Intraparenchymal Hemorrhage - Acute Intraparenchymal Hemorrhage

Acute Intraparenchymal Hemorrhage

Clinical History: 81 year old diabetic male presents with a change in mental status.

Findings: Axial CT images through the brain demonstrate two areas of hyperdensity, one measuring approximately 2 x 1.5 cm and a second measuring approximately 3 x 4 cm. There is some surrounding edema with mass effect upon the left ventricle. In addition, there is extension into the ventricular system.

Diagnosis: Acute intraparenchymal hemorrhage.

Discussion: There are many causes for intraparenchymal hemorrhage. A common cause is secondary to hypertension. These most commonly occur within the basal ganglia, subcortical white matter, cerebellum, thalamus and pons. Hemorrhage into the posterior fossa with mass effect or extension into the ventricular system carries poor prognosis.

In younger patients, vascular malformations, specifically AVMs and cavernous angiomas are more common causes for hemorrhage. In addition, venous malformations are associated with hemorrhage.

In the elderly population, amyloid angiopathy is associated with cerebral infarcts as well as hemorrhage in superficial locations, rather than deep white matter or basal ganglia. These are usually described as "lobar". These bleedings are not associated with systemic amyloidosis.

Hemorrhagic neoplasms are more complex, heterogeneous bleeds often with associated edema. These hemorrhages are related to tumor necrosis, vascular invasion and neovascularity. Glioblastomas are the most common primary malignancies to hemorrhage while thyroid, renal cell carcinoma, melanoma, and lung cancer are the most common causes of hemorrhage from metastatic disease.

Other causes of intraparenchymal hemorrhage include hemorrhagic transformation of infarction which is usually in a classic vascular distribution and is seen in approximately 24 to 48 hours following the ischemic event. This hemorrhage rarely extends into the ventricular system.