressure (ICP), all of which can lead to neural tissue compression.

A swirl sign on CT imaging— representing areas of low density with surrounding areas of high density— suggest active intracranial bleeding. The presence of this sign is associated with an increase in risk of death within one month and a poor functional prognosis at three months among survivors.

Intra-axial hemorrhage refers to bleeding that occurs within the brain parenchyma or ventricular system. These injuries result from the disruption of small arterial or venous vessels, leading to hemorrhage within the brain parenchyma. Such microhemorrhages are frequently associated with diffuse axonal injury and located near the grey–white matter junction.

When the epidural hematoma is large enough, it will cause mass effect on contralateral brain which lead to midline, subfalcine (below the falx cerebri), and trans-tentorial (crossing tentorium cerebelli) herniations. This phenomenon can cause the subject to lose consciousness and eventually death.

On CT imaging, traumatic SAH is usually localized to the cerebral sulci near the vertex of the head and typically spares the basal cisterns. CT scan has 100% sensitivity of detecting SAH at 6 to 24 hours after symptoms onset.

From limited observational data, it may be relatively safe to restart blood thinners after an ICH as it is associated with reduced thromboembolic complications with similar risk of recurrent hemorrhage when compared to those did not start blood thinners after an ICH.

Intracranial hemorrhage

Epidemiology

Comparison

References

Further reading

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