Intracranial hemorrhage

Intracranial hemorrhage
Classification and external resources
CT scan of a spontaneous intracranial hemorrhage
ICD-10	I60.0-I62., S06.
ICD-9	430-432, 850-854
DiseasesDB	6870
MedlinePlus	000796
eMedicine	neuro/177
MeSH	D020300

An intracranial hemorrhage is a hemorrhage, or bleeding, within the skull.

Causes

Intracranial bleeding occurs when a blood vessel within the skull is ruptured or leaks. It can result from physical trauma (as occurs in head injury) or nontraumatic causes (as occurs in hemorrhagic stroke) such as a ruptured aneurysm. Anticoagulant therapy, as well as disorders with blood clotting can heighten the risk that an intracranial hemorrhage will occur.^[1]

Prognosis

Intracranial hemorrhage is a serious medical emergency because the buildup of blood within the skull can lead to increases in intracranial pressure, which can crush delicate brain tissue or limit its blood supply. Severe increases in intracranial pressure can cause potentially deadly brain herniation, in which parts of the brain are squeezed past structures in the skull.

Diagnosis

CAT scan (computed axial tomography) is the definitive tool for accurate diagnosis of an intracranial hemorrhage.

Classification

Types of intracranial hemorrhage are roughly grouped into intra-axial and extra-axial. The hemorrhage is considered a focal brain injury; that is, it occurs in a localized spot rather than causing diffuse damage over a wider area.

Intra-axial hemorrhage

Intra-axial hemorrhage is bleeding within the brain itself, or cerebral hemorrhage. This category includes intraparenchymal hemorrhage, or bleeding within the brain tissue, and intraventricular hemorrhage, bleeding within the brain's ventricles (particularly of premature infants). Intra-axial hemorrhages are more dangerous and harder to treat than extra-axial bleeds.^[2]

Extra-axial hemorrhage

Extra-axial hemorrhage, bleeding that occurs within the skull but outside of the brain tissue, falls into three subtypes:

• Epidural hemorrhage(Extradural hemorrhage) which occur between the dura mater (the outermost meninx) and the skull, is caused by trauma. It may result from laceration of an artery, most commonly the middle meningeal artery. This is a very dangerous type of injury because the bleed is from a high-pressure system and deadly increases in intracranial pressure can result rapidly. However , it is the least common type of meningeal bleeding and is seen in 1% to 3% cases of head injury .
  • Patients have a loss of consciousness (LOC), then a lucid interval, then sudden deterioration (vomiting, restlessness, LOC)
  • Head CT shows lenticular (convex) deformity.
• Subdural hemorrhage results from tearing of the bridging veins in the subdural space between the dura and arachnoid mater.
  • Head CT shows crescent-shaped deformity
• Subarachnoid hemorrhage, which occur between the arachnoid and pia meningeal layers, like intraparenchymal hemorrhage, can result either from trauma or from ruptures of aneurysms or arteriovenous malformations. Blood is seen layering into the brain along sulci and fissures, or filling cisterns (most often the suprasellar cistern because of the presence of the vessels of the circle of Willis and their branchpoints within that space). The classic presentation of subarachnoid hemorrhage is the sudden onset of a severe headache (a thunderclap headache). This can be a very dangerous entity, and requires emergent neurosurgical evaluation, and sometimes urgent intervention.

References

External links

• McCaffrey P. 2001. "The Neuroscience on the Web Series: CMSD 336 Neuropathologies of Language and Cognition." California State University, Chico.
• Orlando Regional Healthcare, Education and Development. 2004. "Overview of Adult Traumatic Brain Injuries." Retrieved on January 16, 2008.
• Shepherd S. 2004. "Head Trauma." Emedicine.com.
• Vinas FC and Pilitsis J. 2004. "Penetrating Head Trauma." Emedicine.com.